Small Risk of Breast Cancer Death After Invasive Recurrence in DCIS Patients

LOS ANGELES—A study of 839 patients presented at the San Antonio Breast Cancer Symposium has found that women with ductal carcinoma in situ (DCIS) run a very small risk of death from invasive recurrence regardless of type of surgery.

“Invasive recurrences in DCIS patients are seen in a small minority of patients after breast conservation, and, when it does recur, an even smaller number of patients are destined for distant metastatic disease,” said James R. Waisman, MD, associate professor of medical oncology, University of Southern California/Norris Comprehensive Cancer Center, Los Angeles.

Of the 839 patients in this study, 316 patients had a mastectomy, 223 had excision and radiation therapy, and 300 were treated with excision alone. Invasive recurrence was found in 2 women in the mastectomy group, 22 in the excision/radiation group, and 19 in the excision-alone group. With a median follow-up of 10.3 years, of these 43 patients with invasive recurrences, 8 have developed distant metastases and 5 have now died of breast cancer. (There have been no breast-cancer-related deaths among the 47 patients in this series who had a recurrence of DCIS.)

The stage at the point of invasive recurrence was stage I disease in 50% of patients, stage IIA disease in 14%, stage IIB in 21%, stage IIIB in 14%, and stage IV in 2%.

“The patients with invasive recurrence clearly present more often with palpable disease,” Dr. Waisman said. In the radiation group, 45% of invasive recurrences were palpable, and in the excision-alone group, 42% were palpable. “And this is in contradistinction to our patients with recurrent DCIS, which is so infrequently palpable (4% to 10%).”

Invasive recurrences were larger, with a median size of 28 mm in the excision/radiation therapy patients and 14 mm in the excision-alone group, compared with 10 to 11 mm in patients with recurring DCIS, he said.

Radiation Fibrosis

“Local recurrences were most difficult to diagnose in women treated with excision/radiation in whom radiation fibrosis developed,” Dr. Waisman said. “These recurrences were larger, more likely to be palpable, and had a longer median time to recurrence, compared with those in women treated by excision alone (5.5 years vs 4.4 years).”

Women treated with breast-conserving surgery had a 10% chance of developing an invasive recurrence within 12 years after surgery, compared with 1% for women who had a mastectomy, but breast-cancer-specific mortality did not differ between the two groups. “Looking at the most significant outcome of breast cancer, which is fatality,” Dr. Weisman said, there was a 0% fatality rate in the mastectomy group and 1.8% in the breast-conserving-therapy group.

“Comparing these DCIS patients with invasive recurrence to our series of 569 patients who presented with invasive disease (T1cN0), the breast-cancer-specific survival curves at 12 years are remarkably similar,” Dr. Waisman said.

However, among the patients who originally had invasive disease and then developed an invasive recurrence, distant disease-free survival and breast-cancer-specific survival were markedly lower than in the patients who originally had DCIS and later had an invasive recurrence. “How you interpret this and whether there is a lead time bias is certainly open for further evaluation,” Dr. Waisman commented.

At 12 years, breast-cancer-specific survival after an invasive recurrence was 100% for mastectomy patients, 99.5% for excision-only breast conservation patients, and 97.4% for excision plus radiation therapy patients.

“Whether the small difference in the irradiated patients vs the mastectomy patients is going to materialize as significant over time is unclear, but certainly for now, these curves are basically superimposable,” Dr. Waisman said. He noted that overall survival by treatment, whether mastectomy, or excision-radiation, or excision alone, is also virtually the same.

Dr. Waisman concluded that DCIS patients who undergo breast-conserving therapy should be followed closely, especially those with progressive radiation fibrosis.