Is educational level associated with breast cancer risk in Iranian women?

A high educational level has been found to be a risk factor of breast cancer. However, it is not clear whether such association persists after adjustment for individual risk factors of breast cancer such as parity in Iranian women.

We conducted a case-control study of 100 histologically confirmed breast cancer cases and 200 age-matched controls in a genetically homogenous population, in Babol, northern Iran. Demographic, reproductive, and lifestyle data were collected by in-person interviews and clinical examination. Educational level was classified into three levels: (1) illiterate and primary level, (2) elementary level and those who did not finish high school, and (3) high school graduates and those receiving more education. The adjusted odds ratio (OR) was estimated using multiple logistic regression model after controlling for parity and several other potential confounding factors.

The unadjusted OR showed a nonsignificant negative association of educational levels with breast cancer risk, but after controlling for several potential confounding factors, higher education level was significantly correlated with a lower breast cancer risk [OR 0.17, 95% confidence interval (CI) 0.06-0.45 for educational level of elementary plus some high school and OR 0.10, 95% CI 0.03-0.34 for educational level of high school or more compared to illiterate and primary level].

The inverse association of educational level with breast cancer risk observed in this study is not in accordance with education inequalities found in breast cancer risk in Western countries. The present findings provide a rationale for earlier screening in Iranian women with low education.