Adjuvant chemotherapy increase survival and decrease recurrence in stage IIA colon cancer.

BACKGROUND/AIMS: The aim of the present study is to evaluate the prognostic factors and efficacy of adjuvant chemotherapy in stage IIA colon cancer patients. METHODOLOGY: From 1994 to 2004, we retrospectively analyzed 447 patients with stage IIA colon cancer. The patients were divided into the surgery only and the surgery with adjuvant chemotherapy. The reviewed factors were age, gender, the size of tumor, differentiation, the number of harvested lymph nodes, lymphovascular invasion, perineural invasion and obstruction. RESULTS: Of the 447 patients, 351 patients (78.5%) received the adjuvant chemotherapy and 96 patients (21.5%) underwent the surgery alone. The significant predictors of survival were lymphovascular invasion (p=0.045) and adjuvant chemotherapy (p<0.001) on the multivariate analysis. For the recurrence, male (p=0.014), the number of harvested lymph node (>=15 vs. <15) (p=0.021), lymphovascular invasion (p=0.050) and adjuvant chemotherapy (p=0.049) were significant on the multivariate analysis. There were similar therapeutic efficacy for survival and recurrence among 5-fluorouracil, capecitabine and uracil/tegafur (p=0.854 and p=0.937, respectively). CONCLUSIONS: Lymphovascular invasion and adjuvant chemotherapy were independent prognostic factors. Adjuvant chemotherapy was effective in preventing recurrence and improving survival for the stage IIA colon cancer patients, especially for those patients with less than 15 harvested lymph nodes.

Relationship of polymorphism of the tandem repeat sequence in the thymidylate synthase gene and the survival of stage III colorectal cancer patients receiving adjuvant 5-flurouracil-based chemotherapy.

BACKGROUND: The aim of this study was to determine whether the different polymorphisms in the thymidylate synthase (TS) gene, novel G>C single nucleotide polymorphism (SNP) and variable number of tandem repeat (VNTR), may be related with disease-free survival (DFS) in patients with stage III colorectal cancer receiving adjuvant chemotherapy. METHODS: The study included 201 patients with pathologic TNM stage III colon cancer who received adjuvant 5-fluorouracil (5-FU)-based chemotherapy after surgery. DNA was extracted from fresh tumor tissue and sequenced. Patients with TS genotypes of 2R3G, 3C3G, or 3G3G were assigned to a high expression group, and those with 2R2R, 2R3C, or 3C3C, to a low expression group. RESULTS: Frequencies of the TS tandem repeat polymorphisms among the tumor genotypes were 6.0% in 2R2R, 25.4% in 2R3R, and 68.7% in 3R3R. The low expression group included 52 patients (25.9%), and the high expression group included 149 patients (74.1%). Groups classified according to possession of VNTR, SNP, and low- or high-expression genotypes did not differ significantly in DFS. In multivariate analysis, only tumor stage showed significant prognostic value (hazard ratio (HR) 2.05, 95% CI = 1.24-3.37, P = 0.005). CONCLUSIONS: TS polymorphisms do not predict clinical outcome of colorectal cancer patients treated with adjuvant 5-FU-based chemotherapy.

Tumor localization for laparoscopic colorectal surgery.

BACKGROUND: Because palpating colonic tumors during laparoscopy is impossible, the precise location of a tumor must be identified before operation. The aim of this study was to evaluate the accuracy of various diagnostic methods that are used to localize colorectal tumors and to propose an adequate localization protocol for laparoscopic colorectal surgery. METHODS: A total of 310 patients underwent laparoscopy-assisted colectomy between April 2000 and March 2006. We investigated if the locations of the tumors that were estimated preoperatively were consistent with the actual locations according to the operation. RESULTS: All the tumors were correctly localized and resected. Altogether, 203 patients had complete endoscopic reports available. Colonoscopy was inaccurate for tumor localization in 23 cases (11.3%). In total, 104 patients (33.5%) underwent barium enema; five tumors (4.8%) were not visualized, and three tumors were incorrectly localized. Another group of 94 patients (30.3%) underwent computed tomography (CT) colonography, which identified 91 of 94 lesions (96.8%). Finally, 96 patients (31.0%) underwent endoscopic tattooing; 2 patients (2.1%) did not have tattoos visualized laparoscopically and required intraoperative colonoscopy to localize their lesions during resection. Dye spillage was found in six patients intraoperatively, but only one patient experienced clinical symptoms. Intraoperative colonoscopy was performed in four patients; two of the four were followed by endoscopic tattooing, and the other two underwent intraoperative colonoscopy for localization. All lesions were correctly localized by intraoperative colonoscopy. The accuracy of tumor localization was as follows: colonoscopy (180/203, 88.7%), barium enema (97/104, 93.3%), CT colonography (89/94, 94.7%), endoscopic tattooing (94/96, 97.9%), and intraoperative colonoscopy (4/4, 100%). CONCLUSIONS: With a combination of methods, localization of tumors for laparoscopic surgery did not seem very different from that during open surgery. Preoperative endoscopic tattooing is a safe, highly effective method for localization. In the case of tattoo failure, intraoperative colonoscopy can be used for accurate localization.