[A Case of Anastomotic Recurrence of Rectal Cancer Treated by Laparoscopic Total Pelvic Exenteration after Neoadjuvant Chemoradiation]

Patient is 69-year-old man, who underwent a high anterior resection with laparoscopic support for rectal cancer. The patient was diagnosed with anastomotic recurrent rectal cancer after 14 months after surgery. The pelvic MRI scan showed invasion of the prostate and seminal vesicles, so NACRT was performed. Tumors were found to have decreased in size, although there was still some residual invasion of the prostate and seminal vesicle. Laparoscopic total pelvic exenteration (Lap-TPE), and combined excision of the anal elevator muscle and bladder were performed. Preoperative diagnosis was ycT4b, N0, M0, ycStage Ⅱ, and pathological diagnosis was pT4b (prostate and seminal vesicles), INF b, Ly2, v2, Pn1b, pPM0, pDM0, pRM0, and pN0. Laparoscopic surgery allowed to operate safely, with minimal blood loss and a good field of vision. After postoperative adjuvant chemotherapy, lung and liver metastasis appeared after 6 months after surgery, but there was no local recurrence. The patient is treated with chemotherapy, and the metastases are under control. The patient is survive 17 months after Lap-TPE.

[A Case of Gastrointestinal Stromal Tumor of the Lower Rectum That Enabled Minimally Invasive Surgery with Imatinib Mesylate as Neoadjuvant Chemotherapy]

A 67-year-old woman was admitted with melena. A colonoscopy detected a 50 mm submucosal tumor close to the dentate line. We diagnosed the rectal gastrointestinal stromal tumor by EUS-FNA. With the expectation of tumor shrinkage and strong hope of the patient, we started imatinib mesylate as neoadjuvant chemotherapy. A CT scan after 3 months after administration of imatinib mesylate showed the reduction of the size to 35 mm. We operated transanal endoscopic surgery considering the localization of the tumor. From histopathological findings, the tumor was low risk in the modified-Fletcher classification, and low risk in the Miettinen classification. Eight months after the operation, no recurrence was observed without further adjuvant chemotherapy. In this case, we were able to resect the tumor without injuring the film of tumor by operating transanal endoscopic surgery, because of tumor shrinkage with imatinib mesylate as neoadjuvant chemotherapy. I considered that using imatinib mesylate preoperatively was contributed to minimally invasive surgery.

[Two Cases of Unresectable Gastric Cancer Where Bleeding Was Controlled by Radiation]

Case 1: The patient was a 74-year-old man with a performance status(PS)of 0. He was referred to our department for pyloric gastric cancer with multiple liver, lung, and lymph node metastases. We started chemotherapy after making the diagnosis of an unresectable gastric cancer. During chemotherapy, the hemoglobin level dropped due to bleeding from the tumor. We attempted endoscopic hemostasis, which was not successful; therefore, we attempted a palliative radiotherapy. The total dose was 30 Gy in 10 Fr and hemostasis was achieved on the 10th day from the start of the radiotherapy. There were no adverse events due to the radiation, and the chemotherapy could be restarted 5 days after the end of the radiotherapy. Case 2: The patient was a 78-year-old man with a PS of 2. He was referred to our department because of vomiting and anemia. As a result of a close inspection, we made the diagnosis of an unresectable gastric body cancer with para-aortic lymph node metastasis and peritoneal dissemination, for which chemotherapy was initiated. Anemia was observed at the first visit, and we started radiotherapy to stop the tumor bleeding. The total dose was 30 Gy in 10 Fr, and hemostasis was achieved on the 12th day. There were no adverse events during the radiotherapy, and chemotherapy could be continued. Palliative radiotherapy is an available method of hemostasis that is less invasive than surgery or transcatheter arterial embolization and can be expected to have a certain effect for gastric cancer bleeding, although it takes several days to obtain a therapeutic effect.

