The risk of developing subsequent nonmelanoma skin cancers Michael M. Schreiber, MD, Thomas E. Moon, PhD, Sarah H. Fox, BSN, and Janelle Davidson, MS Tucson, Arizona Data from the Southeast Arizona Skin Cancer Registry collected during 1985 through June 1988 were used in this study. Patients who had a nonme1anoma skin cancer (basal cell or squamous cell carcinoma) removed in 1985 were observed until subsequent nonmelanoma skin cancers developed or until June 30, 1988. Twelve categories of nonmelanoma skin cancers were developed on the basis of the type of first nonmelanoma skin cancer and type of second, third, and fourth nonmelanoma skin cancers. Analyses showed the highest risk of a subsequent nonme1anoma skin cancer developing was within 1 year (36.39%), the rate of developing another nonmelanoma skin cancer depended on type (squamous cell carcinoma, 100%; basal cell carcinoma, 44.23% to 83.65%), and total risk decreased during the 1277 days ofthe study. (J AM ACAD DERMATOL 1990;23:1114-8.) Nonmelanoma skin cancers (NMSCs), that is, basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), are the most common malignancies in the United States. More than 500,000 diagnoses of NMSC are made annually in the United States. 1 Surveys of NMSC indicate an increasing incidence throughout the past few decades 2, 3 and the possibility the incidence will double during the next 30 years. Persons with a history of NMSC are at great risk of developing subsequent NMSCs.4, 6 Our epidemiologic survey of NMSC in Arizona from 1985 through June 1988 indicates that the risk of subsequent NMSCs is high and prolonged. We have quantified this risk to develop a follow-up schedule for clinicians with NMSC patients.
METHOD Information from the Southeast Arizona Skin Cancer Registry collected from 1985 through June 1988 was used. These data were collected from 21 sources in Pima, Cochise, and Santa Cruz counties. All sources of patholFrom the Arizona Cancer Center. Department of Family and Community Medicine, and Department of Internal Medicine, University of Arizona College of Medicine. Supported in part by research grants from Arizona Disease Control Research Corrunission (8277-000000-1-Q..YR9301) and the National Institutes of Health, U.S. Department of Health and Human Services (CA 34256, CA 27502). Accepted for publication April 1. 1990. Reprint requests: Michael M. Schreiber, MD, 5402 East Grant Rd., Building F, Tucson, AZ 85712.
16/1/21318
1114
ogy information were included (i.e., 16 dermatologists, 12 hospitals, and an independent pathology laboratory). The hospital and laboratory cases were from patients of dermatologists, plastic and general surgeons, and general practitioners, a total of 184 physicians. Dermatologists removed 83% of the tumors, plastic and general surgeons removed 8%, and general practitioners removed 9%. The data were uploaded to a mainframe computer at the Arizona Cancer Center where it was edited and analyzed with SAS software (SAS Institute, Inc., Cary, N.C.). The demographic information was kept in a separate file from the pathology data to ensure patient confidentiality. Because a given patient may have been seen in more than one medical care facility and because the same specimen may have been evaluated at more than one place, computerized record linkage was used to prevent duplication. All histopathology specimens were evaluated by a board-certified pathologist and/or board-certified dermatopathologist. Reexcision tumors and metastatic tumors or specimens labeled "possible" or "uncertain" were identified and not counted. Specimens diagnosed as BCC or BCC/SeC (same tumor) were coded as BCC. Specimens diagnosed as keratoacanthoma (less than 2% and only in 1988) were coded as sec. Only persons with residence in the three counties were counted. Patient addresses were identified from clinical records in 56% of the cases. Residency in the remaining 44% were assumed to be the same as the referring physician. If there was only one address and it was outside the three counties, the case was not included in this report. Cases were coded by type of NMSC, age, and gender.
Volume 23 Number 6, Part 1 December 1990
Risk ofdeveloping nonmelanoma skin cancers 1115
Table I. Patients with a nonmelanoma skin cancer (NMSC) in 1985 and subsequent NMSCs before June 30, 1988 No. of patients
Category No.
