Multiple infusions of ex vivo-expanded regulatory T cells promote CD163+ myeloid cells and kidney allograft survival in non-lymphodepleted non-human primates.

Clinical verification of adoptively transferred regulatory T cell (Treg) efficacy in transplantation remains challenging. Here, we examined the influence of autologous ex vivo-expanded polyclonal Tregs on kidney graft survival in a clinically relevant non-human primate model. Peripheral blood Tregs were isolated and expanded using artificial antigen presenting cells. Immunosuppression was comprised of tapered tacrolimus and CTLA4 immunoglobulin, in five animals each without or with Treg infusions. Escalating Treg doses were administered 6, 10, 13, 16, 20, 23, 27 and 30 days after transplant. Infused Tregs were monitored for Treg signature, anti-apoptotic (Bcl-2) and proliferation (Ki67) marker expression. Treg infusions prolonged median graft survival time significantly from 35 to 70 days. Treg marker (Ki67 and Bcl-2) expression by infused Tregs diminished after their infusion but remained comparable to that of circulating native Tregs. No major changes in circulating donor-reactive T cell responses or total Treg percentages, or in graft-infiltrating T cell subsets were observed with Treg infusion. However, Treg infusion was associated with significant increases in CD163 expression by circulating HLA-DR+ myeloid cells and elevated levels of circulating soluble CD163. Further, graft-infiltrating CD163+ cells were increased with Treg infusion. Thus, multiple Treg infusions were associated with M2-like myeloid cell enhancement that may mediate immunomodulatory, anti-inflammatory and graft reparative effects.

Significance of Comprehensive Analysis of Preoperative Sarcopenia Based on Muscle Mass, Muscle Strength, and Physical Function for the Prognosis of Patients with Esophageal Cancer.

BACKGROUND: The assessment of muscle mass loss, muscle strength, and physical function has been recommended in diagnosing sarcopenia. However, only muscle mass has been assessed in previous studies. Therefore, this study investigated the effect of comprehensively diagnosed preoperative sarcopenia on the prognosis of patients with esophageal cancer. METHODS: The study analyzed 115 patients with esophageal cancer (age ≥ 65 years) who underwent curative esophagectomy. Preoperative sarcopenia was analyzed using the skeletal mass index (SMI), handgrip strength, and gait speed based on the Asian Working Group for Sarcopenia 2019 criteria. Clinicopathologic factors, incidence of postoperative complications, and overall survival (OS) were compared between the sarcopenia and non-sarcopenia groups. The significance of the three individual parameters also was evaluated. RESULTS: The evaluation identified 47 (40.9%) patients with low SMI, 31 (27.0%) patients with low handgrip strength, and 6 (5.2%) patients with slow gait speed. Sarcopenia was diagnosed in 23 patients (20%) and associated with older age and advanced pT stage. The incidence of postoperative complications did not differ significantly between the two groups. Among the three parameters, only slow gait speed was associated with Clavien-Dindo grade 2 or greater complications. The sarcopenia group showed significantly worse OS than the non-sarcopenia group. Those with low handgrip strength tended to have worse OS, and those with slow gait speed had significantly worse OS than their counterparts. CONCLUSIONS: Preoperative sarcopenia diagnosed using skeletal muscle mass, muscle strength, and physical function may have an impact on the survival of patients with esophageal cancer.

Clinical Impact of Early Tumour Shrinkage in Metastatic or Unresectable Oesophageal Cancer Treated with Pembrolizumab plus Chemotherapy.

INTRODUCTION: Metastatic or unresectable locally advanced oesophageal cancer remains a disease with high mortality. More recently, pembrolizumab plus chemotherapy has been indicated as the first-line treatment for those patients, but the predictive factors for treatment efficacy remain controversial. This study investigated the clinical utility of early tumour shrinkage (ETS) and depth of response (DpR) in metastatic or unresectable oesophageal cancer treated with pembrolizumab plus CF therapy. METHODS: ETS and DpR, defined as the percent decreases at the second evaluation and the percentage of the maximal tumour shrinkage during treatment, were measured in 53 eligible patients. The ETS and DpR cut-off values were 20% and 30%, respectively, based on survival outcomes. RESULTS: Twenty-seven patients (51%) were treatment-naïve, while 26 (49%) had received any treatment before initiating pembrolizumab plus CF therapy. The median progression-free survival (PFS) and overall survival (OS) for ETS ≥20% and <20% were 12.7 and 5.5 months and 14.4 and 8.2 months, and 12.7 and 4.9 months and 14.4 and 8.0 months for DpR ≥30% and <30%, respectively. ETS <20% showed early tumour growth, whereas ETS ≥20% had a good response rate with sufficient longer response duration. In addition, an ETS cut-off of 20% predicted the best overall response and was not associated with prior treatment. In multivariable analysis, ETS ≥20% and DpR ≥30% were independent factors of longer PFS. CONCLUSION: Our findings suggest that an ETS is a promising on-treatment marker for early prediction of further sensitivity to pembrolizumab plus CF therapy.