Cathepsin B is highly expressed in pancreatic cancer stem-like cells and is associated with patients' surgical outcomes

Cancer stem-like cells (CSLCs) in solid tumors are resistant to conventional chemotherapy and molecularly targeted therapy, which is thought to contribute to cancer recurrence and metastasis. The present study aimed to identify biomarkers for pancreatic CSLCs (P-CSLCs). Using our previously reported methods, P-CSLC-enriched populations were generated from pancreatic cancer cell lines. The protein expression profiles of these populations were compared with those of parental cells using two-dimensional electrophoresis, tandem mass spectrometry, flow cytometry and immunohistochemistry. Protein expression in surgical specimens was also evaluated for relationships with clinical outcomes. A lysosomal cysteine protease, cathepsin B (CTSB), was significantly upregulated in P-CSLCs compared with that in the parental cells, as shown using western blotting. Flow cytometry analysis also confirmed that CTSB was more highly expressed on the surface of P-CSLCs compared with that on parental cells. Moreover, PCLCs had elevated cellular secretions of CTSB compared with the parental cells. Finally, CTSB expression was evaluated in 69 resected tumor specimens, and high expression was associated with the patients' clinicopathological features and surgical outcomes. The present results suggested that CTSB is a biomarker for poor survival in patients with pancreatic cancer, which is possibly associated with P-CSLCs. This novel biomarker may also have potential as a therapeutic target.

Siglec-7 is a predictive biomarker for the efficacy of cancer vaccination against metastatic colorectal cancer

Cancer immunotherapy, including vaccination, is considered a major scientific and medical breakthrough. However, cancer immunotherapy does not result in durable objective responses against colorectal cancer (CRC). To improve the efficacy of immunotherapy, the present study investigated several biomarkers for selecting patients who were expected to respond well to immunotherapy. Firstly, a comprehensive proteomic analysis was performed using tumor tissue lysates from patients enrolled in a phase II study, in which five human leukocyte antigen (HLA)-A*24:02-restricted peptides were administered. Sialic acid-binding immunoglobulin type lectin (Siglec)-7 was identified as a potential predictive biomarker. Subsequently, this biomarker was validated using western blot analysis, and immunofluorescence using tissue samples from the patients enrolled in the phase II study. The expression levels of Siglec-7 detected by immunofluorescence were quantified and their association with overall survival (OS) in patients treated with the peptide vaccine was examined. Furthermore, considering the important role of tumor-infiltrating lymphocytes (TILs) for CRC prognosis, the densities of CD3⁺, CD4^+, CD8⁺ and forkhead box P3 (FOXP3)⁺ T cells in CRC tissues were examined and compared with Siglec-7 expression. The mean expression levels of Siglec-7 were significantly higher in patients with poor prognosis, with an OS of ≤2 years, as shown in comprehensive proteomic analysis (P=0.016) and western blot analysis (P=0.025). Immunofluorescence analysis demonstrated that Siglec-7 was expressed in intratumoral macrophages. The OS in patients with high Siglec-7 expression was significantly shorter than in that in patients with low Siglec-7 expression (P=0.017) in the HLA-A*24:02-matched patients. However, this difference was not observed in the HLA-unmatched patients. There was no significant difference in OS between patients according to the numbers of TILs, nor significant correlation between TILs and Siglec-7 expression. In conclusion, Siglec-7 expression in macrophages in tumor tissue may be a novel predictive biomarker for the efficacy of immunotherapy against metastatic CRC.

Novel adjuvant dendritic cell therapy with transfection of heat-shock protein 70 messenger RNA for patients with hepatocellular carcinoma: a phase I/II prospective randomized controlled clinical trial

INTRODUCTION

A proteomic analysis of hepatocellular carcinoma (HCC) has revealed that Heat Shock Protein 70 (HSP70) is among the cancer antigen proteins of HCC. Moreover, we confirmed that HSP70 was highly expressed in HCC by immunohistochemical staining. Based on these results, we developed an HSP70 mRNA-transfected dendritic cell (DC) therapy for treating unresectable or recurrent HCC, and the phase I trial was completed successfully. Thus, we aimed to investigate the safety and efficacy of this therapy as a postoperative adjuvant treatment after curative resection for HCC to prevent recurrence by conducting a phase I/II randomized controlled clinical trial.

