Cervical intraepithelial neoplasia in patients with breast cancer: a cytological and colposcopic study.

Twenty-six patients with treated breast cancer who had been randomised previously to receive combination chemotherapy including alkylating agents (n = 14) or to undergo oophorectomy (n = 12) following surgery underwent cytological and colposcopic screening of the uterine cervix. Colposcopically directed cervical punch biopsies were taken from all patients in whom a colposcopic abnormality was detected. Breast cancer patients were compared with 79 controls with normal cervical cytology and no known breast malignancy. Colposcopically directed punch biopsies were taken from the cervical transformation zone of all controls. Significantly more breast cancer patients who had received chemotherapy (43%) than controls (10%) had CIN (P < 0.01) and significantly more patients who had received chemotherapy (14%) than controls (3%) had CIN 2 or 3 (P < 0.05). The proportion of breast cancer patients in the oophorectomy group with CIN (17%) did not differ significantly from the control group. No case of CIN was detected by cervical cytology. This study suggests that breast cancer patients receiving combination chemotherapy including alkylating agents are at increased risk of CIN, and that cervical cytology alone may be an inadequate form of screening for these patients.