0022-5347/78/1192-0244$02.00/0 The Journal of Urology Copyright © 1978 by The Williams & Wilkins Co.
Vol. 119, February Printed in U .SA.
CLINICAL SIGNIFICANCE OF SERUM ALKALINE PHOSPHATASE ISOENZYME LEVELS IN ADVANCED PROSTATIC CARCINOMA ZEW WAJSMAN, T. M. CHU, DEAN BROSS, JACK SAROFF,* GERALD P. MURPHY,t DOUGLAS E. JOHNSON, WILLIAM W. SCOTT, ROBERT P. GIBBONS, GEORGE R. PROUT AND JOSEPH D. SCHMIDT From the Roswell Park Memorial Institute, Buffalo, New York; M. D. Anderson Hospital and Tumor Institute, Houston, Texas; Johns Hopkins Hospital, Baltimore, Maryland; Virginia Mason Medical Center, Seattle, Washington; Massachusetts General Hospital, Boston, Massachusetts, and University of Iowa Hospitals and Clinics, Iowa City, Iowa
ABSTRACT
The alkaline phosphatase isoenzymes in 105 patients with stage D carcinoma of the prostate who entered the National Prostatic Cancer Study were analyzed and these values were correlated to clinical response. Only patients with at least 3 measurements of alkaline phosphatase were evaluated. In 91 per cent of patients with metastatic bone disease, bone alkaline phosphatase was elevated. Those patients with higher pre-treatment levels of alkaline phosphatase generally showed a poorer response to therapy. The results of alkaline phosphatase isoenzyme estimation indicate that these biological markers may be used in the evaluation of patients with metastatic prostatic cancer to predict and monitor their response to chemotherapy. The evaluation of bone and liver alkaline phosphatase isoenzymes in earlier stages also may be valuable. Assays of serum alkaline phosphatase activity are routine examinations for diagnosis and monitoring of patients with many malignant diseases. Together with acid phosphatase 1 they represent excellent biological markers in the diagnosis and followup of patients with prostatic carcinoma. Herein we review our new experience using serum alkaline phosphatase isoenzymes as an indicator or prediction of clinical response to treatment of metastatic prostatic carcinoma. The results are encouraging. MATERIAL AND METHODS
Three hundred and fifty-seven men with a histologic diagnosis of prostatic carcinoma who had metastases and had relapsed after orchiectomy were entered into the cooperative study to determine the value of different chemotherapeutic agents in the treatment of advanced prostatic carcinoma. 2 Assays of total serum alkaline phosphatase levels were performed on each patient on entry into the study at the patient's cooperating institution (Johns Hopkins Hospital, The Mason Clinic, M. D. Anderson Hospital and Tumor Institute, University oflowa Hospitals and Clinics, and Massachusetts General Hospital) as well as on serum collected and mailed to Roswell Park Memorial Institute for duplicate assays. At Roswell Park Memorial Institute, in addition to total alkaline phosphatase determination, the level of different isoenzymes of alkaline phosphatase was measured by a combination of 4 manually performed parameters: 3 1) the chemical inhibition method, including urea denaturation, which differentially separated bone and liver isoenzymes; 2) the L-phenylalanine inhibition, which denatured intestinal and placental isoenzymes, as modified from the method of Fishman and Groh, 4 and O'Carroll and associates; 5 3) heat
denaturation at 56C for 5 minutes and 4) cellulose acetate electrophoresis. 6• 7 The latter 2 parameters were used to compare and confirm the results obtained from specific chemical inhibition measurements. 5 The total alkaline phosphate activity was determined spectrophotometrically, using p-nitrophenylphosphate as a substrate by the method of Bowers and McComb. 8 The spectrophotometric measurement of total alkaline phosphatase activity was analyzed with a Gilford 300-N Micro Sample spectrophotometer.+ An electrophoresis pattern was performed with a Beckman Microzone R-112 system§ The calculations for determining the quantitative amounts of alkaline phosphatase isoenzymes using total alkaline phosphatase were obtained on an Olivetti 101 Programma. 11 The chemicals, p-nitrophenylphosphate, urea and L-phenylalanine, were purchased from Sigma'll and Eastman**, respectively. Only 105 patients who had at least 3 measurements of alkaline phosphatase performed were analyzed for correlation with clinical response. The average time of observation was 18 months. The initial values of the alkaline phosphatase enzymes as well as followup levels were correlated to the clinical response to therapy. This was determined as complete objective regression, partial objective regression, objectively stable and objective progression, according to the criteria of the National Prostatic Cancer Project. 9 The results of the liver examinations were compared to the results of the alkaline phosphatase isoenzyme determinations in patients on whom autopsies were performed. Statistical methods of data analysis were chi-square and Student's t test. 10 RESULTS
Of the 105 patients 6 were considered to have partial response to the treatment, 31 became stable and 68 had progressive disease. 10
