The relationship between cancer and nutritional status has been of increasing concern. The predictive effects of nutritional markers, for instance PNI and body mass index is related to cancer[26, 27]. The main treatment for patients with ICC is hepatectomy, after surgery, it is very important to evaluate the prognostic indicators or models effectively. In our cohort study, we established a nomogram based on PMI and PNI to identify patients with the highest risk of mortality after radical hepatectomy. We found that PMI and PNI were independent prognostic factors for OS and RFS in these patients. Meanwhile, the patients with the worst OS and RFS were those with a combination of low PMI and low PNI. Our established nomogram had a very good predictive ability for the postoperative survival of these patients. The prognostic value of combined PMI and PNI in predicting patients undergoing radical hepatectomy in ICC has not been reported, our cohort study is the first report.
PNI is a classic immune and nutrition marker, which is measured using serum albumin levels and peripheral lymphocyte counts. Albumin is usually used to evaluate the nutritional status of patients. Patients with malnutrition often have a poor prognosis, . Lymphocytes are responsible for regulating the body’s immune function against tumor attacks. Several studies have confirmed the prognostic value of lymphocytes in patients with ICC[32, 33]. PNI is a new indicator to synthesize albumin and lymphocyte. And it is a comprehensive indicator to reflect the nutritional status, systemic inflammatory response and immunity function of patients. In our cohort study, we also found that PNI was an independent factor affecting the OS of ICC patients, which was the same as previous reports[22, 27].
There are many factors that cause sarcopenia, such as neuromuscular dysfunction, trauma, hormones, inflammation, decreased physical activity, and genetic factors; Malnutrition is also an important cause of sarcopenia. Moreover, some study have found that serum albumin level in patients without sarcopenia is significantly higher than that of patients with sarcopenia . Similarly, sarcopenia can also cause decreased appetite and insufficient nutritional intake; thereby, further increasing the risk of malnutrition. Therefore, sarcopenia and malnutrition are mutually causal, and can form a vicious circle. Several studies have found that sarcopenia is an independent poor prognostic factor for patients with ICC after hepatectomy[6–8, 37]. Our findings are consistent with those of previous reports.
Nomograms have been developed for some cancers. Several studies have shown that nomograms have a better predictive accuracy than traditional staging systems[38–40]. Many studies have assessed a single biomarker, while few have assessed the effect of multiple comprehensive markers on prognosis. We established a nomogram composed of multiple marks that can significantly improve prognosis prediction in these patients. Our nomogram’s better predictive power (compared to single marks) was proven by the C-index and calibration curve. Several studies demonstrated that the C-index for prediction of postoperative survival for patients with ICC is 0.64–0.67 for the traditional staging system, and 0.74 for the nomogram C-index; this has been validated in multiple centers.Compared with the TNM staging system, the nomogram prognostic evaluation system has a personalized function and can provided important reference for individualized treatment of patients, which deserves to be promoted in clinical practice.
In our nomogram, we found that PMI and PNI play an important role in the score and were significant affecting the prognosis. Therefore, the role of PNI and PMI in influencing the prognosis of ICC patients should not be ignored in clinical practice. Based on our established nomogram, improving the nutrition of patients with both a low PNI and low PMI can improve the prognosis to an extent. Supportive care centered on nutrition and exercise can benefit patients with ICC. Multiple studies have shown that exercise and the intake of certain nutrients (such as proteins, vitamin D, antioxidants, and long-chain polyunsaturated fatty acids) are beneficial in patients with ICC having sarcopenia, and can positively improve the prognosis,[42, 43]. Therefore, preoperative correction of hypoproteinemia and reduction of inflammation in patients, which can significantly increase the muscle mass of patients, may improve their prognosis. This should be confirmed with more prospective studies.
The potential limitations should be considered in this study. First, as a retrospective study, it has its own flaws. Second, the results of this cohort study may be limited by a small sample size, requiring a larger sample size to be confirmed. Third, the nomogram was created using data collected from two-institutions, and its accuracy needs to be verified in multiple single-center or multi-center studies. Finally, prospective multicenter cohort studies are needed to determine the clinical utility of our nomogram.