Risk factors for breast cancer in Pakistani women aged less than 45 years

There has been an increase in the incidence of breast cancer in previously low-risk Asian countries. It is important to identify the risk factors for Asian women, as little information currently exists for this population.

The objective of the study was to determine risk factors for breast cancer among Pakistani women.

498 cases younger than 45 years were interviewed from 1 July 1997 to 31 December 1998 at two major cancer hospitals. Age-matched population-based controls were selected from two cities and two villages to represent urban and rural areas. For the variables under study, cases and controls were compared by t-test. Conditional multiple logistic regression models were applied to the data set.

Women with BMI >or= 30, with a family history of breast cancer and who were parous were at increased risk. Among parous women risk factors included BMI >or= 30, being in a consanguineous marriage, later age at menarche, later age at first full-term pregnancy, high parity and a history of abortion.

The risk factors identified for Pakistani women below 45 years were similar to those observed in other studies. However, obesity in pre-menopausal women and late menarche were not protective and consanguinity was identified as a risk.