Chemoradiation Did Not Affect Surgical Margins for Pancreatoduodenectomy

Use of hypofractionated chemoradiation prior to undergoing pancreatoduodenectomy for pancreatic ductal adenocarcinoma resulted in similar margin-negative resection rates and outcomes vs the use of standard fractionated chemoradiation, according to the results of a study published in Cancer. Both regimens resulted in better locoregional control than neoadjuvant chemotherapy.

According to the study led by Jordan M. Cloyd, MD, of the University of Texas MD Anderson Cancer Center, and colleagues, prior research had suggested that the use of preoperative chemoradiation could be associated with improved margin-negative resection rates for pancreatoduodenectomy. However, an optimal chemoradiation regimen was not established. Therefore, in this study, Cloyd and colleagues reviewed data from 472 patients at a single institution who underwent chemotherapy or chemoradiation prior to pancreatoduodenectomy between 1999 and 2014.

The patients in the retrospective study had undergone either preoperative chemotherapy alone (5.7%), or preoperative chemoradiation with a standard course of 50.4 Gy in 28 fractions (46.8%) or a hypofractionated course of 30 Gy in 10 fractions (47.5%).

The researchers observed that those patients who had the standard regimen of chemoradiation were more likely to have advanced-stage disease and to have received induction and postoperative chemotherapy. Despite this, no significant differences in R1 margin status, treatment effect, locoregional recurrence, or overall survival were found between the two chemoradiation groups.

“The differences observed in disease stage between the 30- and 50.4-Gy groups likely reflect, at least in part, a provider selection bias for treating more advanced tumors with higher doses of radiation,” the researchers wrote. “Therefore, although the data herein could be interpreted as indicating that the 2 radiation regimens were equally effective, an alternative interpretation might be that the higher dose of radiation is necessary to achieve equivalent clinical results in advanced-disease settings.”

In addition, the study showed that those patients who underwent chemoradiation as compared with chemotherapy alone had lower rates of locoregional recurrence (P < .01). In fact, a multivariate analysis showed that patients who did not undergo preoperative chemoradiation had rates of locoregional recurrence that were more than twice as high as those for patients who did receive radiation (odds ratio, 2.21 [95% CI, 1.04–4.70]).