Samuel Swisher-McClure, MD
A recent retrospective, observational cohort study examined use and survival outcomes with adjuvant chemoradiotherapy (CRT) in patients with resected locally advanced head and neck cancer (LAHNC) with negative surgical margins and no extracapsular extension (ECE).
The purpose of the study, said study author Samuel Swisher-McClure, MD, was not to change the standard of care, but to identify patients who would derive greater benefit from CRT.
“The study findings highlight a need to look closer at these patients and improve our selection of patients that are most likely to benefit from chemotherapy,” said Swisher-McClure, an assistant professor of Radiation Oncology in the Perelman School of Medicine at the University of Pennsylvania.
The analysis included 10,870 patients from the National Cancer Database with AJCC stage III to IVB squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, and larynx treated with definitive surgery and adjuvant radiotherapy (RT) or CRT.
Results showed that the use of adjuvant CRT in patients with resected LAHNC with negative surgical margins and no ECE is common. Overall survival was significantly improved with CRT compare to RT alone (HR, 0.90; 95% CI, 0.86-0.94; P
<.001). In patients with multiple positive lymph nodes, survival benefits increased with CRT.
In an interview with OncLive
, Swisher-McClure discussed the results of the study and steps moving forward in the treatment of patients with head and neck cancer.
OncLive: Could you provide an overview of the study?
For patients with locally advanced head and neck cancer who receive surgery as primary therapy, the role of chemotherapy combined with radiation therapy has been previously studied by two randomized control trials. The findings of those 2 trials concluded that patients with these 2 pathological findings—ECE and positive margins—were the patients that benefitted the most from chemotherapy. It was unclear whether patients with other pathologic risk factors should receive chemotherapy with radiation or not.
Our study looked at how patients were treated in real-world practice in this clinical situation over approximately the past decade. We specifically examined patients without traditional indications for chemotherapy to assess how often are they getting chemotherapy and is there any potential benefit seen with the administration of chemotherapy in that setting. We also wanted to try to identify any patients that seem to benefit more from that chemotherapy than others.
The overall findings of this study indicated that large portions of those patients receive chemotherapy, and these are patients for whom there is not level 1 evidence to support its use. We found that about half received more intensive treatment with chemotherapy in addition to radiation therapy. We saw a small benefit associated with the use of chemotherapy in the overall group of patients who received it, in this retrospective study.
When we looked at patients according to number of lymph nodes that were involved by cancer, we found that a higher number of positive lymph nodes was an adverse prognostic factor. However, there was a more substantial benefit associated with chemotherapy in these patients with multiple involved lymph nodes compared to RT alone. On the other hand, we did not observe a benefit with chemotherapy in patients with fewer lymph nodes involved.
This is retrospective research, and it does not define a new standard of care for these patients, but I think that the findings are interesting for several reasons. First a large number of patients in the United States are receiving chemotherapy with RT, which is more intensive and has more side effects, despite uncertainty regarding its benfit. Our study indicates that there are potentially groups of patients who may benefit from chemotherapy, and so I think it underscores the need for additional studies to help better defineuse of adjuvant therapy to improve disease outcomes in these intermediate-risk patients.