LAUSR

The author confirmed that there was a survival difference between high MCV and normal MCV (Figure 2A), and proposed that MCV could be used as an effective indicator to predict the survival outcome of esophageal cancer after surgery. However, the author also mentioned that the survival difference disappeared when non-esophageal cancer-caused of deaths were excluded (Figure 2B, P = 0.1477). One possible explanation was that high MCV group was accompanied by increases of multiple primary cancer occurrence, but we found that the proportion of synchronous/metachronous malignancies was discrepant between the two groups, for example, the head and neck malignancies was 11% higher in the high MCV group compared to that in the normal MCV group. Considering high MCVs were reported to be associated with prognosis in the head and neck cancer and other malignancies, it is difficult for clinicians to define patients with high MCV are patients with poor prognosis in esophageal cancer. 3 Thus, the author should discuss the survival predictive value of MCV in esophageal cancer after excluding interference from other malignancies.