Durable Response after Repeat Cytoreductive Surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in a Patient with Extensive Mucinous Adenocarcinoma of the Appendix

Mucinous adenocarcinoma of the appendix is a rare form of lower gastrointestinal (GI) tract cancer. These cancers have a high tendency to progress towards peritoneal metastasis and their response to systemic treatment is typically low. Together, cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have become an established form of therapy used to prolong the survival of patients with this disease. Repeat CRS and HIPEC have been shown to be feasible in selected patients with GI peritoneal carcinomatosis (PC), among which those with appendix cancer receive the greatest benefit. The peritoneal cancer index (PCI) and completeness of cytoreduction have been shown to be important predictors of outcomes. However, repeat cytoreduction in patients with a high-volume peritoneal tumor burden (peritoneal cancer index (PCI) > 30) is not typically performed due to concerns regarding morbidity and mortality. Herein, we describe a case of repeat CRS and HIPEC for extensive appendiceal mucinous peritoneal carcinomatosis after initial incomplete cytoreduction and durable remission of 28 months without adjuvant chemotherapy. In appendiceal mucinous cancers, repeat CRS can achieve a durable response despite an initial failed CRS and high-volume disease.