Accepted for publication April 22, 1977. Supported in part by Public Health Services Grant CA-14716 through the National Prostatic Cancer-Project, the National Cancer Institute, National Institutes of Health, Department of Health, Education and Welfare. Read at annual meeting of American Urological Association, :j: Gilford Instrument, Oberlin, Ohio. Chicago, Illinois, April 24-28, 1977. § Beckman Instruments, Fullerton, California. * Died November 13, 1977. Olivetti, New York, New York. t Requests for reprints: Roswell Park Memorial Institute, 666 Elm '11 St. Louis, Missouri. ** Rochester, New York. St., Buffalo, New York 14263. 244 11
SERUM ALKALINE PHOSPHATASE ISOENZYME LEVELS IN PROSTATIC CARCINOMA
Figure 1 shows the relationship between the initial levels of total and bone alkaline phosphatase and 3 categories of clinical response (partial regression, stable and progression) of the patients, regardless of the treatment given. The patients with the lowest total and/or bone alkaline phosphatase level at the beginning of the treatment achieved the best clinical response. Those with high levels of the enzyme at the start of therapy did not respond to treatment. The differences in the enzyme levels in these 3 groups of patients were statistically significant at the level ofp < 0.01. A significant number of patients had more than 25 per cent reduction of the enzyme level when they obtained a partial response or when the disease had stabilized (table 1). Of 22 patients with progression of disease 20 (90 per cent) did not show reduction of the total alkaline phosphatase level. The differences between the responders and progression group were statistically significant. A decrease of the bone alkaline phosphatase level was found in 17 of 24 patients (75 per cent) with partial response and in those with stabilization of the disease (table 2). Of the 22 patients who failed to respond to treatment 16 (72. 7 per cent) did not show a decrease in the enzyme level. The alkaline phosphatase levels also were analyzed in another group of patients of the National Prostatic Cancer Project (table 3). In 357 patients with proved bone metastases 305 (85 per cent) had elevated total alkaline phosphatase levels, mainly owing to elevation of the bone isoenzyme fraction. Fifty•two patients (15 per cent) had a normal level of total alkaline phosphatase, despite having widespread bone metastases. However, 22 of these 52 patients had abnormal high levels of bone alkaline phosphatase, despite normal total alkaline phosphatase levels. Liver alkaline phosphatase isoenzyme. In 12 of 17 patients no liver involvement was found at autopsy and the mean total alkaline phosphatase level was elevated (233.0/mU./ml.) INITIAL TOTAL ALKALINE PHOSPHATASE
A
vs
INITIAL BONE ALKALINE PHOSPHATASE B \IS RESPONSE
RESPONSE
600
!100
~ ~
~
.
400
J2
i
!l
!
.
.!: .,.0
C
:;;
200
ct
200
g
r+
E
~ en
300
0
.c
Q.
300
l. ~
400
::
0
a,
100
TABLE
2. Bone alkaline phosphatase at the time of response
Response Partial response Stable Progression Totals
No. Pts. With More Than 25% Decrease
No. Pts. With Less than 25% Decrease
Totals
5
0
5
12
7
6
16 23
19 22 46
23
p < 0.0. -partial response versus progression. p < 0.03-stable versus progression.
TABLE
3. Bone alkaline phosphatase isoenzyme value No.
No. pts. with bone metastases Elevated total alkaline phosphatase Normal total alkaline phosphatase High bone alkaline phosphatase
(%)
357 (100) 305 (85) 52 (15) 22/52 (44)
owing to an increase in the bone isoenzyme fraction. The liver isoenzyme was normal with a mean value of 46.3 mU./ ml. In the 5 patients with proved liver metastases the elevation of alkaline phosphatase was mainly owing to an increased liver isoenzyme fraction with a mean value of 309 mU./ml. In 3 patients no clinical suspicion ofliver metastases was encountered and the elevation of the liver alkaline phosphatase could have been the early sign to lead to the discovery of liver involvement. CASE REPORT
A 60-year-old white man had prostatic cancer with lung metastases in September 1974. A bone survey revealed no evidence of bone metastases. Total alkaline phosphatase was normal. He was treated by orchiectomy and supplemental estrogen therapy and 3 months later there was progression of the lung metastases. The patient was then randomized by the National Prostatic Cancer Project for daily treatment with 600 mg./M. 2 estramustine phosphate orally. At the time of randomization no evidence of bone metastasis was found. After 6 months of treatment progression of the disease was again noted and he was crossed over to be treated with 500 mg./M. 2 streptozotocin for 5 days intravenously every 3 weeks. Two months later an elevation in total alkaline phosphastase was seen, and repeat bone scan and survey did not reveal bone metastases. Alkaline phosphatase isoenzyme determination revealed that the total alkaline phosphatase elevation was consistent only with the liver alkaline phosphatase fraction and the bone alkaline phosphatase isoenzyme measurement was normal (fig. 2). As a result of these findings a liver scan was performed and confirmed the biochemical indications of liver metastases. The patient died 1 month later.