Preoperative FDG-Positive Lymph Nodes Predict the Postoperative Prognosis in Resectable Biliary Tract Cancers.

BACKGROUND: F-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) has been used to diagnose and stage various cancers. In regard to biliary tract cancer (BTC), due to cholangitis it is difficult to evaluate FDG uptake caused by cancer. We previously showed that FDG-positive lymph nodes (LNs) of resectable BTC had a possibility of predicting postoperative prognosis. OBJECTIVE: This study aimed to validate the usability of FDG-PET for LNs using another cohort and to investigate in detail the relationship between FDG-positive LNs and the prognosis of BTC. METHODS: We measured the preoperative maximum standardized uptake value (SUVmax) at each of the 190 surgically dissected LN areas in 67 patients and investigated the prognosis using our previously determined SUVmax cut-off values of ≥ 2.8. RESULTS: Regarding the prognosis of patients with resectable BTC, a LN SUVmax ≥ 2.8 [PET N (+)] was a poor prognostic factor for recurrence-free survival (RFS) compared with a LN SUVmax < 2.8 [PET N (-)]. It was confirmed that the hazard ratio forest plot [PET N (+)/PET N (-)] for RFS indicated a similar tendency among subcategories. Moreover, we investigated patients with pN0 disease and demonstrated that the PET N (+) group also had a significantly worse RFS outcome compared with the PET N (-) group. Recurrence of the PET N (+) group has significantly occurred more often in LNs than that of the PET N (-) group. CONCLUSION: High LN SUVmax was confirmed to be the preoperatively diagnosed prognostic risk factor for RFS in resectable BTC and could be helpful for clinical decision making regarding the perioperative treatment strategy.

Endogenous CXCL9 affects prognosis by regulating tumor-infiltrating natural killer cells in intrahepatic cholangiocarcinoma.

CXCL9, an IFN-γ inducible chemokine, has been reported to play versatile roles in tumor-host interrelationships. However, little is known about its role in intrahepatic cholangiocarcinoma (iCCA). Here, we aimed to elucidate the prognostic and biological implications of CXCL9 in iCCA. Endogenous CXCL9 expression and the number of tumor-infiltrating lymphocytes were immunohistochemically assessed in resection specimens. These data were validated in mice treated by silencing CXCL9 with short hairpin RNA. In addition, the induction of endogenous CXCL9 and the effects of CXCL9 on tumor biological behaviors were evaluated in human cholangiocarcinoma cell lines. Immunohistochemical analyses revealed that high CXCL9 expression was closely correlated with prolonged postoperative survival and a large number of tumor-infiltrating natural killer (NK) cells. In fact, due to the trafficking of total and tumor necrosis factor-related apoptosis-inducing ligand-expressing NK cells into tumors, CXCL9-sufficient cells were less tumorigenic in the liver than CXCL9-deficient cells in mice. Although CXCL9 involvement in tumor growth and invasion abilities differed across cell lines, it did not exacerbate these abilities in CXCL9-expressing cell lines. We showed that CXCL9 was useful as a prognostic marker. Our findings also suggested that CXCL9 upregulation might offer a therapeutic strategy for treating CXCL9-expressing iCCA by augmenting anti-tumor immune surveillance.

Impact of CD36 on Chemoresistance in Pancreatic Ductal Adenocarcinoma.