Category description
1 2 3 4 5 6 7 8 9 10 11 12
Index NMSC to next NMSC Index NMSC to two new NMSC Index NMSC to three new NMSC Index BCC to next BCC Index BCC to two new BCC Index BCC to three new BCC Two BCC to 3rd BCC Index SCC to next SCC Index SCC to two new SCC Index SCC to three new SCC Index BCC to first SCC Index SCC to first BCC
No. of patients withNMSC
with subsequent
1985
No. of patients with subsequent NMSC(%)
NMSCwithin 400 days (%)
% All subsequent NMSC that occur within 400 days
6310 6310 6310 4670 4670 4670 1188 2192 2192 2192 4670 2192
3154 (49.98) 1898 (30.08) 1222 (19.37) 2190 (46.90) 1236 (26.83) 789 (16.90) 782 (65.82) 380 (17.34) 111 (5.06) 36 (1.64) 907 (19.42) 942 (42.97)
2296 (36.39) 1019 (16.15) 543 (8.61) 1549 (33.17) 650 (13.92) 349 (7.47) 605 (50.93) 380 (17.34) III (5.06) 36 (1.64) 559 (11.97) 788 (35.95)
72.80 53.69 44.44 70.73 51.88 44.23 77.37 100.00 100.00 100.00 61.63 83.65
Ethnicity (Anglo-American or Hispanic) was defined by means of the 1980 U.S. Census Bureau's list of selfreported Hispanic surnames. The proportion of subsequent NMSCs was not different for Anglo-American, Hispanic, and combined populations. Thus only the combined figures are presented. A cross-tabulation of groups by gender, and mean and median age groups at 10-year intervals for categories with first BCC, first sce, and two BCes in 1985 were calculated. All patients with an NMSe diagnosed in 1985 were included in this report. The number of days from the index NMSC diagnosed in 1985 to a subsequent one or until the last date of follow-up was calculated. If more than one NMSC was diagnosed at the time of the index cancer, a value of zero was used as the number of days to a subsequent NMSC. The latest date of follow-up was chosen to be June 30, 1988. Follow-up for all patients was not possible from the date of the index NMse through June 1988. Mortality and out-migration rates from the three-county area were determined to be 2% and 4%, respectively, per year.7 These figures were assumed to apply to the NMSC cohort identified in 1985 but not included in the calculation of time to new skin cancer. Thus these calculations may slightly underestimate the percentage of outpatients with a new skin cancer during the period of follow-up. Study patients were classified into 12 categories on the basis of the pathology type of the index cancer and their subsequent cancer. These categories were as follows: 1, index NMSe (BeC or SCC) to a new NMSC; 2, index NMSC to two new NMSCs; 3, index NMse to three new NMSCs; 4, index BCe to new BeC; 5, index BCC to two new BCCs; 6, index Bce to three new BCCs; 7, two BCCs (two BCes in 1985) to next BCC; 8, index
SCC to new sec; 9, index sce to two new SCCs; 10, index sec to three new sees; 11, index BCC to new sec; 12, index sce to new BCe. For each category life-table methods were used to calculate estimates and plots of the proportion of patients with a subsequent diagnosis of NMSC after diagnosis of the index NMSC. 8 RESULTS In 1985, 6310 patients residing in southeast Arizona were diagnosed with an index NMSC (not always their first NMSC). The median age was 69 years for all patients and ranged from 68 to 71 years for each category. Median age of women was similar to that of men (68 vs 69 years). Because of comparable ages for each category, no adjustment was made for age or gender. All 12 categories we analyzed (Table I) showed that the highest risk ofdeveloping one new, two new, or three new NMSCs occurred during the first year (400 days is referred to as 1 year in this article) after removal of the index NMSC. After the first year the risk decreases. The chances of other NMSCs (categories 1 through 3) developing within 1 year decreased from 36.39% for one new to 16.15% for two new and to 8.61 %for three new. During the period of our study 49.98% had another NMSC, 30.08% had two more, and 19.37% had three more subsequent NMSCs. The percentage of all patients with subsequent NMSCs developing within 1 year was 72.80% for the first new NMSC, 53.69% for two additional, and
Journal of the American Academy of Dermatology
1116 Schreiber et al.
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Fig. 1. Time until patients with an NMSC in 1985 had new NMSC.
