In 2023, the Japan Pancreas Society (JPS) published the new eighth edition of the Japanese classification of pancreatic carcinoma. We present here an excerpted version in English, based on the latest edition. The major changes in this revision are as follows: In the eighth edition of the Union for International Cancer Control (UICC), the T category was changed to be based on tumor size; however, the eighth edition of the Japanese classification retains the previous T category based on local invasion factors. Lymph nodes have been renamed, and regional lymph nodes have been defined by location. Peritoneal cytology, which was not previously included in distant metastasis (M), has now been included in the M category. Moreover, significant additions have been made regarding the pathological diagnosis of endoscopic ultrasound‐guided fine‐needle aspiration biopsy (EUS‐FNAB) and criteria for histological assessment of the effects after chemotherapy and radiation therapy. Although this classification is aimed at carcinoma originating in the pancreas, not in the bile duct or duodenum, if the differentiation of the primary organ is difficult, this classification should be applied. It is also desirable to describe tumors other than carcinoma and metastatic tumors to the pancreas in accordance with this classification.

Detection of pancreatic cancer (PC) at a resectable stage is still difficult because of the lack of accurate detection tests. The development of accurate biomarkers in low or non-invasive biofluids is essential to enable frequent tests, which would help increase the opportunity of PC detection in early stages. Polyamines have been reported as possible biomarkers in urine and saliva samples in various cancers. Here, we analyzed salivary metabolites, including polyamines, using capillary electrophoresis-mass spectrometry. Salivary samples were collected from patients with PC (n = 39), those with chronic pancreatitis (CP, n = 14), and controls (C, n = 26). Polyamines, such as spermine, N₁-acetylspermidine, and N₁-acetylspermine, showed a significant difference between patients with PC and those with C, and the combination of four metabolites including N₁-acetylspermidine showed high accuracy in discriminating PC from the other two groups. These data show the potential of saliva as a source for tests screening for PC.

Pancreatic cancer frequently is associated with venous invasion and hematogenous metastasis. To determine morphologic features of invaded veins, intratumoral vascular composition, the correlation with liver metastasis, and expression of vascular endothelial growth factor (VEGF), matrix metalloproteinase (MMP)-2 and MMP-9, and the mechanism of development of hematogenous metastasis. We examined 32 patients with resected pancreatic cancer: 18 had postoperative liver metastasis, and 14 had no liver metastasis. Specimens were examined to determine the composition of veins and microvessels by staining of victoria-blue and CD34. We also investigated expression of VEGF, MMP-2, and MMP-9 by immunohistochemical staining. Venous invasion was detected in 31 of 32 patients. Invaded venous densities of middle- and large-sized veins were significantly higher in patients with liver metastasis than in those with nonliver metastasis, and they were related to MMP-2 and MMP-9 overexpression. Invaded veins with fragmentation of the lumen through cancer cells were considered to be an intravasation of cancer (destroyed type vein), and their numbers were significantly related to liver metastasis, and MMP-2 and MMP-9 overexpression. In conclusion, almost all the patients with pancreatic cancer showed venous invasion, indicating that invasion into large veins and destroyed type veins could be a risk factor for liver metastasis and that increased expression MMP-2 and MMP-9 were related to such invasion.