(ChemotherapyAdvisor) – Crizotinib may improve overall survival in ALK-positive non-small cell lung cancer (NSCLC) patients, researchers from Pfizer Inc, New York, NY, said at the annual meeting of the American Association for Cancer Research (AACR) in Chicago. The poster, entitled “Retrospective study of clinicopathologic factors associated with ALK rearrangement and survival outcome in Chinese patients with NSCLC”, was presented by the lead author, Pfizer’s Xu-chao Zhang as Abstract No. 4504.

The researchers tested a large cohort of NSCLC patients for ALK, EGFR, and KRAS abnormalities, which are significant “molecular subtypes” of patients with NSCLC, and correlated clinical factors with the ALK fusion gene and overall survival (OS). ALK status was detected by RACE sequencing; EGFR and KRAS status were detected by direct DNA sequencing. OS was estimated by the Kaplan-Meier method.

Of the 294 consecutive, unselected, banked NSCLC cases tested, the distribution of abnormalities was 27 (9.2%) ALK-positive (with EML4 as the only fusion partner), 79 (29.2%) EGFR-positive, and 26 (9.6%) KRAS-positive. Most patients were positive for either the ALK rearrangement or the EGFR mutation (r=-0.15, P=0.007), but two patients were positive for both abnormalities.

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“In non-parametric tests, ALK-positivity was associated with female gender (χ2=5.189; P=0.023), non/light-smoking (χ2=6.067; P=0.014) and adenocarcinoma (χ2=4.301; P=0.038),” the authors wrote.

The authors concluded: “Overall, the ALK fusion gene occurred in 9.2% of NSCLC patients, and was associated with non/light-smoking history, adenocarcinoma histology and female gender. ALK rearrangement was not a favorable prognostic factor in NSCLC, although smoking history may influence OS in ALK-positive patients. A TKI (crizotinib) now exists for ALK-positive NSCLC and may improve OS in these patients.”