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Fig. 2. Time until patients with an sec in 1985 had new sec.
44.44% for three additionaL The plots of time to new NMSCs (category 1) (plots 2 and 3 similar to plot 1) show this increased risk during the first 400 days, followed by a gradual decrease in risk over the period of the study (Fig. t). The risk of another SCC (categories 8 through 11) developing was 17.34%. The risk decreased from 5.06% for two new SCCs to 1.64% for three new SCCs during the study period. Of the persons developing another SCC, 100% did so within 1 year; the only exception was those whose first NMSC was a BCC (61.63%). The plots (categories 8 through 11 similar) for all subsequent categories show an
sec
even more rapid drop than the subsequent NMSC and BCC category plots and thus a shorter high risk period (Fig. 2). Here the plot drops in fewer than 200 days (the highest risk period) followed by a straight horizontal line running the remaining 1000 days (near zero risk). In contrast to the low risk of a subsequent SCC, developing, the risk for BCC (categories 4 through 6) was 46.60% for the next BCe. The risk decreased for two new BCCs to 26.83% and 16.90% for three new BCes during this study. The risk for the third BCC was even greater (65.82%) when the patient had two BCCsin 1985 (category 7). During the first
Volume 23 Number 6, Part 1 December 1990
Risk ofdeveloping nonmelanoma skin cancers 1117 100
0l,---.---..-----r--,..-----,....----r----. 600 800 1000 1200 1400 400 a 200 Time (days)
Fig. 3. Time until patients with a BCC in 1985 had new BCC.
year after removal of the index BCC, the chances of second, third, and fourth BCCs were 33.17%, 13.92%, and 7.47%, respectively. For persons with an index SCC and a subsequent BCC, the I-year risk was 35.95% (category 12). When a patient had two BCCs in 1985, the risk at 1 year was 50.93%. To emphasize the high first-year new BCC occurrence risk is the high percentage of the subsequent BCCs that occur during this time. In this first year 70.73% had their next BeC, 51.70% had two additional, and 44.23% had three additional. Of those patients with two BCCs in 1985, 77.37% had a third. The plot of category 4 (categories 7 and 12 are similar to category 4) for subsequent BCCs shows a rapid drop over the first year, thus a high risk (Fig. 3). Then there is a gradual decrease in the curve through the follow-up period, representing a declining risk. Differing are the plots (categories 5 and 6) for third and fourth subsequent BCCs, which show a gradual de..cline in the plot line over the period ofthe study, thus a gradual lessening of the risk. DISCUSSION
The calculated rates reflect a community of approximately 750,000 persons in a high NMSC incidence area. The mortality and out-migration rates have been estimated to be 2% and 4%, respectively, per year. The use of cross-sectional access NMSCs diagnosed histologically and loss offollow-up for patients who moved out of our area resulted in an underestimation of subsequent NMSC frequency.
