Medline ® Abstracts for References 3,58
of 'Cancer of the appendix and pseudomyxoma peritonei'
Importance of histologic subtype in the staging of appendiceal tumors.
Turaga KK, Pappas SG, Gamblin T
Ann Surg Oncol. 2012;19(5):1379.
BACKGROUND: Malignant neoplasms of the appendix have different behavior based on their histologic subtypes in anecdotal series. Current staging systems do not capture the diversity of histologic subtypes in predicting outcomes.
METHODS: We queried all patients with appendiceal malignancies captured in the Surveillance, Epidemiology, and End Results (SEER) database from 1973 to 2007. Tumors were classified as colonic type adenocarcinoma, mucinous adenocarcinoma, signet ring cell type, goblet cell carcinoid, and malignant carcinoid. We compared incidence, overall survival, and disease-specific survival for these tumors on the basis of patient, tumor, and therapy characteristics. Estimates from Cox proportional hazard modeling were used to predict hazard ratios for differing histologic subtypes with similar tumor, node, metastasis system (TNM) stages.
RESULTS: Of the 5672 patients identified, we included 5655 (99%) in our analysis. The 5-year disease-specific survival rates were 93% for malignant carcinoid, 81% for goblet cell carcinoid, 55% for colonic type adenocarcinoma, 58% for mucinous adenocarcinoma, and 27% for signet ring cell type. Predicted estimates of adjusted hazard ratios revealed an 8-fold difference between histologic subtypes for similar TNM stages.
CONCLUSIONS: Histologic subtype is an important predictor of disease-specific survival and overall survival in patients with appendiceal neoplasms. Addition of the histologic subtype to the TNM staging is simple and may improve prognostication.
Division of Surgical Oncology, Medical College of Wisconsin, Milwaukee, WI, USA. firstname.lastname@example.org
Varying malignant potential of appendiceal neuroendocrine tumors: importance of histologic subtype.
Hsu C, Rashid A, Xing Y, Chiang YJ, Chagpar RB, Fournier KF, Chang GJ, You YN, Feig BW, Cormier JN
J Surg Oncol. 2013;107(2):136.
BACKGROUND: Neuroendocrine tumors (NETs) of the appendix include malignant carcinoid tumor (MCT), goblet cell carcinoid (GCT), and composite goblet cell carcinoid-adenocarcinoma (CGCC-A).
METHODS: We compared characteristics and outcomes of these histologic subtypes. Patients with appendiceal NETs were identified from the National Cancer Database (1998-2007). Descriptive statistics were used to compare cohorts and associations between clinicopathologic factors and overall survival (OS) were examined using Cox proportional hazards models.
RESULTS: A total of 2,812 patients with appendiceal NETs were identified. The most common histologic subtype was GCT (59.6%), followed by MCT (32.1%), CGCC-A (6.9%), and others (1.4%). CGCC-A had a significantly higher incidence of lymph node metastases (odds ratio [OR], 3.2; 95% confidence interval [CI], 2.1-4.8) and distant metastases (OR, 6.0; 95% CI = 3.8-9.3) than GCT. The 5-year OS was 86.3% (95% CI, 81.4-89.9) for MCT, 77.6% (95% CI, 74.0-80.8) for GCT, and 56.3% (95% CI, 42.1-68.4) for CGCC-A (P<0.0001).
CONCLUSION: Appendiceal NETs represent a spectrum of disease with varying malignant potential: MCT (low), GCT (intermediate), and CGCC-A (high). GCTs represent the most common subtype, whereas CGCC-As place the patient at highest risk for regional and distant metastases and have the worst prognosis.
Department of Surgical Oncology and Cancer Surgical Outcomes Group, The University of Texas, MD Anderson Cancer Center, Houston, TX 77030-1402, USA.