Expression of autophagy-related factor p62 for lung cancer diagnosis and prognosis: A systematic review and meta-analysis

p62/SQSTM1 is the scaffold protein implicated in selective autophagy, which is induced by cellular stress. Research has shown that p62 is highly expressed in cancer. Moreover, p62 can easily promote tumor metastasis. However, studies have not reached a consensus on the relationship of p62 expression with the diagnosis and prognosis of lung cancer. We conducted a systematic review and meta-analysis of studies on p62 expression in the prognosis and clinical-pathological parameters of lung cancer patients. Literature search was performed with PubMed, Web of Science, EMBASE, Cochrane Library, and SpringerLink databases. Fixed-effects and random-effects models were used to study the relationship of p62 expression with patients' overall survival (OS) and clinical-pathological parameters. I2 was used to test for heterogeneity. Egger's test was used to assess publication bias. The meta-analysis collected and considered 13 articles, which included 1393 lung cancer patients. The studies show that the high expression of p62 is associated with poor OS in lung cancer patients. The clinical-pathological parameters of patients show that p62 is more highly expressed in high TNM stage (II + III + IV VS. I), Lymph node metastasis (N1 VS. N0), and distant metastases (D1 VS. D0). However, there is no correlation between the p62 expression and the Beclin 1 and LC3B in lung cancer patients. In conclusion, the over-expression of p62 is associated with poor OS in lung cancer patients and can be used as a biomarker for lung cancer diagnosis and prognosis.