Our findings of a 49.98% risk of a subsequent NMSC developing during this study emphasize the importance of careful and frequent follow-up examinations of all patients with an NMSC. As would be expected, the risk of a subsequent NMSC of the BCC type developing is much greater than for an SCC. This concurs with the findings of Goldberg et al.,4 Robinson,S and Epstein. 6 In 1988 Goldberg et a1. 4 found that in 2 and 5 years after patients had an NMSC, 16% and 38%, respectively, had a new NMSC. In a 1987 study of BCes Robinson 5 showed that at the end of the first year 22% of patients had a second BCe, the second year 33%, the third year 34%, and the fourth and fifth years 36%. Epstein6 had similar findings in 1973; 20% of patients with a BCC had another within 1 year. The risk percentages and accompanying plots we developed show that the first year after removal of an NMSC is critical for subsequent new cancer occurrences. During the first year the bulk of subsequent NMSCs develop, virtually 100% ofnew SCCs and between 44.23% and 83.65% of new BCCs. After this first year, it is only BeCs that continue to develop at a significant rate. Our data confirm the appropriateness, after an NMSC removal, of checking the patient for new tumors at 3-month intervals for at least 1 year. After the first year, a checkup every 6 to 12 months for an indefinite period is advisable. Early removal of NMSCs found at these follow-up visits could decrease morbidity and mortality.
Journal of the American Academy of Dermatology
Schreiber et al. REFERENCES 1. American Cancer Society. Facts and figures. Atlanta: 1988. 2. Scotto J, Fears TR, Fraumeni JF Jr. Incidence ofnonmelanoma skin cancer in the United States. Bethesda, Md: National Institutes of Health, 1983; Publication No. 832433. 3. Moon TE, Davidson J, Schreiber MM, et al. Sunlight intensity and skin cancer incidence in Arizona. Abstract presented at Proceedings of the American Academy of Dermatology 1989. 4. Goldberg LH, Carter-Campbell S, Yiannias JA. The risk
5. 6. 7. 8.
of acquiring a new skin cancer in patients with a previously diagnosed skin cancer. Skin Cancer Foundation Journal, World Congress IlIon Cancers of the Skin, 1988:25-6. Robinson JK. Risk of developing another basal cell carcinoma. Cancer 1987;60:118-20. Epstein E. Value of follow-up after treatment of basal cell carcinoma. Arch Dermatol 1973;108:798-800. Kalbfleisch JD, Prentice RL. The statistical analysis of failure time data. New York: John Wiley & Sons, 1980. Population Statistics Unit. A demographic guide to Arizona, 1985. Phoenix: Arizona Department of Economic Security, 1985; report 14.
Histologic pattern analysis of basal cell carcinoma Study of a series of 1039 consecutive neoplasms Mack Sexton, MD,a,c Daniel B. Jones, MD,b and Mary E. Maloney, MDC
Hershey, Pennsylvania This study attempts to define histologic patterns in 1039 consecutive cases of basal cell carcinoma and to correlate these patterns with adequacy of margins of surgical excision. Five major histologic patterns were identified: nodular, 218 cases (21%); superficial, 181 cases (17%); micronodular, 151 cases (15%); infiltrative, 77 cases (7%); and morpheic, 11 cases (1 %). A mixed pattern (two or more major histologic patterns) was present in 401 cases (38.5%). Our study indicates that nodular and superficial basal cell carcinomas can be completely removed by simple surgical excision in a high percentage of cases (93.6% and 96.4%, respectively) whereas the micronodular, infiltrative, and morpheic basal cell carcinomas have a higher incidence of positive tumor margins (18.6%,26.5%, and 33.3%, respectively) after excision. Mixed patterns that consisted of combinations of the nodular, micronodular, or infiltrative types exhibited a behavior similar to the pattern that resulted in a greater chance of incomplete surgical removal. (J AM ACAD DERMATOL 1990;23:1118-26.) Basal cell carcinomas are by far the most common primary cutaneous malignant neoplasm. Most are relatively innocuous and result in infrequent patient morbidity or mortality. However, some may cause extensive tissue destruction and directly contribute to death through either local infiltration of vital structures or metastatic disease. Historically, basal cell carcinomas have been histologically segregated into undifferentiated and differentiated types. 1,2 Differentiated basal cell carciFrom the Department of Pathology, a The College of Medicine,b and the Department of Medicine; Division of Dermatology, M. S. Hershey Medical Center, The Pennsylvania State University. Accepted for publication Aprill, 1990. Reprint requests: Mack Sexton, MD, University of Florida Medical Center, P.O. Box 1-275, JHMHC, Gainesville, FL 32610-0275.
