Heavier breasts linked to increased cancer risk

TORONTO - Women with heavier busts who have been treated for breast cancer are at higher risk of its recurrence, says a new study.

These findings indicate that such patients may benefit from additional therapies, such as radiation, following surgery.

Researchers suspected that high breast density (heavier breasts) may also increase the risk of cancer recurrence after lumpectomy, but this theory has not been thoroughly studied.

Lumpectomy is a surgical procedure that involves removing a suspected malignant (cancerous) tumour, or lump, and a small portion of the surrounding tissue from a woman’s breast.

Researchers led by Steven A. Narod, Women’s College Research Institute (WCRI) in Toronto reviewed the medical records of 335 patients who had undergone lumpectomy for breast cancer.

Researchers found that patients with the highest breast density had a much greater risk of cancer recurrence than did women with the lowest breast density.

Over 10 years, women in the highest breast density category had a 21 percent chance of cancer recurrence, compared to a five percent chance among women in the lowest category, according to a WCRI release.

“The composition of the breast tissue surrounding the breast cancer is important in predicting whether or not a breast cancer will return after surgery,” Narod said.

The study authors say their findings indicate that women with low breast density, who have a low chance of recurrence after surgery, may not need radiation but that women with high breast density could significantly benefit from the additional therapy.

These findings are slated for publication in December issue of Cancer, a journal of the American Cancer Society.