100
E ::, ~
DISCUSSION
V,
(6)
(31)
(68)
Pcrtial Stobl• ProQr•Hion Re9rehion
Partial Sklbl• PTOQr111lon RnponH
(} Number of potu1nt1
( ) Number of patients
Fm. I 1. Total alkaline phosphatase at the time of response No. Pts. No. Pts. Clinical Status With More Than With Less than Totals 25% Decrease 25% Decrease TABLE
Partial response* Stable* Progression* Totals
4 8 2 14
1 11
20 32
5 19 22 46
p < 0.003-partial response versus progression group and stable versus progression group. * As defined by Schmidt and associates. 9
Serum alkaline phosphatase originates from bone, the hepatobiliary tract, intestinal mucosa and placenta. 11- 13 Additional alkaline phosphatase may be of direct tumor origin. 14 Increased serum alkaline phosphatase activity has been found in 60 per cent of patients with untreated prostatic cancer and in only 6 per cent of those free of metastatic disease. 15 In our study 85 per cent of patients with disseminated prostatic cancer had elevated total alkaline phosphatase levels, with bone alkaline phosphatase isoenzyme responsible for this elevation in most of the patients. This is probably because the patients in our studies had far advanced metastatic disease with a widespread tumor burden. Some of the patients with metastatic disease had normal total alkaline phosphatase but an elevated bone isoenzyme fraction. This fact suggests that the bone alkaline phosphatase determination rather than total alkaline phosphatase may be more helpful to detect at
246
WAJSMAN AND ASSOCIATES
ALKALINE PHOSPHATASE ISOENZYME LEVELS IN A PATIENT WITH STAGE D PROSTATIC CANCER 1600
e---e TOTAL AP 1400
~--X
BONE AP
&-·-& LIVER AP
1200
1000
AP mU/ml
800
600
evidence of liver metastases. Those patients with a short life expectancy may be unsuitable for some new chemotherapeutic protocol studies. However, other beneficial therapeutic measures might be considered favorably at an early stage. The number of patients in our study of liver alkaline phosphatase isoenzymes is relatively small. More studies will be helpful to evaluate the significance of this isoenzyme in all stages of prostatic cancer. The status of the current results offers more than reasonable optimism that the isoenzyme levels can aid in monitoring the clinical status of the patients who have advanced disease and are being afforded non-hormonal chemotherapy. The isoenzymes appear to offer additional value in earlier clinical stages of prostatic cancer.
REFERENCES
400
200 100 oL...JLl__j_.....L.-L...L..l.Jl,,...i.l'*l,"""'M=lll,,tL-L:1:,t11..._-L_L_
MONTHS
Fm.2
an early stage bone metastases in patients without clinical evidence of bone lesions. Total and bone alkaline phosphatase estimations were found frequently to be elevated in metastatic disease and should be used with acid phosphatase for the evaluation of prostatic cancer metastases. Acid phosphatase may, indeed, be normal in some cases with elevated alkaline phosphatase. 15 The success of chemotherapy in the treatment of cancer is related closely to the initial tumor burden. In prostatic cancer with frequent widespread bony metastases it can be difficult to estimate the amount of tumor burden based on surveys or scans. We found that estimation of total and bone alkaline phosphatase at the beginning of treatment may aid in predicting the response to some of the chemotherapeutic agents used. The higher the level of alkaline phosphatase the smaller the chances were of obtaining a good clinical response. Thus, the alkaline phosphatase levels indirectly may measure the tumor burden. With a clinical response the levels of alkaline phosphatase diminish and sometimes a gradual increase of total or bone alkaline phosphatase is noticed before any clinical objective or subjective sign of progression of the disease may be seen. Although alkaline phosphatase is an indicator of bone production and may represent bone healing, 16 a strikingly increased phosphatase activity of bone at the site of osteoplastic skeletal metastases has been observed in patients with carcinoma of the prostate. 