Hormones factor into spread of Edwards's cancer

Once breast cancer returns to spread beyond the breast, it's no longer curable—but it can be held in check, sometimes for years, depending on how aggressive the tumor proves to be.

Doctors don't yet know exactly how widespread Elizabeth Edwards's returned cancer is, beyond a small but definite spot found in her right rib after she coincidentally broke a rib on the other side. Also being checked out is a suspicious spot in her lung.

''We can suppress it, we can even shrink it, but we can't eradicate it,'' said Lisa Carey, MD, Edwards's oncologist.

But the key question when breast cancer turns metastatic—the doctor's ominous term for spreading cancer—is whether it is hormone-sensitive.

No matter where breast cancer turns up in the body, if its growth is fueled by estrogen, women have a better chance of longer survival—and a shot at controlling the cancer with a battery of anti-estrogen drugs instead of needing harsher chemotherapy, at least right away.

Carey didn't reveal whether Edwards's cancer is this better ''estrogen receptor-positive'' form, saying that she was awaiting further test results before deciding on a treatment.

''It's hopefully and very likely treatable,'' said Julia Smith, MD, Ph.D, head of the New York University Cancer Institutes' breast cancer prevention program. But ''it will limit her life.... The goal now is to give the least amount of therapy and least toxic therapy, and drag it out for as long as possible, so she can have the best quality of life as long as possible.''

Almost 213,000 U.S. women will be diagnosed with breast cancer this year, and almost 41,000 will die, according to the American Cancer Society. When caught early, the vast majority survive with a combination of surgery, chemotherapy, and radiation, just as Edwards had in November 2004.

But about 20% of women thought to have been treated successfully at first nonetheless see their cancer return. How soon that happens, where it happens, and how soon it's caught helps determines their prognosis.

There are few good estimates of survival time for these patients. But treatment is easiest if the recurrence is limited to the breast or surrounding lymph nodes. Survival is much shorter if the cancer spreads aggressively to vital organs like the liver, lungs, or brain.

The bone seems to be somewhere in the middle. Indeed, a subset of patients with estrogen receptor-positive tumors that appear in only the bone have a good chance at surviving for 10 years, said NYU's Smith. ''Unfortunately, we don't know who that group is in advance,'' she said.

Edwards's oncologist offered no survival predictions either.

''I don't have a crystal ball about how she is going to do. I can tell you that many patients with exactly the circumstances that she has do very well for a number of years,'' Carey said. ''And the fact that she is a healthy person, and that there isn't a lot of the cancer, and that she doesn't have symptoms all work in her favor.''

Edwards's recurrence happened fairly early, just over two years after her initial diagnosis. But she said she blessed the broken rib that warranted the X-ray this week, which in turn uncovered the cancer lurking nearby.

''I'm very lucky I cracked this rib,'' she said. (AP)