Repeat cytoreductive surgery with or without intraperitoneal chemotherapy for recurrent epithelial appendiceal neoplasms.

Background: With recurrence rates after primary cytoreductive surgery (CRS) in excess of 50 per cent, repeat CRS is being performed increasingly, but survival outcomes have not been reported widely. This study examined the outcomes following repeat CRS for appendiceal cancer with peritoneal surface malignancy (PSM), and evaluated its feasibility and safety.

Methods: A retrospective cohort of patients who had surgery between 1996 and 2018 were analysed. Patients who underwent a single CRS procedure with or without heated intraperitoneal chemotherapy (HIPEC) were compared with those who had multiple procedures with or without HIPEC. Perioperative morbidity and survival outcomes were analysed.

Results: Some 462 patients were reviewed, 102 of whom had repeat procedures. For high-grade tumours, patients who had a single CRS procedure had significantly reduced overall survival (OS) compared with those who had repeat CRS (55·6 versus 90·7 months respectively; P = 0·016). For low-grade tumours, there was no difference in OS (P = 0·153). When patients who had a single procedure were compared with those who had multiple procedures, there was no significant difference in major morbidity (P = 0·441) or in-hospital mortality (P = 0·080). For multiple procedures, no differences were found in major morbidity (P = 0·262) or in-hospital mortality (P = 0·502) when the first procedure was compared with the second. For low-grade cancers, the peritoneal carcinomatosis index was a significant prognostic factor for OS (hazard ratio (HR) 1·11, 95 per cent c.i. 1·05 to 1·17; P < 0·001), whereas for high-grade cancers repeat CRS (HR 0·57, 0·33 to 0·95; P = 0·033), complete cytoreduction score (HR 1·55, 1·01 to 2·40; P = 0·046) and presence of signet ring cells (HR 2·77, 1·78 to 4·30; P < 0·001) were all significant indicators of long-term survival.

Conclusion: In selected patients presenting with PSM from epithelial appendiceal neoplasms, repeat CRS performed in high-volume centres could provide survival benefits.