MA15.05 Rates of Guideline-Concordant Surgery and Adjuvant Chemotherapy Among Patients in The U.S. ALCHEMIST Study (Alliance)

Abstract

The standard of care for resectable non-small cell lung cancer (NSCLC) includes anatomic surgical resection with adequate lymph node dissection and adjuvant chemotherapy for appropriate patients. Historically, many patients with early-stage NSCLC have not received such guideline-concordant therapy. Longstanding disparities have also existed in the delivery of quality cancer care by sociodemographic factors such as race and ethnicity. This could impact interpretation of adjuvant therapy trials. In this descriptive analysis, we examined rates of guideline-concordant treatment among patients enrolled in ALCHEMIST, a large U.S.-wide screening trial to facilitate enrollment to targeted adjuvant treatment trials for resectable NSCLC, enrolling at 754 sites. Patients who enrolled in ALCHEMIST (Alliance A151216) from August 18, 2014-April 1, 2019 who did not enroll in a therapeutic adjuvant therapy clinical trial were included; these patients had stage IB-IIIA disease (AJCC 7th edition), with tumors at least 4 cm in size and/or positive lymph nodes. Four outcomes are reported: whether patients (1) had adequate lymph node dissection per National Comprehensive Cancer Network criteria (≥ one N1 nodal station plus ≥ three N2 nodal stations); (2) received any adjuvant chemotherapy; (3) received any cisplatin-based adjuvant chemotherapy; and (4) received at least 4 cycles of adjuvant chemotherapy. Associations between these binary outcomes and sociodemographic variables were explored using unadjusted modified Poisson regression models accounting for trial site-level correlation. 2,834 patients were analyzed; 53.4% had adequate lymph node dissection; 57.1% received any adjuvant chemotherapy; 34.1% received any cisplatin-based adjuvant chemotherapy; and 43.7% received at least four cycles of adjuvant platinum-based chemotherapy. The distribution of treatment by key clinical and demographic characteristics is provided in Table 1; adjuvant chemotherapy was delivered more often to patients who were younger, had more advanced stage, had non-squamous NSCLC, and did not have EGFR-mutant tumors. Rates were similar across categories of race and ethnicity. Many patients with early-stage NSCLC did not receive adequate lymph node dissection or adjuvant chemotherapy despite indications for such treatment, even among patients who consented for testing to inform eligibility for an adjuvant therapy clinical trial. No substantial disparities in treatment were observed by race or ethnicity in this clinical trial cohort, contrary to historical patterns in population-based cohorts. Efforts are needed to optimize utilization of therapies with proven benefit for early-stage NSCLC. These results may inform the generalizability of clinical trials of novel therapies in the adjuvant setting. Support: U10CA180821, U10CA180882; U10CA180820 (ECOG-ACRIN); https://acknowledgments.alliancefound.org; Clinicaltrials.gov Identifier: NCT02194738