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I always tell my patients about the well know association between numerous skin tags under the breast and neck area and polyps in the colon. These polyps can at times become or turn into colon cancer. Here is another association worth noticing.

Number of moles may be a predictor of breast cancer

Zhang M. PLOS Medicine. 2014. doi:10.137/journal/pmed.1001659.

• June 12, 2014

The number of cutaneous nevi, or moles, on the body may be a reflection of plasma hormone levels and help predict patients’ risk for breast cancer independently of other known factors, study results have shown.

Using the Nurses’ Health Study, researchers prospectively analyzed the relative risk of breast cancer among 74,523 female nurses based on the number of cutaneous nevi reported. The participants were followed from 1986 to 2010.

Participants reported the number of cutaneous nevi on their left arms, from shoulder to wrist, that were 3 mm or greater in diameter. The researchers grouped the women into four categories based on the number of reported nevi: none, one to five, six to 14 and 15 or more.

Invasive breast cancer was documented in 5,483 cases. Women with more cutaneous nevi had a significantly increased risk of developing subsequent breast cancer, according to the researchers (P = .003).

During the 24-year follow-up, absolute risk of developing breast cancer increased from 8.48% among women without cutaneous nevi to 8.82% for women with one to five nevi, 9.75% for women with six to 14 nevi, and 11.4% for women with 15 or more nevi. Every five additional nevi found was reported to increase breast cancer risk by 8%.

The researchers also reported that the number of nevi seemed to be associated only with the risk of estrogen receptor-positive tumors. Women with more nevi had higher levels of estradiol and testosterone (P = .02 and P = .06, respectively).