ELCC News: Validation of the prognostic role of tumour lymphocytic infiltration on overall survival in patients with resectable NSCLC

LACE-Bio team confirms intense lymphocytic infiltration as a favourable prognostic factor

The benefit from platinum-based adjuvant chemotherapy in non-small cell lung cancer (NSCLC) was demonstrated in 4 randomised trials (IALT, JBR10, CALGB 9633 and ANITA). Central histopathological review by one or two specialised pathologists on 1,587 NSCLC cases showed the following histology distribution: 624 adenocarcinoma, 727 squamous cell carcinomas and 236 other types of NSCLC. Concurrently with histology, the LACE-Bio team assessed the presence of lymphocytic infiltration, which has been shown as a borderline favourable prognostic factor on overall survival in the IALT study (n=783 patients), p=0.04. Therefore the LACE-Bio group performed a validation of the results concerning the prognostic role of lymphocytic infiltration on the ANITA, JBR10 and CALGB trials.

Prognostic role of lymphocytic infiltration

The study authors considered lymphocytic infiltration as intense, mimicking “lymph node”, or not intense (null, mild or moderate). A logistic model, stratified on trial, was used to study the correlation of lymphocytic infiltration with other co-variables. Since there was no evidence of a different prognostic role in the chemotherapy and control arms in the IALT study, the prognostic values were studied for validation in all patients with adjustment for the treatment arm. Prognostic analyses were performed with Cox models stratified by studies and adjusted for treatment, sex, age, performance status, type of surgery, stage and histology.

From 804 analysed patients, 763 were valuable for lymphocytic infiltration assessment. Intense lymphocytic infiltration was observed in 6% of patients in the validation set, as compared to 11% in the IALT study. Lymphocytic infiltration was associated with histology - 10% in squamous cell carcinoma and approximately 4% in adenocarcinoma and other histology types of NSCLC (p=0.001). No correlation was found with the other covariates. Intense lymphocytic infiltration was correlated with longer overall- (p=0.01) and disease-free survival (p=0005) without heterogeneity among trials.

The authors concluded that the results are consistent across all trials in the validation set. Intense lymphocytic infiltration, found in only a minority of tumours, was validated as a favourable prognostic factor for survival in patients with resectable NSCLC.

The research was made possible by unrestricted grants from the Ligue Nationale Contre le Cancer (France) and Sanofi-Aventis.

The study was presented by Dr Elisabeth Brambilla from Grenoble at the 3rd European Lung Cancer Conference - ELCC (18-21 April, 2012, Geneva, Switzerland). ELCC is organised by top experts in lung cancer and thoracic malignancies from ESMO and IASLC.

Abstract 77O
Translational research, Biology and Pathology
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