When counting family members with breast cancer, women tend to forget that their fathers' families count as much as their mothers' families.

The finding comes from a study of how women talk with their doctors about breast cancer. It means that many women are missing an important breast cancer risk factor.

John M. Quillin, PhD, of Virginia Commonwealth University, and colleagues, studied nearly 900 women attending an urban women's health clinic.

They found that 16 percent of the women reported breast cancer in a relative on their mother's side of the family. But only 10 percent reported breast cancer in a relative on their father's side of the family.

The most likely explanation for this is that women simply underreport breast cancer when it occurs in their fathers' families.

"Patients may not know that paternal family history is also relevant for their health," Quillin and colleagues conclude. "Primary care physicians might pay particular attention to getting information about the father's side of the family."

Quillin and colleagues report their findings in the September issue of theAmerican Journal of Preventive Medicine.

What Increases a Woman’s Breast Cancer Risk?

The Breast Cancer Gene: What Should You Do?

By Daniel J. DeNoon, reviewed by Louise Chang, MD

SOURCE: Quillin, J.M. American Journal of Preventive Medicine, September 2006; vol 31.