Skin rash as a surrogate marker of clinical response of targeted therapy using gefitinib in advanced or metastatic non-small-cell lung cancer--a retrospective study.

This retrospective review of a single institution case series study was conducted to correlate the objective response and skin rash of gefitinib in patients with advanced or metastatic non-small-cell lung cancer(NSCLC). One hundred and forty-nine patients with advanced or metastatic NSCLC were treated with gefitinib (250 mg/day) as second line systemic therapy. Baseline patient characteristics were: More than 75% patients were above 50 years of age, males 64%; adenocarcinoma 52%. Sixty-one patients were excluded from the analysis due to varying reasons; only 88 remaining in the analysis. Partial response was observed in 15 patients (17%), and 34 patients (38.6%) had stable disease. The rest 39 patients (44.3%) had progressive disease on gefitinib therapy. There was a significantly longer median time to progression (TTP) of 7 months in females as compared to 5 months in males (p = 0.001). A highly significant association (p = 0.001) was observed between the grade of skin toxicity and the median time to disease progression, with the median TTP being 4 months in patients experiencing no skin toxicity as compared to 7 months with those grade 2 skin toxicity and 12 months with grade 3 skin toxicity. Gender (p = 0.003), and presence of skin toxicity (p = 0.0001) were having significant difference in median overall survival. On multivariate testing of the same using Cox regression analysis only presence of skin toxicity (p = 0.012) and gender (p = 0.003) was found to significant factors. Thus it can be concluded that occurrence of skin rash and female gender were associated with improved survival with gefitinib for recurrent NSCLC patients.