17 The elevation of alkaline phosphatase in progressive metastatic prostatic cancer may be explained by the presence of more foci of osteoplastic responses at the sites of the increasing number of metastatic bone lesions leading to an increased production of alkaline phosphatase with leakage into serum. This would provide an indirect marker of clinical progression of the disease. With clinical stabilization or regression of the disease this alkaline phosphatase production diminishes, with resultant lower levels as found in our studies. Liver metastases in prostatic cancer were found in only 20 per cent of the autopsies in this study. When recognized clinically, these generally have mdicated a poor prognosis and short life expectancy. The finding of elevated liver alkaline phosphatase isoenzyme, as illustrated in the case,report, may be an earlier sign ofliver involvement and might lead the physician to obtain more studies to confirm or rule out the
1. Johnson, D. E., Scott, W. W., Gibbons, R. P., Prout, G. R., Schmidt, J. D. and Murphy, G. P.: Clinical significance of serum acid phosphatase levels in advanced prostatic carcinoma. Urology, 8: 123, 1976. 2. Scott, W. W., Johnson, D. E., Schmidt, J. E., Gibbons, R. P., Prout, G. R., Joiner, J. R., Saroff, J. and Murphy, G. P.: Chemotherapy of advanced prostatic carcinoma with cyclophosphamide or 5-fluorouracil: results of first national randomized study. J. Urol., 114: 909, 1975. 3. Killian, D. S., Chu, T. M., Drzewiecki, G., Schmidt, K., Kajdasz, R., Santalucia, J., Saroff, J. and Murphy, G. P.: A simple and reliable method for alkaline phosphatase isoenzymes in prostatic cancer. Clin. Chem., 22: 1174, 1976. 4. Fishman, W. H. and Groh, N. K.: Isoenzymes of human alkaline phosphatase. Adv. Clin. Chem., 10: 255, 1967. 5. O'Carroll, D., Statland, B. E., Steele, B. W. and Burke, M. D.: Chemical inhibition method for alkaline phosphatase isoenzymes in human serum. Amer. J. Clin. Path., 63: 564, 1975. 6. Moss, D. W.: Alkaline phosphatase isoenzymes. Enzymes, 20: 20, 1975. 7. Rhone, D. P. and Mizuno, F. M.: Separation of isoenzymes of alkaline phosphatase by substrate-gel imprint after electrophoresis in cellulose acetate. Clin. Chem., 18: 662, 1972. 8. Bowers, G. N. and McComb, R. B.: Measurement of total alkaline phosphatase activity in human serum. Clin. Chem., 21: 1988, 1975. 9. Schmidt, J. D., Johnson, D. E., Scott, W. W., Gibbons, R. P., Prout, G. R. and Murphy, G. P.: Chemotherapy of advanced prostatic cancer. Evaluation of response parameters. Urology, 7: 602, 1976. 10. Dixon, W. J. and Massey, F. J.: Introduction to Statistical Analysis, 2nd ed. New York: McGraw-Hill Book Co., Inc., p. 115, 1957. 11. Schlamowitz, M. and Bodansky, 0.: Tissue sources of human serum alkaline phosphatase as determined by immunochemical procedures. J. Biol. Chem., 234: 1433, 1959. 12. Posen, S., Neale, F. C. and Clubb, J. S.: Heat inactivation in the study of human alkaline phosphatases. Ann. Intern. Med., 62: 1234, 1965. 13. McMaster, Y., Tennant, R., Clubb, J. S., Neale, F. C. and Posen, S.: The mechanism of the ele'l:ation of serum alkaline phosphatase in pregnancy. J. Obst. Gynaec., 71: 735, 1964. 14. Stolbach, L. L., Krant, M. J. and Fishman, W. H.: Ectopic production of an alkaline phosphatase in patients with cancer. New Engl. J. Med., 281: 757, 1969. 15. Goldberg, D. M. and Ellis, G.: An assessment of serum acid and alkaline pi,osphatase determinations in prostatic cancer with a clinical validation of an acid phosphatase assay utilizing adenosine 3'-monophosphate as substrate. J. Clin. Path., 27: 140, 1974. 16. Gutman, A. B., Tyson, T. L. and Gutman, E. B.: Serum calcium, inorganic phosphorous and phosphatase activity in hyperparathyroidism, Roget's disease, multiple myeloma and neoplastic disease of the bones. Ann. Intern. Med., 57: 379, 1936. 17. Gutman, E. B., Sproul, E. E. and Gutman, A. B.: Significance of increased phosphatase activity of bone at the site of osteoplastic metastases secondary to carcinoma of the prostate gland. Amer. J. Cancer, 28: 485, 1936.
