Proportion of Never-Smoker Non-Small Cell Lung Cancer Patients at Three Diverse Institutions.

Background: Approximately 10% to 15% of lung cancer cases in the United States occur in never smokers, but there has been much debate about whether this rate is increasing. To determine whether the proportion of never smokers among lung cancer cases is increasing, we conducted a retrospective study using registries from The University of Texas Southwestern Medical Center, Parkland Hospital, and Vanderbilt University. Methods: Registries were queried for demographic information from 1990 to 2013 including sex, age, stage, and self-reported smoking history. Ten thousand five hundred ninety-three non-small cell lung cancer (NSCLC) case patients and 1510 small cell lung cancer (SCLC) case patients were captured, and logistic regression analysis was performed. All statistical tests were two-sided. Results: The proportion of never-smoker NSCLC patients increased from 8.0% in the years 1990 to 1995 to 14.9% in 2011 to 2013 (P < .001). This increase was also observed using multivariable logistic regression after controlling for sex, stage at diagnosis, and race/ethnicity. The percentage of never smokers among SCLC case patients (1.5% in 1990-1995 to 2.5% in 2011-2013, P = .36) or squamous cell NSCLC case patients did not statistically significantly change during this period. Conclusions: This study demonstrates an increasing proportion of NSCLC patients who have never smoked in a large, diverse patient population between 1990 and 2013. Given that this increase appears independent of sex, stage, and race/ethnicity and also occurred in our county hospital, this trend is unlikely due to changes in referral patterns and suggests that the actual incidence of lung cancer in never smokers is increasing.

Early onset pancreatic malignancies: Clinical characteristics and survival associations.

Diagnosed before age 50, early onset pancreatic malignancy (EOPM), is hypothesized to be a distinct subset of disease, although research is limited. To better characterize EOPM, and the effect of age at diagnosis on pancreatic cancer survival, we examined clinical characteristics and survival in EOPM and typical age-at-onset pancreatic malignancy (TOPM) cases. Vanderbilt University Medical Center (VUMC) Cancer Registry confirmed pancreatic adenocarcinomas (PDACs) and malignant pancreatic neuroendocrine tumors (PNETs) were evaluated. Clinical characteristics were compared using χ(2) tests. Overall survival was visualized with Kaplan-Meier functions; Cox proportional hazards regression was used to evaluate hazard ratios (HRs) and 95% confidence intervals (CIs). A total of 1,697 pancreatic malignancies were diagnosed at the VUMC between 1988 and 2013. Of 1,407 PDACs, 118 (8.4%) were EOPM, which was associated with significantly better survival (adjusted HR: 0.82, 95% CI: 0.67-1.00). EOPM and TOPM PDACs significantly differed with regard to having multiple malignancies; survival associations significantly differed by race, stage of disease, treatment and multiple malignancies. Of 190 PNETs, 63 (33.1%) were EOPM, which was not significantly associated with survival (adjusted HR: 0.80, 95% CI: 0.46-1.40). Malignant neuroendocrine EOPM and TOPM cases significantly differed by stage of disease and tumor location; survival associations significantly differed by family history of pancreatic cancer, stage of disease and multiple malignancies. Differences in clinical characteristics and associations with survival were identified, indicating that EOPM is distinct from TOPM, and exists among both pancreatic adenocarcinomas and malignant pancreatic neuroendocrine tumors.