Second primary cancers in men with prostate cancer: an increased risk of male breast cancer.

PURPOSE Evaluation of second primary cancers provides valuable insight about etiology and shared risk factors. Studies of second primary cancers following prostate cancer conclude that overall risk of second primary cancers decreases. However, risk of bladder cancer and kidney cancer increases. We examine the risk of common and rare second primary cancers following prostate cancer in a large population based cohort to identify possible common etiological factors. MATERIALS AND METHODS All prostate cancer cases in the Swedish Cancer Registry (135, 713) from 1958 to the end of 1996 constituted the study base. Risk (standardized incidence ratio) of second primary cancers was calculated as the ratio between observed and expected number of cancers. We used 2-tailed 95% confidence intervals (CI) to test significance. RESULTS An overall increased risk (standardized incidence ratio 1.17, 95% CI 1.15-1.19) of second primary cancers was found but was only seen in the first 6 months of followup (ratio 3.45, 3.32-3.57). The most interesting finding was an increased risk (ratio 2.01, 95% CI 1.44-2.74) of male breast cancer. Other tumor sites with increased risk were the small intestine (standardized incidence ratio 1.39, 95% CI 1.09-1.51), skin melanoma (ratio 1.33, 95% CI 1.16-1.51) and endocrine tumors (ratio 1.41, 95% CI 1.13-1.74). CONCLUSIONS A small but increased risk of second primary cancers following prostate cancer was found, most likely due to increased surveillance during the first 6 months after diagnosis. However, following prostate cancer there is an increased risk of endocrine related second primary cancers such as male breast cancer and carcinoids in the small intestine. To our knowledge these associations have not been reported previously, and they warrant more study.

[1]  D. Winn,et al.  Second cancer following cancer of the digestive system in Connecticut, 1935-82. , 1985, National Cancer Institute monograph.

[2]  M. Ro̸rth,et al.  Second cancer following cancer of the male genital system in Denmark, 1943-80. , 1985, National Cancer Institute monograph.

[3]  R N Hoover,et al.  Second cancer following cancer of the female genital system in Connecticut, 1935-82. , 1985, National Cancer Institute monograph.

[4]  O. Schlappack,et al.  Report of two cases of male breast cancer after prolonged estrogen treatment for prostatic carcinoma. , 1986, Cancer detection and prevention.

[5]  W. S. Clark,et al.  Risk of genitourinary malignancies after cancer of the prostate , 1988, Cancer.

[6]  T H Beaty,et al.  Family history and the risk of prostate cancer , 1990, The Prostate.

[7]  M. Stratton,et al.  A germline mutation in the androgen receptor gene in two brothers with breast cancer and Reifenstein syndrome , 1992, Nature Genetics.

[8]  H. Olsson,et al.  Population‐based cohort investigations of the risk for malignant tumors in first‐degree relatives and wives of men with breast cancer , 1993, Cancer.

[9]  C. la Vecchia,et al.  Incidence of invasive cancers following cutaneous malignant melanoma , 1997, International journal of cancer.

[10]  J. Montie,et al.  Risk of multiple primary cancers in prostate cancer patients in the Detroit metropolitan area: A retrospective cohort study , 1997, The Prostate.

[11]  J. Eyfjörd,et al.  BRCA2 mutation in Icelandic prostate cancer patients , 1997, Journal of Molecular Medicine.

[12]  J. Frödin,et al.  Multiple primary malignant tumors in a national cancer registry--reliability of reporting. , 1997, Acta oncologica.

[13]  Å. Borg,et al.  BRCA2 germ-line mutations are frequent in male breast cancer patients without a family history of the disease. , 1998, Cancer research.

[14]  T. Hayes,et al.  Male breast cancer: a review of the literature. , 1998, European journal of cancer.

[15]  H. Olsson.  Cancer risks in BRCA2 mutation carriers. , 1999, Journal of the National Cancer Institute.

[16]  R. Gupta,et al.  Immunoreactivity of prostate‐specific antigen in male breast carcinomas: Two examples of a diagnostic pitfall in discriminating a primary breast cancer from metastatic prostate carcinoma , 1999, Diagnostic cytopathology.

[17]  E. Riboli,et al.  Plasma insulin-like growth factor-I, insulin-like growth factor-binding proteins, and prostate cancer risk: a prospective study. , 2000, Journal of the National Cancer Institute.

[18]  D. Brenner,et al.  Second malignancies in prostate carcinoma patients after radiotherapy compared with surgery , 2000, Cancer.

[19]  O. Cussenot,et al.  Early onset and familial predisposition to prostate cancer significantly enhance the probability for breast cancer in first degree relatives , 2000, International journal of cancer.

[20]  M. McCredie,et al.  Second primary cancers following cancers of the kidney and prostate in New South Wales (Australia), 1972–91 , 1996, Cancer Causes & Control.