The Effect of Prior Nondefinitive Surgery on Perioperative Outcomes and Survival in Mucinous Appendix Cancer Patients Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy.

Introduction

Peritoneal metastases (PM) from mucinous appendix cancer (MAC) are common and often mismanaged. While cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is standard, many patients undergo nondefinitive surgery. We compared outcomes in MAC patients undergoing CRS/HIPEC after limited vs excessive prior surgeries.

Methods

We conducted a retrospective analysis of MAC patients (1998-2023) from a single-center prospective database who underwent CRS/HIPEC. Surgical history was evaluated using the prior surgical score (PSS). Perioperative characteristics were compared between PSS-0/1 and PSS-2/3 groups. Logistic regression identified factors associated with extensive prior surgery. Overall survival (OS) was analyzed with Kaplan-Meier and Cox regression.

Results

Of 351 eligible cases, 221 (63%) had PSS-0/1 and 130 (37%) had PSS-2/3. Most individuals with PSS-2/3 were women (89.2%, n = 116). Only female sex was significantly associated with the higher likelihood of PSS-2/3 (odds ratio: 9.02, P < .001). PSS-2/3 patients had longer time from diagnosis to CRS/HIPEC (P < .001), longer CRS/HIPEC procedure (P = .007), and greater blood loss (P = .038). Complete cytoreduction (CC) rates were similar (P = .227). Despite comparable major complication rates, PSS-2/3 patients had more transfusions (P = .016), infections (P = .048), and pulmonary complications (P = .028). Five-year OS was 76% and 66% for PSS-0/1 and PSS-2/3 groups, respectively (P = .049). After adjusting for age, tumor burden, CC-score, and histology, PSS-2/3 was not significantly associated with shorter OS (hazard ratio: 1.32; P = .139).

Conclusion

Females with MAC are more likely to have extensive surgeries, delaying CRS/HIPEC and compromising safety. This highlights the importance of general surgeons and gynecologists limiting the surgical extent and referring patients to an HIPEC center.