K. B. Golisch1, E. Price1, T. S. Riall1, A. K. Arrington1 1University Of Arizona,Surgery,Tucson, AZ, USA
Introduction: Pancreatic cancer continues to be a leading cause of cancer mortality. Even local or resectable tumors have poor survival outcomes and treatment options are suboptimal. The current NCCN standard of care for pancreatic cancer is surgery first in resectable disease. Clinical trials are ongoing investigating the benefits and role of neoadjuvant chemotherapy and prior literature has shown favorable outcomes. Neoadjuvant chemoradiation (NACXRT) is becoming standard consideration in the setting of borderline resectable cancers, to improve R0 resection rates. We hypothesize NACXRT may effect lymph node (LN) positive status and down-staging of the patient at the time of surgery.
Methods: This is a NCDB retrospective study of resected pancreatic adenocarcinoma from 2008-2015. Three treatment groups were investigated: surgery first (n= 21,723), neoadjuvant chemotherapy (NAC) (n= 1905), and NACXRT (n= 1806). Charlson-Deyo index, location of tumor, pathologic stage, clinical stage, positive LNs, total LNs were compared between treatment groups.
Results: A total number of patients 25,434 were included in the study. Positive lymph node status is significantly lower in NACXRT compared to surgery first (χ2= 838, p<.0001) and compared to NAC (χ2 = 216, p<.0001). Positive LN status is also significantly lower in NAC compared to surgery alone (χ2 = 66, p<.0001). Figure 1 demonstrates the difference in percentage of positive LN among groups. Of cases with both pathologic and clinic stage available, a significant higher percentage of cases were downstaged with NACXRT (38.2%) compared to the other groups (14.6% NAC and 2.5% surgery respectively) while fewer cases were upstaged (34.7% NACXRT, 46.2% NAC, 54.5% surgery). The number of LN examined was similar for each treatment group. Mean(SD): surgery first= 16.9(9.6), NAC= 20.0(10.5), NACXRT= 16.2(9.3).
Conclusion: Overall, patients who received neoadjuvant therapy had lower positive LN status at time of surgical resection and a higher rate of downstaging. This effect was most significant in the NACXRT group. Currently, NACXRT is primarily used to improve R0 resection rates in borderline resectable pancreatic cancers. However, these results suggest that resectable pancreatic cancer patients should be considered for NACXRT prior to surgery. Though many clinical trials are looking at NAC in resectable pancreatic cancer, more evaluation of NACXRT in pancreatic cancer is certainly warranted.