16/1/21315
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nomas are named on the basis of their resemblance to cutaneous appendages. Undifferentiated basal cell carcinomas lack these differentiating features. However, this histologic classification is inadequate because of difficulties in its uniform application to therapy and its acceptance by dermatopathologists. This study attempts to define the histologic patterns encountered in 1039 consecutive cases of basal cell carcinoma. These patterns were correlated with adequacy of surgical excision because adequacy of excision is an effective predictor of the tendency of basal cell carcinomas to recur. 3
MATERIAL AND METHODS The cases in this study were retrieved from the pathology and dermatopathology archives at the M. S. Hershey Medical Center. A total of 1039 consecutive primary
METHOD Information from the Southeast Arizona Skin Cancer Registry collected from 1985 through June 1988 was used. These data were collected from 21 sources in Pima, Cochise, and Santa Cruz counties. All sources of patholFrom the Arizona Cancer Center. Department of Family and Community Medicine, and Department of Internal Medicine, University of Arizona College of Medicine. Supported in part by research grants from Arizona Disease Control Research Corrunission (8277-000000-1-Q..YR9301) and the National Institutes of Health, U.S. Department of Health and Human Services (CA 34256, CA 27502). Accepted for publication April 1. 1990. Reprint requests: Michael M. Schreiber, MD, 5402 East Grant Rd., Building F, Tucson, AZ 85712.
16/1/21318
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ogy information were included (i.e., 16 dermatologists, 12 hospitals, and an independent pathology laboratory). The hospital and laboratory cases were from patients of dermatologists, plastic and general surgeons, and general practitioners, a total of 184 physicians. Dermatologists removed 83% of the tumors, plastic and general surgeons removed 8%, and general practitioners removed 9%. The data were uploaded to a mainframe computer at the Arizona Cancer Center where it was edited and analyzed with SAS software (SAS Institute, Inc., Cary, N.C.). The demographic information was kept in a separate file from the pathology data to ensure patient confidentiality. Because a given patient may have been seen in more than one medical care facility and because the same specimen may have been evaluated at more than one place, computerized record linkage was used to prevent duplication. All histopathology specimens were evaluated by a board-certified pathologist and/or board-certified dermatopathologist. Reexcision tumors and metastatic tumors or specimens labeled "possible" or "uncertain" were identified and not counted. Specimens diagnosed as BCC or BCC/SeC (same tumor) were coded as BCC. Specimens diagnosed as keratoacanthoma (less than 2% and only in 1988) were coded as sec. Only persons with residence in the three counties were counted. Patient addresses were identified from clinical records in 56% of the cases. Residency in the remaining 44% were assumed to be the same as the referring physician. If there was only one address and it was outside the three counties, the case was not included in this report. Cases were coded by type of NMSC, age, and gender.
Volume 23 Number 6, Part 1 December 1990
Risk ofdeveloping nonmelanoma skin cancers 1115
Table I. Patients with a nonmelanoma skin cancer (NMSC) in 1985 and subsequent NMSCs before June 30, 1988 No. of patients
Category No.
