The peritoneal cancer index (PCI) was first described by Sugarbaker in 1998 and was considered as the standard for describing carcinomatosis of colorectal cancer and mesothelioma [2]. Regardless of tumor histologic origin, the PCI has been used to describe and explain the patients' tumor spread pattern, disease severity. This manuscript provides the PCI as new prognostic factor for patients who diagnosed serous epithelial ovarian cancer [1].

For the best understanding of the study, several issues need to be discussed. In Table 1 for characteristics of the patient cohort, the information baseline characteristics such as age, performance status, tumor burden, site of metastasis or largest mass could be added in the analysis. Second, different clinical parameters were tested according to the calculated cut-off level of the PCI score in Table 2. The cut-off PCI value was set to 13 in this study. The characteristics of patients with >13 PCI scores were ‘low grade’ and ‘suboptimal surgical cytoreduction’. Therefore, multivariate analysis is needed to know the pure impact of PCI on the survival. Third, the women with BRCA1 and BRCA2 mutations showed high PCI value more frequently [3]. Therefore, the authors could evaluate the correlation of the PCI score with the BRCA status or hereditary predisposition. Fourth, at this point, clinical application of neoadjuvant chemotherapy has been expanding [4]. Clinical role of PCI in the interval cytoreductive surgery after neoadjuvant chemotherapy should be evaluated in near future.

In conclusion, this is the first study to explore the possibility of applying the PCI as ovarian cancer prognosis. Even with some limitations, it can be a guide for clinicians who has interest in PCI concept.