Study Suggests Axillary Surgery Not Necessary for All Women with Invasive Breast Cancer

November 19, 2020
Hannah Slater
Hannah Slater

“In the current era of effective multimodality therapy for breast cancer, the need for [axillary lymph node dissection] for patients with axillary lymph node metastases must be re-evaluated, even for patients with clinically positive nodal disease,” the study authors wrote.

A study published in Annals of Surgical Oncology found that over 40% of women with lymph node involvement at diagnosis have only 1 to 3 positive nodes at surgery with the remainder of nodes removed being normal, suggesting that more women could possibly be spared an axillary lymph node dissection (ALND).

Even further, the researchers also identified certain features of a patient’s tumor, including tumor size, lobular histology, and nodal metastasis size, that can predict which patients might be suitable for omission of the procedure.

“In the current era of effective multimodality therapy for breast cancer, the need for ALND for patients with axillary lymph node metastases must be re-evaluated, even for patients with clinically positive nodal disease,” the authors wrote.

For the purposes of this study, researchers retrospectively identified patients who underwent ALND for breast cancer between 2010 and 2019 at the University of California, Los Angeles. However, those with clinical N1 disease were excluded from the analysis. In addition, patients who received neoadjuvant chemotherapy (NAC) or had surgery for sentinel node positive disease or axillary recurrence were excluded as well.

Of a total of 111 patients who met the inclusion criteria, 61.3% were found to have a palpable node on exam. Overall, 41.4% had pN1 disease. Most tumors were ER positive (91.5%) and 21.7% were invasive lobular cancers.

Importantly, lobular histology, tumor size, and metastasis size were all associated with a higher nodal stage.

On multivariable analysis, nodal metastasis size 10 mm or larger (OR, 0.12; 95% CI, 0.02-0.69); P = .02) was revealed to have significantly lower odds of having pN1 disease. However, in a subset analysis of patients with palpable nodes, tumor size and histology were still found to be significantly associated with nodal stage.

“These data suggest that preoperative nodal metastasis size may be a meaningful marker predictive of pathologic nodal stage that could assist in stratifying patients for treatment,” the authors explained. “However, small numbers in our study limit any substantial conclusion. It may nonetheless be beneficial for pathologists to report nodal metastasis size as a routine measure on biopsy results to allow further evaluation of this variable in future studies.”

Importantly, this study is limited by its retrospective design and small sample size. Additionally, a lack of documented metastasis size on core biopsy for more than half of the study cohort also limits the interpretation of these findings.

“Nonetheless, to our knowledge, this is the first study to assess nodal disease burden in patients with clinically palpable nodes, and therefore adds critical data for this subgroup of patients who have otherwise been excluded from practice-changing clinical trials,” the authors concluded. “Future studies to validate these identified predictors against an independent patient dataset are an important next step.”

The investigators noted that as studies addressing de-escalation of axillary surgery continue to expand, recommendations for multimodality adjuvant therapies also continue to increase. For instance, following the release of the results from the Early Breast Cancer Trialist Cooperative Group (EBCTCG) meta-analysis, patients with 1-3 positive nodes are now more often considered for radiotherapy treatment for a benefit in locoregional recurrence and survival.

Thus, the researchers indicated that as more patients with pN1 axillary disease are treated with radiation, the benefit of ALND with its associated morbidities must be re-evaluated, even for patients with clinically palpable nodes. Further, for patients with ER-positive disease, additional options for targeted therapies are likely to become available as studies shift CDK 4/6 inhibitor therapy, fulvestrant (Faslodex), and PI3K inhibitors into the adjuvant setting.

References:

Angarita S, Ye L, Rünger D, et al. Assessing the burden of nodal disease in breast cancer patients with clinically positive nodes: hope for more limited axillary surgery. Annals of Surgical Oncology. doi: 10.1245/s10434-020-09228-5