Kenjiro Okada

Background/Purpose: Prognostic significance of preoperative patient‐related factors, including oral health status, in pancreatic ductal adenocarcinoma (PDAC) remains unclear. We evaluated the association between preoperative factors—particularly oral health parameters—and long‐term survival after curative PDAC resection. Methods: Patients who underwent radical pancreatectomy for PDAC (2014–2022) were retrospectively analyzed. Preoperative factors, including oral health status (natural tooth count and posterior teeth occlusion), clinical characteristics, and immuno‐nutritional markers, were assessed for their association with overall survival (OS). Multivariate models adjusted for established pathological and treatment‐related prognostic variables were further analyzed. Results: Of 343 eligible patients, 339 underwent preoperative dental examinations; 135 had ≤ 20 teeth and 204 had ≥ 21 teeth. Patients with ≤ 20 teeth had significantly poorer OS (median survival: 39.1 vs. 60.7 months, p < 0.001). Posterior teeth occlusion was not associated with OS. In multivariate analysis of preoperative factors, natural tooth count was independently associated with OS ( p = 0.003). This association remained significant after adjustment for established prognostic variables ( p = 0.016), whereas other immuno‐nutritional markers did not emerge as independent prognostic factors. Conclusions: Post‐PDAC resection, natural tooth count, but not posterior teeth occlusion, is independently associated with OS. Tooth count may reflect long‐term host vulnerability and serve as a prognostic marker in PDAC patients.

Background: Recently, surgical resection has been attempted for postoperative recurrence of pancreatic ductal adenocarcinoma ( PDAC ). This multicenter study aimed to investigate whether resection of any recurrent lesion contributes to the survival of patients with PDAC. Methods: This retrospective study of the Hepato‐Pancreato‐Biliary Scientific Network for Clinical Oncology Research Working Cohort involved patients with resectable/borderline resectable PDAC who underwent surgery between 2013 and 2019 and who subsequently developed recurrence after resection of the primary PDAC . A time‐dependent Cox regression model adjusted for various patient background and clinicopathological factors was used. Results: The study cohort comprised 1527 patients; 96 underwent resection for recurrence, including hepatectomy in 12 patients, pneumonectomy in 40, and pancreatectomy in 42. Overall survival after the initial treatment of primary PDAC was significantly better in patients who underwent resection compared with those who did not (75.0 vs. 25.8 months). The time‐dependent Cox regression model indicated that pneumonectomy for lung metastasis ( HR = 0.12) and pancreatectomy for recurrence in the pancreatic remnant ( HR = 0.20) significantly affected overall survival, whereas hepatectomy for liver metastasis was not ( HR = 0.46). Conclusion: Resection for postoperative recurrence of PDAC may offer survival benefits for selected patients, especially for lung metastasis and residual pancreatic recurrence. Trial Registration: https://ClinicalTrials.gov identifier: UMIN000049664

Background: Antimicrobial prophylaxis is routinely administered in patients undergoing distal pancreatectomy, with cephalosporins being the most frequently used agents. However, there is limited evidence regarding optimal duration of antimicrobial prophylaxis. This study aimed to evaluate the optimal duration of antimicrobial prophylaxis in distal pancreatectomy.Methods: A multicenter cohort study was performed using a common database of patients who underwent distal pancreatectomy between April 2017 and March 2022 at four high‐volume centers in Japan. Eligible patients were divided into two groups according to the duration of antimicrobial prophylaxis: intraoperative or up to 24 h after surgery and more than 24 h after surgery. Primary endpoint was the incidence of surgical site infections.Results: A total of 496 patients were enrolled in this study, including 254 and 242 patients categorized into the intraoperative or up to 24‐h and more than 24‐h groups, respectively. Surgical site infections occurred in 129 patients (26%). The intraoperative or up to 24‐h group had a significantly lower incidence of surgical site infection (19% vs. 33%, p < 0.001) and infectious clinically relevant postoperative pancreatic fistula (8% vs. 17%, p = 0.002). There were no significant differences in severe surgical site infection rates between the groups. Multivariate logistic regression identified more than 24‐h administration of antimicrobial prophylaxis as an independent risk factor for surgical site infections (p = 0.001).Conclusion: Prolonged administration of antimicrobial prophylaxis may not be effective in preventing surgical site infections after distal pancreatectomy compared to intraoperative or up to 24‐h administration.

Aim: To evaluate the prognostic effect of initiation timing and completion of adjuvant therapy in patients with pancreatic ductal adenocarcinoma.Methods: The medical records of patients with pancreatic ductal adenocarcinoma who underwent radical pancreatectomy between 2006 and 2022 at Hiroshima University were retrospectively reviewed. Patient characteristics, perioperative outcomes, clinicopathological factors, and survival rates were analyzed. Adjuvant indications were for all patients who had a good postoperative status as early as possible. Early initiation was defined as adjuvant initiation within 4 weeks after surgery, and completion was defined as a total of 6 months of administration.Results: In total, 444 (294, resectable; 150, borderline resectable or locally advanced) patients who received adjuvant therapy were enrolled in this study. The median time to adjuvant therapy initiation was 20 days. In total, 328 patients with early initiation had better overall survival than those with delayed initiation, and 409 patients with adjuvant completion had better survival rates than those with incompletion. Multivariate overall survival analysis demonstrated that early adjuvant therapy initiation and completion were independent prognostic factors for prolonged survival. In total, 310 adjuvant completions with early initiation resulted in a median survival period of 81.8 months. Multivariate analysis identified severe postoperative complication as an independent risk factor preventing adjuvant completion with early initiation.Conclusion: Adjuvant completion with early initiation may contribute to the improved survival of patients with pancreatic ductal adenocarcinoma. Preventing severe postoperative complications may facilitate adjuvant completion with early initiation.

