Authors: Joseph M Obeid Nolan A Wages Yinin Hu Donna H Deacon Craig L Slingluff
Publish Date: 2016/10/21
Volume: 66, Issue: 1, Pages: 33-43
Abstract
Infiltration of nonsmallcell lung cancer NSCLC by CD8+ T lymphocytes predicts improved patient survival however heterogeneity of intratumoral localization complicates this assessment Strategies for tumor sampling may not accurately represent the whole tumor We hypothesized that sampling strategies may alter the identification of tumors with high CD8 density and affect the prognostic significanceTwentythree primary NSCLC tumors were immunohistochemically stained for CD8 and were assessed using automated software with eight different sampling strategies or the whole tumor Results of all sampling strategies were compared to the whole tumor counts paired t tests Pearson’s r Associations between CD8 densities and overall survival were assessed logrank testCounts from all eight sampling strategies significantly correlated with whole tumor counts p ≤ 0001 However the magnitude of CD8+ cell counts and categorization into high vs low infiltrate groups were affected by the sampling strategy The most concordant values were derived from random sampling of 20 of the tumor a simulated core biopsy or from sampling the tumor center TIL infiltration was associated with survival when sampling the center p = 0038 but not the invasive margin p 02 or other strategiesDifferent tumor sampling strategies may yield discordant TIL density results and different stratification for risk assessment Small biopsies may be particularly unrepresentative Random sampling of larger tumor areas is recommended Enumerating CD8+ T cells in the tumor center may have prognostic value
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