(HealthDay News) — Positive lymph node status is not a reliable indicator of the need for adjuvant chemotherapy, and sentinel node biopsy may not be helpful in older women with certain low-risk breast cancers, according to a study presented at the annual meeting of the American Society of Breast Surgeons, held from April 6 to 10 in Las Vegas.
Kyra Nicholson, M.D., from University of Chicago, and colleagues examined the distribution of Oncotype DX breast recurrence scores in older women (older than 70 years) with hormone receptor-positive American Joint Committee on Cancer clinical stage I breast cancers and identified clinical factors associated with a high recurrence score.
The analysis included 28,338 patients diagnosed from 2010 to 2018.
The researchers found that the strongest independent factor associated with an Oncotype DX score ≥26 was tumor grade 3 for both node-positive (odds ratio, 12.71) and node-negative (odds ratio, 18.00) patients, followed by negative progesterone receptor status (odds ratio, 6.20 for node-positive versus 7.19 for node-negative).
Additionally, patients with larger tumors (>2 cm) and those on Medicaid were more likely to have an Oncotype DX score ≥26. Compared with other minority patients (Black and Asian), Hispanic patients tended to be less likely to have an Oncotype DX score ≥26.
“These findings suggest that sentinel node biopsy may not be helpful for adjuvant chemotherapy decisions in this patient population, but certain tumor factors may be more helpful,” the authors write.