[Metal endoprosthesis in the treatment of acute neoplastic occlusion of the colon. Our experience]. / Endoprotesi metalliche nel trattamento delle occlusioni acute neoplastiche del colon. Nostra esperienza.

BACKGROUND: Acute large-bowel obstruction represents a surgical challenge whose management is controversial, usually requiring emergent surgery in adverse circumstances with increased morbidity and mortality compared with elective situations. METHODS: We report our experience with self-expanding metal stents in the initial management of acute neoplastic colorectal obstruction. From December 2000 to February 2003, insertion of self-expanding metal stents under endoscopic and fluoroscopic guidance was attempted in 22 patients, in 9 as primary palliative measure (group A) whereas in 13 as a bridge to surgery (group B). RESULTS: Stenting was technically successful in 20 patients. There were 2 perforations, and one patient died as a consequence. Nine of the 11 patients in the group B underwent elective colonic resection while in two patients with advanced malignancy the stent was considered as a definitive palliative treatment. In all 10 patients with ultimate prosthesis (8 group A, 2 group B) two dislocations and one recurrent obstruction were noted in the mean follow-up of 12 months. CONCLUSION: Self expanding metal stents represent a good option in the treatment of large bowel obstruction, providing time for a complete preoperative evaluation and mechanical bowel preparation as well as for restoring patient's general conditions thus avoiding emergency surgery with considerably lower morbidity and mortality rates. In patients with advanced cancer, they provide an alternative to surgery with satisfactory results.

Effects of calcium and vitamin supplementation on colon cell proliferation in colorectal cancer.

Calcium and antioxidant vitamins, such as A, C, and E, have been shown to reduce colorectal epithelial proliferation and thereby to act as possible chemoprotective agents in colorectal cancer. We investigated the effects of an intervention with calcium and vitamins on cell proliferation in the colonic mucosa of patients operated on for colorectal cancer. Patients with resected colorectal cancer Dukes' stage B-C were randomized to receive daily 30,000 IU of axerophthol palmitate (vitamin A) plus 1 g ascorbic acid (vitamin C) plus 70 mg of dl-alpha-tocopherol acetate (vitamin E) and 2 g natural calcium daily or indistinguishable placebo for 6 months. At the time of surgery and after 6 and 12 months of treatment, cell kinetics of normal colonic mucosa were assessed by using proliferating cell nuclear antigen (PCNA). Ninety patients were enrolled and 77 were assessable: 34 in the treatment group and 43 in the placebo group. A significant reduction of mean total PCNA labeling index (PCNALI) was evident in both groups after 6 months (vitamins/calcium, from 16.11 +/- 2.43 to 10.71 +/- 2.81; placebo, from 17.30 +/- 2.63 to 12.53 +/- 3.40). The difference in the percentage of reduction of mean PCNALI between baseline and after 6 months was not statistically significant in the treatment and placebo groups: 34% and 28%, respectively. A second control, 6 months after discontinuation of vitamin and calcium supplementation, showed a further decrease of mean total PCNALI in both groups, but this was not statistically significant. Our randomized trial showed that calcium and vitamin supplementation does not reduce cell kinetics of colon epithelium. Furthermore, this study suggests the need for extreme caution in the interpretation and publication of studies on chemoprotectants in colon cancer without a control group.