Objective  To investigate the relationship between pigmentation and clinicopathological features and the therapeutic effect of pemetrexed in patients with lung adenocarcinoma in advanced non-small cell lung cancer (NSCLC).

  Methods  A total of 117 patients with lung adenocarcinoma, confirmed by histopathology studies conducted from January 2016 to December 2018 at Affiliated Tumor Hospital of Xinjiang Medical University, were recruited. The adverse reaction of skin pigmentation caused by pemetrexed was graded using Common Terminology Criteria for Adverse Events (CTCAE) version 4.0, and the clinicopathological characteristics and efficacy of pemetrexed in hemotherapy were analyzed.

  Result  The overall incidence of skin pigmentation was 43.6%. There was no significant dif-ference in skin pigmentation with respect to age, sex, tumor stage, tumor differentiation degree, and smoking history (P > 0.05). The ef-ficacy rate of chemotherapy in patients with skin pigmentation was significantly higher (P < 0.05) when compared to that in those with-out skin pigmentation. The progression-free survival (PFS) in patients with skin pigmentation was longer when compared to that in pa-tients without skin pigmentation (6.2 months vs. 4.1 months, P < 0.05).

  Conclusions  The efficacy rate of chemotherapy in patients with skin pigmentation was higher than that in those without skin pigmentation. Skin pigmentation may become prognostic indicators in ad-vanced NSCLC treated with pemetrexed.