Retrospective study on melanosis coli as risk factor of colorectal neoplasm: a 3-year colonoscopic finding in Zhuhai Hospital, China.

BACKGROUND: Melanosis coli (MC) is a colonoscopic finding in which the colonic mucosa appears darkly pigmented than usual and generally caused by extended anthranoid laxative use. METHODS: We performed a retrospective study at Zhuhai Hospital to investigate the risk of MC for CR neoplasm development. A total of 12,776 patients who underwent colonoscopy from 2013 to 2016 including 250 diagnosed with MC and 500 controls were included in this study. Odds ratios (OR) and 95% confidence intervals (95%CI) for associations of MC with CR neoplasm detection were estimated using univariate and multivariable multinomial logistic analyses for known risk factors. RESULTS: The presence of MC was associated with a significant increase in the CR neoplasm detection rate compared with controls (OR = 1.701, 95% CI = 1.252-2.31; P = 0.001). The effect was also observed in different tumor sites, age group, gender, and lifestyle. Using univariate multinomial analysis, patients with MC were significantly associated with both hyperplastic polyp (OR = 2.069, 95% CI = 1.253-3.415; P = 0.005) and low-grade (LG) adenoma (OR = 1.585, 95% CI = 1.115-2.254; P = 0.010). However, there was no significant difference with adenocarcinoma (OR = 1.701, 95% CI = 0.990-2.924; P = 0.055). Using multivariate multinomial analysis, MC patients remained associated with increased hyperplastic polyp (OR = 1.870, 95% CI = 1.119-3.125; P = 0.017) and LG adenoma (OR = 1.474, 95% CI = 1.027-2.114; P = 0.035), but not adenocarcinoma (OR = 1.620, 95% CI = 0.914-2.871; P = 0.098). A significant increase in CR neoplasm rate was observed with drinker, smoker, and elderly patients but not with gender. CONCLUSION: Patients with MC were more likely to have both hyperplastic polyp and LG adenoma. If confirmed, such findings could suggest the discontinuation of anthranoid laxative use particularly in the elderly.

Clinicopathologic and epidemiological characteristics of prognostic factors in post-surgical survival of colorectal cancer patients in Jiangsu Province, China.

Poor survival among colorectal cancer (CRC) patients has been widely associated with clinico-epidemiological features and treatment regimen. In Jiangsu (China), however, it is not known which one of the prognostic factors explains the survival disparities among patients with CRC. This prospective study using 1078 patients (stages I-IV) that underwent surgery at Jiangsu Hospital, explored the relevant factors affecting the prognoses of right-side colon cancer (RCC), left-side colon cancer (LCC) and rectal cancer (ReC) patients. Of these cases, 234 (21.7%), 241 (22.4%) and 603 (55.9%) were found to have RCC, LCC and ReC respectively. Compared to LCC, RCC exhibited a greater proportion of older patients, poorly differentiated carcinomas, higher T-stage and higher TNM-stage. The overall survival (OS) for RCC was 60 vs.78 or 77 months for LCC or ReC respectively (P = 0.030). There were no significant differences in OS between LCC and ReC across the subgroups (P = 0.633). In multivariate analysis, RCC patients had age (>60 vs. ≤60 years, HR = 1.529, P = 0.019), N-stage (N1 vs. N0, HR = 4.056, P = 0.012) and M-stage (M1 vs. M0, HR = 3.442, P < 0.0001) as independent prognostic factors, whereas smoking status was found to be a predictor of mortality (smoker vs. nonsmoker, HR = 2.343, P = 0.017) for LCC. In addition, age (>60 vs. ≤60 years, HR = 2.199, P < 0.0001), alcohol consumption (drinker vs. nondrinker, HR = 0.510, P = 0.034), tumor grade (Poor vs. well/moderate, HR = 2.759, P = 0.031) and T-stage (T3-4 vs. T1-2, HR = 1.742, P < 0.0001) were found to be predictors of mortality for ReC. There were significant pairwise interactions across subgroups. Furthermore, significant differences were observed for LCC vs. RCC (OS, HR = 0.783, P = 0.039), but no statistically significant differences for ReC vs. RCC (P = 0.149) and LCC vs. ReC (P = 0.355). Nevertheless, significant differences remained between ReC vs. RCC for male (HR = 0.591, P = 0.009), drinker (HR = 0.396, P = 0.005), rural resident (HR = 0.437,P = 0.022), tumor grade (well/moderate, HR = 0.475, P = 0.022), T-stage (T1-2, HR = 0.362, P = 0.001), N-stage (N0, HR = 0.604, P = 0.011), M-stage(M0, HR = 0.401, P = 0.006) and TNM-stage (I-II, HR = 0.567, P = 0.005). Statistically significant differences were observed for LCC vs. RCC for gender (female, HR = 0.495, P = 0.003) and T-stage (T1-2, HR = 0.417, P = 0.010) as well as for LCC vs. ReC in patients with smoking habits (HR = 1.951, P = 0.002) and M-stage (M0, HR = 2.291, P = 0.003). These findings suggest that the variations in CRC post-surgical survival in China may be primarily explained with the clinicopathologic features and epidemiological characteristic of the patients. Patients with RCC had significantly worse OS compared to both LCC and ReC in several subgroups.