Long noncoding RNA HOTTIP as a novel predictor of lymph node metastasis and survival in human cancer: a systematic review and meta-analysis

HOXA transcript at the distal tip (HOTTIP), a functional lncRNA transcribed from the 5' tip of the HOXA locus, has been functionally characterized as an oncogene in various cancers. To further explore the clinical value of HOTTIP in cancer, we collected all relevant studies and investigated the association between HOTTIP level and lymph node metastasis (LNM) or overall survival (OS). Literature collection was conducted by searching electronic databases PubMed, Cochrane Library, OVID, Web of Science and Chinese National Knowledge Infrastructure (CNKI)(up to July 7, 2016). Seven studies with 652 cancer patients were included in the meta-analysis according to the inclusion and exclusion criteria. The results showed a significant positive association between HOTTIP levels and LNM (Odds ratio, OR = 2.30, 95 % CI: 1.58-3.35, p < 0.0001) in a fixed-effects model (I2 = 0 %, p = 0.949) and it could also predict poor OS in cancer patients (Hazard ratio HR = 2.24, 95% CI: 1.74-2.90, p < 0.00001) in a fixed-effects model (I2 = 0%, p = 0.925). In conclusion, this meta-analysis demonstrated that the higher expression level of HOTTIP is correlated with positive LNM and poor OS in different types of cancer and HOTTIP might serve as a novel predictor of LNM and survival in human cancer.