Re: Second primary cancers in patients with nasopharyngeal carcinoma: a pooled analysis of 13 cancer registries

摘要

In the above-captioned paper, Scelo and colleagues present a pooled analysis of the occurrence of second primary cancers in nasopharyngeal carcinoma (NPC) patients from 13 cancer registries from Europe, Canada, Australia, and Singapore. This paper provides an important contribution as previous studies of second malignancies, following NPC, have been based on small sample sizes. However, there is a serious methodological issue arising from their study that needs to be discussed. Although the authors justifiably stratify the analysis, geographically into high risk (Singapore) and low risk (Europe, Canada, and Australia) areas, there is no mention in the paper of stratification by race or ethnicity.