December 15, 2010 —
For premenopausal women scheduling mammography at regular intervals, the screening may be more sensitive in week 1 of the menstrual cycle, a new study suggests.
The findings currently appear online in Radiology, published by the Radiological Society of North America.
Among women who have had a mammogram within the previous 2 years, the test was more sensitive in detecting breast cancer during the first week of the cycle than in those who underwent screening during the second, third, or fourth week.
Researchers, led by Diana L. Miglioretti, PhD, from the Group Health Research Institute, Group Health Cooperative, in Seattle, Washington, reviewed the cancer detection rate of 387,218 screening mammograms linked to 1283 cases of breast cancer. They relied on prospectively collected information from the Breast Cancer Surveillance Consortium, a network of research sites nationwide, to conduct the institutional review board–approved HIPAA [Health Insurance Portability and Accountability Act]-compliant study. Using logistic regression analysis, they computed differences in screening performance according to the week of the menstrual cycle, adjusting for age and mammography registries.
Included in the review were screen-film and digital images taken between 1996 and 2007 in premenopausal women aged 35 to 54 years and without any history of breast cancer, mastectomy, or breast augmentation; these mammograms had been read by more than 770 radiologists. Women were classified as premenopausal if their most recent menstrual period started no more than 35 days before the date of mammography and if they were not using hormone therapy.
Overall, the interpretive performance of mammography did not vary from week to week of the menstrual cycle. However, in subdividing analyses based on prior mammography, different patterns became evident.