METHODS

Patients (n = 45) with resectable HCC of stages II-IVa were registered and randomly assigned into two groups (DC group: 31 patients, control group: 14 patients) before surgery. The primary endpoint was disease-free survival (DFS), and the secondary endpoints were safety and overall survival. The DC therapy was initially administered at approximately 1 week after surgery, and twice every 3-4 weeks thereafter.

RESULTS

No adverse events specific to the immunotherapy were observed in the DC group. There was no difference in DFS between the DC and control groups (p = 0.666). However, in the subgroup with HSP70-expressing HCC, DFS of the DC group tended to be better (p = 0.090) and OS of the DC group was significantly longer (p = 0.003) than those of the control group.

CONCLUSION

The HSP70 mRNA-transfected DC therapy was performed safely as an adjuvant therapy. The prognosis of HSP70-expressing HCC cases could be expected to improve with this therapy.

Determining the protective characteristics and risk factors for the development of anastomotic leakage after low anterior resection for rectal cancer

Purpose

Anastomotic leakage is one of the most serious postoperative complications associated with surgery for rectal cancer. The present study aimed to identify the protective characteristics and risk factors associated with anastomotic leakage after low anterior resection for rectal cancer.

Methods

This was a retrospective, single-center study conducted between January 2009 and December 2017 at our institution. In total, 136 rectal cancer patients who underwent low anterior resection were included in the study. We analyzed preoperative and intraoperative factors. In addition, the pelvic dimensions were measured using computed tomography in all cases.

Results

Among the 136 patients, anastomotic leakage occurred in 21 (15.4%), including 18 males and 3 females. The median body mass index was 21.1 kg/m². The construction of a covering stoma was found to be a protective factor. In addition, the operation time (≥ 373 min), intraoperative blood loss (≥ 105 ml), and size of the pelvic inlet (≥ 113 mm) were identified as risk factors for anastomotic leakage.

Conclusion

The construction of a covering stoma was a possible protective factor. However, a longer operation time, higher intraoperative blood loss, and larger pelvic inlet dimensions were possible risk factors for developing anastomotic leakage after low anterior resection in patients with rectal cancer.

Multicenter International Society for Immunotherapy of Cancer Study of the Consensus Immunoscore for the Prediction of Survival and Response to Chemotherapy in Stage III Colon Cancer

PURPOSE

The purpose of this study was to evaluate the prognostic value of Immunoscore in patients with stage III colon cancer (CC) and to analyze its association with the effect of chemotherapy on time to recurrence (TTR).

METHODS

An international study led by the Society for Immunotherapy of Cancer evaluated the predefined consensus Immunoscore in 763 patients with American Joint Committee on Cancer/Union for International Cancer Control TNM stage III CC from cohort 1 (Canada/United States) and cohort 2 (Europe/Asia). CD3+ and cytotoxic CD8+ T lymphocyte densities were quantified in the tumor and invasive margin by digital pathology. The primary end point was TTR. Secondary end points were overall survival (OS), disease-free survival (DFS), prognosis in microsatellite stable (MSS) status, and predictive value of efficacy of chemotherapy.

RESULTS

Patients with a high Immunoscore presented with the lowest risk of recurrence, in both cohorts. Recurrence-free rates at 3 years were 56.9% (95% CI, 50.3% to 64.4%), 65.9% (95% CI, 60.8% to 71.4%), and 76.4% (95% CI, 69.3% to 84.3%) in patients with low, intermediate, and high immunoscores, respectively (hazard ratio [HR; high v low], 0.48; 95% CI, 0.32 to 0.71; P = .0003). Patients with high Immunoscore showed significant association with prolonged TTR, OS, and DFS (all P < .001). In Cox multivariable analysis stratified by participating center, Immunoscore association with TTR was independent (HR [high v low], 0.41; 95% CI, 0.25 to 0.67; P = .0003) of patient's sex, T stage, N stage, sidedness, and microsatellite instability status. Significant association of a high Immunoscore with prolonged TTR was also found among MSS patients (HR [high v low], 0.36; 95% CI, 0.21 to 0.62; P = .0003). Immunoscore had the strongest contribution χ2 proportion for influencing survival (TTR and OS). Chemotherapy was significantly associated with survival in the high-Immunoscore group for both low-risk (HR [chemotherapy v no chemotherapy], 0.42; 95% CI, 0.25 to 0.71; P = .0011) and high-risk (HR [chemotherapy v no chemotherapy], 0.5; 95% CI, 0.33 to 0.77; P = .0015) patients, in contrast to the low-Immunoscore group (P > .12).

