The analysis, based on the NCI’s SEER data from 2000 – 2007, shows that the incidence of breast cancer in the U.S. is no longer declining. (A drop after 2002 in BC incidence is generally attributed to an abrupt reduction in HRT around that time.)
Since 2003 the overall BC rate has been steady overall, with a few exceptions:
The incidence of BC in non-Hispanic white women ages 60-69 rose by 4.8% in this period. “It remains to be seen if this trend will continue,” according to the study authors.
Among white women ages 40-49 rates of estrogen receptor (ER) positive (ER+) breast cancer significantly increased by an average of 2.7% per year during this period. In contrast, the rate of ER- breast tumors decreased, overall, although the trends were statistically significant only for women ages 40-49 and 60-69.
Apart from women younger than 40, overall BC rates and ER+ case rates were highest among non-Hispanic white women, followed by non-Hispanic black and Hispanic women. Among black women ages 40-49, the incidence of ER+ BC increased (5.2% per year) during 2003-2007, and there were non-significant, recent increases in ER+ BC among older black women.
Of note, in contrast to the pattern for ER+ breast cancer, non-Hispanic black women have the highest rates of ER- breast cancer in every age group. (These ER- cases would include triple negative BC.)
Sorry for the jargon, readers – I hadn’t planned to post now. But I think this information warrants attention.
This matters for a number of reasons. First, it’s bad news in terms of women’s health, plain and simple. Second, these numbers relate to the mammography math, which has been on my mind lately. The point is that if more women between the ages of 40 and 49 are developing ER+ (read: most treatable) tumors, this would influence the net benefit of cancer screening in that age group.
And please don’t misread me here: This is not an academic argument I want to win. Rather, I wish the incidence of breast cancer were declining. And I wish, even more, that so many middle-aged women I know personally weren’t affected by this devastating illness.