Lactation and breast carcinoma risk in a South African population

✍ Scribed by Patricia F. Coogan; Lynn Rosenberg; Samuel Shapiro; Margaret Hoffman

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 89 KB
• Volume: 86
• Category: Article
• ISSN: 0008-543X
• DOI: 10.1002/(sici)1097-0142(19990915)86:6<982::aid-cncr13>3.0.co;2-b

✦ Synopsis

A number of epidemiologic studies have reported a reduced risk of breast carcinoma among women who have lactated but others have not.

The current study presents data regarding lactation and breast carcinoma risk from a hospital-based case-control study of black and colored South African women.

METHODS.

Incident breast carcinoma cases treated between January 1994 and October 1997 (n ϭ 446) at 2 major hospitals in Cape Town and hospital patients admitted for conditions unrelated to breast carcinoma (controls, n ϭ 1471) were queried regarding the duration of breast-feeding each liveborn child and breast carcinoma risk factors. Multivariate logistic regression models were used to calculate odds ratios (ORs) for various categories of lactation compared with a reference category of never having breast-fed among women who had had at least one full term live birth.

RESULTS.

Approximately 83% of cases and 85% of controls had ever breast-fed (OR ϭ 0.9; 95% confidence interval [95% CI], 0.7-1.3). Among all subjects, the ORs for those who lactated for Ͻ3 years were near or at unity. Beyond 3 years, ORs extending up to Ն7 years were less than unity, but the 95% CIs included 1.0 (OR for duration of Ն7 years ϭ 0.7; 95% CI, 0.4 -1.3). ORs did not vary by menopausal status. Breast carcinoma risk was not found to be related to the duration of breast-feeding the first child, the number of children breast-fed, or the patient's age at first lactation.

CONCLUSIONS.

The results of the current study suggest lactation has little or no protective effect on breast carcinoma risk.