Pathological complete response (pCR) with or without the residual intraductal carcinoma component following preoperative treatment for pancreatic cancer: Revisiting the definition of "pCR" from the prognostic standpoint.

Residual CIS in the absence of an invasive component after preoperative treatment does not yield a prognostic impact after receiving perioperative treatment for PDAC. It might be reasonable to define pathological complete response (pCR) from the prognostic standpoint as follows: pCR is the complete absence of an invasive carcinoma component regardless of residual CIS.