Commentary on: undertreatment trend in elderly lung cancer patients in Brazil

To the Editors:

With great interests, we read the article by Prof. Costa et al. (2017), which concluded that lung cancer patients ≥70 years of age were often undertreated in Brazil.

Prof. Costa et al. separate the population with lung cancer in Brazil into two groups (aged <70 and aged ≥70). It is well known that patients with comorbidities usually have higher performance status (PS), and patients with different PS may get different clinical curative efficacy from the same therapy (Singh et al. 2017). However, in the study by Costa and colleagues (Costa et al. 2017), both performance status and comorbidities are not described in detail and seem to be ignored. It is quite possible that patients with higher levels of performance status or more comorbidities may not be given chemotherapy and other treatment modalities. These potential influencing factors may need to be incorporated in multivariate analysis.