BACKGROUND: CD36, a multi-ligand scavenger receptor, has been associated with several cancers. Many studies have revealed that CD36 contributed to cancer malignancy. This study aimed to reveal the function of CD36 expression in pancreatic ductal adenocarcinoma (PDAC). METHODS: CD36 expression was characterized using immunohistochemistry in 95 clinical specimens resected from patients with PDAC. We divided patients into two groups, with different CD36 expression levels, and analyzed and compared their prognoses. CD36 expression was also assessed in PDAC cell lines. Gemcitabine-resistant (GR) PDAC cell lines were transfected with small interfering RNA (siRNA) that specifically targeted CD36 to evaluate chemoresistance and apoptosis. RESULTS: In resected PDAC samples, CD36 expression was significantly correlated with microinvasion into the venous system (p = 0.0284). Patients with high CD36 expression had significantly lower overall survival (OS) and recurrence-free survival (RFS) rates than patients with low expression; thus, CD36 was an independent prognostic factor for OS and RFS. In subgroup analyses, CD36 was an independent risk factor for OS and RFS in 59 patients treated with gemcitabine adjuvant chemotherapy. CD36 expression was upregulated in PDAC-GR cell lines compared with the PDAC parent cell line. Transduction with siRNA downregulated CD36, which reduced PDAC cell resistance to gemcitabine and inhibited anti-apoptosis proteins. CONCLUSION: CD36 expression influenced gemcitabine resistance by regulating anti-apoptosis proteins. High CD36 expression was a significant, unfavorable prognostic factor in PDAC. Anti-CD36 treatment might serve as an optional treatment for lowering resistance to gemcitabine.

Heterogeneity of Treg/Th17 According to Cancer Progression and Modification in Biliary Tract Cancers via Self-Producing Cytokines.

BACKGROUND/AIM: We previously demonstrated that inflammatory cytokine interleukin-6 (IL-6) was produced during cancer progression, worked together with transforming growth factor-beta 1 (TGF-ß1), and induced the epithelial-mesenchymal transition (EMT) with chemo-resistance against gemcitabine (GR) at the invasion front of biliary tract cancers (BTCs). However, the significance of cytokine-induced T cell accumulation at the tumor microenvironment in biliary tract cancer (BTC) is not well understood. Because these cytokines (IL-6 and TGF-ß1) are able to differentiate naïve T cells into Foxp3-expressing T cells (Tregs) and/or IL-17-producing T helper 17 (Th17) cells, we investigated the relationship between heterogeneous, cancer-producing cytokines and T cell differentiation. METHODS: In total, 127 curative resected specimens from patients with BTCs at Osaka University Hospital between 2000 and 2012 were evaluated for IL-6, TGF-ß1, Tregs, and Th17 cells by immunohistochemistry. The ability of BTC-GR cells to undergo T cell differentiation was investigated in vitro. RESULTS: Tregs accumulated at the tumor center and Th17 cells accumulated at the invasion front during cancer progression and/or metastasis; each signaled poor prognosis. Treg accumulation was related to TGF-ß1 expression by cancer cells, and Th17 cell accumulation was related to IL-6 expression by cancer cells, in resected specimens; this was confirmed in vitro. Compared with parent cells, GR cells produced IL-6 but not TGF-ß1 in a time-dependent manner, had EMT features, and induced T cell differentiation to Th17 cells but not Tregs. CONCLUSION: Cytokines produced by cancer cells (IL-6 and TGF-ß1) induced heterogeneity of Tregs and Th17 cells in the tumor microenvironment, supporting progression of BTC.

Exosomal miR-155 Derived from Hepatocellular Carcinoma Cells Under Hypoxia Promotes Angiogenesis in Endothelial Cells.

PURPOSE: In this study, we aim to clarify whether exosomes secreted from hepatocellular carcinoma (HCC) cells under hypoxia affect angiogenesis in endothelial cells. METHODS: Exosomes derived from human liver cancer cell lines were cultured under hypoxic or normoxic conditions for 24 h, isolated using ExoQuick-TC®, and co-cultured with HUVECs to evaluate angiogenic activity. We also evaluated the expression of miR-155 in the exosomes from 40 patients with HCC. RESULTS: Exosomes under hypoxia remarkably enhanced tube formation of HUVECs. Both cellular and exosomal miR-155 were significantly up-regulated under hypoxic conditions. Knockdown of miR-155 in HCC cells attenuated the promotion of tube formation by exosomes under hypoxia in HUVECs, and high expression of exosomal miR-155 in preoperative plasma was significantly correlated with early recurrence. CONCLUSION: These results suggest that exosomes derived from HCC cells under hypoxia induce tube formation of HUVECs and that exosomal miR-155 may affect angiogenic activity in HCC.

