Late axillary recurrence infrequent after negative SLNB

SAN FRANCISCO — The infrequency of long-term axillary recurrence among women with invasive breast cancer who had a negative sentinel lymph node biopsy provides support for the biopsy’s role in staging, according to study results presented at the Breast Cancer Symposium.

Although axillary recurrence occurs in fewer than 2% of patients shortly after negative sentinel lymph node biopsy (SLNB), more data were needed on long-term outcomes, according to background information provided by the researchers.

Cindy Brown Matsen, MD, of the breast service in the department of surgery at Memorial Sloan Kettering Cancer Center, and colleagues evaluated data from 1,529 women who had a negative SLNB without additional axillary surgery from 1997 to 2000. The median age of the population was 57 years (range, 12-88). Most women underwent breast conservation surgery (85%), whereas 15% underwent mastectomy.

Nuclear grade data were available from 1,189 of the women. Most of these women had an intermediate nuclear grade (60%), whereas 12% had a low grade and 28% had a high nuclear grade.

Median follow-up was 10.8 years (range, 0-16).

Thirteen patients experienced axillary recurrence as a first event. Five patients experienced axillary recurrence after 5 years; four of those patients had ER-positive disease and one had HER-2–positive disease.

Among women who experienced axillary recurrence, median OS was 4.6 years and median distant DFS was 3.8 years.

Matsen and colleagues calculated an overall cumulative incidence of axillary recurrence of 1% (95% CI, 0.5-1.6). The cumulative incidence of axillary recurrence was higher in the first 5 years (0.6%; 95% CI, 0.2-0.9) after negative SLNB than it was in the period 5 to 10 years after negative SLNB (0.4%).

Researchers then compared these data with a cohort of 902 women with positive SLNB who underwent axillary dissection. After more than 10 years of follow-up in that population, the overall cumulative incidence of axillary recurrence was 0.8% (95% CI, 0.2-1.5).

Results of a univariate analysis indicated high nuclear grade significantly predicted axillary recurrence after negative SLNB (P=.01).

“Late axillary recurrence was an infrequent event after negative SLNB alone, emphasizing its long-term safety as a staging procedure,” Matsen and colleagues concluded. “Axillary recurrence after SLNB, like axillary recurrence after axillary lymph node dissection, portends a poor prognosis.”

For more information:

Matsen CB. Abstract #63. Presented at: Breast Cancer Symposium; Sept.4-6, 2014; San Francisco.

Disclosures: The researchers report no relevant financial disclosures.