Axillary Surgery Can be Omitted Among Older Women with ER+, Node-Negative, Breast Cancer

Older women with estrogen receptor (ER)-positive, clinically node-negative, early-stage breast cancer can safely have axillary surgery omitted from treatment, according to a study published in Cancer.

Nodal positivity decline coincides with advancing age, suggesting varying biology between older and younger patients. This decrease occurred independent of “histologic subtype (ductal vs lobular), race, comorbidities, and socioeconomic factors,” the researchers explained.

“We have found that nodal positivity declines with age in women with T1, ER-(positive), clinically node-negative breast cancer who undergo axillary surgery, and among the small minority of older women with positive nodes, the vast majority are N1mi or N1,” they added.

Of the study’s population, 115,918 (75%) underwent sentinel lymph node biopsy (SLNB), 10,389 (7%) underwent axillary lymph node dissection (ALND), 18,133 (12%) underwent both SLNB and ALND, and 9712 (6%) did not undergo surgery. More specifically, of the patients 70 years or older, 35,981 (69%) underwent SLNB alone, 3394 (7%) underwent ALND alone, 5188 (10%) underwent both SLNB and ALND, and 7354 (14%) did not undergo surgery.

The final sample of patients incorporated 102,235 women under the age of 70 (66%) and 51,917 women 70 years or older (34%). Overall, the study consisted of women over the age of 18 diagnosed with early-stage ER-positive, human epidermal growth factor receptor 2 (HER2)–negative invasive breast cancer diagnosed between January 1, 2012, and December 31, 2015, and treated by lumpectomy.

As for nodal positivity, the prevalence decreased with increasing age among women aged 18 to 89 years old. More specifically for those who underwent axillary surgery, patients aged 60 years and older were significantly less likely to have at least 1 positive lymph node than women aged 50 to 59 years old. Meanwhile, patients aged 49 years old and younger were more likely to have at least 1 positive lymph node.

“The results of our study demonstrate a significant decrease in the prevalence of nodal positivity with age in women with T1, ER-(positive), clinically node-negative breast cancer who underwent axillary surgery from the youngest cohort up to patients aged 70 to 89 years,” wrote Downs-Canner and colleagues.

In some cases, the researchers suggest adjuvant chemotherapy for patients in the study. Specifically, among node-positive patients aged 60 years old and above, it was significantly less likely that adjuvant chemotherapy would be recommended than women aged 50 to 59 hears old. Contrarily, women aged 49 years old and younger were much more likely to be recommended adjuvant chemotherapy. Among the women aged 70 to 89 years old, nodal-positive women were significantly more likely to be recommended adjuvant radiation than node-negative women of the same age group.

The researchers described a number of limitations to their research, including the sample of patients who underwent axillary surgery. This selection bias likely “overestimated the actual proportion of women who were node positive, especially among older patients.” Moreover, the data does not allow for the researchers to account for patients’ functional status and life expectancies, both of which are key pieces of information in surgical and adjuvant therapy decision making.

“Among older adults, a multidisciplinary assessment of their life expectancy, goals, and expected tolerance of chemotherapy should be performed before axillary surgery,” wrote Downs-Canner and colleagues. “Moreover, unless the nodal positivity status is needed to inform their treatment, surgery should be avoided.”

Reference:

Downs-Canner SM, Gaber CE, Louie RJ, et al. Nodal Positivity Decreases with Age in Women with Early-Stage, Hormone Receptor–Positive Breast Cancer. Cancer. 10.1002/cncr.32668.