Vol. 119, February Printed in U .SA.
CLINICAL SIGNIFICANCE OF SERUM ALKALINE PHOSPHATASE ISOENZYME LEVELS IN ADVANCED PROSTATIC CARCINOMA ZEW WAJSMAN, T. M. CHU, DEAN BROSS, JACK SAROFF,* GERALD P. MURPHY,t DOUGLAS E. JOHNSON, WILLIAM W. SCOTT, ROBERT P. GIBBONS, GEORGE R. PROUT AND JOSEPH D. SCHMIDT From the Roswell Park Memorial Institute, Buffalo, New York; M. D. Anderson Hospital and Tumor Institute, Houston, Texas; Johns Hopkins Hospital, Baltimore, Maryland; Virginia Mason Medical Center, Seattle, Washington; Massachusetts General Hospital, Boston, Massachusetts, and University of Iowa Hospitals and Clinics, Iowa City, Iowa
ABSTRACT
The alkaline phosphatase isoenzymes in 105 patients with stage D carcinoma of the prostate who entered the National Prostatic Cancer Study were analyzed and these values were correlated to clinical response. Only patients with at least 3 measurements of alkaline phosphatase were evaluated. In 91 per cent of patients with metastatic bone disease, bone alkaline phosphatase was elevated. Those patients with higher pre-treatment levels of alkaline phosphatase generally showed a poorer response to therapy. The results of alkaline phosphatase isoenzyme estimation indicate that these biological markers may be used in the evaluation of patients with metastatic prostatic cancer to predict and monitor their response to chemotherapy. The evaluation of bone and liver alkaline phosphatase isoenzymes in earlier stages also may be valuable. Assays of serum alkaline phosphatase activity are routine examinations for diagnosis and monitoring of patients with many malignant diseases. Together with acid phosphatase 1 they represent excellent biological markers in the diagnosis and followup of patients with prostatic carcinoma. Herein we review our new experience using serum alkaline phosphatase isoenzymes as an indicator or prediction of clinical response to treatment of metastatic prostatic carcinoma. The results are encouraging. MATERIAL AND METHODS
Three hundred and fifty-seven men with a histologic diagnosis of prostatic carcinoma who had metastases and had relapsed after orchiectomy were entered into the cooperative study to determine the value of different chemotherapeutic agents in the treatment of advanced prostatic carcinoma. 2 Assays of total serum alkaline phosphatase levels were performed on each patient on entry into the study at the patient's cooperating institution (Johns Hopkins Hospital, The Mason Clinic, M. D. Anderson Hospital and Tumor Institute, University oflowa Hospitals and Clinics, and Massachusetts General Hospital) as well as on serum collected and mailed to Roswell Park Memorial Institute for duplicate assays. At Roswell Park Memorial Institute, in addition to total alkaline phosphatase determination, the level of different isoenzymes of alkaline phosphatase was measured by a combination of 4 manually performed parameters: 3 1) the chemical inhibition method, including urea denaturation, which differentially separated bone and liver isoenzymes; 2) the L-phenylalanine inhibition, which denatured intestinal and placental isoenzymes, as modified from the method of Fishman and Groh, 4 and O'Carroll and associates; 5 3) heat
denaturation at 56C for 5 minutes and 4) cellulose acetate electrophoresis. 6• 7 The latter 2 parameters were used to compare and confirm the results obtained from specific chemical inhibition measurements. 5 The total alkaline phosphate activity was determined spectrophotometrically, using p-nitrophenylphosphate as a substrate by the method of Bowers and McComb. 8 The spectrophotometric measurement of total alkaline phosphatase activity was analyzed with a Gilford 300-N Micro Sample spectrophotometer.+ An electrophoresis pattern was performed with a Beckman Microzone R-112 system§ The calculations for determining the quantitative amounts of alkaline phosphatase isoenzymes using total alkaline phosphatase were obtained on an Olivetti 101 Programma. 11 The chemicals, p-nitrophenylphosphate, urea and L-phenylalanine, were purchased from Sigma'll and Eastman**, respectively. Only 105 patients who had at least 3 measurements of alkaline phosphatase performed were analyzed for correlation with clinical response. The average time of observation was 18 months. The initial values of the alkaline phosphatase enzymes as well as followup levels were correlated to the clinical response to therapy. This was determined as complete objective regression, partial objective regression, objectively stable and objective progression, according to the criteria of the National Prostatic Cancer Project. 9 The results of the liver examinations were compared to the results of the alkaline phosphatase isoenzyme determinations in patients on whom autopsies were performed. Statistical methods of data analysis were chi-square and Student's t test. 10 RESULTS
Of the 105 patients 6 were considered to have partial response to the treatment, 31 became stable and 68 had progressive disease. 10