[A Case of Resection for Lymph Node Recurrence around the Inferior Vena Cava after Radical Surgery of Undifferentiated Carcinoma of the Pancreatic Head Region].

A 60-year-old man underwent palliative surgery with a diagnosis of unresectable cancer, and he visited our hospital for further treatment. Since the cancer was unresectable and multiple hepatic tumors were revealed in CT images that were not metastases, we decided to perform curative surgery for the pancreatic cancer accompanied by partial liver invasion. Pancreaticoduodenectomy plus partial hepatectomy were performed, and 2 tumors were detected in the resected specimen: one in the pancreas-duodenum region and a submucosal tumor in the duodenum bulb. The large tumor that occupied the pancreasduodenum region was histologically diagnosed as an undifferentiated carcinoma, and the duodenal submucosal tumor was consistent with findings of a poorly differentiated adenocarcinoma. Two years after surgery, CT examination revealed a mass extending into the inferior vena cava(IVC)from near the right renal vein. We eventually diagnosed lymph node recurrence with tumor thrombosis inthe IVC and started chemotherapy(FOLFIRINOX). After the tumor decreased, we performed salvage surgery involving resection of the lymph node, thrombectomy, and right nephrectomy. The tumor revealed atypical cells in the region of thrombosis, and the pathological findings were not in conflict with the findings of metastases from pancreatic cancer 2 years prior. After the treatment, chemotherapy was administered and he survived without any recurrence for 15 months after surgery.

[Examination of the Usefulness of Laparoscopic Resection for Primary Lesions of Stage â £ Colorectal Cancer].

For patients with Stage Ⅳ colorectal cancer, primary site resection improves survival and relieves symptoms of bleeding and obstruction by the primary lesion. Laparoscopic surgery is thought to be useful for Stage Ⅳ colorectal cancer because of its low aggressiveness and the short recovery time. We examined the usefulness of laparoscopic resection of primary lesions for Stage Ⅳ colon cancer patients. Forty-one cases of Stage Ⅳ colorectal cancer treated by resection of the primary lesion were investigated, and we compared the group of patients with laparoscopic surgery (LAC) to the group of patients with open laparotomy (OP). The LAC Group was superior to the OP Group from the viewpoint of blood loss, days of hospitalization, and length of time from operation to start of chemotherapy. For Stage Ⅳ colorectal cancer, laparoscopic resection of the primary lesion is thought to be a useful method to reduce the invasiveness of treatment.

[Two Effective Cases of Re-Insertion of Self-Expanding Metallic Stent(SEMS)for Re-Obstruction of Colon Cancer after SEMS Treatment].

Recently, self-expanding metallic stent (SEMS) have been found to be useful for treatment of intestinal obstruction by colorectal cancer, either as a bridge to surgery or terminal treatment. When SEMS are used for patients in the terminal stage with obstruction due to colorectal cancer, re-obstruction is a severe problem. We report 2 cases of re-insertion of SEMS for obstruction of colon cancer after the first insertion of SEMS. No major problems occurred in either the 2 cases. In the first case, the patient suffered from re-obstruction of colon cancer 6 months after the first SEMS treatment and died 9 months after the second SEMS treatment. In the second case, the patient suffered from re-obstruction of colon cancer 5 months after the first SEMS treatment and died 7 months after the second SEMS treatment. Re-insertion of SEMS for a second obstruction due to colorectal cancer after SEMS treatment is useful for terminal treatment for maintaining QOL.

[A Case of Liposarcoma Occurring in the Retroperitoneum Treated by Laparoscopic Excision].

We experienced a rare case of liposarcoma that we were able to remove laparoscopically based on a preoperative diagnosis. The patient in this case was a 67-year-old woman. Abdominal CT and pelvic MRI showed a mass of 15 cm in diameter on the left side of the pelvis. Well-differentiated liposarcoma was diagnosed based on these images. Based on imaging findings, the possibility of permeation to the neighboring organs was considered to be low, and so the operation was performed laparoscopically. The location of the tumor was similar to that seen during preoperative imaging diagnosis, and we were able to remove it laparoscopically without resecting the organ. The postoperative progress was good, and the patient left the hospital on the fourth postoperative day. This case shows how with detailed preoperative imaging, a minimally invasive approach is possible for the treatment of liposarcoma.

