Postoperative Carbohydrate Antigen 19-9 Level as a Good Indicator of Ineffective Response to the Currently Recommended S-1 Adjuvant Chemotherapy for Pancreatic Ductal Adenocarcinoma: A Single-Center, Retrospective Study.

PURPOSE: The intensity of adjuvant treatment for pancreatic ductal adenocarcinomas (PDACs) has not been stratified according to the risk after resection. This study was designed to identify patients with PDACs in whom the current S-1 adjuvant treatment is ineffective. METHODS: This single-center, retrospective study included patients who underwent pancreatectomy for PDACs from 2009 to 2020 at Sendai Open Hospital and were receiving S-1 adjuvant treatment. The independent risk factors for recurrence and survival were determined by using a Cox proportional hazards regression model. The effects of S-1 adjuvant treatment and detailed patterns of recurrence were evaluated in patients with high-risk factors. RESULTS: Overall, 118 patients with PDAC received S-1 adjuvant treatment. Postoperative nonnormalized carbohydrate antigen (CA19-9) was a predictive risk factor for recurrence (p < 0.010; hazard ratio [HR], 3.87; 95% confidence interval [CI], 2.26-6.62) and survival (p = 0.008; HR, 2.25; 95% CI, 1.24-4.11) after S-1 adjuvant treatment. In 24 patients with nonnormalized postoperative CA19-9, S-1 monotherapy was ineffective in preventing recurrence, even during the treatment period, compared with that noted in patients who did not receive adjuvant treatment. The recurrence rate during adjuvant treatment was 41.7%; in all cases, recurrence was caused by distant metastasis. The total recurrence rate was up to 95.8%, and distant recurrence was especially frequent. CONCLUSIONS: The current S-1 adjuvant treatment regimen is ineffective for patients with postoperative nonnormalized CA19-9. The postoperative CA19-9 level may be a good indicator for further aggressive treatment. This study may lead to further discussions on intensity stratification of adjuvant treatments for PDAC.

Quantitative digital image analysis of somatostatin receptor 2 immunohistochemistry in pancreatic neuroendocrine tumors.

Immunohistochemical analysis of somatostatin receptor 2 (SSTR2) provides important information regarding the potential therapeutic efficacy of somatostatin analogues (SSAs) in patients with neuroendocrine tumors. HER2 scoring has been proposed to interpret SSTR2 immunoreactivity but their reproducibility was relatively low because of its intrinsic subjective nature. Digital image analysis (DIA) has recently been proposed as an objective and more precise method of evaluating immunoreactivity. Therefore, in this study, we used DIA for analyzing SSTR2 immunoreactivity in pancreatic neuroendocrine tumors (PanNETs) to obtain its H score and "(%) strong positive cells" and compared the results with those of manually obtained HER2 scores. Membranous SSTR2 immunoreactivity evaluated by DIA was calculated by two scales as: "Membrane Optical Density" and "Minimum Membrane Completeness". PanNETs with HER2 score of > 2 demonstrated the highest concordance with results of "(%) strong positive cells" obtained by DIA when "Minimum Membrane Completeness" was tentatively set at 80%. The SSTR2 immunoreactivity, evaluated based on all scoring systems, was different between grades G1 and G2 in insulinoma but not in non-functional PanNETs. DIA provided reproducible results of SSTR2 immunoreactivity in PanNETs and yielded important information as to the potential application of SSAs.

Lymph nodes around the posterior gastric artery: their existence, frequency, and clinical implications.

PURPOSE: The lymphatic flow along the posterior gastric artery (PGA) is considered of possible clinical importance in terms of lymphatic metastasis; however, little is known about the lymph nodes (LNs) around this artery. The purpose of this study was to establish if LNs exist around the PGA and to evaluate their clinical implications. METHODS: We examined the tissues surrounding the PGA from 21 cadavers to search for LNs. We also investigated the patterns of lymphatic metastases in patients who underwent surgery for gastric neoplasms at our institute to detect their presence along the PGA. RESULTS: The PGA was identified in 11 cadavers, and LNs around the PGA were detected microscopically in 2 of these. Lymphatic metastasis directly to the LNs at the splenic artery without any metastases was regarded as skip metastasis along the PGA. Skip metastasis was found in two of ten patients who underwent surgery for remnant gastric cancer. CONCLUSIONS: The existence of LNs around the PGA was confirmed, and based on our findings, lymphatic metastasis through the PGA is possible in patients with remnant gastric cancer.

