Taxane-based Chemotherapy is Effective in Metastatic Appendiceal Adenocarcinoma

Appendiceal cancer is a rare, orphan disease with no therapies currently approved by the FDA for its treatment. Given the limited data regarding drug efficacy, these tumors have historically been treated with chemotherapy designed for colon cancer. However, an overwhelming body of molecular data has demonstrated that appendiceal adenocarcinoma is a distinct entity with key molecular differences from colon cancer, notably rare APC mutation. Recognizing that APC loss-of-function is thought to contribute to taxane resistance, and that taxanes are effective in the treatment of other gastrointestinal tumors including gastric, esophageal, and small bowel adenocarcinoma, we completed a single-center retrospective study to assess efficacy. In a cohort of 13 patients with metastatic appendiceal adenocarcinoma, treated with taxane chemotherapy the median overall survival was 8.3 months. Of 10 evaluable patients we observed 3 responses, 4 patients with stable disease, and 3 with progression (30% response rate, 70% disease control rate). The results of this study showing activity of taxane-based chemotherapy in appendiceal adenocarcinoma support further clinical investigation of taxane therapy in this orphan disease. ### Competing Interest Statement Consulting/advisory relationship JPS (Engine Biosciences, NaDeNo Nanoscience) Research Funding JPS (NIH, ASCO, CPRIT) ### Funding Statement This work was supported by the Col. Daniel Connelly Memorial Fund, the National Cancer Institute (K22 CA234406 to J.P.S., and the Cancer Center Support Grant (P30 CA016672), the Cancer Prevention & Research Institute of Texas (RR180035 to J.P.S., J.P.S. is a CPRIT Scholar in Cancer Research), and a Conquer Cancer Career Development Award to J.P.S. Any opinions, findings, and conclusions expressed in this material are those of the author(s) and do not necessarily reflect those of the American Society of Clinical Oncology or Conquer Cancer. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The University of Texas MD Anderson Cancer Center Institutional Review Board (IRB) granted ethical approval for this work under protocol Lab09-0373 (PI: Dr. Scott Kopetz). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data other than individual patient level data are contained in the manuscript, patient level data produced in the present study are available upon reasonable request to the authors