Pancreatic ductal adenocarcinoma (PDAC) is highly malignant. While cancers in other organs have shown clear improvements in 5‐year survival, the 5‐year survival rate of pancreatic cancer is approximately 10%. Early relapse and metastasis are not uncommon, making it difficult to achieve an acceptable prognosis even after complete surgical resection of the pancreas. Studies have been performed on various treatments to improve the prognosis of PDAC, and multidisciplinary approaches including non‐surgical treatments have led to gradual improvement. In the present literature review, we have described the significance of anatomical and biological resectability criteria, the concept of R0 resection in surgical treatment, the feasibility of minimally invasive surgery, the remarkable development of perioperative chemotherapy, the effectiveness of conversion surgery for unresectable PDAC, and ongoing challenges in PDAC treatment. We also provide an essential update on these subjects by focusing on recent trends and topics.

Background: Resectable pancreatic ductal adenocarcinoma (R-PDAC) often recurs early after radical resection, which is associated with poor prognosis. Predicting early recurrence preoperatively is useful for determining the optimal treatment. Patients and methods: One hundred and seventy-eight patients diagnosed with R-PDAC on computed tomography (CT) imaging and undergoing radical resection at Hirosaki University Hospital from 2005 to 2019 were retrospectively analyzed. Patients with recurrence within 6 months after resection formed the early recurrence (ER) group, while other patients constituted the non-early recurrence (non-ER) group. Early recurrence prediction score (ERP score) was developed using preoperative parameters. Results: ER was observed in 45 patients (25.3%). The ER group had significantly higher preoperative CA19-9 (p = 0.03), serum SPan-1 (p = 0.006), and CT tumor diameter (p = 0.01) compared with the non-ER group. The receiver operating characteristic (ROC) curve analysis identified cutoff values for CA19-9 (133 U/mL), SPan-1 (78.2 U/mL), and preoperative tumor diameter (23 mm). When the parameter exceeded the cutoff level, 1 point was given, and the total score of the three factors was defined as the ERP score. The group with an ERP score of 3 had postoperative recurrence-free survival (RFS) of 5.5 months (95% CI 3.02–7.98). Multivariate analysis for ER-related perioperative and surgical factors identified ERP score of 3 [odds ratio (OR) 4.63 (95% CI 1.82–11.78), p = 0.0013] and R1 resection [OR 3.20 (95% CI 1.01–10.17), p = 0.049] as independent predictors of ER. Conclusions: For R-PDAC, ER could be predicted by the scoring system using preoperative serum CA19-9 and SPan-1 levels and CT tumor diameter, which may have great significance in identifying patients with poor prognoses and avoiding unnecessary surgery.

Pancreatic ductal adenocarcinoma (PDAC), with its extremely poor prognosis, presents a substantial health problem worldwide. Outcomes have improved thanks to progress in surgical technique, chemotherapy, pre‐/postoperative management, and centralization of patient care to high‐volume centers. However, our goals are yet to be met. Recently, exome sequencing using PDAC surgical specimens has demonstrated that the most frequently altered genes were the axon guidance genes, indicating involvement of the nervous system in PDAC carcinogenesis. Moreover, perineural invasion has been widely identified as one poor prognostic factor. The combination of innovative technologies and extensive clinician experience with the nervous system come together here to create a new treatment option. However, evidence has emerged that suggests that the relationship between cancer and nerves in PDAC, the underlying mechanism, is not fully understood. In an attempt to tackle this lethal cancer, this review summarizes the anatomy and physiology of the pancreas and discusses the role of the nervous system in the pathophysiology of PDAC.

Background: The differential diagnosis between gallbladder cancer (GBC) and xanthogranulomatous cholecystitis (XGC) remains quite challenging, and can possibly lead to improper surgery. This study aimed to distinguish between XGC and GBC by combining computed tomography (CT) images and deep learning (DL) to maximize the therapeutic success of surgery.Methods: We collected a dataset, including preoperative CT images, from 28 cases of GBC and 21 XGC patients undergoing surgery at our facility. It was subdivided into training and validation (n = 40), and test (n = 9) datasets. We built a CT patch‐based discriminating model using a residual convolutional neural network and employed 5‐fold cross‐validation. The discriminating performance of the model was analyzed in the test dataset.Results: Of the 40 patients in the training dataset, GBC and XGC were observed in 21 (52.5%), and 19 (47.5%) patients, respectively. A total of 61 126 patches were extracted from the 40 patients. In the validation dataset, the average sensitivity, specificity, and accuracy were 98.8%, 98.0%, and 98.5%, respectively. Furthermore, the area under the receiver operating characteristic curve (AUC) was 0.9985. In the test dataset, which included 11 738 patches, the discriminating accuracy for GBC patients after neoadjuvant chemotherapy (NAC) (n = 3) was insufficient (61.8%). However, the discriminating model demonstrated high accuracy (98.2%) and AUC (0.9893) for cases other than those receiving NAC.Conclusion: Our CT‐based DL model exhibited high discriminating performance in patients with GBC and XGC. Our study proposes a novel concept for selecting the appropriate procedure and avoiding unnecessary invasive measures.

Calcifying nested stromal epithelial tumor (CNSET) is a primary neoplasm of the liver, characterized by well-demarcated nests consisting of spindle and epithelioid cells with calcification and bone formation. An association of Cushing syndrome with CNSET has drawn attention, but the origin of CNSET has not been clarified. We report here the case of a 20-year-old male with Klinefelter syndrome who underwent liver resection for an increasing liver tumor that was pathologically diagnosed with CNSET. He was postoperatively followed up and received several examinations, and recurrences and extrahepatic lymph node metastases were detected on the 64th day after surgery. Chemoembolization and chemotherapy were not effective, leading to tumor progression with development of progressive liver failure, and the patient finally died 164 days after hepatectomy. This case suggests that an imbalance of hormones affects the genesis and progression of CNSET, and indicates the importance of closely following patients with CNSET by imaging with attention to hepatic recurrence and extrahepatic metastases.