Monthly Breast Pain May Signal Lower Breast Cancer Risk

VIENNA, Austria—Women with monthly breast pain appear to have a reduced risk of breast cancer, S. A. Khan and colleagues reported at a poster session of the 9th World Congress on Pain. The study also showed that women with a high consumption of dairy products had less severe pain and that regular consumption of soy products appeared to increase the likelihood of regular breast pain. Dr. Khan is in the Departments of Surgery, State University of New York Health Science Center, Syracuse.

The study was initiated because 30% of new patients seen at the SUNY Breast Care Center reported breast pain. A group of 600 such patients were identified from the Breast Care Center database and sent a short diet questionnaire and a modified version of the short form of the McGill Pain Questionnaire.

Dr. Khan reported that the mean intensity of patients’ pain was 4.9 on a 10-point scale, and the mean present pain index was 2 on a scale of 0 to 5. Pain was described as “aching, heavy, and tender,” and was most severe on the 23rd day of the menstrual cycle. The mean painful area extended over 30% of the two breasts. The size of the painful area directly correlated with impact on quality of life (P < .05).

 Dr. Khan calculated the age-adjusted odds ratio of a breast cancer diagnosis for 4,681 patients from the breast cancer database. Those with breast pain had an odds ratio of 0.42 (95% CI 0.34-0.51), which suggests that periodic breast pain may be an indication of a significantly reduced risk of breast cancer.

The mechanism of this potential reduction in breast cancer risk associated with breast pain remains unknown. “We are considering the possibility that painful breasts may have greater infiltration with immune competent cells, or may express pain modulating cytokines such as tumor necrosis factor (TNF)-alpha,” Dr. Khan said.

The relation of diet to breast pain and to risk of breast cancer continues to be a topic of contention. Dr. Khan reported an inverse correlation between consumption of dairy foods and sensory magnitude of pain (P < .05). Soy consumption was positively correlated with periodicity of breast pain (P < .05).

“Breast pain has a significant adverse impact on quality of life. Dietary habits seem to impact the intensity of breast pain, and its presence may be protective against breast cancer,” Dr. Khan concluded.