High serum proteinase-3 levels predict poor progression-free survival and lower efficacy of bevacizumab in metastatic colorectal cancer

BACKGROUND

To improve the prognosis of patients with metastatic colorectal cancer (mCRC), investigating predictive biomarkers of their prognosis and chemotherapeutic responsiveness is necessary. This study aimed to analyze the clinical significance of serum proteinase-3 (PRTN3) as a predictor for prognosis and chemosensitivity, especially to bevacizumab therapy, in mCRC.

METHODS

This single-center retrospective observational study enrolled 79 patients with mCRC in our hospital and 353 patients with colorectal cancer in the TCGA database. Preoperative serum PRTN3 levels were measured using an enzyme-linked immunosorbent assay. The clinicopathological characteristics and prognosis according to serum PRTN3 levels were then evaluated. PRTN3 expression in tumor and stromal cells was evaluated immunohistochemically. The impact of PRTN3 levels on angiogenesis and bevacizumab sensitivity was evaluated using the tube formation assay.

RESULTS

Serum PRTN3 levels were an independent poor prognostic factor for progression-free survival (PFS) (hazard ratio, 2.082; 95% confidence interval, 1.118-3.647; P=0.010) in patients with mCRC. Similarly, prognostic analysis with TCGA data sets showed poorer overall survival in patients with PRTN3 expression than that in patients without PRTN3 expression, especially in patients with stage IV. Immunohistochemical analysis of resected specimens revealed that stromal neutrophils expressed PRTN3, and their expression level was significantly correlated with serum PRTN3 levels. Interestingly, the effectiveness of first-line chemotherapy was significantly poorer in the high serum PRTN3 level group. High serum PRTN3 was significantly associated with poor PFS (hazard ratio, 3.027; 95% confidence interval, 1.175-7.793; P=0.0161) in patients treated with bevacizumab, an anti-angiogenic inhibitor. The tube formation assay revealed that PRTN3 administration notably augmented angiogenesis while simultaneously attenuating the anti-angiogenic influence exerted by bevacizumab therapy.

CONCLUSIONS

Serum PRTN3 levels could be a novel predictive biomarker of PFS of first-line chemotherapy, especially for bevacizumab therapy, in patients with mCRC.

[A Recurrent Colon Cancer Successfully Treated by Nivolumab plus Ipilimumab with On and Off for Preventing Exacerbation of Skin Disorders]

Here, we report a case in which nivolumab plus ipilimumab combination therapy was significantly effective for MSI-high recurrent colon cancer with acute exacerbation after 5-FU/L-OHP/CPT-11 treatment. At the end of 4 cycles of combination therapy, clinical CR was obtained on diagnostic imaging. At the end of the 2 cycles of transition from combination therapy to monotherapy, eosinophilia was observed in a quadratic function, and exacerbation of skin disorders was observed. Eosinophil counts normalized promptly after discontinuation of treatment, and skin disorders gradually improved. Two months after the discontinuation of treatment, monotherapy was restarted. After the resumption of treatment, an increase in eosinophils and worsening of skin symptoms were observed again, and stopped treatment. We report an interesting case in which immune checkpoint inhibiter were turned on and off according to eosinophil counts for preventing exacerbation of skin disorders, and for maintaining cancer remission by continuing immune checkpoint inhibitor treatment.

IL-6 Levels Correlate with Prognosis and Immunosuppressive Stromal Cells in Patients with Colorectal Cancer

BACKGROUND

The prognosis for patients with colorectal cancer (CRC) is determined by tumor characteristics as well as the host immune response. This study investigated the relationship between an immunosuppressive state and patient prognosis by evaluating the systemic and tumor microenvironment (TME) interleukin (IL)-6 levels.

METHODS

Preoperative serum IL-6 levels were measured using an electrochemiluminescence assay. Expression of IL-6 in tumor and stromal cells was evaluated immunohistochemically in 209 patients with resected CRC. Single-cell analysis of tumor-infiltrating immune cells was performed using mass cytometry in 10 additional cases.