Accepted for publication April 22, 1977. Supported in part by Public Health Services Grant CA-14716 through the National Prostatic Cancer-Project, the National Cancer Institute, National Institutes of Health, Department of Health, Education and Welfare. Read at annual meeting of American Urological Association, :j: Gilford Instrument, Oberlin, Ohio. Chicago, Illinois, April 24-28, 1977. § Beckman Instruments, Fullerton, California. * Died November 13, 1977. Olivetti, New York, New York. t Requests for reprints: Roswell Park Memorial Institute, 666 Elm '11 St. Louis, Missouri. ** Rochester, New York. St., Buffalo, New York 14263. 244 11
SERUM ALKALINE PHOSPHATASE ISOENZYME LEVELS IN PROSTATIC CARCINOMA
Figure 1 shows the relationship between the initial levels of total and bone alkaline phosphatase and 3 categories of clinical response (partial regression, stable and progression) of the patients, regardless of the treatment given. The patients with the lowest total and/or bone alkaline phosphatase level at the beginning of the treatment achieved the best clinical response. Those with high levels of the enzyme at the start of therapy did not respond to treatment. The differences in the enzyme levels in these 3 groups of patients were statistically significant at the level ofp < 0.01. A significant number of patients had more than 25 per cent reduction of the enzyme level when they obtained a partial response or when the disease had stabilized (table 1). Of 22 patients with progression of disease 20 (90 per cent) did not show reduction of the total alkaline phosphatase level. The differences between the responders and progression group were statistically significant. A decrease of the bone alkaline phosphatase level was found in 17 of 24 patients (75 per cent) with partial response and in those with stabilization of the disease (table 2). Of the 22 patients who failed to respond to treatment 16 (72. 7 per cent) did not show a decrease in the enzyme level. The alkaline phosphatase levels also were analyzed in another group of patients of the National Prostatic Cancer Project (table 3). In 357 patients with proved bone metastases 305 (85 per cent) had elevated total alkaline phosphatase levels, mainly owing to elevation of the bone isoenzyme fraction. Fifty•two patients (15 per cent) had a normal level of total alkaline phosphatase, despite having widespread bone metastases. However, 22 of these 52 patients had abnormal high levels of bone alkaline phosphatase, despite normal total alkaline phosphatase levels. Liver alkaline phosphatase isoenzyme. In 12 of 17 patients no liver involvement was found at autopsy and the mean total alkaline phosphatase level was elevated (233.0/mU./ml.) INITIAL TOTAL ALKALINE PHOSPHATASE
A
vs
INITIAL BONE ALKALINE PHOSPHATASE B \IS RESPONSE
RESPONSE
600
!100
~ ~
~
.
400
J2
i
!l
!
.
.!: .,.0
C
:;;
200
ct
200
g
r+
E
~ en
300
0
.c
Q.
300
l. ~
400
::
0
a,
100
TABLE
2. Bone alkaline phosphatase at the time of response
Response Partial response Stable Progression Totals
No. Pts. With More Than 25% Decrease
No. Pts. With Less than 25% Decrease
Totals
5
0
5
12
7
6
16 23
19 22 46
23
p < 0.0. -partial response versus progression. p < 0.03-stable versus progression.
TABLE
3. Bone alkaline phosphatase isoenzyme value No.
No. pts. with bone metastases Elevated total alkaline phosphatase Normal total alkaline phosphatase High bone alkaline phosphatase
(%)
357 (100) 305 (85) 52 (15) 22/52 (44)
owing to an increase in the bone isoenzyme fraction. The liver isoenzyme was normal with a mean value of 46.3 mU./ ml. In the 5 patients with proved liver metastases the elevation of alkaline phosphatase was mainly owing to an increased liver isoenzyme fraction with a mean value of 309 mU./ml. In 3 patients no clinical suspicion ofliver metastases was encountered and the elevation of the liver alkaline phosphatase could have been the early sign to lead to the discovery of liver involvement. CASE REPORT
A 60-year-old white man had prostatic cancer with lung metastases in September 1974. A bone survey revealed no evidence of bone metastases. Total alkaline phosphatase was normal. He was treated by orchiectomy and supplemental estrogen therapy and 3 months later there was progression of the lung metastases. The patient was then randomized by the National Prostatic Cancer Project for daily treatment with 600 mg./M. 2 estramustine phosphate orally. At the time of randomization no evidence of bone metastasis was found. After 6 months of treatment progression of the disease was again noted and he was crossed over to be treated with 500 mg./M. 2 streptozotocin for 5 days intravenously every 3 weeks. Two months later an elevation in total alkaline phosphastase was seen, and repeat bone scan and survey did not reveal bone metastases. Alkaline phosphatase isoenzyme determination revealed that the total alkaline phosphatase elevation was consistent only with the liver alkaline phosphatase fraction and the bone alkaline phosphatase isoenzyme measurement was normal (fig. 2). As a result of these findings a liver scan was performed and confirmed the biochemical indications of liver metastases. The patient died 1 month later.
