Predictors of survival in patients with high-grade peritoneal metastases undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

Background Peritoneal metastases in patients with high-grade adenocarcinoma have been typically associated with a poor outcome. Recent literature has suggested that cytoreduction surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) may improve survival. We examined this subset of patients in an effort to better delineate those factors which contribute to improved survival. Methods A retrospective review was performed looking at patients who had undergone CRS/HIPEC. Patients were identified as high-grade histology on the basis of pathology reports indicating their lesion as high grade, moderately, or poorly differentiated and/or associated with signet ring or goblet cell carcinoid features. Peritoneal cancer index and completeness of cytoreduction (CC) were used to define disease burden. Survival analysis was performed by the method of Kaplan-Meier with the log-rank test used to determine significance. Results Of the 250 patients who underwent CRS/HIPEC between 1999 and 2011, 36 (14%) were identified as having peritoneal metastases from a high-grade gastrointestinal primary. Actual overall survival from the time of diagnosis was 11.1% at 5 years. Median survival from time of surgery was 21.6 months. Survival advantage was conferred to those patients who underwent a CC0/CC1 resection, had a peritoneal cancer index score at time of surgery ≤20, appendiceal primary, or moderately differentiated histopathology. Receipt of neoadjuvant chemotherapy and nodal status was not significantly predictive of improved survival. Patients with signet ring cell histology had a particularly poor prognosis. Conclusion For those patients with high-grade peritoneal metastases and historically a poor prognosis, prolonged survival may be achieved through CRS/HIPEC, optimally with a CC0/CC1 resection.