CONCLUSION

This study shows that a high Immunoscore significantly associated with prolonged survival in stage III CC. Our findings suggest that patients with a high Immunoscore will benefit the most from chemotherapy in terms of recurrence risk.

Abstract CT251: Immunological and histopathological tumor responses to a novel neoadjuvant peptide vaccine targeting HSP70 and GPC3 antigens in patients with resectable HCC

Background: Even with curative resection, the recurrence rate of HCC remains high, and effective adjuvant therapies are not currently available. Our previous Phase I study with novel therapeutic peptides and immune adjuvants demonstrated safety, antigen-specific CTL induction in PBMC, and a sign of efficacy (ASCO 2017 Abstract # 3086). We thus started a Phase I study of the same vaccination therapy as a perioperative immunotherapy setting in patients with resectable HCC (jRCTs061180058). Methods: Two mg each of HLA-A*24:02, 02:01, or 02:06-restricted HSP70- and GPC3-derived peptides, in combination with hLAG-3Ig (1.0 mg) + poly-IC:LC (1.4 mg) were injected intradermally at four sites of the inguinal and axillary regions every week for 6 weeks before surgery. Patients subsequently received 10 injections of adjuvant immunotherapy over 4 months. Surgical specimens and PBMCs were analyzed by mass cytometry (CyTOF), using 66 antibodies to monitor T-cell exhaustion, T-cell activation, and effector Treg induction. Tumor specimens were also subjected to HE staining and immunohistochemical staining for CD3, CD8, PD1, HSP70, and GPC3. Results: Nine patients were treated with preoperative vaccination, and resected surgical specimens and PBMC were examined. Pathohistological analysis revealed three response types: “hot cellular immunity”, “intermediate fumoral immunity”, and “cold response”. In three patients, massive infiltration of CD8+ and PD1+ T cells accompanied necrotic and fibrous regions, in which the targeted tumor antigens HSP70 and GPC3 were highly expressed, representing “hot cellular immunity”. Regarding “intermediate”, three patients showed necrotic regions with infiltrating macrophages. HSP70 and/or GPC3 were also highly expressed, but little infiltration of lymphocytes was evident. In the remaining three patients, “cold response” manifested as tumor comprising a pseudo-glandular pattern with no infiltration of T cells or macrophages. Two of these three patients showed no expression of targeted tumor antigens. CyTOF analysis of the tumors also revealed the percentages of CD3+ cells among live cells and of PD1+ cells among CD8+ cells were extremely low in cold response. However, this trend was not observed in PBMCs, suggesting the critical importance of TIL analysis. Conclusions: This novel therapeutic peptide and immune adjuvant combination induced sustained immune cell infiltration into tumor microenvironments, especially in those presenting target tumor-associated antigens with a non-pseudo-glandular type. Our novel immunotherapy may convert cold tumors into hot tumors containing PD1+ lymphocytes. Combining this novel strategy with PD (L) 1 antibody may be warranted.

Citation Format: Masao Nakajima, Shoichi Hazama, Koji Tamada, Keiko Udaka, Shun Doi, Michiie Sakamoto, Akira Saito, Shiro Akinaga, Hiroto Matsui, Yoshitaro Shindo, Satoshi Matsukuma, Yukio Tokumitsu, Shinobu Tomochika, Michihisa Iida, Shin Yoshida, Ryouichi Tsunedomi, Yuki Nakagami, Nobuaki Suzuki, Shigeru Takeda, Hiroaki Nagano. Immunological and histopathological tumor responses to a novel neoadjuvant peptide vaccine targeting HSP70 and GPC3 antigens in patients with resectable HCC [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT251.