RESULTS

Elevated serum IL-6 levels were associated with elevated stromal IL-6 levels and a poor prognosis for patients with CRC. High IL-6 expression in stromal cells was associated with low-density subsets of CD3+ and CD4+ T cells as well as FOXP3+ cells. Mass cytometry analysis showed that IL-6+ cells among tumor-infiltrating immune cells were composed primarily of myeloid cells and rarely of lymphoid cells. In the high-IL-6-expression group, the percentages of myeloid-derived suppressor cells (MDSCs) and CD4+FOXP3highCD45RA- effector regulatory T cells (eTreg) were significantly higher than in the low-IL-6-expression group. Furthermore, the proportion of IL-10+ cells in MDSCs and that of IL-10+ or CTLA-4+ cells in eTregs correlated with IL-6 levels.

CONCLUSION

Elevated serum IL-6 levels were associated with stromal IL-6 levels in CRC. High IL-6 expression in tumor-infiltrating immune cells also was associated with accumulation of immunosuppressive cells in the TME.

A phase I study of a novel therapeutic vaccine as perioperative treatment for patients with surgically resectable hepatocellular carcinoma: The YCP02 trial

BACKGROUND

Developing effective adjuvant therapies is essential for improving the surgical outcomes in patients with hepatocellular carcinoma (HCC). Immunotherapy against HCC has become a promising strategy; however, only approximately 30% of all HCC patients respond to immunotherapy. Previously, we generated the novel therapeutic vaccine comprising multi-HLA-binding heat shock protein (HSP)70/glypican-3 (GPC3) peptides with a novel adjuvant combination of hLAG-3Ig and poly-ICLC. We also confirmed the safety of this vaccination therapy, as well as its capacity for the effective induction of immune responses in a previous clinical trial.

METHODS

In this phase I study, we administered this vaccine intradermally six times before surgery and ten times after surgery to patients with untreated, surgically resectable HCC (stage II to IVa). The primary endpoints of this study were the safety and feasibility of this treatment. We also analyzed the resected tumor specimens pathologically using hematoxylin and eosin staining and immunohistochemistry for HSP70, GPC3, CD8 and PD-1.

RESULTS

Twenty HLA-matched patients received this vaccination therapy with an acceptable side-effect profile. All patients underwent planned surgery without vaccination-related delay. Immunohistochemical analyses revealed that potent infiltration of CD8+ T cells into tumors with target antigen expression was observed in 12 of 20 (60%) patients.

CONCLUSIONS

This novel therapeutic vaccine was safe as perioperative immunotherapy for patients with HCC and has the potential to strongly induce CD8+ T cells infiltration into tumors. This article is protected by copyright. All rights reserved.

Development of multiple AI pipelines that predict neoadjuvant chemotherapy response of breast cancer using H&E-stained tissues

In recent years, the treatment of breast cancer has advanced dramatically and neoadjuvant chemotherapy (NAC) has become a common treatment method, especially for locally advanced breast cancer. However, other than the subtype of breast cancer, no clear factor indicating sensitivity to NAC has been identified. In this study, we attempted to use artificial intelligence (AI) to predict the effect of preoperative chemotherapy from hematoxylin and eosin images of pathological tissue obtained from needle biopsies prior to chemotherapy. Application of AI to pathological images typically uses a single machine-learning model such as support vector machines (SVMs) or deep convolutional neural networks (CNNs). However, cancer tissues are extremely diverse and learning with a realistic number of cases limits the prediction accuracy of a single model. In this study, we propose a novel pipeline system that uses three independent models each focusing on different characteristics of cancer atypia. Our system uses a CNN model to learn structural atypia from image patches and SVM and random forest models to learn nuclear atypia from fine-grained nuclear features extracted by image analysis methods. It was able to predict the NAC response with 95.15% accuracy on a test set of 103 unseen cases. We believe that this AI pipeline system will contribute to the adoption of personalized medicine in NAC therapy for breast cancer.

