Breast Cancer: Skip Radiation After Chemo?
- Women with breast cancer who initially test positive for axillary nodes may be able to forgo regional nodal irradiation if those nodes test negative following neoadjuvant chemotherapy, according...
- Mamounas of AdventHealth Cancer Institute in Orlando, Fla., suggests treatment strategies can be adjusted based on how lymph nodes respond to chemotherapy. The study, published in The New...
- The trial involved 1,641 breast cancer patients with clinical stages of T1 to T3, N1, and M0, whose nodes became negative after chemotherapy.
Study Assesses Radiation Therapy Role After Chemo for Breast Cancer
Women with breast cancer who initially test positive for axillary nodes may be able to forgo regional nodal irradiation if those nodes test negative following neoadjuvant chemotherapy, according to a new study.
The research, lead by Dr. Eleftherios P. Mamounas of AdventHealth Cancer Institute in Orlando, Fla., suggests treatment strategies can be adjusted based on how lymph nodes respond to chemotherapy. The study, published in The New England Journal of Medicine, found that regional nodal irradiation did not reduce invasive breast cancer recurrence or death within five years for patients whose positive axillary nodes became negative after chemotherapy.
The trial involved 1,641 breast cancer patients with clinical stages of T1 to T3, N1, and M0, whose nodes became negative after chemotherapy. The median age was 52. Most had T2 disease, with the rest split between T1 and T3. Over half the tumors were HER2 positive, and nearly a quarter were triple-negative. More patients underwent lumpectomy than mastectomy.
Patients were divided by surgery type, hormone receptor status, HER2 status, chemotherapy use, and pathological complete response in the breast. They were then assigned to either regional nodal irradiation or no regional nodal irradiation.
The primary analysis included 1,556 patients. After nearly 60 months,109 primary endpoint events occurred: 50 in the irradiation group and 59 in the no-irradiation group. Researchers found regional nodal irradiation did not significantly increase the time to invasive breast cancer recurrence or death.
Dr. Kathy Miller,co-director of the Breast Cancer Program at Indiana University Health Simon Cancer Center in Indianapolis,said the results should impact practise for most patients. However, she noted the exclusion of patients with inflammatory disease and extensive lymph node disease.
Miller also pointed out the relatively short follow-up for estrogen receptor-positive disease. “That is always an issue given the long timeline in that phenotype. That,however,isn’t a reason to recommend therapy with toxicity and cost,” Miller said.
Dr. Nancy Chan, a breast medical oncologist at NYU Langone Health’s Perlmutter Cancer Center in New York City, also wants longer follow-up for this subgroup. “Hormone-positive tumors can have late recurrences,and we need longer follow-up to have evidence that these results continue to hold,” Chan said.
Researchers concluded that a pathological complete response in axillary lymph nodes indicates no benefit from regional nodal irradiation, expanding the utility of the neoadjuvant approach.
Chan added that the B-51 trial provides “meaningful data as we try to figure out how we can optimize treatment and omit toxicity where it’s not necessary. From this study, it looks like we can safely omit radiation for some patients who achieve a pathological nodal complete response.”
Chan cautioned,“However,every breast cancer patient who sits in front of us is different,and there are many different factors to consider,such as subtype,age,and initial nodal burden,when making treatment decisions.”
What’s next
Continued monitoring of patients will offer more insight into long-term results, especially among different breast cancer subtypes, to further refine the role of radiation therapy.