Serum LOX-1 is a novel prognostic biomarker of colorectal cancer

BACKGROUND

Colorectal cancer is the third most common cancer worldwide. If biomarkers can be identified in liquid biopsy, diagnosis and treatment can be optimized even when cancerous tissues are not available. The purpose of this study was to identify proteins from liquid biopsy that would be useful as markers of poor prognosis.

METHODS

First, we comprehensively analyzed serum proteins to identify potential biomarkers and focused on serum lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1). The relationship between LOX-1 and the prognosis of patients with colorectal cancer has not been reported. Next, we validated this marker using serum samples from 238 patients with colorectal cancer by ELISA and 100 tissue samples by immunohistochemical staining.

RESULTS

The optimal cut-off value of serum LOX-1 was 538.7 pg/mL according to time-dependent receiver operating characteristics curve analysis. The overall survival of patients with high levels of serum LOX-1 was significantly poorer than that of individuals with low levels of LOX-1 in the training and test datasets. In multivariate analysis for overall survival, serum LOX-1 was an independent prognostic factor identified in liquid biopsy (hazard ratio = 1.729, p = 0.027). The prognosis of patients with high LOX-1 expression in tumor tissues was significantly poorer than that of individuals with low expression (p =0.047 ). Additionally, inflammatory factors such as white blood cell count, C-reactive protein level, neutrophil/lymphocyte ratio, and monocyte/lymphocyte ratio were significantly higher in the group with high serum LOX-1 levels.

CONCLUSIONS

Serum LOX-1 might be a useful biomarker of poor prognosis in colorectal cancer.

A phase I study of multi-HLA-binding peptides derived from heat shock protein 70/glypican-3 and a novel combination adjuvant of hLAG-3Ig and Poly-ICLC for patients with metastatic gastrointestinal cancers: YNP01 trial

Background

This phase I study aimed to evaluate the safety, peptide-specific immune responses, and anti-tumor effects of a novel vaccination therapy comprising multi-HLA-binding heat shock protein (HSP) 70/glypican-3 (GPC3) peptides and a novel adjuvant combination of hLAG-3Ig and Poly-ICLC against metastatic gastrointestinal cancers.

Methods

HSP70/GPC3 peptides with high binding affinities for three HLA types (A*24:02, A*02:01, and A*02:06) were identified with our peptide prediction system. The peptides were intradermally administered with combined adjuvants on a weekly basis. This study was a phase I dose escalation clinical trial, which was carried out in a three patients’ cohort; in total, 11 patients were enrolled for the recommended dose.

Results

Seventeen patients received this vaccination therapy without dose-limiting toxicity. All treatment-related adverse events were of grades 1 to 2. Peptide-specific CTL induction by HSP70 and GPC3 proteins was observed in 11 (64.7%) and 13 (76.5%) cases, respectively, regardless of the HLA type. Serum tumor marker levels were decreased in 10 cases (58.8%). Immunological analysis using PBMCs indicated that patients receiving dose level 3 presented with significantly reduced T cell immunoglobulin and mucin-domain containing-3 (TIM3)-expressing CD4 + T cells after one course of treatment. PD-1 or TIM3-expressing CD4 + T cells and T cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT)-expressing CD8 + T cells in PBMCs before vaccination were negative predictive factors for survival.

Conclusions

This novel peptide vaccination therapy was safe for patients with metastatic gastrointestinal cancers.

Electronic supplementary material

The online version of this article (10.1007/s00262-020-02518-7) contains supplementary material, which is available to authorized users.

[A Case of Locally Advanced Rectal Cancer with Invasion to Other Organs in Which Pathological Complete Response Was Obtained with Neoadjuvant Chemotherapy]

A 67-year-old man was admitted with melena. A colonoscopy detected advanced rectal cancer, and a CT scan revealed invasion of the seminal vesicle and prostate. Given the wild-type RAS status of the tumor, we administered 6 courses of XELOX plus cetuximab as neoadjuvant chemotherapy. After treatment, the tumor had shrunk, and the rectum had narrowed. Later, following a diagnosis of coronary artery disease, colostomy was performed. The patient was treated for the coronary artery disease for 2 months. Following treatment, tumor progression was detected, and hence, the patient was treated with the same chemotherapy regimen for 4 more courses. We performed a laparoscopic assisted abdominoperineal resection of the rectum with combined resection of the seminal vesicle and prostate. Pathological examination revealed a complete response to treatment. Six months after the operation, no recurrence was observed without further adjuvant chemotherapy.

