Organochlorine exposure and colorectal cancer risk.

Organochlorine compounds have been linked to increased risk of several cancers. Despite reductions in their use and fugitive release, they remain one of the most important groups of persistent pollutants to which humans are exposed, primarily through dietary intake. We designed a case-control study to assess the risk of colorectal cancer with exposure to these chemicals, and their potential interactions with genetic alterations in the tumors. A subsample of cases (n = 132) and hospital controls (n = 76) was selected from a larger case-control study in Barcelona, Catalonia, Spain. We measured concentrations in serum of several organochlorines by gas chromatography. We assessed point mutations in K-ras and p53 genes in tissue samples by polymerase chain reaction/single-strand conformation polymorphism and assessed expression of p53 protein by immunohistochemical methods. An elevated risk of colorectal cancer was associated with higher serum concentrations of mono-ortho polychlorinated biphenyl (PCB) congeners 28 and 118. The odds ratio for these mono-ortho PCBs for middle and higher tertile were, respectively, 1.82 [95% confidence interval (CI), 0.90-3.70] and 2.94 (95% CI, 1.39-6.20). Alpha-hexachlorocyclohexane, hexachlorobenzene, and p,p'-DDE (4,4'-dichlorodiphenyltrichloroethene) showed nonsignificant increases in risk. Risk associated with mono-ortho PCBs was slightly higher for tumors with mutations in the p53 gene but was not modified by mutations in K-ras. Mono-ortho PCBs were further associated with transversion-type mutations in both genes. These results generate the hypothesis that exposure to mono-ortho PCBs contributes to human colorectal cancer development. The trend and magnitude of the association, as well as the observation of a molecular fingerprint in tumors, raise the possibility that this finding may be causal.

Emergency operations for nondiverticular perforation of the left colon.

OBJECTIVE: Although diverticulitis is the most common cause of large bowel perforation, other disease may result in left colonic peritonitis. The aim of this study was to evaluate and compare the incidence, management, and outcome of patients with different causes of nondiverticular left colonic perforations. PATIENTS AND METHODS: From January 1992 to September 2000, 212 surgical patients underwent emergency operation for distal colonic peritonitis. Perforations were caused by diverticulitis in 133 patients (63%) and by a nondiverticular process in 79 (37%). Mortality and morbidity in patients with nondiverticular perforation of the distal large bowel its relationship with the general conditions, the grade and the cause of peritonitis were analysed. Four types of surgical procedures were used. Hartmann's procedure was performed in 40 patients (51%); intraoperative colonic lavage, resection, and primary anastomosis (ICL) in 27 patients (34%); colostomy in 7 (9%); and subtotal colectomy in 5 (6%). RESULTS: Perforated neoplasm, the most common cause of peritonitis, was observed in 30 patients, colonic ischemia in 20, iatrogenia in 13, and other causes in 16 patients. One or more complications were observed in 57 patients (72%); among causes of perforation, colonic ischemia was significantly associated with the longest hospital stay and highest mortality. Eighteen patients (23%) died. CONCLUSIONS: Left large bowel perforation by nondiverticular disease is associated with high mortality and morbidity. The prognosis of patients is determined by the development of septic shock and colonic ischemia, as underlying disease, may influence patient survival.

[Survival and recurrence in the multidisciplinary approach of colorectal cancer]. / Supervivencia y recidiva en el tratamiento multidisciplinario del carcinoma colorrectal.

BACKGROUND AND OBJECTIVE: Colorectal cancer is one of the most frequent causes of death in the general population. Our aim was to analyze our experience in the multidisciplinary approach of colorectal carcinoma during a three year period. PATIENTS AND METHOD: Between January 1996 and December 1998, we studied prospectively 807 patients with colorectal cancer. The epidemiology, treatment and outcome(recurrence and survival) were analyzed. The minimum follow-up was 3 years. RESULTS: There were 598 colon (65.5%) and 279 rectal (34.5%) tumors in all the series. Surgical treatment was elective in 84% and urgent in 16%, and was considered radical in 598 cases (74.1%). Chemotherapy or radiotherapy was administered in 49.6% and 18.3% patients, respectively. The overall 3-year survival was as follows: stage I 97.5%, stage II 90.6%, stage III 75.2%, and stage IV 12.6%. The 3-year free-disease survival was as follows: in colon cancer 97.8% for stage I, 87.3% for stage II, and 71.4% for stage III; and in rectal cancer 96.8% for stage I, 85.1% for stage II, and 75.4% for stage III. During the follow-up 124 patients (20.7%) developed recurrence: local (2.8%), systemic (15.9%) or both (2%). The three-year survival in operated patients with liver metastases was 61.9%. CONCLUSIONS: We have observed adequate survival and recurrence rates which are the result are of systematic protocols established by a multidisciplinary team.