1976, British Journal of Radiology, 49, 944-947

Treatment of locally advanced prostatic carcinoma By G. F. G. O. De Muelenaere, M.B., Ch.B., M.Med.(Rad.T.), M.D. and A. G. Sandison, M.B., B.Ch., M.Med.(Rad.T.), M.D. Department of Radiotherapy, H. F. Verwoerd Hospital and University of Pretoria, Private Bag X169, Pretoria, 0001, Republic of South Africa {Received January, 1976 and in revisedform July, 1976) ABSTRACT

An analysis of 66 patients with prostatic carcinoma treated by telecobalt therapy more than two years ago shows that this can be curative in a high percentage of cases. Local failure occurred in 20.5%. Well-differentiated tumours are more radiosensitive. Clinical regression can take a long time and histology can remain positive for even longer in an inactive prostate gland. A high dose is however required. The use of oestrogens should be delayed until further treatment is needed, as oestrogen seems to increase the radioresistance of the tumour. Radiotherapy seems to be the treatment of choice in inoperable (and even operable) patients with carcinoma of the prostate limited to the pelvis.

Only about 5% of all patients presenting with prostatic carcinoma are medically or surgically suitable for radical curative surgery (Flint and Hsiao, 1967). The vast majority are not curable by means of surgery alone owing to local spread of the tumour in the capsule and periprostatic tissues. Some patients present with metastatic disease, while the general condition of others rules out radical surgery. One also meets patients who are not able to face such a procedure, due to the unavoidable impotency. In South Africa, prostatic cancer is the second most common malignancy in white males (Bradshaw and Harington, 1975). A similar incidence is found all over the world (Corriere et al., 1970). Consequently there are a vast number of patients with locally advanced disease, without metastatic spread beyond the pelvis, who require help. Radiotherapy was tried early in the century, but results were very disappointing, and this modality fell in disrepute. In the early '40's it was noted that a high percentage of prostatic carcinomas regressed when the patients were given oestrogens (Huggins and Hodges, 1941; Herbst, 1942). This breakthrough was accepted throughout the world with immense relief, and was applied everywhere. Despite early reports that this modality was not a complete panacea (Andersen, 1950; Gahagan and Fischman, 1949), all inoperable patients with cancer of the prostate were manipulated with hormones. One big disadvantage was that most carcinomas escaped from the oestrogenic control. In 1967 the Veteran's Administration Group published results showing that the average survival of patients treated with oestrogens was no longer than that of patients who did not receive oestrogens. The difference, how-

ever, was in the cause of death, being due to cancer in the second group, while the first group had a much higher incidence of thrombo-embolitic incidents with fatal results. Over the past few years an increasing number of reports have appeared showing that very useful results can be obtained with modern radiotherapy (Ray et al., 1973; Rodriguez-Antunez et al., 1973; Hill et al., 1974; de Muelenaere et al, 1974). The difference from the early reports is due to the fact that a higher tumour dose can be given with modern apparatus. MATERIAL

Our department has actively advised radiotherapy for patients with carcinoma of the prostate since 1967. Our technique has already been published (de Muelenaere et al., 1974). Our therapy is based on that used for bladder cancer. A telecobalt unit is used and four fields at 45, 135, 225 and 315 deg. are treated daily, five days per week. The field sizes are mostly 9 x 9 cm2 and are aimed at the depth of the 50% contour below the symphysis pubis. We originally gave a tumour dose of 5 130 rad in 20 treatments over 26-28 days. This dose was later increased to 5 415 rad in 20 treatments in four weeks. We have now changed to a split course technique, where 2 850 rad is given in ten treatments over 12-14 days, then a rest period of 2-2J weeks, after which another 2 850 rad is given in ten treatments over 12 days. When these doses are expressed as TDF factors (Orton and Ellis, 1973) the original dose gives a T D F of 96, 5 700 rad in four weeks gives 105 and 6000 rad as a split course equals 107. It must be emphasised that our patients were not selected; all patients were treated. The stage of the disease varied, but the overwhelming majority were in stage B2 or C. Several of the patients had been given oestrogens for shorter or longer times (six months to ten years) before being referred to us when there was proof of reactivation of the tumours. Other patients were treated by radiation immediately after diagnosis, and of these some received oestrogens concomitantly whereas others did not, depending on the referring urologist. We give oestrogens during

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Treatment of locally advanced prostatic carcinoma radiotherapy only when the urologist specifically asks for it as we ourselves are not in favour of routine oestrogen administration. It must be stressed that no clinical condition except secondaries outside the pelvis was considered by us to require the administration of oestrogens. A total of 66 patients were treated between 1967 and 1973, with a minimum follow up of two years. The average age of these patients was 66 years when registered for radiation, whereas the median age was 70 years. These ages were not those at the time of diagnosis, as a number of the patients had received oestrogens before they were referred to us. RESULTS