Clinical implications of cancer stem cells in digestive cancers: acquisition of stemness and prognostic impact

Digestive system cancers are the most frequent cancers worldwide and often associated with poor prognosis because of their invasive and metastatic characteristics. Recent studies have found that the plasticity of cancer cells can impart cancer stem-like properties via the epithelial-mesenchymal transition (EMT). Cancer stem-like properties such as tumor initiation are integral to the formation of metastasis, which is the main cause of poor prognosis. Numerous markers of cancer stem cells (CSCs) have been identified in many types of cancer. Therefore, CSCs, via their stem cell-like functions, may play an important role in prognosis after surgery. While several reports have described prognostic analysis using CSC markers, few reviews have summarized CSCs and their association with prognosis. Herein, we review the prognostic potential of eight CSC markers, CD133, CD44, CD90, ALDH1A1, EPCAM, SOX2, SOX9, and LGR5, in digestive cancers including those of the pancreas, colon, liver, gastric, and esophagus.

Efficacy of primary liver organoid culture from different stages of non-alcoholic steatohepatitis (NASH) mouse model

Non-alcoholic steatohepatitis (NASH) is associated with liver fibrosis and cirrhosis, which eventually leads to hepatocellular carcinoma. Although several animal models were developed to understand the mechanisms of NASH pathogenesis and progression, it remains obscure. A 3D organoid culture system can recapitulate organ structures and maintain gene expression profiles of original tissues. We therefore tried to generate liver organoids from different degrees [defined as mild (NASH A), moderate (NASH B) and severe (NASH C)] of methionine- and choline-deficient diet-induced NASH model mice and analyzed the difference of their architecture, cell components, organoid-forming efficacy, and gene expression profiles. Organoids from each stage of NASH model mice were successfully generated. Interestingly, epithelial-mesenchymal transition was observed in NASH C organoids. Expression of Collagen I and an activated hepatic stellite cell marker, α-sma was upregulated in the liver organoids from NASH B and C mice. The analysis of RNA sequencing revealed that several novel genes were upregulated in all NASH liver organoids. These results suggest that our generated liver organoids from different stages of NASH diseased mice might become a useful tool for in vitro studies of the molecular mechanism of NASH development and also for identifying novel biomarkers for early diagnosis of NASH disease.

[A Case of Surgical Resection of an Esophageal Gastrointestinal Stromal Tumor after Neoadjuvant Therapy with Imatinib]

A 64-year-old man presented with dysphagia. Esophagogastroduodenoscopy revealed a submucosal tumor of 52mm in size at the lower thoracic esophagus. Biopsy yielded a pathological diagnosis of c-kit-positive esophageal gastrointestinal stromal tumor(GIST). We started neoadjuvant therapy with imatinib to avoid excessive surgical invasion. After 6 months of treatment, CT revealed a reduction in tumor size to 27 mm. We performed laparoscopic lower esophagectomy, proximal gastrectomy, double-tract reconstruction, and complete tumor resection. Neoadjuvant imatinib therapy was effective for the esophageal GIST.

[A Case of Borderline Resectable Pancreatic Adenosquamous Carcinoma Achieving Pathological Complete Response]

The patient was a 66-year-old man presenting with epigastric pain and jaundice. PET-CT demonstrated limited-accumulation on the tumor at the head of the pancreas, diagnosed as borderline resectable adenosquamous carcinoma. The patient was treated with preoperative chemoradiation therapy with 2 courses of gemcitabine followed by administration of S-1 and gemcitabine for 13 months, which reduced the tumor size. After preoperative therapy, pancreaticoduodenectomy was performed. Histopathological examination revealed that no viable tumor cells were detected in the pancreas or lymph nodes, and the patient had achieved a pathological complete response. Postoperative adjuvant chemotherapy was not performed, and the patient is still alive without recurrence for 66 months after surgery.