[Examination of the usefulness of the self-expanding metallic stent for ileus due to colorectal cancer].

Ileus due to colon cancer often develops from a timing and the method of the operation and perioperative care, comparing with ordinary cases. The use of self-expanding metallic stent (SEMS) was first authorized by insurance and became available nationwide in Japan in 2012. Insertion of SEMS for ileus due to colorectal cancer is useful as a bridge to surgery (BTS) approach and releases stenosis as palliative care. Here we report 5 successful cases of anastomosis performed during a laparoscopic operation for ileus due to colorectal cancer after BTS using SEMS. Successful SEMS insertion for colon cancer ileus enables observation of the proximal side. Because the decompression efficiency with SEMS is high, laparoscopic surgery becomes possible. SEMS insertion as a BTS is useful for ileus due to colorectal cancer.

Assessing Intra-abdominal status for clinically relevant postoperative pancreatic fistula based on postoperative fluid collection and drain amylase levels after distal pancreatectomy.

Aim: The aim of this study was to evaluate the intra-abdominal status related to postoperative pancreatic fistula by combining postoperative fluid collection and drain amylase levels. Methods: We retrospectively reviewed the data of 203 patients who underwent distal pancreatectomy and classified their postoperative abdominal status into four groups based on postoperative fluid collection size and drain amylase levels. We also evaluated the incidence of clinically relevant postoperative pancreatic fistula in each group according to C-reactive protein values. Results: The incidence of clinically relevant postoperative pancreatic fistula in the entire cohort (n = 203) was 28.1%. Multivariate analysis revealed that postoperative fluid collection, drain amylase levels, and C-reactive protein levels are considerable risk factors for clinically relevant postoperative pancreatic fistula. In the subgroup with large postoperative fluid collection and high drain amylase levels, 65.9% of patients developed clinically relevant postoperative pancreatic fistula. However, no significant difference was observed in C-reactive protein levels between patients with clinically relevant postoperative pancreatic fistula and those without it. In contrast, in the subgroup with a large postoperative fluid collection size or a high amylase level alone, a significant difference was observed in C-reactive protein values between the patients with clinically relevant postoperative pancreatic fistula and those without it. Conclusion: Postoperative fluid collection status and the C-reactive protein value provide a more precise assessment of intra=abdominal status related to postoperative pancreatic fistula after distal pancreatectomy. This detailed analysis may be a clinically reasonable approach to individual drain management.

Short-term Outcomes of Adjuvant Nivolumab After Neoadjuvant Chemotherapy in Patients With Resected Esophageal Squamous Cell Carcinoma.

BACKGROUND/AIM: CheckMate 577 evaluated adjuvant nivolumab therapy after neoadjuvant chemoradiotherapy and surgery for esophageal cancers. However, the efficacy of this treatment in patients who received neoadjuvant chemotherapy remains unknown. This study investigated the short-term outcomes of adjuvant nivolumab therapy in patients with advanced esophageal squamous cell carcinoma post-neoadjuvant chemotherapy. PATIENTS AND METHODS: Out of 956 patients with thoracic esophageal cancer who underwent radical esophagectomy, 227 who exhibited ypN1-3 after neoadjuvant chemotherapy and surgery were included in this study. RESULTS: Among 227 patients, 30 received adjuvant nivolumab and 197 received non-nivolumab adjuvant therapy. The nivolumab group displayed a higher number of lymph node metastases compared to the control group. Patients with ypN1-2 tended to have longer recurrence-free survival (RFS) in the nivolumab group than in the non-nivolumab group (p=0.095). In the propensity score-matched cohort, no differences in patient characteristics were observed. Adjuvant nivolumab therapy significantly prolonged RFS in patients who received neoadjuvant chemotherapy (p=0.013). Patients with ypN1-2 in the nivolumab group had significantly longer RFS than their counterparts in the non-nivolumab group (p=0.001), but not in ypN3 (p=0.784). The 1-year postoperative recurrence rates were 59% for the non-nivolumab group and 24% for the nivolumab group (p=0.007). Nivolumab-related adverse events in patients receiving neoadjuvant chemotherapy were mostly consistent across all grades, while the frequency of increased aspartate aminotransferase (AST) levels was relatively higher compared to CheckMate577. CONCLUSION: Adjuvant nivolumab was more likely to prolong 1-year RFS in patients receiving neoadjuvant chemotherapy, especially in those with ypN1-2, and had acceptable adverse events.

