An analysis of combined data suggests that the presence of a rash during treatment of non-small cell lung cancer may predict better efficacy of the anti-epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor class of drugs erlotinib or gefitinib. The investigators conducted a literature search to identify 17 prospective trials of relevant companies and seven case series studies involving more than 3,000 patients. As a result, 36% of patients who developed a rash responded to treatment, compared with 26% of patients who did not develop a rash or developed a mild rash. In addition, a higher percentage of patients with a grade 2-4 rash responded to treatment compared to those without a rash (42% vs. 7%). The rash was significantly associated with a reduced risk of disease progression and death with either erlotinib or gefitinib. The results of the study were published in the journal Lung Cancer. The study also noted that although rash is a sign that treatment is working, it should still be treated to avoid patient discomfort and the risk of secondary infections.