Pathological Complete Response in Patients With Resected Pancreatic Adenocarcinoma After Preoperative Chemotherapy.

Importance: Preoperative chemo(radio)therapy is increasingly used in patients with localized pancreatic adenocarcinoma, leading to pathological complete response (pCR) in a small subset of patients. However, multicenter studies with in-depth data about pCR are lacking. Objective: To investigate the incidence, outcome, and risk factors of pCR after preoperative chemo(radio)therapy. Design, Setting, and Participants: This observational, international, multicenter cohort study assessed all consecutive patients with pathology-proven localized pancreatic adenocarcinoma who underwent resection after 2 or more cycles of chemotherapy (with or without radiotherapy) in 19 centers from 8 countries (January 1, 2010, to December 31, 2018). Data collection was performed from February 1, 2020, to April 30, 2022, and analyses from January 1, 2022, to December 31, 2023. Median follow-up was 19 months. Exposures: Preoperative chemotherapy (with or without radiotherapy) followed by resection. Main Outcomes and Measures: The incidence of pCR (defined as absence of vital tumor cells in the sampled pancreas specimen after resection), its association with OS from surgery, and factors associated with pCR. Factors associated with overall survival (OS) and pCR were investigated with Cox proportional hazards and logistic regression models, respectively. Results: Overall, 1758 patients (mean [SD] age, 64 [9] years; 879 [50.0%] male) were studied. The rate of pCR was 4.8% (n = 85), and pCR was associated with OS (hazard ratio, 0.46; 95% CI, 0.26-0.83). The 1-, 3-, and 5-year OS rates were 95%, 82%, and 63% in patients with pCR vs 80%, 46%, and 30% in patients without pCR, respectively (P < .001). Factors associated with pCR included preoperative multiagent chemotherapy other than (m)FOLFIRINOX ([modified] leucovorin calcium [folinic acid], fluorouracil, irinotecan hydrochloride, and oxaliplatin) (odds ratio [OR], 0.48; 95% CI, 0.26-0.87), preoperative conventional radiotherapy (OR, 2.03; 95% CI, 1.00-4.10), preoperative stereotactic body radiotherapy (OR, 8.91; 95% CI, 4.17-19.05), radiologic response (OR, 13.00; 95% CI, 7.02-24.08), and normal(ized) serum carbohydrate antigen 19-9 after preoperative therapy (OR, 3.76; 95% CI, 1.79-7.89). Conclusions and Relevance: This international, retrospective cohort study found that pCR occurred in 4.8% of patients with resected localized pancreatic adenocarcinoma after preoperative chemo(radio)therapy. Although pCR does not reflect cure, it is associated with improved OS, with a doubled 5-year OS of 63% compared with 30% in patients without pCR. Factors associated with pCR related to preoperative chemo(radio)therapy regimens and anatomical and biological disease response features may have implications for treatment strategies that require validation in prospective studies because they may not universally apply to all patients with pancreatic adenocarcinoma.

Resection rates and intention-to-treat outcomes in borderline and locally advanced pancreatic cancer: real-world data from a population-based, prospective cohort study (NORPACT-2).

BACKGROUND: Systemic chemotherapy is the initial treatment strategy for borderline resectable and locally advanced pancreatic cancer to facilitate curative resection. The aim of this study was to investigate the resection rates and overall survival in patients with borderline resectable pancreatic cancer and locally advanced pancreatic cancer. METHODS: Consecutive patients with borderline resectable pancreatic cancer/locally advanced pancreatic cancer discussed by Oslo University Hospital multidisciplinary team between 2018 and 2020, serving a population of 3.1 million within a geographically defined area in south-eastern Norway, were included in this prospective Norwegian Pancreatic Cancer Trial-2 study, according to intention-to-treat principles. The total number of patients with pancreatic cancer was sought from the Cancer Registry of Norway. RESULTS: A total of 1178 patients were diagnosed with pancreatic cancer, of whom 618 were referred to Oslo University Hospital. After multidisciplinary team evaluation, 230 patients were considered to have borderline resectable pancreatic cancer/locally advanced pancreatic cancer. The final study group consisted of 188 patients (borderline resectable pancreatic cancer n = 96, locally advanced pancreatic cancer n = 92) who were fit to receive primary chemotherapy. Resection rates were 46.9% (45 of 96) for borderline resectable pancreatic cancer and 13% (12 of 92) for locally advanced pancreatic cancer (P <0.001). Median overall survival was 14.6 months (borderline resectable pancreatic cancer 16.4 months; locally advanced pancreatic cancer 13.7 months, (P = 0.2)). Adjusted for immortal time bias, median overall survival for patients undergoing resection versus only chemotherapy was 24.4 months versus 10.1 months (P <0.001) for borderline resectable pancreatic cancer and 28.4 months versus 12.6 months for locally advanced pancreatic cancer (P = 0.001). CONCLUSION: Resection rates and survival in patients with borderline resectable pancreatic cancer and locally advanced pancreatic cancer treated at a high-volume centre in a universal healthcare system compare well with those treated at international expert centres.Registration number: NCT04423731 (http://www.clinicaltrials.gov).