Primary appendiceal carcinoma--epidemiology, surgery and survival: results of a German multi-center study

While carcinoma of the colon is a common malignancy, primary carcinoma of the appendix is rare. Many retrospective reviews outlined experience from different centers on appendiceal neoplasms. However, the study population is often small because it is so rare. The aim of this study was to analyze the type of surgery and survival of patients with appendiceal malignancies using data from a German multi-center observational study (31 341 patients).

During a five-year period, 196 consecutive patients with malignant appendiceal tumors were distributed into four groups: appendiceal carcinoids, adenocarcinoma, mucinous adenocarcinoma and adenosquamous carcinoma. The following parameters were analyzed: demographics, clinical presentation, comorbidities, type and appropriateness of surgery, final pathology and survival.

Adenocarcinoma had the highest incidence (50.5%). The most common presentation was that of acute appendicitis. Mean age at presentation was youngest for carcinoid tumors. Carcinoid tumors had lowest tumor size and localized disease was present in 72.9%. Metastatic spread at presentation was highest for adenosquamous and mucinous adenocarcinoma and each had a distinct pattern. Right hemicolectomy was performed in 71.4%, limited resection in 11.7%. Overall 5-year survival was 83.1% for carcinoid vs. 49.2% for non-carcinoid tumors. Histological subtype and tumor stage significantly affected survival.

Long-term outcome of carcinoid tumors is superior to non-carcinoid neoplasms. Among all appendiceal neoplasms, adenosquamous carcinoma is the rarest histological subtype which is most commonly associated with advanced tumor stage and worst prognosis. Appropriate oncologic resection is being performed in a significant percentage of cases in Germany. However, the high rate of right hemicolectomy in patients with small carcinoid tumors needs to be critically discussed.