Women diagnosed with breast cancer know one basic fact: the earlier their malignant cells were detected, the better the odds for survival. But things aren't so simple when it comes to treatment--especially if the diagnosis is ductal carcinoma in situ, or DCIS. Many patients have never even heard of the condition and doctors, who call it everything from pre-cancer to noninvasive breast cancer, are still trying to figure out the best treatment: Mastectomy? Lumpectomy? Radiation? "There's a lot of confusion out there," says Dr. Kimberly Van Zee of New York's Memorial Sloan-Kettering Cancer Center.
Unlike tumor cells, which ball up into lumps, DCIS fans out along the milk ducts--patients usually can't feel a thing. But thanks to mammography, DCIS detection has soared over the last three decades, now making up almost 20 percent of new breast-cancer diagnoses. This year alone, it will strike 43,000 American women. On its own, DCIS stays confined to the ducts and is highly curable. The prognosis is excellent. But certain patients later develop invasive breast cancer so doctors want to be sure they treat the condition aggressively. The question is, how aggressive is too aggressive?
For years, DCIS was treated by mastectomy. The procedure, which has a 99 percent cure rate, is still recommended for women with large and especially virulent areas of DCIS. But many experts now believe lumpectomy is a good option for most patients since success rates are so high: the chance of developing invasive cancer after excision is about 1 percent per year.
The biggest debate today is over radiation. A major study by the National Surgical Adjuvant Breast and Bowel Project (NSABP) found that radiation after lumpectomy significantly cut the risk of developing a DCIS recurrence or an invasive cancer, and it has been considered the standard of care. But researchers found no difference in survival rates and some doctors say that radiation--which can cause side effects like skin irritation and fatigue--may be unnecessary for certain women. "Why do anything that could potentially hurt a patient if they don't need it?" says Dr. Melvin Silverstein of the University of Southern California. Doctors are now attempting to identify the best DCIS patients for radiation-free treatment. Silverstein has found that if lumpectomies have disease-free borders of at least 10 millimeters, radiation is of no additional benefit. Other factors, like the character and the size of cells, are likely to play a role as well. But more research needs to be done. Large clinical trials are now underway (check with the National Cancer Institute at 800-4-CANCER or http://cancertrials.nci.nih.gov) and doctors are also studying the role of tamoxifen. Last year the NSABP reported that the drug helps reduce recurrences, but it can cause rare adverse effects like blood clots.
Within a few years, preliminary trial results should offer more definitive data. In the meantime, if you're diagnosed with DCIS, read up. Last week the journal Cancer published recommendations made by 35 experts who reviewed the evidence on DCIS thus far. Be sure to get a second opinion from both your surgeon and your pathologist. And feel free to take a few weeks to decide on treatment. A timely diagnosis of DCIS is not a medical emergency--it's, as one patient says, "the gift of early detection." Use it wisely.