Recurring cancers in women with a history of breast cancer differ from the original tumors

When women with a history of breast cancer learn they have breast cancer again, one of the first questions they and their doctors ask is: Has my cancer come back, or is this a new case? Now, new data from Fox Chase Cancer Center suggest that both new and recurring cancers will differ significantly from the original tumors, regardless of how many months or years women spent cancer-free, and doctors should tailor treatment to the specific qualities of the second tumor, regardless of whether it's old or new. Anita Patt, MD, surgical oncology fellow at Fox Chase and lead author on the study, will be presenting the findings at the 2011 Annual Meeting of the American Society of Clinical Oncology on Monday, June 6.

"There tends to be a stigma and a lot of anxiety about the word 'recurrence,'" says Richard J. Bleicher, MD, FACS, attending surgeon at Fox Chase and senior author on the study. "Sometimes women will worry more if they believe their original cancer is back, meaning they didn't 'beat it' the first time around. These findings suggest they should not get hung up on that idea, because any subsequent diagnosis – whether it's a recurrence or a new tumor – will look significantly different from their first cancer."

In women with a history of breast cancer, doctors often approach new tumors differently depending on whether they believe it's a recurrence of the first tumor, or a totally new one, Bleicher explains. But there are no official ways to distinguish between the two types, so doctors typically rely on a few criteria, then form their own opinion based on an "overall gestalt," he says.

One of the criteria doctors have used to distinguish between new and recurring cancers is the amount of time women spent cancer-free, reasoning that the longer the time between the two tumors, the more likely the second one is to be an entirely new case.

To investigate if this and other criteria indeed distinguish new and recurring tumors, Bleicher, Patt, and their colleagues looked at data collected from 4,420 women with a history of breast cancer. Two-hundred and thirty five women were eventually diagnosed with another tumor in the same breast, suggesting it could be a recurrence.

However, when the researchers compared the first and second tumors, they saw that 89% differed in at least one key characteristic that could potentially affect treatment or prognosis, regardless of whether the second tumors were new cases or a recurrence of the original cancer. Sixty percent of the second tumors differed from the first by at least 2 or more criteria, including whether or not it would respond to hormones, how it was diagnosed, and whether at least 25 percent of the tumor was confined to the ducts, and therefore less able to spread throughout the body.

Half of the women experienced a second tumor within 60.5 months of their first. And, importantly, the amount of time they spent cancer-free appeared to have no bearing on whether the two tumors differed in any key characteristics.

The findings suggest that patients and doctors shouldn't spend much time determining if the second tumor is a recurrence of the first, or a totally new entity, says Bleicher, and should instead tailor treatment to the specific qualities of the second tumor, regardless of whether it's old or new.

"When a patient comes back with a relapse, whether it's a new tumor or a recurrence, it really doesn't make a difference," he says. "We treat them both as potentially curable."

Source: Fox Chase Cancer Center