[A Case of Mucinous Cystoadenocarcinoma with Metastatic Liver Tumor in a Young Woman Lacking Specific Findings]

The patient was a 17-year-old woman. An abnormal urinalysis was observed, and abdominal echography showed a pancreatic cystic mass. At the first examination, computed tomography(CT)and endoscopic ultrasound(EUS)showed a unilocular cystic mass of 60mm in size in the pancreatic body and tail, and no malignant findings were observed. After 14 months, CT and positron emission tomography-computed tomography(PET-CT)showed that the cystic mass had a mural nodule with FDG accumulation, and presence of a tumor in hepatic S8 with FDG accumulation. Laparoscopic distal pancreatectomy and hepatic subsegmentectomy of S8 were performed for diagnostic and therapeutic purposes. The pathological diagnosis was mucinous cystadenocarcinoma(MCC)and metastatic liver cancer in the form of MCC. S-1 was administered after surgery. Nine months after resection, multiple metastatic liver tumors were found, and GEM plus nab-PTX was administered. After 2 courses of treatment, the patient is still alive without new lesions.

Association between polymorphisms in EGFR and tumor response during cetuximab and oxaliplatin-based combination therapy in metastatic colorectal cancer: Analysis of data from two clinical trials

Predicting tumor response prior to starting anti-epidermal growth factor receptor (EGFR) antibody therapy would benefit patients with advanced/metastatic colorectal cancer (mCRC). The present study investigated the association between efficacy of cetuximab treatment and gene polymorphisms of fragment C γ receptor (FcγR) 2A, FcγR3A and EGFR in patients with extended RAS/BRAF wild-type mCRC. Clinical data and specimens were obtained from 90 patients who participated in either of two clinical studies evaluating the first-line, cetuximab plus oxaliplatin-based treatment. It was hypothesized that polymorphisms H/H of FcγR2A, V/V of FcγR3A, K/K of EGFR and <36 CA repeats in the EGFR gene may be associated with a favorable tumor response. Multivariate analysis demonstrated that patients with the H/H polymorphism tended to have an improved tumor response compared with the non-H/H population, although the result was not significant [odds ratio, 2.25; 95% confidence interval (CI), 0.89–5.66; P=0.09]. Univariate analysis revealed increased tumor shrinkage in patients with the K/K polymorphism of EGFR compared with the other polymorphisms (mean ± standard deviation, −55.3±28.4 vs. −39.6±40.8%; P=0.04). Subsequent multivariate analysis confirmed that the K/K polymorphism of EGFR predicted greater tumor shrinkage (multiple linear regression analysis estimate, −19.3; 95% CI, −35.5 to 3.0; P=0.02), with the tendency toward a preferable response in patients with <36 CA EGFR gene repeats (estimate, −16.9; 95% CI; −34.4 to 0.6; P=0.06). However, other polymorphisms and clinical variables did not predict tumor shrinkage. In conclusion, the present study demonstrated that polymorphisms of EGFR, FcγR2A and FcγR3A may differentiate the patients that obtain the maximum benefit from cetuximab treatment.

Intratumoural-infiltrating CD4 + and FOXP3 + T cells as strong positive predictive markers for the prognosis of resectable colorectal cancer

Background

CD3 +  and CD8 + T-cell infiltration were reported as positive predictive markers of survival in colorectal cancer (CRC) patients. Here, we demonstrate the prognostic significance of CD4 + and FOXP3 + T-cell densities in CRC.

Methods

We quantified the intratumoural densities of CD3 + , CD8 + , CD4 +  and FOXP3 + T cells by immunohistochemistry and digital pathology in 342 CRC patients who underwent curative resection. Microsatellite instability was also assessed in 322 specimens. Patient demographics, clinicopathological features and survival rates were analysed.

