WASHINGTON – According to the national Centers for Disease Control and Prevention, about 14.6% of veterans enrolled for VHA care reported being a current cigarette smoker in 2018.
That makes small cell lung cancer especially a concern. According to the VA website, lung cancer is differentiated into non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), with NSCLC making up 85% to 90% of lung cancers and including squamous cell lung cancer, adenocarcinoma, and large cell carcinoma. SCLC, however, is much more deadly, because it grows more quickly and has often metastasized by the time of diagnosis.
Lung cancer also is the leading cause of cancer-related death in veterans, especially because smoking is the primary cause of lung cancer and radon gas exposure is the second. “Environmental carcinogen exposure to asbestos, arsenic, chromium, nickel, tar, mineral oils, mustard gas, silica, diesel exhaust, ionizing radiation, and bis(chloromethyl) ether also increase risk,” the VA explained.
Most commonly associated with smoking are SCLC and squamous cell carcinoma, the report added.
That is why advances in treatment are especially significant for veterans. A recent report in the Journal of Clinical provided updated information on the Impower133 trial. It showed ongoing benefit from adding atezolizumab to carboplatin/etoposide as first-line treatment in patients with extensive-stage small cell lung cancer (SCLC).
In fact, a benefit with atezolizumab was observed despite (anti-programmed death-ligand 1 [PD-L1]) or blood-based tumor mutational burden status.
The randomized, double-blind, phase I/III study, demonstrated that adding atezolizumab to carboplatin plus etoposide (CP/ET) for first-line treatment of extensive-stage small-cell lung cancer (ES-SCLC) resulted in significant improvement in overall survival (OS) and progression-free survival (PFS) vs. placebo plus CP/ET. Results were published in the Journal of Clinical Oncology.1
For the study, patients with untreated ES-SCLC were randomly assigned 1:1 to receive four 21-day cycles of CP (area under the curve 5 mg per mL/min intravenously [IV], day 1) plus ET (100 mg/m2 IV, days 1-3) with atezolizumab (1,200 mg IV, day 1) or placebo. Maintenance atezolizumab or placebo was continued until unacceptable toxicity, disease progression, or loss of clinical benefit occurred.
Overall, 201 patients received atezolizumab plus CP/ET, and 202 were provided placebo plus CP/ET. At the updated analysis, median follow-up for OS was 22.9 months, and 302 deaths had occurred.
Researchers reported that median OS was 12.3 with atezolizumab plus CP/ET and 10.3 months for placebo plus CP/ETy (hazard ratio, 0.76; 95% CI, 0.60 to 0.95; descriptive P = .0154). At 18 months, 34.0% and 21.0% of patients had survived in the atezolizumab plus CP/ET and placebo plus CP/ET arms, respectively. The study added that patients benefited from the addition of atezolizumab, despite PD-L1 immunohistochemistry or bTMB status.
“Adding atezolizumab to CP/ET as 1L treatment for ES-SCLC continued to demonstrate improved OS and a tolerable safety profile at the updated analysis, confirming the regimen as a new standard of care. Exploratory analyses demonstrated treatment benefit independent of biomarker status,” the authors concluded. Background information in the study pointed out that almost Batwo-thirds of SCLC patients have extensive-stage (ES) disease at diagnosis. That is associated with poor prognosis and a 5-year survival rate of less than 7%, according to the report.
For more than two decades, platinum chemotherapy –carboplatin [CP] or cisplatin with etoposide (ET) – has been the standard treatment, but, despite initial high response rates, median survival is limited to approximately 10 months.
That has changed recently, with immune checkpoint inhibitors demonstrating improved outcomes in patients with extensive-stage small-cell lung cancer (ES-SCLC), the authors pointed out.
- Liu SV, Reck M, Mansfield AS, Mok T, et al. Updated Overall Survival and PD-L1 Subgroup Analysis of Patients With Extensive-Stage Small-Cell Lung Cancer Treated With Atezolizumab, Carboplatin, and Etoposide (IMpower133). Journal of Clinical Oncology 2021 39:6, 619-630. https://ascopubs.org/doi/full/10.1200/JCO.20.01055