Adjuvant radiotherapy and chemoradiation with gemcitabine after R1 resection in patients with pancreatic adenocarcinoma

Adjuvant chemotherapy versus chemoradiation in high-risk pancreatic adenocarcinoma: A propensity score-matched analysis

PURPOSE

The American Society of Clinical Oncology guidelines recommend adjuvant chemoradiation (ACR) for margin-positive (R1) and/or node-positive (N+) pancreatic cancers. Our goal was to investigate if there is evidence of superiority of adjuvant chemoradiation (ACR) over adjuvant chemotherapy (AC).

METHODS

We utilized data from the National Cancer Database (NCDB) for N+ and/or R1 pancreatic adenocarcinoma patients diagnosed from 2004 to 2012 who underwent ACR or AC. Patients who received neoadjuvant radiation, no adjuvant treatment, or adjuvant radiation alone were excluded. Propensity score nearest-neighbor 1:1 matching (PSM) was performed between ACR and AC groups based on age, sex, race, insurance, year of diagnosis, comorbidities, tumor site and size, T-stage, nodal status, margin status, grade, and treatment facility. Primary outcome was overall survival (OS).

RESULTS

A total of 8297 patients were eligible. After PSM, two well-balanced groups of 3244 patients each were analyzed. ACR resulted in superior OS compared with AC alone (Hazard ratio [HR] 0.83, 95% CI 0.79-0.87; median OS 22 vs 19 months, P < .0001). Subset analyses demonstrated OS benefit of ACR compared with AC in N+, R0 patients (HR: 0.82, 95% CI 0.77-0.88; Median OS 24 vs 20 months, P < .001) as well as N+, R1 patients (HR: 0.77, 95% CI 0.68-0.87; Median OS 17 vs 15 months, P < .001); but not in node-negative, R1 patients (HR: 1.12, 95% CI 0.84-1.48; Median OS 18 vs 22 months, P = .63).

CONCLUSION

The addition of radiation to AC was associated with a clinically small but meaningful increase in survival of patients undergoing curative-intent pancreatic resections. This association was not evident in patients with microscopically positive margins but node-negative disease and larger studies will be needed.

Postoperative serum CA19-9, CEA and CA125 predicts the response to adjuvant chemoradiotherapy following radical resection in pancreatic adenocarcinoma

OBJECTIVE

To evaluate the prediction of benefits from adjuvant chemoradiotherapy by postoperative serum CA19-9, CA125 and CEA.

METHODS

The relations between benefits from adjuvant chemoradiotherapy and levels of postoperative serum CA19-9, CA125 and CEA were investigated in 804 pancreatic adenocarcinoma patients who received radical resection.

RESULTS

Adjuvant chemoradiotherapy was an independent factor for late recurrence [12.2 vs. 8.5 months, P = 0.001 for recurrence free survival (RFS)] and long survival [23.7 vs. 17.0 months, P < 0.001 for overall survival (OS)] in resected pancreatic adenocarcinoma. Postoperative serum CA19-9, CA125 and CEA were independent risk predictors for poor surgical outcome in pancreatic adenocarcinoma (P < 0.001 for all). Adjuvant chemradiotherapy (hazard ratio: 0.359, 95% confidence interval: 0.253-0.510, P < 0.001 for OS; hazard ratio: 0.522, 95% confidence interval: 0.387-0.705, P < 0.001 for RFS) were confirmed to improve the surgical outcome in patients with abnormal levels of any one of the three postoperative markers, but not in patients with normal levels of the three postoperative markers. In the subgroup of patients with negative lymph node, its improvement of surgical outcome was also significant in patients with abnormal levels of any one of postoperative serum CA19-9, CA125 and CEA (hazard ratio: 0.412, 95% confidence interval: 0.244-0.698, P = 0.001 for OS; hazard ratio: 0.546, 95% confidence interval: 0.352-0.847, P = 0.007 for RFS).

CONCLUSION

Postoperative serum CA19-9, CA125 and CEA could serve as predictors of response for adjuvant chemoradiotherapy even if the status of lymph nodes is negative.

miR-216b Targets FGFR1 and Confers Sensitivity to Radiotherapy in Pancreatic Ductal Adenocarcinoma Patients Without EGFR or KRAS Mutation

OBJECTIVES

The success of gemcitabine plus radiotherapy is dependent on the mutation status of pancreatic ductal adenocarcinoma (PDAC) tumors in the EGFR and KRAS genes; however, radiotherapy resistance may also be modulated epigenetically by microRNA (miRNA) regulation. In this study, we examined the potential effect of miRNAs on the resistance to radiotherapy in cases without EGFR or KRAS mutation.

METHODS

The association of EGFR and KRAS mutation status and different expression patterns of 6 selected miRNAs related to the EGFR/KRAS signaling pathway were evaluated in the tumors of 42 patients with PDAC.

RESULTS

Reduced miR-216b and miR-217 expression was associated with aggressive tumor characteristics and shortened disease-free survival. In addition, miR-216b expression was reduced 2.7-fold in the cases that did not benefit from therapy, although they did not demonstrate EGFR or KRAS expression (P = 0.0316). A negative correlation between FGFR1 and miR-216b expression (r = -0.355) was found in the tumors of these cases.

CONCLUSIONS

Further studies and validations are required; in the tumors of patients with PDAC without activating mutations and induced expression of EGFR/KRAS genes, down-regulated miR-216b expression may be associated with a poor response to radiotherapy via deregulation of another signaling pathway related to FGFR1 signaling.