Results

High CD3 + , CD4 +  and FOXP3 + T-cell densities were associated with improved relapse-free survival (RFS); high CD8 + , CD4 +  and FOXP3 + T-cell densities were associated with improved disease-specific survival (DSS). Patients with low CD4 + and low FOXP3 + T-cell densities exhibited extremely poor prognoses. T stage, vascular/lymphatic invasion and CD4 + T-cell density were independent prognostic indicators for DSS. The distributions of CD4 + and FOXP3 + T-cell densities were not significantly different between the high microsatellite instability group and other groups, in contrast to those of CD3 + and CD8 + T-cell densities.

Conclusions

Intratumoural CD4 + T-cell density and combined CD4 + and FOXP3 + T-cell densities were stronger prognostic indicators than other clinicopathological features. These results may facilitate the establishment of novel prognostic factors and therapeutic strategies for CRC.

[Cancer Vaccine Focused on Neoantigens]

Recent advances in cancer immunotherapies, such as immune checkpoint inhibitors(ICIs), have shown some durable clinical responses in patients with various types of advanced cancers. The development of the next-generation sequencing technologies can result in a comprehensive characterization of the human cancer genomes. Personalized immunotherapy and precision cancer medicine might enable the next generation of rational cancer immunotherapy. Conventional cancer vaccines are designed to target tumor-associated antigens(TAAs), which are overexpressed in cancers. However, since TAAs are also expressed in normal tissues, cancer vaccine against TAAs can potentially initiate central and peripheral tolerance responses, which results in low vaccination efficiency. Cancer neoantigens derived from somatic mutations in tumor tissue represent highly immunogenic and can escape from central thymic tolerance. They are suggested to provide tumor specific targets for personalized cancer vaccines. Therefore, neoantigen-based cancer vaccine, which can induce tumor-specific cytotoxic T lymphocytes( CTLs), should be developed. The efficacy of current immunotherapies also remains limited due to the immunosuppressive tumor microenvironment, which leads to CTLs exhaustion or anergy and the escape of tumor cells from immune attack. The combination of neoantigen-based cancer vaccine and ICIs should be a potential therapeutic approach. In this paper, we provide a brief overview of the recent advances in the development of neoantigen-based cancer vaccines.

Novel Biomarkers for Personalized Cancer Immunotherapy

Cancer immunotherapy has emerged as a novel and effective treatment strategy for several types of cancer. Immune checkpoint inhibitors (ICIs) have recently demonstrated impressive clinical benefit in some advanced cancers. Nonetheless, in the majority of patients, the successful use of ICIs is limited by a low response rate, high treatment cost, and treatment-related toxicity. Therefore, it is necessary to identify predictive and prognostic biomarkers to select the patients who are most likely to benefit from, and respond well to, these therapies. In this review, we summarize the evidence for candidate biomarkers of response to cancer immunotherapy.

Genomic profiles of colorectal carcinoma with liver metastases and newly identified fusion genes

Every year, approximately 1.2 million cases of colorectal carcinoma (CRC) are newly diagnosed worldwide. Although metastases to distant organs are often fatal complications of CRC, little information is known as to how such metastatic lesions are formed. To reveal the genetic profiles for CRC metastasis, we conducted whole‐exome RNA sequencing on CRC tumors with liver metastasis (LM) (group A, n = 12) and clinical stage‐matched larger tumors without LM (group B, n = 16). While the somatic mutation profiles were similar among the primary tumors and LM lesions in group A and the tumors in group B, the A‐to‐C nucleotide change in the context of “AAG” was only enriched in the LM regions in group A, suggesting the presence of a DNA damage process specific to metastasis. Genes already known to be associated with CRC were mutated in all groups at a similar frequency, but we detected somatic nonsynonymous mutations in a total of 707 genes in the LM regions, but not in the tumors without LM. Signaling pathways linked to such “LM‐associated” genes were overrepresented for extracellular matrix‐receptor interaction or focal adhesion. Further, fusions of the ADAP1 (ArfGAP with dual PH domain 1) were newly identified in our cohort (3 out of 28 patients), which activated ARF6, an ADAP1‐substrate. Infrequently, mutated genes may play an important role in metastasis formation of CRC. Additionally, recurrent ADAP1 fusion genes were unexpectedly discovered. As these fusions activate small GTPase, further experiments are warranted to examine their contribution to CRC carcinogenesis.