Right hemicolectomy does not confer a survival advantage in patients with mucinous carcinoma of the appendix and peritoneal seeding

Background: Traditionally epithelial malignancies of the appendix with or without carcinomatosis have been treated by right hemicolectomy. Recent accumulation of a large number of patients with this disease has enabled a re-evaluation of this surgical judgement. Methods: Clinical data on 501 patients with epithelial malignancy of the appendix were collected prospectively. All patients had peritoneal seeding at the time of referral and were treated by cytoreductive surgery and perioperative intraperitoneal chemotherapy. The main independent variable for statistical analysis was the surgical procedure used to resect the primary cancer (appendicectomy alone versus right hemicolectomy). Nineteen other clinical and pathological variables were considered as control variables. The endpoint for all analyses was survival. Results: Median follow-up after the initial diagnosis was 4 years. The rate of regional lymph node positivity was 5.0 per cent. When the incidence of lymph node metastasis was determined by histological type, it was statistically significantly higher in intestinal (66.7 per cent) than in mucinous (4.2 per cent) tumours (P < 0.001). The presence of lymph node metastases had no influence on prognosis (P = 0.155). The surgical procedure (appendicectomy alone versus right hemicolectomy) had an influence on patient survival by univariate analysis (P < 0.001), but not by multivariate analysis (P = 0.258). Conclusion: Right hemicolectomy does not confer a survival advantage in patients with mucinous appendiceal tumours with peritoneal seeding. These data suggest that tight hemicolectomy should be avoided unless metastatic involvement of the appendiceal or distal ileocolic lymph nodes is documented by biopsy, or the resection margin is inadequate.