Category description
1 2 3 4 5 6 7 8 9 10 11 12
Index NMSC to next NMSC Index NMSC to two new NMSC Index NMSC to three new NMSC Index BCC to next BCC Index BCC to two new BCC Index BCC to three new BCC Two BCC to 3rd BCC Index SCC to next SCC Index SCC to two new SCC Index SCC to three new SCC Index BCC to first SCC Index SCC to first BCC
No. of patients withNMSC
with subsequent
1985
No. of patients with subsequent NMSC(%)
NMSCwithin 400 days (%)
% All subsequent NMSC that occur within 400 days
6310 6310 6310 4670 4670 4670 1188 2192 2192 2192 4670 2192
3154 (49.98) 1898 (30.08) 1222 (19.37) 2190 (46.90) 1236 (26.83) 789 (16.90) 782 (65.82) 380 (17.34) 111 (5.06) 36 (1.64) 907 (19.42) 942 (42.97)
2296 (36.39) 1019 (16.15) 543 (8.61) 1549 (33.17) 650 (13.92) 349 (7.47) 605 (50.93) 380 (17.34) III (5.06) 36 (1.64) 559 (11.97) 788 (35.95)
72.80 53.69 44.44 70.73 51.88 44.23 77.37 100.00 100.00 100.00 61.63 83.65
Ethnicity (Anglo-American or Hispanic) was defined by means of the 1980 U.S. Census Bureau's list of selfreported Hispanic surnames. The proportion of subsequent NMSCs was not different for Anglo-American, Hispanic, and combined populations. Thus only the combined figures are presented. A cross-tabulation of groups by gender, and mean and median age groups at 10-year intervals for categories with first BCC, first sce, and two BCes in 1985 were calculated. All patients with an NMSe diagnosed in 1985 were included in this report. The number of days from the index NMSC diagnosed in 1985 to a subsequent one or until the last date of follow-up was calculated. If more than one NMSC was diagnosed at the time of the index cancer, a value of zero was used as the number of days to a subsequent NMSC. The latest date of follow-up was chosen to be June 30, 1988. Follow-up for all patients was not possible from the date of the index NMse through June 1988. Mortality and out-migration rates from the three-county area were determined to be 2% and 4%, respectively, per year.7 These figures were assumed to apply to the NMSC cohort identified in 1985 but not included in the calculation of time to new skin cancer. Thus these calculations may slightly underestimate the percentage of outpatients with a new skin cancer during the period of follow-up. Study patients were classified into 12 categories on the basis of the pathology type of the index cancer and their subsequent cancer. These categories were as follows: 1, index NMSe (BeC or SCC) to a new NMSC; 2, index NMSC to two new NMSCs; 3, index NMse to three new NMSCs; 4, index BCe to new BeC; 5, index BCC to two new BCCs; 6, index Bce to three new BCCs; 7, two BCCs (two BCes in 1985) to next BCC; 8, index
SCC to new sec; 9, index sce to two new SCCs; 10, index sec to three new sees; 11, index BCC to new sec; 12, index sce to new BCe. For each category life-table methods were used to calculate estimates and plots of the proportion of patients with a subsequent diagnosis of NMSC after diagnosis of the index NMSC. 8 RESULTS In 1985, 6310 patients residing in southeast Arizona were diagnosed with an index NMSC (not always their first NMSC). The median age was 69 years for all patients and ranged from 68 to 71 years for each category. Median age of women was similar to that of men (68 vs 69 years). Because of comparable ages for each category, no adjustment was made for age or gender. All 12 categories we analyzed (Table I) showed that the highest risk ofdeveloping one new, two new, or three new NMSCs occurred during the first year (400 days is referred to as 1 year in this article) after removal of the index NMSC. After the first year the risk decreases. The chances of other NMSCs (categories 1 through 3) developing within 1 year decreased from 36.39% for one new to 16.15% for two new and to 8.61 %for three new. During the period of our study 49.98% had another NMSC, 30.08% had two more, and 19.37% had three more subsequent NMSCs. The percentage of all patients with subsequent NMSCs developing within 1 year was 72.80% for the first new NMSC, 53.69% for two additional, and
Journal of the American Academy of Dermatology
1116 Schreiber et al.
-
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Time (days)
Fig. 1. Time until patients with an NMSC in 1985 had new NMSC.
LO
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Fig. 2. Time until patients with an sec in 1985 had new sec.
