Functional Promoter Variant rs2868371 of HSPB1 Is Associated With Risk of Radiation Pneumonitis After Chemoradiation for Non-Small Cell Lung Cancer
Menée sur 146 patients atteints d'un cancer du poumon non à petites cellules et validée sur 125 autres patients, cette étude montre une association entre le variant fonctionnel rs2868371 du promoteur du gène HSPB1 et le risque de pneumopathie radique après une chimioradiothérapie
To date, no biomarkers have been found to predict, before treatment, which patients will develop radiation pneumonitis (RP), a potentially fatal toxicity, after chemoradiation for lung cancer. We investigated potential associations between single nucleotide polymorphisms (SNPs) in HSPB1 and risk of RP after chemoradiation for non-small cell lung cancer (NSCLC). Subjects were patients with NSCLC treated with chemoradiation at 1 institution. The training data set comprised 146 patients treated from 1999 to July 2004; the validation data set was 125 patients treated from August 2004 to March 2010. We genotyped 2 functional SNPs of HSPB1 (rs2868370 and rs2868371) from all patients. We used Kaplan-Meier analysis to assess the risk of grade ≥2 or ≥3 RP in both data sets and a parametric log-logistic survival model to evaluate the association of HSPB1 genotypes with that risk. Grade ≥3 RP was experienced by 13% of those with CG/GG and 29% of those with CC genotype of HSPB1 rs2868371 in the training data set (P=.028); corresponding rates in the validation data set were 2% CG/GG and 14% CC (P=.02). Univariate and multivariate analysis confirmed the association of CC of HSPB1 rs2868371 with higher risk of grade ≥3 RP than CG/GG after adjustment for sex, age, performance status, and lung mean dose. This association was validated both in the validation data set and with Harrell's C statistic. The CC genotype of HSPB1 rs2868371 was associated with severe RP after chemoradiation for NSCLC.
International journal of radiation oncology, biology, physics , résumé, 2012