Aims The prognostic significance of perineural invasion (PNI) for gastric cancer (GC) patients was under debate. This study aimed to review relevant studies and evaluate the impact of PNI on the survival outcome of GC patients.
Methods Systematic literature search was performed using PubMed and Embase databases. The relevant data were extracted, and the association between PNI and clinicopathological characteristics or survival outcome in GC patients were evaluated using a fixed-effect model or random-effect model.
Results A total 13 studies involving 7004 GC patients were included in this meta-analysis. The positive rate of PNI was 35.9% (2512/7004) in GC patients, ranging from 6.9% to 75.6%. There were significant relationships between PNI and a series of unfavourable clinicopathological factors including undifferentiated histology type (OR: 1.78, 95% CI 1.37 to 2.33, p<0.001; I2=75.3%), diffuse type (OR: 1.96, 95% CI 1.07 to 3.60, p=0.029; I2=79.5%), lymphatic invasion (OR: 7.00, 95% CI 3.76 to 13.03, p<0.001; I2=83.6%), vascular invasion (OR: 5.79, 95% CI 1.59 to 21.13, p=0.008; I2=95.8%), deeper tumour invasion (OR: 4.79, 95% CI 3.65 to 6.28, p<0.001; I2=65.0%) and lymph node metastasis (OR: 3.60, 95% CI 2.37 to 5.47, p<0.001; I2=89.6%). In addition, PNI was significantly associated with worse survival outcome in GC patients (HR: 1.69, 95% CI 1.38 to 2.06, p<0.001; I2=71.0%).
Conclusion PNI was frequently detected in surgically resected specimens of GC patients, and it was a predictive factor for survival outcomes in these patients.
- gastric cancer
- perineural invasion
- prognostic factor
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Handling editor Runjan Chetty.
Contributors BZ contributed to study design, data analysis, data interpretation and drafted this manuscript; WL and DM contributed to data analysis, data interpretation and performed statistical analysis; RL contributed to the preparation of this manuscript; SB contributed to the acquisition of data and clinicopathologic information; BH and JL critically reviewed this manuscript and provided important guidance.
Funding This work was supported by the Natural Science Foundation of Liaoning Province (No. 20180530026).
Competing interests None declared.
Patient consent for publication Not required.
Provenance and peer review Not commissioned; internally peer reviewed.
Data availability statement Data are available upon reasonable request.
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