The influence of neural invasion on survival and tumor recurrence in patients with pancreatic ductal adenocarcinoma: A systematic review and meta-analysis

Abstract

Salvage cryosurgery (SC) is a recognised option for patients who fail either primary radiation or cryosurgery.To report outcomes of patients undergoing SC.A consecutive series of 396 patients who had failed either primary radiotherapy or cryosurgery underwent SC between October 1994 and August 2011.Demographic and clinical parameters before primary and salvage treatment were evaluated; disease-free-survival (DFS), overall-survival (OS), disease-specific-survival (DSS), and complications were assessed.Sufficient follow-up data were available for 328 patients. Median age was 65.8 yr (range: 45–81 yr), median serum prostate-specific antigen (PSA) level was 8.0 ng/ml (range: 0.6–290.0 ng/ml). After primary treatment, median time to recurrence was 55 mo (range: 0.0–183.6 mo). SC was performed at a median of 67.5 mo (range: 7.0–212.7 mo) later; median pre-SC PSA level was 4.0 ng/ml (range: 0.1–112.4 ng/ml). Median PSA nadir was 0.2 ng/ml (range: 0.01–70.70 ng/ml), reached after a median of 2.6 mo (range: 2.0–67.3 mo) after SC. Median follow-up was 47.8 mo (range: 1.6–203.5 mo). Respective 5- and 10-yr DFS was 63% and 35%; OS: 74% and 45%; and DSS: 91% and 79%. In univariate analyses, time from primary treatment to SC or recurrence, PSA level before SC, and PSA nadir after SC were all significant predictors of recurrence (p ≤ 0.01). PSA before SC and time to recurrence were also predictive of DSS (p = 0.003 and p = 0.01, respectively). In multivariate analyses, only PSA nadir after SC was predictive of recurrence and DSS (p < 0.001 and p = 0.012, respectively). Complications were rare (range: 0.6–4.6%). Fifty-five patients (16.7%) underwent focal SC. Median PSA nadir after focal SC was 0.44 ng/ml (range: 0.04–20.1 ng/ml). Twenty-seven patients (49%) experienced recurrence. Respective 5- and 10-yr DFS was 47% and 42%; OS: 87% and 81%; and DSS: 100% and 83%.Our analysis confirms SC as an effective treatment option for patients failing primary therapy. Patients experienced excellent survival outcome and minimal associated morbidity after SC. Focal SC is an efficacious treatment for properly selected patients.