44.44% for three additionaL The plots of time to new NMSCs (category 1) (plots 2 and 3 similar to plot 1) show this increased risk during the first 400 days, followed by a gradual decrease in risk over the period of the study (Fig. t). The risk of another SCC (categories 8 through 11) developing was 17.34%. The risk decreased from 5.06% for two new SCCs to 1.64% for three new SCCs during the study period. Of the persons developing another SCC, 100% did so within 1 year; the only exception was those whose first NMSC was a BCC (61.63%). The plots (categories 8 through 11 similar) for all subsequent categories show an
sec
even more rapid drop than the subsequent NMSC and BCC category plots and thus a shorter high risk period (Fig. 2). Here the plot drops in fewer than 200 days (the highest risk period) followed by a straight horizontal line running the remaining 1000 days (near zero risk). In contrast to the low risk of a subsequent SCC, developing, the risk for BCC (categories 4 through 6) was 46.60% for the next BCe. The risk decreased for two new BCCs to 26.83% and 16.90% for three new BCes during this study. The risk for the third BCC was even greater (65.82%) when the patient had two BCCsin 1985 (category 7). During the first
Volume 23 Number 6, Part 1 December 1990
Risk ofdeveloping nonmelanoma skin cancers 1117 100
0l,---.---..-----r--,..-----,....----r----. 600 800 1000 1200 1400 400 a 200 Time (days)
Fig. 3. Time until patients with a BCC in 1985 had new BCC.
year after removal of the index BCC, the chances of second, third, and fourth BCCs were 33.17%, 13.92%, and 7.47%, respectively. For persons with an index SCC and a subsequent BCC, the I-year risk was 35.95% (category 12). When a patient had two BCCs in 1985, the risk at 1 year was 50.93%. To emphasize the high first-year new BCC occurrence risk is the high percentage of the subsequent BCCs that occur during this time. In this first year 70.73% had their next BeC, 51.70% had two additional, and 44.23% had three additional. Of those patients with two BCCs in 1985, 77.37% had a third. The plot of category 4 (categories 7 and 12 are similar to category 4) for subsequent BCCs shows a rapid drop over the first year, thus a high risk (Fig. 3). Then there is a gradual decrease in the curve through the follow-up period, representing a declining risk. Differing are the plots (categories 5 and 6) for third and fourth subsequent BCCs, which show a gradual de..cline in the plot line over the period ofthe study, thus a gradual lessening of the risk. DISCUSSION
The calculated rates reflect a community of approximately 750,000 persons in a high NMSC incidence area. The mortality and out-migration rates have been estimated to be 2% and 4%, respectively, per year. The use of cross-sectional access NMSCs diagnosed histologically and loss offollow-up for patients who moved out of our area resulted in an underestimation of subsequent NMSC frequency.
Our findings of a 49.98% risk of a subsequent NMSC developing during this study emphasize the importance of careful and frequent follow-up examinations of all patients with an NMSC. As would be expected, the risk of a subsequent NMSC of the BCC type developing is much greater than for an SCC. This concurs with the findings of Goldberg et al.,4 Robinson,S and Epstein. 6 In 1988 Goldberg et a1. 4 found that in 2 and 5 years after patients had an NMSC, 16% and 38%, respectively, had a new NMSC. In a 1987 study of BCes Robinson 5 showed that at the end of the first year 22% of patients had a second BCe, the second year 33%, the third year 34%, and the fourth and fifth years 36%. Epstein6 had similar findings in 1973; 20% of patients with a BCC had another within 1 year. The risk percentages and accompanying plots we developed show that the first year after removal of an NMSC is critical for subsequent new cancer occurrences. During the first year the bulk of subsequent NMSCs develop, virtually 100% ofnew SCCs and between 44.23% and 83.65% of new BCCs. After this first year, it is only BeCs that continue to develop at a significant rate. Our data confirm the appropriateness, after an NMSC removal, of checking the patient for new tumors at 3-month intervals for at least 1 year. After the first year, a checkup every 6 to 12 months for an indefinite period is advisable. Early removal of NMSCs found at these follow-up visits could decrease morbidity and mortality.
