Hiroaki Musha

Selective infiltration of CCR5(+)CXCR3(+) T lymphocytes in human colorectal carcinoma.

T cell infiltration in colorectal cancer is associated with a favorable prognosis, suggesting an occurrence of a certain degree of anti‐tumor immunity. T helper type 1 (Th1) and Th2 cells are now known to selectively express CC‐chemokine receptor 5 (CCR5)/CXC‐chemokine receptor 3 (CXCR3) and CCR4, respectively. To clarify the mechanism of T cell infiltration, we examined in situ expression of these chemokine receptors and their respective chemokine ligands in 40 cases of human colorectal cancer. Immunohistochemistry showed a predominant accumulation of T cells expressing CCR5 and CXCR3 mainly along the invasive margin, whereas those expressing CCR4 were rare. Flow cytometric analysis showed that more than half of CD8+ T cells and a fraction of CD4+ cells isolated from fresh tumor tissues co‐expressed CCR5 and CXCR3, and CD8+ T cells and CD4+ cells predominantly produced interferon‐γ (IFN‐γ) over interleukin‐4 (IL‐4) after in vitro stimulation. RANTES/CCL5, a ligand of CCR5, was localized within infiltrating CD8+ T cells in a granular pattern, whereas IP‐10/CXCL10, a ligand of CXCR3, was localized in cancer cells and macrophages along the invasive margin. These data were consistent with an active recruitment of T cells expressing CCR5 or CXCR3 into the invasive margin of colorectal cancer. With the previous clinicopathological studies showing a favorable prognostic impact of T cell infiltration in colorectal cancer, our study supports the occurrence of a certain level of Th1‐shifted cellular immune responses in human colorectal cancer.

The Risk Factors for Metastasis in Non-Ampullary Duodenal Neuroendocrine Tumors Measuring 20 mm or Less in Diameter

Background/Aims: The treatment strategy for non-ampullary duodenal neuroendocrine tumors (NAD-NETs) ≤20 mm in diameter has not been established. In this study, we aimed to evaluate the detailed characteristics of NAD-NETs ≤20 mm in diameter to clarify the risk factors of subsequent metastasis. Methods: The patients with NAD-NETs ≤20 mm in diameter who had been treated at 12 institutions between 1992 and 2013 were enrolled. Clinical records were retrieved, and histopathological findings of all cases were centrally reviewed by 2 pathologists. Results: We studied 49 patients with a mean follow-up period of 66.5 months. Thirty-five patients were initially treated with endoscopic resection (ER), and 14 with surgery. A univariate analysis revealed the ORs and 95% CIs of the risk factors for metastasis were lymphovascular invasion (12.5 [2.01-77.9]), multiple tumors (9.75 [1.46-65.4]), a tumor size of 11-20 mm (6.67 [1.21-36.6]), and World Health Organization grade G2 (7.13 [1.16-43.9]). Five-year overall and disease-specific survival rates were 86.1 and 97.2%, respectively. Conclusion: This is the first study to demonstrate the risk factors of metastasis in NAD-NETs ≤20 mm in diameter. These findings may be helpful for determining the appropriate therapeutic approach and the clinical strategy of treatment following ER.

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

PurposeThe 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.MethodsWe 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.ResultsThe 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.ConclusionsThe 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.

Abstract 2832: Single nucleotide polymorphisms of DPYD and MTHFR predict adverse events associated with 5-fluorouracil in patients with gastrointestinal cancer

Purpose The aim of this study was to investigate the association between 5-fluorouracil (5-FU)-related adverse events (AEs) in Japanese patients with gastrointestinal cancer treated with 5-FU and the patient genotypes DPYD, MTHFR, OPRT, and TYMS. Methods Sequence analyses of 33 gene polymorphisms in four genes were performed using genomic DNA extracted from peripheral blood mononuclear cells of 103 patients with gastric (n = 34) or colorectal (n = 69) cancer. The 5-FU-related AEs of 157 regimens in these 103 patients were evaluated based on the medical records of patients in each of three groups: the intravenous administration group (i.v. group, n = 51), oral administration group (p.o. group, n = 106), and all-regimens group (both i.v. and p.o. group, n = 157). The associations between the incidence of AEs and each genotype were statistically analyzed. Results Six single-nucleotide polymorphisms (SNPs) were identified (three SNPs in DPYD: c.496A>G, c.1905+1G>A, and c.2303C>A; two SNPs in MTHFR: c.677C>T and c.1298A>C; and one SNP in OPRT: c.638G>C). Among them, the patients in the all-regimens group carrying any one of three DPYD SNPs showed statistically significant associations with the incidence of AEs of any type and fatigue. Furthermore, the MTHFR SNP c.1298A>C was significantly associated with the incidence of neutropenia. A similar trend was observed in the p.o. group, but not in the i.v. group. Conclusion These findings suggest that the DPYD SNPs c.496A>G, c.1905+1G>A, and c.2303C>A and the MTHFR SNP c.1298A>C may be predictive factors for the occurrence of severe 5-FU-related AEs. Citation Format: Masahide Toshima, Shinobu Ohnuma, Michiiro Tanaka, Koh Miura, Wataru Fujibuchi, Taiki Kajiwara, Toshihiro Komura, Hiroaki Musha, Sho Haneda, Katsuyoshi Kudoh, Atsushi Kohyama, Takeshi Naitoh, Michiaki Unno. Single nucleotide polymorphisms of DPYD and MTHFR predict adverse events associated with 5-fluorouracil in patients with gastrointestinal cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2832. doi:10.1158/1538-7445.AM2014-2832

