Incidence of Multiple Primary Cancers. IV. Cancers of the Female Breast and Genital Organs

Abstract

The incidence of multiple primary cancers of other organs or tissues was studied in patients with carcinomas of the breast (9,792), ovary (921), endometrium (843), and cervix uteri, vagina, or vulva (2,529). The index patients were treated during 1949–62 at the Memorial Sloan-Kettering Cancer Center, and their observed frequency of new primary cancers was compared with the age- and site-specific incidence rates reported by the population-based central registry maintained for New York State (excluding New York City). The incidence of metachronous primary carcinomas in the opposite breast was 6.1/year/1,000 patients, or 4.5 times expectation; in the patients with carcinoma of the breast, the incidence of multiple primary carcinomas of the ovary was 0.6/year/1,000 patients, or twice the normal risk, but one-tenth the risk for incurring a primary carcinoma in the opposite breast. The risk for incurring a metachronous primary carcinoma of the breast by a patient with a previous ovarian carcinoma was 3–4 times the normal risk. In patients with endometrial carcinoma, the risk of a subsequent breast carcinoma was 1.25–2.0 times the normal risk. The demonstration of a positive association of multiple primary carcinomas of the breast, ovary, and endometrium suggests demographic characteristics and etiologic factors common to these diseases. At least 3 of the 5 observed multiple, primary, soft-tissue sarcomas developed as sequelae of previous breast cancers—1 arising in irradiated tissue and 2 in a lymphedematous upper extremity. We could not conclude whether the mutual increases in the incidence of carcinomas of the breast and thyroid were biologically related or were indicative of common etiologic factors.