Retrospective study of nonmucinous appendiceal adenocarcinomas: role of systemic chemotherapy and cytoreductive surgery

Abstract Background Mucinous appendiceal adenocarcinomas (AAs) are the most common histological subset of AAs. Nonmucinous AAs have been infrequently studied. We performed a single-center retrospective study to investigate this histological subtype. Methods We reviewed 172 patient records with nonmucinous AAs treated at MD Anderson Cancer Center from Jan, 1990 to Jun, 2015 and recorded patient demographics, tumor characteristics, treatment, and outcomes. Response rate (RR) was assessed semi-quantitatively (response/no response) according to the treating physician’s findings. Survival outcomes were calculated using the Kaplan-Meier product-limit method and compared using the log-rank test. Results Median age at diagnosis was 52.9 years. Most patients presented with advanced-stage disease: stage I-II (35%), stage III (15%), and stage IV (50%). Moderate and poorly differentiated histology was seen in 56% and 44% tumors, respectively. Median overall survival (OS) of all patients was stage-dependent and was 88.5, 39.2, and 28.3 months for stages I-II, stage III, and stage IV disease, respectively ( p p  = 0.003), compared to those receiving fluoropyrimidine monotherapy. Conclusions This is one of the first studies to report specifically on nonmucinous AAs. Nonmucinous AAs presented with moderate or poorly differentiated histology with a predilection for peritoneal metastasis. Systemic chemotherapy is active in this AA subtype. Though CRS was infrequently used, complete CRS appears beneficial and warrants further investigation.