RISK OF TESTICULAR CANCER IN COHORT OF BOYS WITH CRYPTORCHIDISM

Objective: To determine the risk of testicular cancer in relation to u ndescended testis and its treatment based on recorded details of the m aldescent, treatment, and biopsy from case notes. Design: Cohort study . Setting: Hospital for Sick Children, Great Ormond Street, London. Su bjects: 1075 boys with cryptorchidism treated by orchidopexy or hormon es at the hospital during 1951-64. Main outcome measures: Relative ris k of testicular cancer in the cohort compared with men in the general population. Results: 12 testicular cancers occurred in 11 of the patie nts during follow up to mid-1990 (relative risk of cancer in males wit h cryptorchidism = 7.5 (95% confidence interval 3.9 to 12.8)). The rel ative risk fell significantly beyond 15 years after orchidopexy but di d not decrease with younger age at orchidopexy. Risk was significantly raised in testes that had had biopsy samples removed during orchidope xy (relative risk = 66.7 (23.9 to 143.3) compared with a testis in a m an in the general population) and was significantly greater in these t estes than in undescended testes that had not had biopsy samples taken at orchidopexy (6.7 (2.7 to 13.5)). No reasons for biopsy or distingu ishing clinical aspects of the testes that had had biopsy samples take n and later developed malignancies were evident in the case notes. No histological abnormalities were evident at initial biopsy except in on e testis that had features of dysgenesis. Conclusions: Biopsy seems to be a stronger risk factor for testicular cancer than any factor previ ously identified. The trauma of open biopsy may contribute substantial ly to risk of malignancy or the testes may have been selected for biop sy on the basis of clinical factors predictive of malignancy but not m entioned in the case notes.