Impact of preoperative radiotherapy on the risk of postpancreatectomy haemorrhage and major morbidity after resection of pancreatic adenocarcinoma including arterial divestment or arterial resection

BACKGROUND: Some centres advocate preoperative radiotherapy in patients with pancreatic cancer and arterial involvement despite a lack of Level 1 evidence on survival benefit. Although it has been suggested that preoperative radiotherapy may increase the risk of postpancreatectomy haemorrhage (PPH) and morbidity, evidence is again lacking. This study investigated the association between preoperative radiotherapy and both PPH and major morbidity following arterial divestment/resection during pancreatic adenocarcinoma resection after chemotherapy.

METHODS: Consecutive patients diagnosed with pancreatic adenocarcinoma and > 180° arterial involvement who were treated with preoperative chemotherapy with or without radiotherapy followed by pancreatic resection with arterial divestment/resection were included in the study. Logistic regression analyses including propensity score-based overlap weighting were performed to investigate associations between radiotherapy and in-hospital PPH grade B/C and major morbidity, expressed as adjusted risk differences (aRDs).

RESULTS: Overall, 246 patients undergoing pancreatic resection with arterial resection (169, 69%) or divestment (77, 31%) were included. Radiotherapy was not associated with PPH (aRD 6%; 95% confidence interval (c.i.) -3 to 14), regardless of arterial divestment (aRD 3%; 95% c.i. -5 to 11) or arterial resection (aRD 12%; 95% c.i. 1 to 23; Pinteraction = 0.189). Radiotherapy was associated with a 14% (95% c.i. 2 to 25) higher risk of major morbidity, especially after arterial resection (aRD 27%; 95% c.i. 11 to 43) compared with arterial divestment (aRD -12%; 95% c.i. -35 to 11; Pinteraction = 0.006) and after external beam radiotherapy (aRD 21%; 95% c.i. 8 to 32) compared with stereotactic body radiotherapy (aRD -12%; 95% c.i. -27 to 6; Pinteraction = 0.0001). Ninety-day mortality was increased, albeit not significantly, after preoperative radiotherapy (10 (8%) versus 3 (3%) deaths with versus without preoperative radiotherapy, respectively; P = 0.067).

CONCLUSIONS: Radiotherapy before resection of pancreatic cancer with > 180° arterial involvement was associated with an increased risk of postoperative major morbidity when arterial resection, but not arterial divestment, was performed. This risk should be taken into account when considering preoperative radiotherapy in patients who may require arterial resection.