Background: This report describes patterns of disease recurrence after optimal cytoreduction (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal carcinomatosis (PC) of colorectal (CRC) and appendiceal adenocarcinoma (AC) origin.
Methods: Patients undergoing optimal CRS/HIPEC (2007-2016) at the authors' institution were retrospectively reviewed from a prospectively maintained database. Data regarding disease recurrence were analyzed.
Results: Of 74 patients who underwent CRS/HIPEC for PC from CRC (n = 46) or AC (n = 28), 49 (66%) had recurrence during a median follow-up period of 39.5 months. The sites of recurrence were peritoneal-only (n = 34, 69%), hematogenous-only (n = 6, 12%), and combined peritoneal and hematogenous (n = 9, 19%) sites. No patients with AC had hematogenous-only recurrence. The median disease-free survival (DFS) time for all the patients was 15 months (95% confidence interval [CI] 12.5-17.5 months). The recurrence rate after CRS/HIPEC was 41% at 1 year, 73% at 3 years, and 76% at 5 years. All the patients with hematogenous-only metastases experienced recurrence within 12 months after CRS/HIPEC. Mucinous or signet ring features predicted peritoneal recurrence (p = 0.041), whereas a complete cytoreduction of 1 was a predictor of early recurrence (p = 0.040). Patients who underwent repeat cytoreduction survived longer than those who received systemic chemotherapy alone. The median survival time after peritoneal-only recurrence was 33 months (95% CI 27.8-38.9 months).
Conclusion: Recurrence for patients with PC is common, even after optimal CRS/HIPEC. Hematogenous-only recurrence occurs early after CRS/HIPEC, suggesting occult disease at the time of treatment and highlighting the need for methods to identify micro-metastases and improve patient selection. Patients experiencing peritoneal-only recurrence had long survival period after CRS/HIPEC, suggesting its effectiveness at controlling peritoneal disease for a time.