The presence of cancer in the lymph nodes may not be the strongest indicator of the need for adjuvant chemotherapy in older women with breast cancer, according to recent study results.
Breast cancer that has spread to the lymph nodes does not always indicate the need for post-surgery chemotherapy treatment in older patients with low-risk breast cancer, according to new study findings.
Moreover, the results — which were recently presented at the American Society of Breast Surgeons Annual Meeting — showed that a sentinel node biopsy (a procedure that determines if disease is in the lymph nodes) may not be necessary in this patient population.
Many doctors perform biopsies on women over the age of 70 to determine if they should receive adjuvant (after surgery) chemotherapy. However, researchers found that regardless of patients’ nodal status, many of them indicated for adjuvant chemotherapy anyway, based on their 21 gene recurrence scores, which considers a person’s individual characteristics and tumor biology and is a reliable tool in treatment decision making.
“Sentinel node biopsy has some associated morbidity and is an additional procedure in the operating room,” lead study author, Dr. Katherine Yao, vice chair of Research at the NorthShore University Health System and clinical professor of Surgery at the Pritzker School of Medicine, University of Chicago, in Illinois said in a press release. “However, it may not provide the necessary information for decision-making about adjuvant chemotherapy. For this patient population, consideration of other tumor factors including possibly an oncotype score may be more useful than nodal status.”
Yao and her team used the National Cancer Database to analyze 28,338 patients who underwent treatment for HR-positive, HER2-negative, breast cancer that was smaller than 5 cm. All patients were aged 70 years and older. The researchers analyzed the correlation between lymph node status, 21 gene recurrence score and other clinical/demographic factors that are associated with high 21 gene recurrence scores and needing chemotherapy.
In the study population, 5,640 patients (19.9%) were node-positive and 22,698 (80.1%) were node-negative. When it came to a 21 gene recurrence score of 26 or higher (indicating that chemotherapy would be beneficial), 3,330 (13.1%) of patients with node-negative disease fell into this category, as did 740 (14.7%) for those with node-positive disease.
The researchers found that having grade 3 cancer was more strongly associated with a high 21 gene recurrence score, as was negative progesterone-receptor status. Patients with tumors that were larger than 2 cm, as well as those covered by Medicaid were also more likely to have cancer recurrence scores of or higher than 26. Black and Asian patients were more likely to have 21 gene recurrence scores that made them eligible for chemotherapy compared with Hispanic patients.
“Women may request sentinel node biopsies because cancer that has spread to the lymph nodes has become virtually synonymous with poor prognosis in the popular media,” Yao said. “However, we are learning that there is more to tumor biology then just nodal status. Sentinel node biopsy for women older than age 70 with hormone receptor-positive breast cancer is not really helpful for making adjuvant chemotherapy decisions. While eliminating sentinel node biopsy may seem counter-intuitive to some patients, it is not likely to have a major impact on their outcomes."
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