C-stage in colon cancer: implications of carcinoembryonic antigen biomarker in staging, prognosis, and management.

BACKGROUND: The American Joint Committee on Cancer (AJCC) has proposed the inclusion of pretreatment serum carcinoembryonic antigen (CEA) level (C-stage) into the conventional TNM staging system of colon cancer. We assessed the prognosis of various stages of colon cancer after such an inclusion. METHODS: Data for all patients (N = 17 910) diagnosed with colonic adenocarcinoma (AJCC stages I, IIA, IIB, IIC, IIIA, IIIB, IIIC, and IV, based on TNM staging system) between January 1, 2004, and December 31, 2004, with a median follow-up of 27 months (range 0-35 months), were collected from the Surveillance, Epidemiology, and End Results database. C-stage (C0-stage = normal CEA level; C1-stage = elevated CEA level) was assigned to all patients with available CEA information (n = 9083). Multivariable analyses using Cox proportional hazards models were used to identify independent factors associated with prognosis. Prognosis of overall stages (AJCC stages I-IV and C0 or C1) was analyzed using Kaplan-Meier survival curves. All statistical tests were two-sided. RESULTS: C1-stage was independently associated with a 60% increased risk of overall mortality (hazard ratio of death = 1.60, 95% confidence interval = 1.46 to 1.76, P < .001). Overall survival was decreased in patients with C1-stage cancer compared with C0-stage cancer of the respective overall stages (P < .05). Similarly, decreased overall survival was noted in patients with stage I C1 cancer compared with stage IIA C0 or stage IIIA C0 cancer (P < .001), in patients with stage IIA C1 cancer compared with stage IIIA C0 (P < .001), and in patients with stage IIB C1 or stage IIC C1 cancer compared with stage IIIB C0 cancer (P < .001). CONCLUSIONS: C-stage was an independent prognostic factor for colon cancer. The results support routine preoperative CEA testing and C-staging upon diagnosis of colon cancer and the inclusion of C-stage in the conventional TNM staging of colon cancer.

Meckel's diverticulum--a high-risk region for malignancy in the ileum. Insights from a population-based epidemiological study and implications in surgical management.

BACKGROUND: Surgical management of incidental Meckel's diverticulum(MD) is a highly debated controversial issue that has never been discussed from the oncological standpoint. OBJECTIVE: To describe the epidemiology and risk of Meckel's diverticulum cancer (MDC) and compare it with other ileal malignancies. METHODS: Data were obtained from 163 cases of MDC and 6214 cases of non-Meckelian ileal cancer, between 1973 and 2006, from the Surveillance, Epidemiology, and End Results database. RESULTS: Mean annual incidence was 1.44 (± 1.12) per 10 million population,with a 5-fold increase in the last few decades. Incidence increases with age,with a mean age at diagnosis of 60.6 (±15.1) years. Adjusted risk of cancer in the MD was at least 70 times higher than any other ileal site. Disease was localized in 67% at presentation and malignant carcinoids constituted the major histologic type (77%). One-third of patients have had lifetime occurrence of other malignancies and in 13% of these patients, MDC was the first malignancy. Median tumor size was 7 mm. Median overall survival was 173 months (95% confidence interval [CI], 124-221 months), with 1- and 5-year relative survival rates of 85.8% (95% CI, 76.9%-91.4%) and 75.8% (95%CI, 64.9%-83.8%), respectively. Cox proportional hazards model revealed that age, histologic type, and metastatic disease were independent factors affecting survival. CONCLUSIONS: MD is a "hot-spot" or high-risk area for cancer in the ileum.With risk that increases with age and high possibility of curative resection with negligible operative mortality, incidental MD is best treated with resection.