Abstract 631: Gastrointestinal toxicities of 5-FU increase the proportion of regulatory T cells in murine intestinal tract: Advantages of alternate-day S-1 administration

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA [Introduction] 5-fluorouracil (5-FU), a core anticancer agent used for various malignancies, induces gastrointestinal (GI) toxicities. The tegafur-based oral 5-FU prodrug S-1 is recognized to be a key drug for GI and other malignancies in Japan and some Asian countries. S-1 was developed to potentiate antitumor activity of 5-FU and to reduce gastrointestinal toxicities. However, S-1 also causes GI toxicities by the standard daily regimen. On the other hand, the alternate-day administration of S-1 has been proposed to minimize toxicities without reducing the anticancer efficacy of 5-FU. Recently, tumor immunology has greatly advanced, and the role of T cells in antitumor immunity has been well investigated. However, it remains unknown how GI toxicities of 5-FU affect T cell subsets related to antitumor immunity. [Purpose] The purpose of this study is to clarify the influence of 5-FU mediated GI toxicities on T cell subsets related to antitumor immunity. [Methods] Two regimens of S-1 were compared to evaluate the impact of GI toxicities of 5-FU on T cells using Balb/c mice. The first regimen consisted of the daily administration of S-1 (daily group) as a 5-FU GI toxicity model, and the second regimen consisted of the alternate-day administration of S-1 (alternate-day group) as a 5-FU non-GI toxicity model. S-1 was orally administered at a dose of 12 mg/kg as tegafur. We then investigated the degree of GI toxicities and T cell subsets in intra-abdominal lymphoid tissues (spleen, mesenteric lymph node and gut-associated lymphoid tissue). [Results] Only the daily group exhibited body weight loss and GI toxicities. Flow cytometric analyses demonstrated that the proportion of regulatory T cells in the intestinal tissue was 6-fold higher in the daily group than that in the control group, and the proportions of Th1 cells in the daily group showed a decreasing trend. However, the alternate-day group exhibited almost no changes in the proportions of T cell subsets. [Conclusions] GI toxicities of 5-FU increase the proportion of regulatory T cells in intestinal tissue and decrease the proportions of Th1 cells systemically, which suggests that GI toxicities of 5-FU have a negative influence on T cell-dependent antitumor immunity, and the alternate-day administration of S-1 has neither GI toxicities nor the influence on T cell subsets, which suggests that 5-FU regimens without GI toxicities are more useful than those with GI toxicities from the viewpoint of antitumor immunity. Citation Format: Taiki Kajiwara, Koh Miura, Shinobu Ohnuma, Tetsuhiko Shirasaka, Toshihiro Komura, Masahide Toshima, Atsushi Kohyama, Katsuyoshi Kudoh, Sho Haneda, Hiroaki Musha, Fuyuhiko Motoi, Yu Katayose, Takeshi Naitoh, Michiaki Unno. Gastrointestinal toxicities of 5-FU increase the proportion of regulatory T cells in murine intestinal tract: Advantages of alternate-day S-1 administration. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 631. doi:10.1158/1538-7445.AM2014-631

Abstract 792: Usefulness of alternate-day administration of S-1 and leucovorin in a xenograft mouse model of colorectal cancer: A shorter drug-free interval leads to more efficient antitumor effects

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA [Background] A clinical trial of S-1 with leucovorin (S-1/LV) in metastatic colorectal cancer (CRC) patients demonstrated promising efficacy; however, the gastrointestinal toxicities were so severe that it has not been applied in the clinical setting. On the other hand, alternate-day administration of S-1 has been proposed to attenuate the adverse events without reducing its anticancer activity. The aim of this study was to confirm the feasibility of alternate-day administration of S-1/LV in in vivo xenograft tumor models. [Methods] Mice were treated with S-1/LV either in a daily group (two weeks of administration followed by two weeks of withdrawal) or an alternate-day group (administration on alternate days for four weeks), then the mice of both groups were sacrificed and the xenograft tumors were resected. To assess the adverse reactions, the body weight changes, the condition of feces, mucosal injury of small intestine and myelosuppression were compared between both groups. Furthermore, tumor volume, tumor growth inhibition (TGI) and the expression of Ki67, TUNEL, cIAP2 and XIAP were analyzed to evaluate the antitumor activity and tumor apoptosis. [Results] Severe weight loss, diarrhea, mucosal injury and myelosuppression were observed only in the daily group; however, no adverse reactions were observed in the alternate-day group, except slight myelosuppression. The TGI in the alternate-day group was better than that in the daily group, possibly resulting from apoptosis of tumor cells due to the suppression of cIAP2. [Conclusion] Our findings suggest that alternate-day administration of S-1/LV for CRC treatment can achieve higher antitumor activity without severe adverse reactions. Therefore, we propose that clinical trials with this regimen should be conducted in CRC patients. Citation Format: Toshihiro Komura, Shinobu Ohnuma, Koh Miura, Tetsuhiko Shirasaka, Taiki Kajiwara, Katsuyoshi Kudoh, Sho Haneda, Masahide Toshima, Atsushi Kohyama, Hiroaki Musha, Takeshi Naitoh, Yu Katayose, Michiaki Unno. Usefulness of alternate-day administration of S-1 and leucovorin in a xenograft mouse model of colorectal cancer: A shorter drug-free interval leads to more efficient antitumor effects. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 792. doi:10.1158/1538-7445.AM2014-792