100
E ::, ~
DISCUSSION
V,
(6)
(31)
(68)
Pcrtial Stobl• ProQr•Hion Re9rehion
Partial Sklbl• PTOQr111lon RnponH
(} Number of potu1nt1
( ) Number of patients
Fm. I 1. Total alkaline phosphatase at the time of response No. Pts. No. Pts. Clinical Status With More Than With Less than Totals 25% Decrease 25% Decrease TABLE
Partial response* Stable* Progression* Totals
4 8 2 14
1 11
20 32
5 19 22 46
p < 0.003-partial response versus progression group and stable versus progression group. * As defined by Schmidt and associates. 9
Serum alkaline phosphatase originates from bone, the hepatobiliary tract, intestinal mucosa and placenta. 11- 13 Additional alkaline phosphatase may be of direct tumor origin. 14 Increased serum alkaline phosphatase activity has been found in 60 per cent of patients with untreated prostatic cancer and in only 6 per cent of those free of metastatic disease. 15 In our study 85 per cent of patients with disseminated prostatic cancer had elevated total alkaline phosphatase levels, with bone alkaline phosphatase isoenzyme responsible for this elevation in most of the patients. This is probably because the patients in our studies had far advanced metastatic disease with a widespread tumor burden. Some of the patients with metastatic disease had normal total alkaline phosphatase but an elevated bone isoenzyme fraction. This fact suggests that the bone alkaline phosphatase determination rather than total alkaline phosphatase may be more helpful to detect at
246
WAJSMAN AND ASSOCIATES
ALKALINE PHOSPHATASE ISOENZYME LEVELS IN A PATIENT WITH STAGE D PROSTATIC CANCER 1600
e---e TOTAL AP 1400
~--X
BONE AP
&-·-& LIVER AP
1200
1000
AP mU/ml
800
600
evidence of liver metastases. Those patients with a short life expectancy may be unsuitable for some new chemotherapeutic protocol studies. However, other beneficial therapeutic measures might be considered favorably at an early stage. The number of patients in our study of liver alkaline phosphatase isoenzymes is relatively small. More studies will be helpful to evaluate the significance of this isoenzyme in all stages of prostatic cancer. The status of the current results offers more than reasonable optimism that the isoenzyme levels can aid in monitoring the clinical status of the patients who have advanced disease and are being afforded non-hormonal chemotherapy. The isoenzymes appear to offer additional value in earlier clinical stages of prostatic cancer.
REFERENCES
400
200 100 oL...JLl__j_.....L.-L...L..l.Jl,,...i.l'*l,"""'M=lll,,tL-L:1:,t11..._-L_L_
MONTHS
Fm.2
an early stage bone metastases in patients without clinical evidence of bone lesions. Total and bone alkaline phosphatase estimations were found frequently to be elevated in metastatic disease and should be used with acid phosphatase for the evaluation of prostatic cancer metastases. Acid phosphatase may, indeed, be normal in some cases with elevated alkaline phosphatase. 15 The success of chemotherapy in the treatment of cancer is related closely to the initial tumor burden. In prostatic cancer with frequent widespread bony metastases it can be difficult to estimate the amount of tumor burden based on surveys or scans. We found that estimation of total and bone alkaline phosphatase at the beginning of treatment may aid in predicting the response to some of the chemotherapeutic agents used. The higher the level of alkaline phosphatase the smaller the chances were of obtaining a good clinical response. Thus, the alkaline phosphatase levels indirectly may measure the tumor burden. With a clinical response the levels of alkaline phosphatase diminish and sometimes a gradual increase of total or bone alkaline phosphatase is noticed before any clinical objective or subjective sign of progression of the disease may be seen. Although alkaline phosphatase is an indicator of bone production and may represent bone healing, 16 a strikingly increased phosphatase activity of bone at the site of osteoplastic skeletal metastases has been observed in patients with carcinoma of the prostate. 