[Tumor Immunogenicity and Immune Checkpoint Inhibitors].

Cancer immunotherapy including immune checkpoint inhibitors(ICIs)have established itself as the fourth cancer therapy. However, the response rate of ICIs is still only about 20%, and tumors resistant to ICIs are often so-called"cold-tumor"with low tumor immunogenicity. Therefore, research and development is being conducted worldwide on how to convert cold- tumors into hot-tumors with high immunogenicity. In this paper, we review the relationship between tumor immunogenicity and ICI, as well as therapeutic methods to enhance tumor immunogenicity, and introduce our research about novel cancer peptide vaccination therapy.

[Relationship between Polymorphisms and the Efficacy of Cetuximab].

BACKGROUND AND OBJECTIVES: Cetuximab has shown efficacy in patients with metastatic colorectal cancer (mCRC). Recent studies have demonstrated that cetuximab induces antibody-dependent cell-mediated cytotoxicity (ADCC), mediated via the fragment c gamma receptors(FcgR)in mCRC. Since the establishment of KRAS mutations as a major negative predictor of efficacy, additional biomarkers have been found to be useful for the improvement of selection of patients likely to be responsive to cetuximab. We investigated the relationship between polymorphisms and the outcome of mCRC patients treated with cetuximab. METHODS: In this study, 57 patients were evaluated. The relationships of FcgR polymorphisms with response rate (RR), progression-free survival (PFS), and overall survival (OS) were analyzed. RESULTS: The FcgR polymorphisms were not significantly related to RR, PFS, and OS. Compared with the other haplotypes, the haplotype containing the 131H and 158V alleles was related to a lower RR (p=0.018). The diplotypes containing 131H and 158V alleles had significantly lower RR than the other diplotypes (p=0.038). CONCLUSION: Our data suggest that FcgR polymorphisms may be associated with the outcome of mCRC patients treated with cetuximab and FOLFIRI. However, these results are currently controversial, and detailed investigations are needed to confirm the relationship between FcgRs polymorphisms and cetuximab efficacy.

Efficacy of perioperative immunonutrition in esophageal cancer patients undergoing esophagectomy.

OBJECTIVE: Malnutrition is common in patients with esophageal cancer, resulting in increased postoperative complications and mortality. Although preoperative immunonutrition can significantly reduce the incidence of postoperative infectious complications, its effect in patietns with esophageal cancer undergoing esophagectomy remains unclear. The aim of this study was to investigate the effects of perioperative immunonutritional support on the postoperative course and long-term survival of this group of patients. METHODS: This prospective, randomized study enrolled 40 patients with thoracic esophageal carcinoma undergoing esophagectomy. The patients were divided into two groups and received either immunomodulating enteral nutrition (IMPACT group; IG) or standard enteral nutrition (Ensure group; EG) continuously for 7 d before and 7 d after surgery. Nutritional status, such as rapid turnover protein, postoperative intensive care unit (ICU) length of stay (LOS), postoperative hospital LOS, morbidity, and mortality were investigated prospectively. RESULTS: There were no significant differences in patient demographic characteristics between the two groups. Levels of retinol-binding protein, as a rapid-turnover protein, were significantly higher on postoperative day (POD) -1, 7, and 14 in the IG compared with the EG group (P = 0.009, P = 0.004, and P = 0.024, respectively). The incidence of postoperative infectious complications and changes to therapeutic antibiotics were significantly lower in the IG group than in the EG group (P = 0.048 and P = 0.012, respectively). There was no significant difference in postoperative ICU or postoperative hospital LOS between the two groups. The 5-y progression-free survival rates in the IG and EG groups were 75% and 64%, respectively (P = 0.188), and the overall survival rates were 68% and 55%, respectively (P = 0.187). CONCLUSIONS: Perioperative immunonutrition may improve early postoperative nutritional status and reduce postoperative infectious complications in patients with esophageal cancer undergoing esophagectomy.

High secreted protein acidic and rich in cysteine expression in peritumoral fibroblasts predicts better prognosis in patients with resectable gastric cancer.

Secreted protein acidic and rich in cysteine (SPARC) is an extracellular matrix glycoprotein that may serve an important role in epithelial-mesenchymal transition. Recent studies have demonstrated that SPARC status is a prognostic indicator in various cancer types; however, its value remains unclear in gastric cancer (GC). In the present study, the localization and prognostic impact of SPARC expression were evaluated in patients with GC. Immunohistochemical analysis of SPARC expression was performed in 117 surgically resected GC specimens, and the localization of SPARC positive cells, as well as the rassociation between SPARC expression and clinicopathological characteristics were evaluated. High SPARC expression was observed in 47 cases; the glycoprotein was localized in the peritumoral fibroblasts, but was rarely observed in the cytoplasm of cancer cells. Heterogeneity of SPARC expression was observed in 52 cases. High stromal SPARC expression was identified to be an independent predictor of more favorable prognosis (overall survival and recurrence free survival) in all patients (P<0.001). On subgroup analysis, this association remained significant in patients who received adjuvant chemotherapy, but not in patients who did not (P<0.001). Stromal SPARC expression predicts better prognosis in GC patients who underwent curative resection; this appears to be associated with improved response to chemotherapy.