Background/Purpose: This study reports the long‐term results of a phase II trial evaluating the clinical efficacy of neoadjuvant gemcitabine, nab‐paclitaxel, and S1 (GAS) in borderline resectable pancreatic cancer with arterial contact (BRPC‐A).Methods: A multicenter, single‐arm, phase II trial was conducted. Patients received six cycles of GAS and patients without progressive disease were intended for R0 resection.Results: Of the 47 patients, 45 (96%) underwent pancreatectomy. At the time of this analysis, all patients were updated with no loss to follow‐up. A total of 30 patients died, while the remaining 17 patients were followed for a median of 68.1 months. The updated median overall survival (OS) was 41.0 months, with 2‐ and 5‐year OS rates of 68.0% and 44.6%, respectively. Multivariate analysis in the preoperative model showed that a tumor diameter reduction rate ≥10% and a CA19‐9 reduction rate ≥95% after neoadjuvant chemotherapy remained independently associated with favorable survival. In the postoperative multivariate model, no lymph node metastasis, no major surgical complications, and completion of adjuvant chemotherapy were independently associated with improved OS.Conclusions: This long‐term evaluation of the neoadjuvant GAS trial demonstrated the high efficacy of the regimen, suggesting that it is a promising treatment option for patients with BRPC‐A.

This study aimed to evaluate the optimal extent of lymphadenectomy in patients with nonfunctioning pancreatic neuroendocrine neoplasms. We retrospectively analyzed the clinicopathological data of patients with nonfunctioning pancreatic neuroendocrine neoplasms who underwent surgical resection. We investigated the frequency of metastases at each lymph node station according to tumor location and analyzed the factors contributing to poor overall survival (OS) and disease-free survival (DFS). Overall, data of 84 patients were analyzed. Among patients with pancreatic head tumors, metastases at stations 8, 13, and 17 were found in one (3.1%), four (12.5%), and three (9.3%) patients, respectively. However, none of the other stations showed metastases. For pancreatic body and tail tumors, metastases only at station 11 were found in two (5.1%) patients. Additionally, multivariate DFS and OS analyses showed that lymph node metastasis was the only independent prognostic factor. In conclusion, lymph node metastasis near the primary tumor was the only independent factor of poor prognosis in patients with nonfunctioning pancreatic neuroendocrine neoplasms after undergoing curative surgery. Peri-pancreatic lymphadenectomy might be recommended for nonfunctioning pancreatic neuroendocrine neoplasms.

This study aimed to evaluate the optimal extent of lymphadenectomy in patients with nonfunctioning pancreatic neuroendocrine neoplasms. We retrospectively analyzed the clinicopathological data of patients with nonfunctioning pancreatic neuroendocrine neoplasms who underwent surgical resection. We investigated the frequency of metastases at each lymph node station according to tumor location and analyzed the factors contributing to poor overall survival (OS) and disease-free survival (DFS). Overall, data of 84 patients were analyzed. For pancreatic head tumors, metastases at stations 8, 13, and 17 were found in one (3.1%), four (12.5%), and three (9.3%) patients, respectively. However, none of the other stations showed metastases. For pancreatic body and tail tumors, only metastases at station 11 were found in two (5.1%) patients. Additionally, multivariate DFS and OS analyses showed that lymph node metastasis was the only independent prognostic factor. Lymph node metastasis was found near the primary tumor and was the only independent factor of poor prognosis in patients with nonfunctioning pancreatic neuroendocrine neoplasms after undergoing curative surgery. Peri-pancreatic lymphadenectomy might be recommended for nonfunctioning pancreatic neuroendocrine neoplasms.

Background/Purpose: The aim of this study was to assess whether the duration of adjuvant gemcitabine plus S‐1 (GS) chemotherapy has any effect on survival in patients with pancreatic ductal adenocarcinoma (PDAC).Methods: Of the 290 patients who received adjuvant GS chemotherapy, 100 (34%) received the standard duration (20‐29 weeks) and 190 (66%) received an extended duration (≥30 weeks). To reduce selection bias, the prognostic impact (recurrence‐free survival [RFS] and overall survival [OS]) based on the duration of adjuvant GS chemotherapy was analyzed using inverse probability of treatment weighting (IPTW). Moreover, to reduce immortal time bias, time‐dependent multivariate analyses in which implementation of adjuvant GS chemotherapy was treated as time‐varying covariate was also performed.Results: Extended duration of adjuvant GS chemotherapy was significantly correlated with prolonged RFS (P < .001) and OS (P < .001) after IPTW adjustment. Time‐dependent multivariate analyses revealed that extended duration of adjuvant GS chemotherapy was an independent prognostic factor for prolonged RFS (hazard ratio [HR], 0.58, P = .002) and OS (HR, 0.56, P = .005).Conclusion: Extended duration (≥30 weeks) of adjuvant GS chemotherapy in patients with PDAC was associated with an improved prognosis. These findings warrant a further prospective trial on PDAC to investigate the survival benefit of extended adjuvant chemotherapy.