An interesting finding is that 30 of these patients, i.e. almost half, developed secondaries. The time at which these metastases were diagnosed varied from before treatment by radiotherapy to 30 months afterwards. Of the original 66 patients, 40 have died. The time of demise varied between one month and 46 months after radiation. Eleven of the 40 deaths were from thrombo-embolitic events. As can be seen in Table I, ten of these had been on oestrogen therapy. Ten out of 34 patients who were given oestrogens had fatal vascular incidents, compared to only one out of 32 patients who did not take oestrogens. This was one of two patients who developed multiple pulmonary embolisms. The difference in thrombo-embolitic incidence between these two groups is remarkable and statistically significant. The patients who died did so on average 17*- months after radiotherapy, or at a median

TABLE I THROMBO-EMBOLITIC DEATHS

Oestrogen

Number

Total

0/

Yes No

10 1

34 32

29.4 3.1

Total

11

66

16.7

survival time of 18 months. Because some patients were referred long after the diagnosis was made, the average and median survival after diagnosis in the patients who died is 34 and 24 months respectively (Table II). Although the median survival for the whole group cannot be computed as some were treated only 24 months ago and are still alive, it seems as if the median survival of the whole group will be in the region of 36 months. After radiation, biopsies were taken of the prostate in 43 patients, on more than one occasion in most of them. An important finding was that in several patients these needle biopsies remained histologically positive for carcinoma, despite the clinical finding of an inactive tumour. The longest time interval after radiation where the biopsy was still positive was 36 months, whereas it was negative in this same patient at 44 months. The clinical regression after radiation is usually very slow, and can take between six and nine months. Of all the cases that became locally active again, only in one patient did the tumour become active more than two years after radiation. Because of the inaccuracy of the biopsies, and due to the fact that clinical activity can recur after a long time, all patients who survived at least two years were analysed separately. Only clinical proof of activity was considered. Of the original group 27 died less than two years after radiation, leaving 39 cases for analysis. Of these eight developed activity, an incidence of 20.5%. The following analysis was made to determine what factors are important in affecting the radiosensitivity of prostatic cancer. In Table III histological differentiation is considered. It can be seen that moderately and poorly differentiated tumours are less radiosensitive than well differentiated

/o

TABLE III HlSTOLOGICAL DIFFERENTIATION

PP>0.02

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49, No. 587 G. F. G. O. de Muelenaere and A. G. Sandison

carcinomas. This difference is of statistical significance. A number of patients received oestrogens before radiation; the effect of this is analysed in Table IV. It can be seen that the tumours in patients who did receive oestrogens had a greater tendency to become active again. This difference is not statistically significant. The effect of oestrogen given concomittantly with radiation is analysed in Table V. It is clear that patients who did receive oestrogen did worse, and not better, although once again this difference is not statistically significant. In Table VI the effect of the dose of radiation is considered. The tumour dose is expressed as T D F factors as suggested by Orton and Ellis (1973). It can be seen that all cases whose tumours became active again had received lower doses. This difference is of statistical significance.

TABLE IV EFFECT OF PRIOR OESTROGEN

Prior oestrogen

Active

Not active

Total

6 2

14 17

20 19

30 10.5

8

31

39

20.5

Yes No Total

0/

/o

0.20 > P > 0.10

TABLE V OESTROGEN WITH RADIATION

Yes No Total

Active

Not active

Total

0/

6 2

13 18

19 20

31.6 10

8

31

39

20.5

0/

/o

0.10>P>0.05

TABLE VI RADIATION DOSE

T.D.F.

Active

Not active

Total

105

8 0

19 12

27 12

29.6

Total

8

31

39

20.5

0.05 > P > 0.02

/o

DISCUSSION

Our findings confirm that prostatic carcinoma is not an innocuous disease. Our experience also shows that oestrogen therapy has its inherent dangers. It is exactly because of these two factors that we recommend radical radiotherapy in all patients who have locally advanced disease with no secondaries outside the pelvis. Oestrogen should be withheld until there is definite proof of secondaries causing symptoms. For widespread disease, palliative radiotherapy can be given with a lower dose to relieve symptoms of obstruction. Our previous report (de Muelenaere et al., 1974) showed an incidence of severe complications, e.g. bladder constriction, in only 5% of patients, which we find acceptable in such a serious disease. Local control of the disease was obtained in almost 80% of all cases, including those where radiotherapy was not. optimal. We think this is a very gratifying result. Follow-up needle biopsies are not very reliable, as has been pointed out before (Rodriguez-Antunez et al., 1973). It must be kept in mind that regression of tumour can be very slow, as has been described previously (Ray et al., 1973). Recurrence of local growth is usually found within two years. The degree of differentiation of prostatic tumours seems to influence radiosensitivity, with the well differentiated carcinomas responding better. Fortunately the majority of tumours are well differentiated. It is of course possible that the well differentiated tumours recur later. It seems to be deleterious to combine radiotherapy with oestrogen, whether these are given before or concomitantly with the radiation. Radiation should thus be given as the first line of attack. Table V confirms that the beneficial effect was in fact due to the radiation and not to hormonal manipulation. Oestrogens definitely increase the risk of thromboembolitic incidents. There are therefore two reasons why oestrogens should be withheld until required by the development of secondaries. It has been shown that the hormonal milieu may influence the radiosensitivity of certain tumours, e.g. endometrial carcinoma (de Muelenaere, 1975). The same principle seems to apply to prostatic cancer, in that oestrogens make the tumour more radioresistant. Our figures are not definite proof as they are not statistically significant, probably due to a paucity of numbers. ANDERSEN,

REFERENCES P. E., 1950. Estrogen therapy in prostatic

carcinoma. Acta Radiologica, 34, 33-46.