Anti-VEGF and Anti-EGFR Antibody Therapy on T-Cell Infiltration and TCR Variation in Metastatic Colorectal Cancer

BACKGROUND/AIM

Chemotherapy combined with anti-EGFR or anti-VEGF monoclonal antibodies (mAb) is widely used to treat patients with metastatic colorectal cancer (mCRC). Here, we investigated the effects of these antibodies on T-cell infiltration and T-cell receptor (TCR) repertoire variation in CRC liver metastases.

MATERIALS AND METHODS

Ten patients with mCRC received chemotherapy in combination with anti-EGFR (n=6) or anti-VEGF (n=4) mAb. T-cell infiltration was examined for CD3 and CD8 by carrying out immunohistochemistry on biopsy or surgical specimens from liver metastases before and after treatment. TCR repertoire analysis was carried out on specimens with post-treatment CD3⁺ T-cell infiltration.

RESULTS

T-cell infiltrations were approximately 83% (5/6) and 50% (2/4), following treatment with anti-EGFR or anti-VEGF mAb, respectively. TCR repertoire analysis revealed higher clonality and lower diversity of TCR alpha and beta (TRA and TRB) in the anti-VEGF mAb group than that in the anti-EGFR group mAb. Furthermore, the percentage of the common TCR clones between infiltrating T cells and T cells in peripheral blood was significantly lower in the anti-VEGF mAb group compared to that in the anti-EGFR mAb group.

CONCLUSION

The population of T cells infiltrating liver metastases in the anti-VEGF mAb group differed from that in the anti-EGFR mAb group.

Association between a single nucleotide polymorphism in the R3HCC1 gene and irinotecan toxicity

OBJECTIVE

Irinotecan is a useful anticancer drug for colorectal cancer treatment. UGT1A1*28 and *6 gene polymorphisms are known risk factors for irinotecan-associated toxicity. However, severe adverse effects due to irinotecan have been observed even in patients who do not harbor UGT1A1*28 or *6. We investigated gene polymorphisms in the whole exome to identify useful biomarkers for irinotecan toxicity other than UGT1A.

METHODS

A total of 178 patients with metastatic colorectal cancer (mCRC) and 87 patients with pancreatic cancer were treated with FOLFIRI, FOLFOX, FOLFOXIRI, modified FOLFIRINOX, or gemcitabine plus nab-paclitaxel. Genome-wide screening was performed using whole-exome sequencing (WES), and validation analysis was performed using qPCR with a hydrolysis probe.

RESULTS

Using WES after a doublet chemotherapy regimen comprising irinotecan and 5-fluorouracil (n = 15), seven single nucleotide polymorphisms (SNPs) were identified as candidate biomarkers for irinotecan-associated toxicity of neutropenia. Among the seven SNPs, an SNP in R3H domain and coiled-coil containing 1 (R3HCC1; c.919G > A, rs2272761) showed a significant association with neutropenia (>grade 3) after doublet chemotherapy. Patients receiving irinotecan including triplet chemotherapy, FOLFOXIRI for mCRC (n = 23) or modified FOLFIRINOX for pancreatic cancer (n = 40), also showed significant linear trends between R3HCC1 polymorphism and neutropenia (p = 0.017 and 0.046, respectively). No significant association was observed in patients treated with irinotecan-free regimens, FOLFOX for mCRC (n = 66), and gemcitabine plus nab-paclitaxel for pancreatic cancer (n = 47).

CONCLUSION

Thus, an SNP in the R3HCC1 gene may be a useful biomarker for the toxicity of irinotecan-containing chemotherapy for mCRC and pancreatic cancer.