Survival Impact of Inflammation-based Prognostic Scores in Metastatic or Unresectable Esophageal Cancer Treated With Pembrolizumab Plus Chemotherapy.

Pembrolizumab plus chemotherapy has been indicated as the first-line treatment for metastatic or unresectable locally advanced esophageal cancer. However, pretreatment biomarkers for predicting clinical outcomes remain unclear. We investigated the predictive value of inflammation-based prognostic scores in patients treated with pembrolizumab and chemotherapy. The Prognostic Nutritional Index (PNI), C-reactive protein/albumin ratio (CAR), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) were calculated before initial treatment in 65 eligible patients with metastatic or unresectable locally advanced esophageal cancer receiving pembrolizumab plus CF therapy, and the relationship between these biomarkers and clinical outcomes was analyzed. The objective response rate (ORR) and progression disease (PD) were observed in 51% and 21% of all patients. Patients with PNI<39 have significantly worse treatment responses than those with PNI≥39 (ORR; 28% vs. 60%, PD; 44% vs. 13%, P=0.020). Progression-free survival (PFS) is significantly associated with the PNI and CAR (P<0.001 and P=0.004, respectively). Overall survival (OS) is associated with PNI, CAR, and PLR (P<0.001, P=0.008, and P=0.018, respectively). The PNI cutoff value of 39 is identified as an independent factor for PFS (odds ratio=0.27, 95% CI: 0.18-0.81, P=0.012) and OS (odds ratio=0.22, 95% CI: 0.08-0.59, P=0.003). Patients with PNI<39 have significantly worse 6-month PFS and 1-year OS than those with PNI≥39 (27.8% vs. 66.7%, 27.2% vs. 81.1%, respectively). In conclusion, inflammation-based prognostic scores are associated with survival in patients treated with pembrolizumab plus CF therapy. Pretreatment PNI is a promising candidate for predicting treatment response and survival.

[Clinical significance of neutrophil to lymphocyte ratio in colorectal cancer patients receiving adjuvant chemotherapy combined with polysaccharide-K].

The neutrophil to lymphocyte ratio (N/L ratio) has been reported to be related to the prognosis of various types of cancer. In particular, a high N/L ratio has been suggested to be associated with poor outcome. We investigated the changes in N/L ratio during treatment in 12 patients who had undergone surgery for colorectal cancer and were receiving postoperative adjuvant therapy with a combination of chemotherapy and polysaccharide-K (PSK). The patients were stratified into 2 groups according to the preoperative N/L ratio (cut-off ratio was 2.5): high N/L (≥2.5) and low N/L (<2.5). The changes in N/L ratio and other clinical parameters over time were investigated. In patients with a high preoperative N/L ratio, the use of postoperative PSK-chemotherapy controlled the N/L ratio at low levels. The N/L ratio tended to remain low in patients with low preoperative N/L ratios. No difference in outcome was observed between patients with high and low N/L ratios. In patients who underwent colorectal cancer surgery, postoperative adjuvant therapy with a combination of chemotherapy and PSK succeeded in controlling the N/L ratio at low levels. Further studies with more patients are required to explore the outcomes associated with changing N/L ratios.

[Response to neoadjuvant chemotherapy in breast cancer as assessed by subtype].

The aim of this study was to investigate the responses to neoadjuvant chemotherapy (NAC) in breast cancer according to subtype. The study included 69 women who received NAC at our hospital between January 2004 and January 2013. Complete response( CR) was achieved in 14 patients( 20.3%) and partial response( PR) was achieved in 37 patients (53.6%).CR and PR rates according to subtype were as follows: 0% and 57.1% for the luminal type, 0% and 66.7% for the luminal-human epidermal growth factor receptor (HER)-2 type, 16% and 56% for the triple negative type, and 58.8% and 41.2% for the HER2 type, respectively. The CR rate was the highest among patients with HER2-type breast cancer. Trastuzumab was additionally administered to 12 patients with HER2-type breast cancer, and the CR rate among these patients was significantly higher after trastuzumab treatment( 75%).Thus, it is important to select a treatment strategy for breast cancer on the basis of the subtype diagnosed.