Prognostic and clinicopathological significance of MLKL expression in cancer patients: a meta-analysis

Background: MLKL is the most important executor of necroptosis pathway. Recent studies have demonstrated that MLKL could serve as a potential prognostic biomarker for cancer patients. However, most studies reported so far are limited in discrete outcome and sample size. Methods: We systematically searched PubMed, Embase, Web of Science and CNKI to obtain all relevant articles about the prognostic value of abnormally expressed MLKL in patients with any type of tumor. Odds ratios or hazards ratios (HRs) with corresponding 95% confidence intervals (CIs) were pooled to estimate the association between MLKL expression and clinicopathological characteristics or survival of cancer patients. Results: A total of 6 eligible studies with 613 cancer patients were enrolled in our meta-analysis. Our results demonstrated that decreased expression level of MLKL was significantly associated with poor overall survival (OS) (pooled HR 0.26, 95%CI 0.17-040, high/low) and event-free survival (EFS) (pooled HR 0.45, 95%CI 0.23-0.87, high/ low) in cancer patients. Furthermoie, subgroup analysis divided by type of cancer, sample size, follow-up time and Newcastle-Ottawa Scale (NOS) score showed consistent prognostic value. In addition, our analysis revealed that decreased expression level of MLKL was significantly associated with advanced tumor stage, more lymph node metastasis and older age. Conclusions: In conclusion, our meta-analysis suggested that decreased MLKL expression might be a convinced unfavorable prognostic factor that could help the clinical decision-making process.