Multicenter International Study of the Consensus Immunoscore for the Prediction of Relapse and Survival in Early-Stage Colon Cancer

Background: The prognostic value of Immunoscore was evaluated in Stage II/III colon cancer (CC) patients, but it remains unclear in Stage I/II, and in early-stage subgroups at risk. An international Society for Immunotherapy of Cancer (SITC) study evaluated the pre-defined consensus Immunoscore in tumors from 1885 AJCC/UICC-TNM Stage I/II CC patients from Canada/USA (Cohort 1) and Europe/Asia (Cohort 2). METHODS: Digital-pathology is used to quantify the densities of CD3+ and CD8+ T-lymphocyte in the center of tumor (CT) and the invasive margin (IM). The time to recurrence (TTR) was the primary endpoint. Secondary endpoints were disease-free survival (DFS), overall survival (OS), prognosis in Stage I, Stage II, Stage II-high-risk, and microsatellite-stable (MSS) patients. RESULTS: High-Immunoscore presented with the lowest risk of recurrence in both cohorts. In Stage I/II, recurrence-free rates at 5 years were 78.4% (95%-CI, 74.4−82.6), 88.1% (95%-CI, 85.7−90.4), 93.4% (95%-CI, 91.1−95.8) in low, intermediate and high Immunoscore, respectively (HR (Hi vs. Lo) = 0.27 (95%-CI, 0.18−0.41); p < 0.0001). In Cox multivariable analysis, the association of Immunoscore to outcome was independent (TTR: HR (Hi vs. Lo) = 0.29, (95%-CI, 0.17−0.50); p < 0.0001) of the patient’s gender, T-stage, sidedness, and microsatellite instability-status (MSI). A significant association of Immunoscore with survival was found for Stage II, high-risk Stage II, T4N0 and MSS patients. The Immunoscore also showed significant association with TTR in Stage-I (HR (Hi vs. Lo) = 0.07 (95%-CI, 0.01−0.61); P = 0.016). The Immunoscore had the strongest (69.5%) contribution χ2 for influencing survival. Patients with a high Immunoscore had prolonged TTR in T4N0 tumors even for patients not receiving chemotherapy, and the Immunoscore remained the only significant parameter in multivariable analysis. CONCLUSION: In early CC, low Immunoscore reliably identifies patients at risk of relapse for whom a more intensive surveillance program or adjuvant treatment should be considered.

Serum CCL7 Is a Novel Prognostic Biomarker of Metastatic Colorectal Cancer

BACKGROUND/AIM

Colorectal cancer is the third most common cancer globally, and the poor prognosis of patients with metastatic colorectal cancer (mCRC) warrants urgent attention. We previously obtained 10 candidate serum biomarkers for mCRC. Our aim with this study was to determine the prognostic performance of the pre-treatment serum C-C motif chemokine ligand 7 (CCL7) concentration in patients with mCRC.

PATIENTS AND METHODS

Protein concentrations of CCL7 were examined using ELISA and immunohistochemistry for serum (n=110) and surgical specimens (n=85), respectively, of patients with mCRC. The relationship between protein concentration and prognosis was examined using Cox regression analysis, receiver operator characteristic curve analysis and the Kaplan-Meier method.

RESULTS

The overall survival (OS) of patients with high concentrations of serum CCL7 was significantly poorer than that of patients with low concentrations. Patients with a high CCL7 concentration in the stroma had significantly poorer outcomes than those with a low concentration. The concentrations of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 were significantly higher in the high-CCL7 group, compared to those in the low-CCL7 group. Univariate and multivariate analysis revealed that serum CCL7 concentration was a significant prognostic factor for mCRC. The combination of serum CCL and CEA concentrations was also useful in this regard (area under the curve=0.71).

CONCLUSION

The combined pre-treatment serum levels of CCL7 and CEA are useful prognostic biomarkers for mCRC.

CD4 and FOXP3 as predictive markers for the recurrence of T3/T4a stage II colorectal cancer: applying a novel discrete Bayes decision rule

Background

We recently reported the relapse-free survival (RFS) significance of the combination of CD4⁺ and forkhead box P3⁺ (FOXP3) T-cell densities identified by immunohistochemistry in patients with stage I, II, and III colorectal cancer (CRC) who underwent curative resections. This study was designed to determine the optimal combination of markers that predict recurrence in patients with T factors of T3/T4a stage II CRC by applying a novel Bayes decision rule.

Methods

Using 137 cancer tissue specimens from T3/T4a stage II patients, 12 clinicopathologic and immune factors were analysed as predictive candidates for recurrence.

