I am very careful about what I put on this page. If I think a research report is weak and could cause unnecessary worrying without adding to our knowledge in any meaningful way, I do not share it. The internet, however, is a wild and wooly place, without gatekeepers and perspective. So I often hear from readers about a study that “proves” things that are counter to what the broader body of research has told us about triple-negative breast cancer.
One recent study, published in BMC Cancer, has caused readers to believe that the recurrence of TNBC after five years is greater than that of other forms of breast cancer. This runs counter to several other studies that have shown the opposite–that TNBC tends to recur within three years if it is going to recur, and that the incidence after five years is significantly lower than for other forms of breast cancer.
Here’s the deal. This new research studied DCIS and found that those cases of DCIS that were TNBC tended to recur after five years at a higher rate than other types of breast cancer. The researchers, though, warned that only 27 women in the study had TNBC, far too small a sample for any generalization. In addition, it does not appear, from the report, that any of the women with DCIS had chemotherapy—the treatments mentioned were surgery and radiation. This is not unusual, as few docs give chemo for DCIS. So the small group of TNBC women studied did not have the insurance most women now have against TNBC—chemo. And most research on long-term survival of invasive breast cancer deals with women who have had chemo. And it shows that chemo often works better for estrogen-negative breast cancer than for estrogen-positive.
A few things this might tell us (although, again, with such a small sample it is difficult to generalize): Chemo works. And DCIS perhaps should be treated more aggressively if it is TNBC.
It does NOT tell us that those of us with TNBC have more cause to worry about long-term recurrence.