In a retrospective cohort study reported in JAMA Oncology, Pathak et al found that tumor size alone was not associated with improved survival with adjuvant therapy vs no adjuvant chemotherapy in patients with early-stage, node-negative non–small cell lung cancer (NSCLC).
As stated by the investigators, “Tumor size larger than 4 cm is accepted as an indication for adjuvant chemotherapy in patients with node-negative NSCLC. Treatment guidelines suggest that high-risk features are also associated with the efficacy of adjuvant chemotherapy among patients with early-stage NSCLC, yet this association is understudied.”
Study Details
The study involved National Cancer Database data from 50,814 treatment-naive patients with completely resected node-negative NSCLC diagnosed between January 2010 and December 2015. Patients had to have survived for at least 6 weeks after surgery. Overall survival with adjuvant chemotherapy vs observation was analyzed by tumor size and according to presence or absence of high-risk pathologic features (visceral pleural invasion, lymphovascular invasion, and high-grade histologic findings) and sublobar surgery.
“In this cohort study, tumor size alone was not associated with improved efficacy of adjuvant chemotherapy in patients with early-stage (node-negative) NSCLC. High-risk clinicopathologic features and tumor size should be considered simultaneously when evaluating patients with early-stage NSCLC for adjuvant chemotherapy.”— Pathak et al
Tweet this quote
Key Findings
Among the 50,814 patients, 4,220 (8.3%) received adjuvant chemotherapy and 46,594 (91.7%) did not.
Among patients with tumors ≤ 3 cm, adjuvant chemotherapy was not associated with improved overall survival vs no chemotherapy (overall hazard ratio [HR] = 1.10, P = .17). For patients with two or more high-risk factors, the hazard ratio was 0.92 (P = .40).
Among patients with tumors > 3 cm to 4 cm, adjuvant chemotherapy was associated with improved survival among patients who underwent sublobar surgery (HR = 0.72, P = .004). The overall hazard ratio among all patients was 0.90 (P = .21).
Among patients with tumors > 4 cm to 5 cm, adjuvant chemotherapy was associated with improved survival in patients with one or more high-risk pathologic feature (HR = 0.67, P = .02). The overall hazard ratio among all patients was 0.75 (P < .001). The hazard ratio among patients with no high-risk factors was 1.06 (P = .37).
Among patients with tumors > 5 cm, adjuvant chemotherapy was associated with a survival benefit among all patients (HR = 0.69, P < .001). The hazard ratio among patients with no high-risk factors was 0.75 (P = .004).
The investigators concluded, “In this cohort study, tumor size alone was not associated with improved efficacy of adjuvant chemotherapy in patients with early-stage (node-negative) NSCLC. High-risk clinicopathologic features and tumor size should be considered simultaneously when evaluating patients with early-stage NSCLC for adjuvant chemotherapy.”
Daniel J. Boffa, MD, of the Section of Thoracic Surgery, Yale School of Medicine, is the corresponding author for the JAMA Oncology article.
Disclosure: For full disclosures of the study authors, visit jamanetwork.com.