Progesteron receptor expression in insulin producing cells of neuroendocrine neoplasms.

Progesterone receptor (PgR) inhibits cell proliferation in pancreatic neuroendocrine neoplasms (PanNEN). In non-neoplastic pancreas, loss of PgR induces ß-cell proliferation and insulin production. However, detailed association between PgR and insulin producing PanNENs is poorly understood. Insulin, proinsulin, and PgR were immunolocalized in 82 PanNENs (54 non-functioning PanNENs: NF-PanNENs and 28 insulinomas). The status of immunoreactivity was compared to the clinicopathological factors of the patients. Immunoreactivity was also confirmed by employing the double-immunohistochemistry. These results were also compared with those in non-neoplastic Langerhans islets. PgR immunoreactivity was significantly higher in insulinomas than that in NF-PanNENs (p < 0.001). Insulin and proinsulin immunoreactivity was also detected in 20 (37 %) of (single cell) insulin positive NFs (Inspos-NF-PanNEN), in which PgR expression was higher than in insulin negative NF-PanNENs (Insneg-NF-PanNEN, p = 0.03). The ratio of PgR-insulin double positive cells to overall insulin positive cells, as well as PgR-proinsulin double positive cells to proinsulin positive cells, was detected to the same degree in insulinoma (PgR-insulin 70 %, PgR-proinsulin 66 %), Inspos-NF-PanNENs (PgR-insulin 65 %, PgR-proinsulin 68 %) and normal islet (PgR-insulin 80 %, PgR-proinsulin 72 %). PgR and insulin expressing cells colocalize in tumor cells of the PanNENs regardless of the hormone-related symptoms of the patients. Inhibitory effect of PgR on tumor cells might be associated with the favourable clinical outcome of insulinoma patients.

Stromal expression of hemopexin is associated with lymph-node metastasis in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma is one of the most aggressive types of cancer. Certain proteins in the tumor microenvironment have attracted considerable attention owing to their association with tumor invasion and metastasis. Here, we used proteomics to identify proteins associated with lymph-node metastasis, which is one of the prognostic factors. We selected lymph node metastasis-positive and -negative patients (n = 5 each) who underwent pancreatectomy between 2005 and 2015 and subjected to comprehensive proteomic profiling of tumor stroma. A total of 490 proteins were detected by mass spectrometry. Software analysis revealed that nine of these proteins were differentially expressed between the two patient groups. We focused on hemopexin and ferritin light chain based on immunohistochemistry results. We assessed the clinicopathological data of 163 patients and found that hemopexin expression was associated with UICC N2 (p = 0.0399), lymph node ratio (p = 0.0252), venous invasion (p = 0.0096), and lymphatic invasion (p = 0.0232). Notably, in vitro assays showed that hemopexin promotes invasion of the pancreatic cancer cells. Our findings suggest that hemopexin is a lymph node metastasis-associated protein that could potentially serve as a useful therapeutic target or biomarker of pancreatic ductal adenocarcinoma.

Progesterone arrested cell cycle progression through progesterone receptor isoform A in pancreatic neuroendocrine neoplasm.

In pancreatic neuroendocrine neoplasms (Pan-NEN) progesterone signaling has been shown to have both inhibitory and stimulatory effects on cell proliferation. The ability of progesterone to inhibit tumor proliferation is of particular interest and is suggested to be mediated through the less abundantly expressed progesterone receptor (PR) isoform A (PRA). To date the mechanistic processes underlying this inhibition of proliferation remain unclear. To examine the mechanism of PRA actions, the human Pan-NEN cell line QGP-1, that endogenously expresses PR isoform B (PRB) without PRA, was transfected with PRA. PRA transfection suppressed the majority of cell cycle related genes increased by progesterone including cyclin A2 (CCNA2), cyclin B1 (CCNB1), cyclin-dependent kinase 1 (CDK1) and cyclin-dependent kinase 2 (CDK2). Importantly, following progesterone administration cell cycle distribution was shifted to S and G2/M phases in the naïve cell line but in PRA-transfected cells, this effect was suppressed. To see if these mechanistic insights were confirmed in patient samples PRA, PRB, CCNA2, CCNB, CDK1 and CDK2 immunoreactivities were assessed in Pan-NEN cases. Higher levels of cell cycle markers were associated with higher WHO grade tumors and correlations between the markers suggested formation of cyclin/CDK activated complexes in S and G2/M phases. PRA expression was associated with inverse correlation of all cell cycle markers. Collectively, these results indicate that progesterone signals through PRA negatively regulates cell cycle progression through suppressing S and G2/M phases and downregulation of cell cycle phases specific cyclins/CDKs.

