Pathologic complete response following neoadjuvant therapy for pancreatic ductal adenocarcinoma: defining the incidence, predictors, and outcomes.

BACKGROUND

Neoadjuvant therapy (NT) is increasingly utilized for patients with pancreatic ductal adenocarcinoma (PDAC) but the nationwide incidence and long-term prognosis of a pathologic complete response (pCR) remains poorly understood.

METHODS

Patients with localized PDAC and known cT and pT stage who received NT prior to pancreatectomy from 2004 to 2016 were identified using the National Cancer Database. The clinicopathologic characteristics and long-term outcomes of patients who did and did not experience a pCR were compared.

RESULTS

Among 7,902 patients who underwent NT prior to pancreatectomy, 244 (3.1%) experienced a pCR while 7,658 (96.9%) did not. On multivariable regression, longer duration of NT (OR 1.20, 95% CI 1.14-1.27 per month) and use of preoperative radiation (OR 9.98, 95% CI 3.05-32.71) were independently associated with a pCR. Median overall survival (OS) was longer among patients who experienced a pCR (77 vs 26 months, p < 0.001). On multivariate analysis, pCR was the strongest predictor of improved OS (HR 0.43, 95%CI 0.32-0.58, p < 0.001).

CONCLUSION

A pCR following NT for PDAC occurs infrequently but is associated with significantly improved OS. Better predictors of response and more effective preoperative regimens should be aggressively sought.