Neoadjuvant Chemoradiotherapy for Locally Advanced Pancreas Cancer Rarely Leads to Radiological Evidence of Tumour Regression

Background: Neo-adjuvant chemo-radiotherapy has been proposed to improve resectability of locally-advanced pancreatic cancer (LAPC). However, the ability of neo-adjuvant therapy to induce radiological tumour regression has not been reported.

Methods: Pre- and post-treatment computed tomography (CT) scans of patients undergoing neo-adjuvant chemo-radiotherapy for LAPC were reviewed. LAPC was sub-classified into borderline resectable disease [≤ 180° involvement of the superior mesenteric artery (SMA); short-segment encasement/abutment of the common hepatic artery; or tumour-associated deformity, abutment or short-segment occlusion of the superior mesenteric vein (SMV)/ portal vein (PV) that was amenable to vascular resection and reconstruction] and locally advanced un-resectable pancreatic cancer (vascular involvement more than that described for borderline resectable pancreatic cancer). The radiological response and surgical resection rates were assessed.

Results: Sixteen patients received neo-adjuvant therapy for LAPC during 2005-2008. Regression of major vascular involvement, i.e. un-encasement or regression of abutment of any involved vessels was not observed in any patient. Pre- and post-treatment tumour densities were not statistically different. Fifty per cent of patients with borderline resectable disease and none of the patients with locally advanced un-resectable pancreatic cancer eventually underwent surgical resection.

Conclusion: Neo-adjuvant treatment does not induce radiological tumour regression of LAPC with major vascular involvement. Patient selection for neo-adjuvant trial enrollment should remain focused on borderline disease which may have a potential for surgical resection.