Results

Our study showed that the combination of low CD4⁺ and low FOXP3⁺ T-cell densities resulted in extremely poor RFS.

Conclusions

Adjuvant chemotherapy may be considered for patients with a combination of low CD4⁺ and low FOXP3⁺ T-cell densities. The discovery of this new prognostic indicator is important for the appropriate management of patients undergoing curative resection for T3/T4a stage II CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10181-7.

Clinical Performance of the Consensus Immunoscore in Colon Cancer in the Asian Population from the Multicenter International SITC Study

BACKGROUND: In this study, we evaluated the prognostic value of Immunoscore in patients with stage I−III colon cancer (CC) in the Asian population. These patients were originally included in an international study led by the Society for Immunotherapy of Cancer (SITC) on 2681 patients with AJCC/UICC-TNM stages I−III CC. METHODS: CD3+ and cytotoxic CD8+ T-lymphocyte densities were quantified in the tumor and invasive margin by digital pathology. The association of Immunoscore with prognosis was evaluated for time to recurrence (TTR), disease-free survival (DFS), and overall survival (OS). RESULTS: Immunoscore stratified Asian patients (n = 423) into different risk categories and was not impacted by age. Recurrence-free rates at 3 years were 78.5%, 85.2%, and 98.3% for a Low, Intermediate, and High Immunoscore, respectively (HR[Low-vs-High] = 7.26 (95% CI 1.75−30.19); p = 0.0064). A High Immunoscore showed a significant association with prolonged TTR, OS, and DFS (p < 0.05). In Cox multivariable analysis stratified by center, Immunoscore association with TTR was independent (HR[Low-vs-Int+High] = 2.22 (95% CI 1.10−4.55) p = 0.0269) of the patient’s gender, T-stage, N-stage, sidedness, and MSI status. A significant association of a High Immunoscore with prolonged TTR was also found among MSS (HR[Low-vs-Int+High] = 4.58 (95% CI 2.27−9.23); p ≤ 0.0001), stage II (HR[Low-vs-Int+High] = 2.72 (95% CI 1.35−5.51); p = 0.0052), low-risk stage-II (HR[Low-vs-Int+High] = 2.62 (95% CI 1.21−5.68); p = 0.0146), and high-risk stage II patients (HR[Low-vs-Int+High] = 3.11 (95% CI 1.39−6.91); p = 0.0055). CONCLUSION: A High Immunoscore is significantly associated with the prolonged survival of CC patients within the Asian population.

[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.

Immune Evasion of Hepatoma Cancer Stem-Like Cells from Natural Killer Cells

BACKGROUND

Poor prognosis in liver cancer is due to its high frequency of intrahepatic metastasis. Cancer stem-like cells (CSLCs), which possess the properties of stemness, tumor initiation capability, and resistance to therapy, also exhibit metastatic potential. Immune surveillance plays an important role in the accomplishment of metastasis. Herein, the property of immune evasion in CSLCs was investigated.

METHODS

Sphere cells were induced as CSLCs using a sphere induction medium containing neural survival factor-1. The expression of genes involved in immune evasion was determined using RNA-sequencing for sphere and parental cells followed by validation using flow cytometric analysis and ELISA. Susceptibility to natural killer (NK) cell-mediated cytotoxicity was examined by a chromium release assay. A xenograft model using BALB/c nu/nu mice was used to assess tumor growth. Gene set enrichment analysis was performed for interpreting RNA sequencing.

RESULTS

The cell surface expressions of PD-L1, PD-L2, and CEACAM1 were upregulated and those of ULBP1 and MICA/MICB were downregulated in SK-sphere, CSLCs derived from SK-HEP-1, compared with that in parental cells. Levels of soluble MICA were elevated in conditioned medium from SK-sphere. Expression of HLA class I was not downregulated in SK-sphere. The susceptibilities to NK cell-mediated killing and secreted perforin were significantly lower in both CSLCs derived from SK-HEP-1 and HLE than in parental cells. Tumors formed upon inoculation of SK-sphere in immunodeficient mice harboring NK cells were larger than those formed upon inoculation of parental cells.

