Can Neoadjuvant Therapy in Pancreatic Cancer Increase the Pool of Patients Eligible for Pancreaticoduodenectomy?
BACKGROUND We systematically reviewed and performed a meta-analysis of the available data regarding neoadjuvant chemo- and/or radiotherapy with special emphasis on tumor response/progression rates, toxicities, and clinical benefit, i.e. resection probabilities and survival estimates. METHODS AND FINDINGS Trials were identified by searching PUBMED, MEDLINE, and the Cochrane Central Register of Controlled Trials from 1966 to Feb 2015. A total of 18 studies (n = 959) were analyzed. the estimated fraction of patients with complete response was 2.8% (CI 0.8-4.7%) and with partial response 28.7% (CI 18.9%-38.5%). Stable disease was averaged to 45.9% (CI 32.9%-58.9%) in all patients and tumor progression under therapy occurred by estimation in 16.9% (CI 10.2%-23.6%) of the patients. The weighted frequency of those who underwent resection was 65.3% (CI 54.2%-76.5%), and the proportion of R0 resection amounted to 57.4% (CI 48.2%-66.5%). The weighted mean of median survival amounted to 17.9 months (range: 14.7-21.2 months) for the overall cohort of patients, 25.9 months (range: 21.1-30.7 months) for those who were resected, and 11.9 months (range: 10.4-13.5 months) for unresected patients. CONCLUSIONS The resection and R0 resection rates in the group of borderline resectable tumor patients after neoadjuvant therapy are similar to the resectable tumor patients, much higher than those in unresectable tumor patients. The survival estimates of borderline resectable tumor patients after neoadjuvant therapy were similar to resectable tumor patients. Patients with borderline resectable pancreatic cancer should be included in neoadjuvant protocols and subsequently be reevaluated for resection. How to find chemo-responsiveness before neoadjuvant chemotherapy so as to give individualized treatment is still an important issue.