Summary
Background
Analyses of microRNA expression profiles have shown that many microRNAs are expressed aberrantly and correlate with tumorigenesis, progression, and prognosis of various haematological and solid tumours. We aimed to assess the relation between microRNA expression and progression and prognosis of gastric cancer.
Methods
353 gastric samples from two independent subsets of patients from Japan were analysed by microRNA microarray. MicroRNA expression patterns were compared between non-tumour mucosa and cancer samples, graded by diffuse and intestinal histological types and by progression-related factors (eg, depth of invasion, metastasis, and stage). Disease outcome was calculated by multivariable regression analysis to establish whether microRNAs are independent prognostic factors.
Findings
In 160 paired samples of non-tumour mucosa and cancer, 22 microRNAs were upregulated and 13 were downregulated in gastric cancer; 292 (83%) samples were distinguished correctly by this signature. The two histological subtypes of gastric cancer showed different microRNA signatures: eight microRNAs were upregulated in diffuse-type and four in intestinal-type cancer. In the progression-related signature, miR-125b, miR-199a, and miR-100 were the most important microRNAs involved. Low expression of let-7g (hazard ratio 2·6 [95% CI 1·3–4·9]) and miR-433 (2·1 [1·1–3·9]) and high expression of miR-214 (2·4 [1·2–4·5]) were associated with unfavourable outcome in overall survival independent of clinical covariates, including depth of invasion, lymph-node metastasis, and stage.
Interpretation
MicroRNAs are expressed differentially in gastric cancers, and histological subtypes are characterised by specific microRNA signatures. Unique microRNAs are associated with progression and prognosis of gastric cancer.
Funding
National Cancer Institute.
BackgroundThe Japanese Gastric Cancer Association (JGCA) started a new nationwide gastric cancer registration in 2008.MethodsFrom 208 participating hospitals, 53 items including surgical procedures, pathological diagnosis, and survival outcomes of 13,626 patients with primary gastric cancer treated in 2002 were collected retrospectively. Data were entered into the JGCA database according to the JGCA classification (13th edition) and UICC TNM classification (5th edition) using an electronic data collecting system. Finally, data of 13,002 patients who underwent laparotomy were analyzed.ResultsThe 5-year follow-up rate was 83.3 %. The direct death rate was 0.48 %. UICC 5-year survival rates (5YEARSs)/JGCA 5YEARSs were 92.2 %/92.3 % for stage IA, 85.3 %/84.7 % for stage IB, 72.1 %/70.0 % for stage II, 52.8 %/46.8 % for stage IIIA, 31.0 %/28.8 % for stage IIIB, and 14.9 %/15.3 % for stage IV, respectively. The proportion of patients more than 80 years old was 7.8 %, and their 5YEARS was 51.6 %. Postoperative outcome of the patients with primary gastric carcinoma in Japan have apparently improved in advanced cases and among the aged population when compared with the archival data. Further efforts to improve the follow-up rate are needed.ConclusionsPostoperative outcome of the patients with primary gastric carcinoma in Japan have apparently improved in advanced cases and among the aged population when compared with the archival data. Further efforts to improve the follow-up rate are needed.
The Japanese Gastric Cancer Association (JGCA) started a new nationwide gastric cancer registry in 2008. Approximately 50 data items, including surgical procedures, pathological diagnoses, and survival outcomes, for 12004 patients with primary gastric cancer treated in 2001 were collected retrospectively from 187 participating hospitals. Data were entered into the JGCA database according to the JGCA Classification of gastric carcinoma, 13th edition and the International Union Against Cancer (UICC) TNM Classification of malignant tumors, 5th edition by using an electronic data collecting system. Finally, data of 11261 patients with gastric resection were analyzed. The 5-year follow-up rate was 83.5%. The direct death rate was 0.6%. TNM 5-year survival rates (5YSRs)/JGCA 5YSRs were 91.8/91.9% for stage IA, 84.6/85.1% for stage IB, 70.5/73.1% for stage II, 46.6/51.0% for stage IIIA, 29.9/33.4% for stage IIIB, and 16.6/15.8% for stage IV. The proportion of patients more than 80 years old was 7.0%, and their 5YSR was 48.7%. Compared to the JGCA archived data, though the follow-up rate needs to be improved, these data suggest that the postoperative results of patients with primary gastric carcinoma have improved in those with advanced disease and in the aged population in Japan.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.