CONCLUSION

Human hepatoma cell line-derived CSLCs may possess immune evasion properties, especially from NK cell-mediated immunity.

Comparison of two primer-probe sets of Fusobacterium nucleatum using droplet digital polymerase chain reaction for the detection of colorectal neoplasia from faecal samples

BACKGROUND

Although faecal DNA testing of Fusobacterium nucleatum (Fn) is expected to be useful for colorectal neoplasia detection, there is no standardized quantification method of Fn. We performed this study to establish a possible standardized method.

METHODS

In this study, 322 participants including 71 subjects without colorectal neoplasia (control group), 31 patients with non-advanced colorectal adenoma, 93 patients with advanced colorectal adenoma, and 127 patients with colorectal cancer were enrolled. Faecal Fn were quantified by droplet digital PCR (ddPCR) using two PCR primer-probe sets reported previously that are tentatively named Fn1 and Fn2. Fn1 has been used in ddPCR by us and Fn2 has been widely used in quantitative real-time PCR.

RESULTS

The Fn copy number using Fn1 was five times higher than that using Fn2, with a linear relationship shown between them. Receiver operating characteristic curve analysis showed the area under the curve (AUC) to be almost the same between Fn1 and Fn2 in discriminating between the control group and the colorectal cancer group (AUC = 0.81 and 0.81, respectively), and between the control/non-advanced colorectal adenoma group and the advanced colorectal adenoma/colorectal cancer group (AUC = 0.74 and 0.74, respectively).

CONCLUSIONS

As the diagnostic performance was quite similar between Fn1 and Fn2, ddPCR-based Fn testing using Fn1 and Fn2 could be a possible standardized method for a colorectal neoplasia screening test, considering that Fn levels quantified by Fn1 are about five times higher than those by Fn2.

Elevated expression of RAB3B plays important roles in chemoresistance and metastatic potential of hepatoma cells

Background

Cancer stem cells (CSCs) are thought to play important roles in carcinogenesis, recurrence, metastasis, and therapy-resistance. We have successfully induced cancer stem-like sphere cells (CSLCs) which possess enhanced chemoresistance and metastatic potential. To enable the development of targeted therapy against CSLCs, we identified a gene responsible for this phenotype in CSLC.

Methods

Human hepatoma cell line SK-HEP-1 was used for CSLC induction with a unique sphere inducing medium, and HuH-7 cells were used as non-sphere forming cells in the same condition. RNA-sequencing was performed followed by validation with quantitative RT-PCR and western blotting. Knockdown experiments were done by using CRISPR-Cas9 genome-editing, and the rescue experiments were performed using the expressing plasmid vector. Chemoresistance and liver metastasis of the cells, was studied following the splenic injection of cells to severely immune deficient mice and evaluated using the MTS assay. Quantification of exosomes in the medium was done using ELISA.

Results

RAB3B was identified as an up-regulated gene in both CSLCs and prognostically poor hepatocellular carcinoma (HCC) by RNA-sequencing. RAB3B-KD cells showed altered CSLC phenotypes such as sphere formation, chemoresistance, and metastatic potentials, and those were rescued by RAB3B complementation. Increased exosome secretion was observed in CSLCs, and it was not observed in the RAB3B-KD cells. In addition, the RAB3B expression correlated with the expression of ABCG2, APOE, LEPR, LXN, and TSPAN13.

Conclusion

The up regulation of RAB3B may play an important role in the chemoresistance and metastatic potential of CSLCs.

HLA Class I Analysis Provides Insight Into the Genetic and Epigenetic Background of Immune Evasion in Colorectal Cancer With High Microsatellite Instability

BACKGROUND & AIMS

A detailed understanding of antitumor immunity is essential for optimal cancer immune therapy. Although defective mutations in the B2M and HLA-ABC genes, which encode molecules essential for antigen presentation, have been reported in several studies, the effects of these defects on tumor immunity have not been quantitatively evaluated.