Journal of the American Academy of Dermatology
Schreiber et al. REFERENCES 1. American Cancer Society. Facts and figures. Atlanta: 1988. 2. Scotto J, Fears TR, Fraumeni JF Jr. Incidence ofnonmelanoma skin cancer in the United States. Bethesda, Md: National Institutes of Health, 1983; Publication No. 832433. 3. Moon TE, Davidson J, Schreiber MM, et al. Sunlight intensity and skin cancer incidence in Arizona. Abstract presented at Proceedings of the American Academy of Dermatology 1989. 4. Goldberg LH, Carter-Campbell S, Yiannias JA. The risk
5. 6. 7. 8.
of acquiring a new skin cancer in patients with a previously diagnosed skin cancer. Skin Cancer Foundation Journal, World Congress IlIon Cancers of the Skin, 1988:25-6. Robinson JK. Risk of developing another basal cell carcinoma. Cancer 1987;60:118-20. Epstein E. Value of follow-up after treatment of basal cell carcinoma. Arch Dermatol 1973;108:798-800. Kalbfleisch JD, Prentice RL. The statistical analysis of failure time data. New York: John Wiley & Sons, 1980. Population Statistics Unit. A demographic guide to Arizona, 1985. Phoenix: Arizona Department of Economic Security, 1985; report 14.
Histologic pattern analysis of basal cell carcinoma Study of a series of 1039 consecutive neoplasms Mack Sexton, MD,a,c Daniel B. Jones, MD,b and Mary E. Maloney, MDC
Hershey, Pennsylvania This study attempts to define histologic patterns in 1039 consecutive cases of basal cell carcinoma and to correlate these patterns with adequacy of margins of surgical excision. Five major histologic patterns were identified: nodular, 218 cases (21%); superficial, 181 cases (17%); micronodular, 151 cases (15%); infiltrative, 77 cases (7%); and morpheic, 11 cases (1 %). A mixed pattern (two or more major histologic patterns) was present in 401 cases (38.5%). Our study indicates that nodular and superficial basal cell carcinomas can be completely removed by simple surgical excision in a high percentage of cases (93.6% and 96.4%, respectively) whereas the micronodular, infiltrative, and morpheic basal cell carcinomas have a higher incidence of positive tumor margins (18.6%,26.5%, and 33.3%, respectively) after excision. Mixed patterns that consisted of combinations of the nodular, micronodular, or infiltrative types exhibited a behavior similar to the pattern that resulted in a greater chance of incomplete surgical removal. (J AM ACAD DERMATOL 1990;23:1118-26.) Basal cell carcinomas are by far the most common primary cutaneous malignant neoplasm. Most are relatively innocuous and result in infrequent patient morbidity or mortality. However, some may cause extensive tissue destruction and directly contribute to death through either local infiltration of vital structures or metastatic disease. Historically, basal cell carcinomas have been histologically segregated into undifferentiated and differentiated types. 1,2 Differentiated basal cell carciFrom the Department of Pathology, a The College of Medicine,b and the Department of Medicine; Division of Dermatology, M. S. Hershey Medical Center, The Pennsylvania State University. Accepted for publication Aprill, 1990. Reprint requests: Mack Sexton, MD, University of Florida Medical Center, P.O. Box 1-275, JHMHC, Gainesville, FL 32610-0275.
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nomas are named on the basis of their resemblance to cutaneous appendages. Undifferentiated basal cell carcinomas lack these differentiating features. However, this histologic classification is inadequate because of difficulties in its uniform application to therapy and its acceptance by dermatopathologists. This study attempts to define the histologic patterns encountered in 1039 consecutive cases of basal cell carcinoma. These patterns were correlated with adequacy of surgical excision because adequacy of excision is an effective predictor of the tendency of basal cell carcinomas to recur. 3
MATERIAL AND METHODS The cases in this study were retrieved from the pathology and dermatopathology archives at the M. S. Hershey Medical Center. A total of 1039 consecutive primary
