PD-L1 Expression in Non-Small Cell Lung Cancer Specimens: Association with Clinicopathological Factors and Molecular Alterations

Immune checkpoint inhibitors (ICI) targeting programmed cell death-1 or its ligand (PD-L1) have improved outcomes in non-small cell lung cancer (NSCLC). High tumor PD-L1 expression, detected by immunohistochemistry (IHC) typically on formalin-fixed paraffin-embedded (FFPE) histological specimens, is linked to better response. Following our previous investigation on PD-L1 in cytological samples, the aim of this study was to further explore the potential impacts of various clinicopathological and molecular factors on PD-L1 expression. Two retrospective NSCLC cohorts of 1131 and 651 specimens, respectively, were investigated for PD-L1 expression (<1%/1–49%/≥50%), sample type, sample site, histological type, and oncogenic driver status. In both cohorts, PD-L1 was positive (≥1%) in 55% of the cases. Adenocarcinomas exhibited lower PD-L1 expression than squamous cell carcinomas (p < 0.0001), while there was no difference between sample types, tumor locations, or between the two cohorts in multivariate analysis (all p ≥ 0.28). Mutational status correlated significantly with PD-L1 expression (p < 0.0001), with the highest expression for KRAS-mutated cases, the lowest for EGFR-mutated, and the KRAS/EGFR wild-type cases in between. There was no difference in PD-L1 levels between different prevalent KRAS mutations (all p ≥ 0.44), while mucinous KRAS-mutated adenocarcinomas exhibited much lower PD-L1 expression than non-mucinous (p < 0.0001). Our data indicate that cytological and histological specimens are comparable for PD-L1 evaluation. Given the impact of KRAS mutations and the mucinous growth pattern on PD-L1 expression, these factors should be further investigated in studies on ICI response.     

A community-oriented evaluation of two prevention programs for college freshmen.

Evaluated 2 preventive interventions aimed at reducing the stress of the 1st yr of college for freshmen; 3,713 Ss were used. The cohort program, a written-interactive program, was compared to a peer-led group program both for their possible impact on the college freshman population on a variety of measures available in the campus community and for their effectiveness as treatments on traditional questionnaire measures. The programs were found to differ in the type of students they attracted, with the cohort program attracting more nonusers of traditional services and the group program attracting those who would otherwise use traditional services. While both the programs were seen as effective by their respective participants, neither treatment was effective in reducing dropout rate or improving GPA. Results are discussed both in terms of the treatment impact on the individuals participating and in terms of program impact on freshman population experiencing psychological stress in their 1st yr of school. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)