Prognostic significance of the immuno-peritoneal cancer index in peritoneal metastatic patients treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

PURPOSE: A valid comparison of immune function among different patients with different primary pathologies or even with different tumour burdens requires the common use of a reliable assessment of the patient's condition. The combined immuno-PCI system can translate a complex clinical situation into a simple point value to improve postoperative outcomes to assess the prognostic significance of combined immuno-PCI in peritoneal metastatic patients treated with cytoreductive surgery(CRS) and hyperthermic intraperitoneal chemotherapy(HIPEC).

PATIENTS AND

METHODS

Four hundred twenty-four patients from the prospectively maintained database of Dokuz Eylul University Peritoneal Surface Malignancy Center were retrospectively analysed. In addition to the demographic findings and the well-known clinicopathologic factors, several systemic inflammation-based prognostic scores, including the modified Glasgow prognostic score (mGPS), CRP-albumin ratio (CAR), neutrophil-lymphocyte ratio (NLR), neutrophil-thrombocyte ratio (NTR), and thrombocyte count, were all searched and stratified into scoring categories as prognostic determinants of surgical complications, final oncologic outcomes, recurrent disease, disease-free survival (DFS), and overall survival (OS). ROC analyses were performed, and cut-off values were obtained for all immune parameters by using the Youden index method.

RESULTS

There were 314 (74%) women and 110 (26%) men. The median age was 56 (ranging from 18 to 86) years. The most frequent sites of peritoneal metastasis were colorectal (n = 204; 48%) and gynaecologic carcinomas (n = 187; 44%). Thirty-three patients (8%) had primary malignant peritoneal mesothelioma. The median follow-up was 37.8 (ranging from 1 to 124) months. The overall survival was 51.7%. The 1-year, 3-year, and 5-year survival rates were estimated as 80%, 48.4%, and 32.6%, respectively. PCI-CAR-NTR (1 to 3) (p < .001) scoring was an independent prognostic factor for DFS. In a Cox backwards regression analysis, anastomotic leak (p = .002), completeness of cytoreduction (p = .0014), number of organ resections (p = .002), lymph node involvement (p = .003), and PCI-CAR-NTR (1 to 3) scoring (p = .001) were found to be independently significant prognostic factors for overall survival.

CONCLUSION

The PCI is a reliable and consistently valid prognostic factor to evaluate the tumour burden and tumour extent in patients treated with CRS/HIPEC. Staging the host by combining the PCI with an immunoscore may help to improve the outcomes of complications and overall survival in these complex cancer patients. The aggregate maximum immuno-PCI tool may be a better prognostic measure for outcome evaluation.