Risk of testicular cancer in cohort of boys with cryptorchidism

Objective: To determine the risk of testicular cancer in relation to undescended testis and its treatment based on recorded details of the maldescent, treatment, and biopsy from case notes. Design: Cohort study. Setting: Hospital for Sick Children, Great Ormond Street, London. Subjects: 1075 boys with cryptorchidism treated by orchidopexy or hormones at the hospital during 1951-64. Main outcome measures: Relative risk of testicular cancer in the cohort compared with men in the general population. Results: 12 testicular cancers occurred in 11 of the patients during follow up to mid-1990 (relative risk of cancer in males with cryptorchidism = 7.5 (95% confidence interval 3.9 to 12.8)). The relative risk fell significantly beyond 15 years after orchidopexy but did not decrease with younger age at orchidopexy. Risk was significantly raised in testes that had had biopsy samples removed during orchidopexy (relative risk = 66.7 (23.9 to 143.3) compared with a testis in a man in the general population) and was significantly greater in these testes 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 distinguishing clinical aspects of the testes that had had biopsy samples taken and later developed malignancies were evident in the case notes. No histological abnormalities were evident at initial biopsy except in one testis that had features of dysgenesis. Conclusions: Biopsy seems to be a stronger risk factor for testicular cancer than any factor previously identified. The trauma of open biopsy may contribute substantially to risk of malignancy or the testes may have been selected for biopsy on the basis of clinical factors predictive of malignancy but not mentioned in the case notes.