17 The elevation of alkaline phosphatase in progressive metastatic prostatic cancer may be explained by the presence of more foci of osteoplastic responses at the sites of the increasing number of metastatic bone lesions leading to an increased production of alkaline phosphatase with leakage into serum. This would provide an indirect marker of clinical progression of the disease. With clinical stabilization or regression of the disease this alkaline phosphatase production diminishes, with resultant lower levels as found in our studies. Liver metastases in prostatic cancer were found in only 20 per cent of the autopsies in this study. When recognized clinically, these generally have mdicated a poor prognosis and short life expectancy. The finding of elevated liver alkaline phosphatase isoenzyme, as illustrated in the case,report, may be an earlier sign ofliver involvement and might lead the physician to obtain more studies to confirm or rule out the
1. Johnson, D. E., Scott, W. W., Gibbons, R. P., Prout, G. R., Schmidt, J. D. and Murphy, G. P.: Clinical significance of serum acid phosphatase levels in advanced prostatic carcinoma. Urology, 8: 123, 1976. 2. Scott, W. W., Johnson, D. E., Schmidt, J. E., Gibbons, R. P., Prout, G. R., Joiner, J. R., Saroff, J. and Murphy, G. P.: Chemotherapy of advanced prostatic carcinoma with cyclophosphamide or 5-fluorouracil: results of first national randomized study. J. Urol., 114: 909, 1975. 3. Killian, D. S., Chu, T. M., Drzewiecki, G., Schmidt, K., Kajdasz, R., Santalucia, J., Saroff, J. and Murphy, G. P.: A simple and reliable method for alkaline phosphatase isoenzymes in prostatic cancer. Clin. Chem., 22: 1174, 1976. 4. Fishman, W. H. and Groh, N. K.: Isoenzymes of human alkaline phosphatase. Adv. Clin. Chem., 10: 255, 1967. 5. O'Carroll, D., Statland, B. E., Steele, B. W. and Burke, M. D.: Chemical inhibition method for alkaline phosphatase isoenzymes in human serum. Amer. J. Clin. Path., 63: 564, 1975. 6. Moss, D. W.: Alkaline phosphatase isoenzymes. Enzymes, 20: 20, 1975. 7. Rhone, D. P. and Mizuno, F. M.: Separation of isoenzymes of alkaline phosphatase by substrate-gel imprint after electrophoresis in cellulose acetate. Clin. Chem., 18: 662, 1972. 8. Bowers, G. N. and McComb, R. B.: Measurement of total alkaline phosphatase activity in human serum. Clin. Chem., 21: 1988, 1975. 9. Schmidt, J. D., Johnson, D. E., Scott, W. W., Gibbons, R. P., Prout, G. R. and Murphy, G. P.: Chemotherapy of advanced prostatic cancer. Evaluation of response parameters. Urology, 7: 602, 1976. 10. Dixon, W. J. and Massey, F. J.: Introduction to Statistical Analysis, 2nd ed. New York: McGraw-Hill Book Co., Inc., p. 115, 1957. 11. Schlamowitz, M. and Bodansky, 0.: Tissue sources of human serum alkaline phosphatase as determined by immunochemical procedures. J. Biol. Chem., 234: 1433, 1959. 12. Posen, S., Neale, F. C. and Clubb, J. S.: Heat inactivation in the study of human alkaline phosphatases. Ann. Intern. Med., 62: 1234, 1965. 13. McMaster, Y., Tennant, R., Clubb, J. S., Neale, F. C. and Posen, S.: The mechanism of the ele'l:ation of serum alkaline phosphatase in pregnancy. J. Obst. Gynaec., 71: 735, 1964. 14. Stolbach, L. L., Krant, M. J. and Fishman, W. H.: Ectopic production of an alkaline phosphatase in patients with cancer. New Engl. J. Med., 281: 757, 1969. 15. Goldberg, D. M. and Ellis, G.: An assessment of serum acid and alkaline pi,osphatase determinations in prostatic cancer with a clinical validation of an acid phosphatase assay utilizing adenosine 3'-monophosphate as substrate. J. Clin. Path., 27: 140, 1974. 16. Gutman, A. B., Tyson, T. L. and Gutman, E. B.: Serum calcium, inorganic phosphorous and phosphatase activity in hyperparathyroidism, Roget's disease, multiple myeloma and neoplastic disease of the bones. Ann. Intern. Med., 57: 379, 1936. 17. Gutman, E. B., Sproul, E. E. and Gutman, A. B.: Significance of increased phosphatase activity of bone at the site of osteoplastic metastases secondary to carcinoma of the prostate gland. Amer. J. Cancer, 28: 485, 1936.
