First-cycle acneiform rash may act as a surrogate marker for which patients with advanced non–small-cell lung cancer (NSCLC) will have positive outcomes with cetuximab treatment, according to a subgroup analysis of FLEX data (Lancet Oncol. Dec 17, 2010. Epub ahead of print).
To perform their analysis, investigators used data from patients with advanced NSCLC enrolled in the FLEX study whose tumors expressed epidermal growth factor receptor and who were alive on day 21. Of this group, 518 patients received cisplatin/vinorelbine plus cetuximab and 540 received chemotherapy alone; 290 patients in the cetuximab group had first-cycle rash.
Overall survival almost doubled for patients treated with cetuximab who experience rash compared with those who did not (median 15.0 months [95% CI, 12.8-16.4] vs 8.8 months [95% CI, 7.6-11.1]; HR, 0.631 [95% CI, 0.515-0.774]; P <.0001, respectively). Progression-free survival also was increased (median 5.4 months [95% CI, 5.2-5.7] vs 4.3 months [95% CI, 4.1-5.3]; HR, 0.741 [95% CI, 0.607-0.905]; P = .0031, respectively).
Patients in the cetuximab group who did not experience rash had similar outcomes to those in the chemotherapy alone group. In addition, the survival benefits for those with first-cycle rash were seen in all histology subgroups: adenocarcinoma, squamous cell carcinoma, and other histology.