High interlaboratory and interobserver agreement of somatostatin receptor immunohistochemical determination and correlation with response to somatostatin analogs.

Monoclonal antibodies to somatostatin receptors 2A (SSTR2A, UMB-1) and 5 (SSTR5, UMB-4) were reported to be highly reliable for immunohistochemical detection of these receptors in neuroendocrine neoplasms. However, the standardization of either the immunohistochemical procedure and the methods of evaluation has yet to be established. Fifty-two tissues from 38 patients with neuroendocrine neoplasm were retrieved from 2 institutions in Italy and Japan. The tissues were immunostained using 3 staining methodologies: 1 automated and 2 manual protocols from the Italian and Japanese institutions. The slides were independently evaluated by 3 observers (2 experienced pathologists and 1 medical student) using 3 scoring systems (Volante-Score, HER2-Score, and H-Score). The scores obtained from the staining methods were highly correlated with each other (r>0.85, P<.0001). Especially, the Volante- and HER2-Scores were highly concordant (r≥0.95, P≤.0001). Very high interobserver agreement was obtained irrespective of the method used and the experience of the evaluator, with the best concordance obtained by experienced pathologists evaluating automated system-stained slides (SSTR2A, r>0.97; SSTR5, r>0.96). HER2- and H-Scores were reliable to represent the characteristics of the patients. SSTR2A expression evaluated by the HER2-Score was significantly associated with clinical efficacy to somatostatin analogs (P=.04). SSTRs determination is an easily standardizable tool in different laboratories and is highly reproducible irrespective of the method of evaluation used. Given the positive association with clinical efficacy to somatostatin analogs, as well as the simple and widespread use, HER2-Score can be proposed as a standard evaluation procedure of SSTR2A and SSTR5 expression in neuroendocrine neoplasms.

A long-term survival case treated with conversion surgery following chemotherapy after diagnostic metastasectomy for pancreatic cancer with synchronous liver metastasis.

BACKGROUND: Pancreatic cancer with distant metastases is classified as "unresectable," for which the standard treatment is systemic chemotherapy. The effectiveness of radical resection for pancreatic cancer with distant metastases is unknown. Here, we report a case of long term survival treated with conversion surgery following chemotherapy after diagnostic metastasectomy for pancreatic cancer with synchronous liver metastasis. CASE PRESENTATION: A 73-year-old man was referred to our hospital to examine and treat for cancer of the pancreatic body. Computed tomography (CT) scan revealed a 26-mm hypovascular tumor in contact with the common hepatic artery (CHA) (> 180°), the celiac artery (< 180°), and portal vein at the pancreatic body. Resectability was determined as "borderline resectable." Two courses of gemcitabine plus S-1 combination therapy (GS) were administered as neoadjuvant chemotherapy (NAC). CT scan showed tumor shrinkage (21 mm), determined as stable disease (SD) according to Response Evaluation Criteria in Solid Tumors (RECIST). Although the abdomen was opened for radical resection, a small nodule on the liver was detected and removed. Since the nodule was diagnosed as adenocarcinoma by intraoperative frozen section, resection of the primary tumor was not performed. After three subsequent courses of GS therapy, no distant metastases were detected under radiological findings. Distal pancreatectomy with celiac artery resection (DP-CAR) was performed as radical surgery 6 months after the initial diagnosis. Histological diagnosis was well-differentiated tubular adenocarcinoma, showing ypT1 ypN1 M1 stage IV, negative surgical margin (R0), and grade III in the Evans classification. S-1 was administered every other day from 6 months after resection up to the present. The patient has been alive with no recurrence for 5 years after the initial diagnosis and 4.5 years after the resection. CONCLUSION: There is a case that received survival benefits from conversion surgery following chemotherapy after diagnostic metastasectomy in pancreatic cancer with synchronous liver metastasis.