The recent decline in invasive breast cancer in the US was significantly less pronounced in the poor and those who live in rural areas. Researchers writing in the open access journal BMC Medicine suggest this may be due to varying reductions in the numbers of women taking hormone therapy (HT).
Christina Clarke, Ph.D., led a team of researchers from the Northern California Cancer Center who studied breast cancer incidence data from the largest cancer database available in the US for the years 1997-2004, comparing poor areas against rich and urban areas against rural.
She said, "Between 2001 and 2004, incidence rates of invasive breast cancer declined more than 8% in the United States. "One possible explanation for this is widespread discontinuation of and/or failure to initiate HT. Because this cessation of HT use was more pronounced in rich/urban areas, we wanted to see if there was a corresponding difference in breast cancer incidence between these areas and poor/rural parts of the country".