Chemotherapy plus radiation improves survival in R1 NSCLC patients
medwireNews: US researchers have identified a survival benefit of postoperative combination chemotherapy and radiation treatment in patients with non-small-cell lung cancer (NSCLC) who have microscopically positive (R1) surgical margins, regardless of pathological stage (p).
Incomplete resections are associated with reduced survival in NSCLC, explain Daniel Boffa (Yale University School of Medicine, New Haven, Connecticut) and co-researchers, but clinicians lack “concrete recommendations” to treat such patients.
The team used records from the National Cancer Database to evaluate the longitudinal outcomes of various adjuvant therapies in 581 pI, 517 pII and 590 pIII NSCLC patients with an R1 resection.
In line with previous studies, Boffa et al report that positive surgical margins have an adverse effect on survival for all stages of disease. For R1 patients, the unadjusted 5-year overall survival was 37%, 29% and 19% for stages pI, pII and pIII, respectively – this compared with rates of 62%, 41% and 33%, respectively, in patients without residual tumour.
Compared with no adjuvant treatment, the combination of chemotherapy and radiation increased the unadjusted 5-year overall survival in patients with stage pI, pII and pIII malignancies from 35% to 44%, 21% to 33% and 12% to 30%, respectively.
Multivariate analysis showed that in pI patients, chemotherapy alone and chemotherapy plus radiation improved survival, but the results were statistically significant only for the former. Radiation alone did not extend survival in this group.
By contrast, all three modalities led to significantly improved survival in pII patients, while only the combination treatment was significantly associated with a superior outcome in participants with pIII NSCLC.
The authors say that other studies have reported on the lack of a survival benefit with radiation alone, but add that the inconsistent results in pI and pII patients are “unclear”.
Older age predicted poorer survival in all three stages and, in addition, the use of sublobar resection was significantly associated with an increased mortality risk in pI and pIII participants.
“There does appear to be an advantage to adjuvant therapy, with the most consistent outcomes across all pathologic stages being associated with chemotherapy [plus] radiation”, Boffa et al write in The Annals of Thoracic Surgery.
They add: “Further study is needed to clarify the optimal stage-specific adjuvant approach to incompletely resected NSCLC.”
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