BRADSHAW, E., and HARINGTON, J. S., 1975. The changing

pattern of cancer mortality in South Africa, 1949-1969. South African Medical Journal, 49, 919-925.

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Treatment of locally advanced prostatic carcinoma CORRIERE, J. N., Jr., CORNOG, J. L., and MURPHY, J. J.,

HUGGINS, C , and HODGES, C. V., 1941. Studies on prostatic

1970. Prognosis in patients with carcinoma of the prostate. Cancer, 25, 911-918.

cancer; effect of castration, of estrogen and of androgen injection on serum phosphatases in metastatic carcinoma of the prostate. Cancer Research, 1, 293—297.

DE MUELENAERE, G. F. G. O., 1975. The radiosensitivity of

endometrial carcinoma. British Journal of Radiology, 48, ORTON, C. G., and ELLIS, F., 1973. A simplification in the 652-655. use of the N.S.D. concept in practical radiotherapy. DE MUELENAERE, G. F. G. O., SANDISON, A. G., and COETBritish Journal of Radiology, 46, 529-537. ZEE, F. C , 1974. Radioterapie in prostaatkarsinoom. RAY, G. R., CASSADY, J. R., and BAGSHAW, M. A., 1973. South African Medical Journal, 48, 321-324. Definitive radiation therapy of carcinoma of the prostate. FLINT, L. D., and HSIAO, J. H., 1967. Radical prostatectomy A report on 15 years of experience. Radiology, 106, for carcinoma: a review and perspective. Surgical Clinics 407-418. of North America, 47, 695-706. RODRIGUEZ-ANTUNEZ, A., COOK, S. A., JELDEN, G. L., GAHAGAN, H. Q., and FISCHMAN, J. L., 1949. Carcinoma of

HUNTER, T. W., STRAFFON, R. A., and STEWART, B. H.,

the prostate; statistical study and evaluation of endocrine therapy, with preliminary report on additional method of treatment. Journal of Urology, 61, 587-590. HERBST, W. P. 1942. Biochemical therapeusis in carcinoma of the prostate gland; preliminary report. Journal of

1973. Management of primary and metastatic carcinoma of the prostate by the radiotherapist. American Journal of Roentgenology, Radium Therapy and Nuclear Medicine, 118, 876-880.

American Medical Association, 120, 111 6-1120. HILL, D. R., CREWS, Q. E., Jr. and WALSCH, P. C , 1974.

Prostate carcinoma: radiation treatment of the primary and regional lymphatics. Cancer, 34, 156—160.

VETERANS ADMINISTRATION CO-OPERATIVE UROLOGICAL RESEARCH GROUP, 1967. Treatment and survival of

patients with cancer of the prostate. Surgery, Gynecology and Obstetrics, 124, 1011-1017.

Book review Traite de Radiodiagnostic. Tome XI: Rhumatologie, Articul- and although it will not replace the need for monographs on ations, Parties mol/es. By R. Trial, M. Laval-Jeantet and these topics, it will be most useful as an introduction for M.Chr. Plainfosse, 464 pp. with 545 illustrations and anyone learning these methods. different colourplates, 1976 (Masson - Paris), 540F. The last section (83 pages) covers the radiography of the Rhumatologie, Articulations, Parties molles represents articular and periarticular soft tissues as well as of the muscles and the skin. part XI of the French Traite de Radiodiagnostic. This is a most original and remarkable section. New ideas The first section (68 pages) covers the morphological and biological basis of articular pathology as well as a remarkable and technical developments concerning radiography of the chapter on arthroscopy (with beautiful colour plates) and soft tissues are here developed and nicely supplemented by some technical aspects and new developments in osteo- drawings and pertinent radiographs. It provides a totally new view of a field that has been too much neglected in the articular radiology. The second section (221 pages) is devoted to the radio- past. Printing and radiographs are, as usual in this prestigious diagnosis of articular and periarticular diseases. It provides, in a concise manner, a complete view of common and rare French handbook, of superb quality. An up-to-date biblioarticular conditions. A minor criticism concerns the covering graphy is given after each chapter. This book can be recommended for each medical or of Reiter's disease where the lesions of the vertebral column are not mentioned. radiological library. It should prove an excellent work for The third section (52 pages) deals with arthrography of medical students and residents and a valuable aid for each the shoulder, elbow, wrist, hip, knee and ankle. Basic radiologist in charge of teaching. A. BAERT. information concerning technique, normal anatomy and pathological findings is provided for each of these methods

947

Treatment of locally advanced prostatic carcinoma.

An analysis of 66 patients with prostatic carcinoma treated by telecobalt therapy more than two years ago shows that this can be curative in a high pe...
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