Women with newly diagnosed stage I to stage III non-small cell lung cancer appeared to have longer OS than their male counterparts, according to results of a trial presented at International Association for the Study of Lung Cancer’s World Conference on Lung Cancer.
“Women with NSCLC live longer, even when we control for every factor that might influence survival in NSCLC, including tobacco and other exposures, lifestyle factors, disease stage, treatment, tumor biology and hormonal factors,” Kathy Albain, MD, the Huizenga Family Endowed chair in oncology research at Loyola University Chicago Stritch School of Medicine, said in a press release.
Albain and colleagues of SWOG S0424, a prospective trial, followed 981 patients with newly diagnosed stage I to stage III NSCLC for 5 years or until death to determine OS.
The analysis included groups of patients divided according to gender and smoking history: female ever-smokers (n = 337), male ever-smokers (n = 383), female never-smokers (n = 188), and male never-smokers (n = 49); the latter group under-accrued despite extension, according to the researchers.
Researchers pooled data on patient demographics, lung cancer stage and histology, treatment and OS rates, and they evaluated tumor tissue for EGFR, RAS and p53 mutations.
The results showed significantly higher OS rates among women than men, regardless of smoking history or any other factor.
Five-year OS was 69% for female ever-smokers, 52% for male ever-smokers, 73% for female never-smokers and 58% for male never-smokers.
The researchers constructed four multivariate OS models: all patients (model 1), women only (model 2), all patients with mutations and ER expression added (model 3), and women only with mutations and ER expression added (model 4).
For model 1, researchers observed better OS among women (HR = 0.56; P < .001); those with a higher BMI (continuous HR = 0.98; P = .045); and among those with adenocarcinoma (HR = 0.84), bronchioloalveolar carcinoma (HR = 0.48) and large cell disease (HR = 0.57) compared with squamous histology.
Worse OS was associated with stage II (HR = 1.87) and stage III lung cancer (HR= 3.76; each P < .001) and older age.
For model 2, women who ever smoked had poorer OS (HR = 1.48; P = .05); however, other histology and hormonal exposure variables did not reach significance.
For model 3, better OS was associated with EGFR mutations (HR = 0.53; P = .013); other factors associated with improved OS included female sex, stage I disease, greater BMI and taller height. Worse OS was observed among those with a p53 mutation or higher ER-alpha cytoplasmic or ER-beta nuclear H-scores.
For model 4, worse OS was associated with higher-stage lung cancer, p53 mutation or ER-alpha cytoplasmic H-score.
“Hormonal influences, [including] persistent association of ER expression with OS, were independently significant,” Albain and colleagues wrote in the abstract. “Despite adjustments, favorable female survival could not be explained away. Randomized studies should stratify by gender, and validation analyses should be conducted in targeted therapy and immunotherapy trials.” – by Jennifer Southall
Albain KS, et al. Abstract OA06.01. Presented at: International Association for the Study of Lung Cancer’s World Conference on Lung Cancer; Sept. 23-26, 2018; Toronto, Canada.
Disclosures: Albain reports no relevant financial disclosures. Please see the abstract for all other authors’ relevant financial disclosures.