Perineural invasion as a prognostic factor for cervical cancer: a systematic review and meta-analysis.

BACKGROUND

Recent observational studies have reported that perineural invasion (PNI) may be a negative prognostic factor in cervical cancer.

OBJECTIVES

The purpose of this meta-analysis is to systematically analyse the effect of PNI on overall survival and disease-free survival.

SEARCH STRATEGY

The PubMed and Cochrane clinical trials databases were searched for articles with publication dates up to September 2013.

SELECTION CRITERIA

Retrospective observational studies with survival analysis for perineural invasion after radical hysterectomy plus lymphadenectomy of cervical cancer were selected.

DATA COLLECTION AND ANALYSIS

Trial characteristics and outcomes and quality measures based on the Newcastle-Ottawa scale (NOS) were independently extracted. The overall survival and disease-free survival of patients with PNI were measured using a hazard ratio (HR) for time to event outcomes.

MAIN RESULTS

The meta-analysis of these studies demonstrated that cervical cancer with PNI was associated with a lower overall survival rate (HR 2.21, 95 % CI 1.36-3.59, P = 0.001). Although the disease-free survival was lower in the PNI group (HR 1.35, 95 % CI 0.78-2.31, P = 0.28), the results were not statistically significant.

CONCLUSION

Patients with PNI-positive cervical cancer have a poor overall survival rate; therefore, we can conclude that perineural invasion (PNI) is an adverse prognostic factor in cervical cancer. Based on these results, PNI should be an independent prognostic factor for cervical cancer and the decision to proceed with adjuvant therapy after surgery.