No abstract

Purposes In addition to its role in cellular progression and cancer, SIRT6, a member of nicotinamide adenine dinucleotide (NAD+)-dependent class III deacylase sirtuin family, serves a variety of roles in the body's immune system. In this study, we sought to determine the relationship between the expression of SIRT6 and the clinicopathological outcomes of patients with solid tumours by conducting a meta-analysis of the available data. Methods The databases PubMed and ISI Web of Science were searched for relevant literature, and the results were presented here. Using Stata16.0, a meta-analysis was conducted to determine the impact of SIRT6 on clinicopathological characteristics and prognosis in malignancy patients. The results were published in the journal Cancer Research. The dataset from the Cancer Genome Atlas (TCGA) was used to investigate the prognostic significance of SIRT6 in various types of tumors. Results The inclusion and exclusion criteria were met by 15 studies. In patients with solid tumours, reduced SIRT6 expression was found to be related with improved overall survival (OS) (HR = 0.66, 95% CI = 0.45–0.97, P < 0.001) as well as improved disease-free survival (DFS) (HR = 0.48, 95% CI = 0.26–0.91, P < 0.001). Low SIRT6 expression was found to be associated with a better OS in breast cancer (HR = 0.49, 95% CI = 0.27–0.89, P = 0.179), but was found to be associated with a worse OS in gastrointestinal cancer (gastric cancer and colon cancer) (HR = 1.83, 95% CI = 1.20–2.79, P = 0.939) after subgroup analysis. In terms of clinicopathological characteristics, SIRT6 expression was found to be linked with distant metastasis (OR = 2.98, 95% CI = 1.59–5.57, P = 0.694). When the data from the TCGA dataset was compared to normal tissue, it was discovered that SIRT6 expression was significantly different in 11 different types of cancers. Meanwhile, reduced SIRT6 expression was shown to be associated with improved OS (P < 0.05), which was consistent with the findings of the meta-analysis. Aside from that, the expression of SIRT6 was found to be associated with both gender and clinical stage. Conclusion The overall data of the present meta-analysis indicated that low expression of SIRT6 may predict a favorable survival for patients with solid tumors.

Background and Objectives Previous studies have concluded that colorectal cancer patients with deficient mismatch repair (dMMR) usually have a good prognosis. However, some studies have suggested that the prognosis of rectal cancer patients with dMMR appears to be worse. Our aim was to investigate chemoradiotherapy resistance in dMMR rectal tumors. Methods A retrospective study of 217 patients with locally advanced rectal adenocarcinoma treated with chemoradiotherapy and total mesorectal excision surgery was conducted using immunohistochemistry to determine MMR status and propensity score matching models to reduce potential confounders. Kaplan–Meier analysis, log‐rank test, and Cox regression models were used to assess overall survival (OS) and disease‐free survival (DFS) in patient subgroups. Results The 3‐year DFS rates were 77.1% and 56.7% in the pMMR and dMMR groups, respectively. The pMMR group had significantly better DFS than the dMMR group (hazard ratio [HR], 2.07; 95% confidence interval [CI], 1.10–3.91; p = 0.019). However, there was no significant difference in OS between the two groups (45.7 [interquartile range, IQR], 39.3–72.1] vs. 47.5 [IQR, 29.5–72.1]) (HR, 1.39; 95% CI, 0.70–2.77; p = 0.35). Neither OS nor DFS was significantly different between the neoadjuvant chemoradiotherapy and postoperative chemoradiotherapy groups. Conclusion Locally advanced dMMR rectal adenocarcinoma exhibits greater chemoradiotherapy resistance than pMMR.