Impact of signet ring cells on overall survival in peritoneal disseminated appendix cancer treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

Impact of neoadjuvant systemic chemotherapy followed by cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for appendiceal adenocarcinoma

AIM

Peritoneal dissemination of infiltrative appendiceal tumors is a rare and poorly understood phenomenon. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is a well-recognized treatment option for selected patients. Neoadjuvant systemic chemotherapy (NAC) has been shown to be associated with improved overall survival (OS) in colorectal peritoneal metastases but little is known of the impact of this from an appendiceal adenocarcinoma perspective.

METHOD

A prospective database of 294 patients with advanced appendiceal primary tumors undergoing CRS ± HIPEC between June 2009 and December 2020 was reviewed. Baseline characteristics and long-term outcomes were compared between patients with adenocarcinoma who received neoadjuvant chemotherapy or upfront surgery.

RESULTS

Eighty-six (29%) patients were histologically diagnosed with an appendiceal cancer. These included intestinal-type adenocarcinoma (11.6%), mucinous adenocarcinoma (43%), and goblet cell adenocarcinoma (GCA) or signet ring cell adenocarcinoma (SRCA) (45.4%). Twenty-five (29%) of these underwent NAC, of which eight (32%) exhibited some degree of radiological response. There was no statistical difference in OS at 3 years between the NAC and upfront surgery groups (47.3% vs. 75.8%, p = 0.372). Appendiceal histology subtypes, particularly GCA and SRCA (p = 0.039) and peritoneal carcinomatosis index >10 (p = 0.009), were factors independently associated with worse OS.

CONCLUSION

Administration of NAC did not appear to prolong OS in the operative management of disseminated appendiceal adenocarcinomas. GCA and SRCA subtypes display a more aggressive biological phenotype.

The contemporary management of peritoneal metastasis: A journey from the cold past of treatment futility to a warm present and a bright future

Peritoneal metastasis (PM) is often regarded as a less frequent pattern of spread; however, collectively across all spectra of primary tumors, the consequences of PM impact a large population of patients annually. Unlike other modes of metastasis, symptoms at presentation or during the treatment course are common, representing an additional challenge in the management of PM. Early efforts with chemotherapy and incomplete surgical interventions transiently improved symptoms, but durable symptom control and survival extension were rare, which established a perspective of treatment futility for PM through most of the 20th century. Notably, the continued development of better systemic therapy combinations, optimization of cytoreductive surgery (CRS), and rigorous investigation of combining regional therapy-specifically hyperthermic intraperitoneal chemotherapy-with CRS, have resulted in more effective multimodal treatment options for patients with PM. In this article, the authors provide a comprehensive review of the data establishing the contemporary approach for tumors with a high frequency of PM, including appendix, colorectal, mesothelioma, and gastric cancers. The authors also explore the emerging role of adding hyperthermic intraperitoneal chemotherapy to the well established paradigm of CRS and systemic therapy for advanced ovarian cancer, as well as the recent clinical trials identifying the efficacy of poly(adenosine diphosphate ribose) polymerase maintenance therapy. Finally, recent data are included that explore the role of precision medicine technology in PM management that, in the future, may help further improve patient selection, identify the best systemic therapy regimens, detect actionable mutations, and identify new targets for drug development.