Preoperative serum methylation signature as prognostic tool after curative hepatectomy in patients with hepatocellular carcinoma.

AIM: This study aimed to investigate the relationship between prognosis after curative hepatectomy and serum methylation signature (SMS), defined by methylation levels of six specific genes (cyclin D2, Ras association (RalGDS/AF-6) domain family member 1, serine peptidase inhibitor Kunitz type 2, cystic fibrosis transmembrane conductance regulator, brain abundant membrane attached signal protein 1, and steroid-5-alpha-reductase alpha polypeptide 2). PATIENTS AND METHODS: Serum samples were collected preoperatively from 125 patients with hepatocellular carcinoma associated with hepatitis C virus infection who underwent curative hepatectomy. We measured the methylation levels of the preceding six genes. We defined the methylation of three genes or more in the serum as SMS-positive in this study. We investigated the prognosis of SMS-positive patients. RESULTS: SMS-positive patients exhibited significantly shorter disease-free survival (DFS) and overall survival (OS) than SMS-negative patients (p=0.0002 and p<0.0001, respectively). Multivariate analysis showed that SMS positivity was an independent risk factor for shorter DFS (hazard ratio (HR)=2.182; p<0.001) and OS (HR=4.198; p<0.001). CONCLUSION: SMS is useful as a prognostic predictor in patients with hepatocellular carcinoma after curative hepatectomy.

A stem cell medium containing neural stimulating factor induces a pancreatic cancer stem-like cell-enriched population.

Cancer stem cells (CSCs) have been studied for their self-renewal capacity and pluripotency, as well as their resistance to anticancer therapy and their ability to metastasize to distant organs. CSCs are difficult to study because their population is quite low in tumor specimens. To overcome this problem, we established a culture method to induce a pancreatic cancer stem-like cell (P-CSLC)-enriched population from human pancreatic cancer cell lines. Human pancreatic cancer cell lines established at our department were cultured in CSC-inducing media containing epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), leukemia inhibitory factor (LIF), neural cell survivor factor-1 (NSF-1), and N-acetylcysteine. Sphere cells were obtained and then transferred to a laminin-coated dish and cultured for approximately two months. The surface markers, gene expression, aldehyde dehydrogenase (ALDH) activity, cell cycle, and tumorigenicity of these induced cells were examined for their stem cell-like characteristics. The population of these induced cells expanded within a few months. The ratio of CD24high, CD44high, epithelial specific antigen (ESA) high, and CD44variant (CD44v) high cells in the induced cells was greatly enriched. The induced cells stayed in the G0/G1 phase and demonstrated mesenchymal and stemness properties. The induced cells had high tumorigenic potential. Thus, we established a culture method to induce a P-CSLC-enriched population from human pancreatic cancer cell lines. The CSLC population was enriched approximately 100-fold with this method. Our culture method may contribute to the precise analysis of CSCs and thus support the establishment of CSC-targeting therapy.

Efficient detection of hepatocellular carcinoma by a hybrid blood test of epigenetic and classical protein markers.

BACKGROUND: There are few blood tests for an efficient detection of hepatocellular carcinoma (HCC) associated with hepatitis C virus (HCV) infection. METHODS: The abilities of quantitative analyses of 7 genes hypermethylation in serum DNA, α-fetoprotein (AFP) and prothrombin-induced vitamin K absence II (PIVKA-II), and various combinations to detect HCC were evaluated in a training cohort of 164 HCV-infected patients (108 HCCs; 56 non-HCCs). An optimal hybrid detector, built using data for 2 methylated genes (SPINT2 and SRD5A2), AFP, and PIVKA-II, achieved the most satisfactory ability to detect HCC in the training cohort. We evaluated the ability of the optimal hybrid detector to detect HCC in an independent validation cohort of 258 consecutive HCV-infected patients (112 HCCs; 146 non-HCCs) who were newly enrolled in 4 distinct institutes. RESULTS: In the validation cohort of 258 patients, accuracy, sensitivity, and specificity of the hybrid detector for detection of HCC were 81.4%, 73.2%, and 87.7%, respectively. Notably, even when detecting HCC ≤ 2 cm in diameter, the hybrid detector maintained markedly high abilities (84.6% accuracy, 72.2% sensitivity, 87.7% specificity). Youden's index (sensitivity+specificity - 1) for HCC ≤ 2cm was 0.60, vastly much superior to the 0.39 for AFP at a cut-off value of 20 ng/ml and the 0.28 for PIVKA-II at a cut-off value of 40 mAU/ml. CONCLUSIONS: These results show that the optimal hybrid blood detector can detect HCV-related HCC more accurately.