CANCER RISK AMONG WOMEN STERILIZED WITH TRANSCERVICAL QUINACRINE HYDROCHLORIDE PELLETS, 1977 TO 1991

Objective: To determine whether a cluster of eight cancers among 572 w omen who had received transcervical quinacrine hydrochloride was a ran dom occurrence or evidence of an increased risk of cancer. Design: Ret rospective cohort study using interviews and reviews of medical record s. Cancer cases were evaluated using cohort analyses and space-time cl uster methods. Setting: Santiago and Valdivia, Chile. Subjects: Fourte en hundred ninety-two women who received transcervical quinacrine pell ets for sterilization between 1977 and 1989. Main Outcome Measure: Age - and site-specific incidence of invasive cancers. Results: Eight hund red two women were interviewed. From 1 to 14 years of data were availa ble on 600 of the noninterviewed women from clinic records. During 7,8 52 woman-years of follow-up, 17 invasive cancers were identified, comp ared with 11.8 expected, based on age-specific rates from the Call, Co lombia cancer registry. Five cases of cervical cancer were observed, c ompared with 3.96 expected. Only one other uterine cancer was observed , a leiomyosarcoma, compared with 0.2 or 0.3 other uterine cancers exp ected. Conclusions: The occurrence of an unusual cluster was confirmed , but no evidence was found of excess cancer risk associated with quin acrine pellet sterilization. However there was a single provocative ob servation (the leiomyosarcoma), and surveillance of the cohort is cont inuing.