Objective: Biological sex differences in cancer are increasingly acknowledged. Here, we examined these differences in clinicopathological characteristics and survival in microsatellite instability ... Show moreObjective: Biological sex differences in cancer are increasingly acknowledged. Here, we examined these differences in clinicopathological characteristics and survival in microsatellite instability (MSI)-high and microsatellite stable (MSS) gastric cancer (GC). Design: We analysed MSI status by polymerase chain reaction (PCR) and/or mismatch repair (MMR) status by immunohistochemistry in a pooled analysis of individual patient data from one retrospective cohort from Cologne, and the randomised phase III clinical trials D1/D2 and CRITICS. All patients had resectable adenocarcinoma of the stomach and/or gastro-oesophageal junction. Patients were treated with either surgery only or perioperative chemo(radio) therapy. Results: MSI and/or MMR analyses on 1307 tumours resulted in 1192 (91.2%) MSS and/or MMR proficient (MMRP) [median age, 65 years; 759 males (63.7%); 619 treated with surgery only (51.9%)], and 115 (8.8%) MSI-high [median age, 69 years; 67 males (58.3%); 76 treated with surgery only (66.1%)] GC cases. Males had shorter overall survival (OS) than female MSI-high GC (5-year OS 34.7% vs. 69.7%; hazard ratio (HR) 2.68, 95%CI 1.60 to 4.49; p < 0.001). Females with MSI-high had longer OS than those with MSS/MMRP GC ( HR 0.61, 95%CI 0.41 to 0.92; p = 0.02). Males with MSI-high did not have longer OS than those with MSS/MMRP GC (HR 1.26, 95%CI 0.94 to 1.69; p = 0.12). Conclusions: MSI-high GC males had a significantly worse prognosis compared to their female counterparts in three independent cohorts. In addition, the favourable prognostic value of MSI was only seen in females and not in males. These observations emphasise the need to consider sex differences in prognosis and treatment effects in oncology. Show less
The studies in this thesis describe the clinical impact of several matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in H. pylori-induced gastritis and gastric... Show moreThe studies in this thesis describe the clinical impact of several matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in H. pylori-induced gastritis and gastric cancer. In patients with H. pylori-induced gastritis, significantly increased mucosal MMP-9 levels were found. By successful H. pylori eradication, active and chronic inflammation decreased, accompanied by a significant decrease of mucosal MMP-9. MMP-2, MMP-7, MMP-8 and MMP-9, lipocalin-2, MMP-9/lipocalin-2 and TIMP-1 were significantly increased in tumour tissue of gastric cancer patients compared to normal gastric mucosa whereas only enhanced levels of MMP-2 and MMP-9/lipocalin-2 complexes were independently related to worse prognosis. Subsequently the genotype distribution of single-nucleotide polymorphisms (SNPs) of MMPs and TIMPs in gastric cancer was studied. The genotype distribution of MMP-7-181A>G was associated with H. pylori status and tumour-related survival of the patients. Single-nucleotide polymorphism TIMP-2-303C>T correlated significantly with tumour-related survival. First-order dendrogram cluster analysis combined with Cox analysis identified the MMP-7-181A>G and TIMP-2-303C>T polymorphism combination to have a major impact on patients survival outcome. Show less