METHODS

Mutations in HLA-ABC genes were analyzed in 114 microsatellite instability-high colorectal cancers using a long-read sequencer. The data were further analyzed in combination with whole-exome sequencing, transcriptome sequencing, DNA methylation array, and immunohistochemistry data.

RESULTS

We detected 101 truncating mutations in 57 tumors (50%) and loss of 61 alleles in 21 tumors (18%). Based on the integrated analysis that enabled the immunologic subclassification of microsatellite instability-high colorectal cancers, we identified a subtype of tumors in which lymphocyte infiltration was reduced, partly due to reduced expression of HLA-ABC genes in the absence of apparent genetic alterations. Survival time of patients with such tumors was shorter than in patients with other tumor types. Paradoxically, tumor mutation burden was highest in the subtype, suggesting that the immunogenic effect of accumulating mutations was counterbalanced by mutations that weakened immunoreactivity. Various genetic and epigenetic alterations, including frameshift mutations in RFX5 and promoter methylation of PSMB8 and HLA-A, converged on reduced expression of HLA-ABC genes.

CONCLUSIONS

Our detailed immunogenomic analysis provides information that will facilitate the improvement and development of cancer immunotherapy.

[A Case of Pseudo-Meigs' Syndrome Caused by Ovarian Metastasis from Colon Cancer]

This case pertains to a female patient in her 60s who was diagnosed with carcinoma in the cecum with lung, ovarian, and peritoneal metastases. She complained of abdominal distension and poor feeding because her ascites and ovarian metastasis worsened 18 months after chemotherapy initiation. Repeated cytologic examination of the ascitic fluid revealed no malignant cells. Therefore, Pseudo-Meigs' syndrome was suspected. Bilateral salpingo-oophorectomy was performed as palliative surgery because of the patient's reduced capacity to perform activities of daily living(ADL)due to ascites. After palliative surgery, her ascites disappeared, and she was able to better perform ADL. Further, chemotherapy was resumed. The patient remains well 10 months after surgery. This case highlights the importance of considering Pseudo-Meigs' syndrome in patients with massive ascites and ovarian metastasis, because surgical resection can improve their quality of life.

[A Resected Case of Advanced Lower Rectal Cancer with Neoadjuvant Chemotherapy by FOLFOXIRI plus Cetuximab]

Although the current standard of care for patients with lower rectal cancer in Japan includes total mesorectal resection with lateral lymph node dissection, postoperative local and distant recurrence rates are high. Multidisciplinary treatment is important to improve the prognosis. A man in his 30s was diagnosed with lower rectal cancer due to bloody stool and referred to our department. He was diagnosed as cT3N3M0, cStage Ⅲc with right obturator lymph node metastasis. Four courses of neoadjuvant chemotherapy(NAC)with FOLFOXIRI plus cetuximab were performed. Because Grade 3 neutropenia was observed in the first cycle(CTCAE v5.0), pegfilgrastim was administered in the second and subsequent cycles, and NAC was completed without dose reduction. The patient underwent laparoscopy-assisted intersphincteric rectal resection and D3+rtLD2 dissection. Histopathological resection margins were negative, and the resection was R0. Lymph node metastasis was found only in No. 263d-rt, and the pathological diagnosis was ypT3N3M0, pStage Ⅲc. Histological evaluation of response to treatment was Grade 2. The postoperative course was good and the patient was discharged on postoperative day 15. The patient received 8 courses of adjuvant chemotherapy with mFOLFOX6 from the 7th postoperative week and is alive and recurrence-free 6 months after surgery.

Transcript-targeted analysis reveals isoform alterations and double-hop fusions in breast cancer

Although transcriptome alteration is an essential driver of carcinogenesis, the effects of chromosomal structural alterations on the cancer transcriptome are not yet fully understood. Short-read transcript sequencing has prevented researchers from directly exploring full-length transcripts, forcing them to focus on individual splice sites. Here, we develop a pipeline for Multi-Sample long-read Transcriptome Assembly (MuSTA), which enables construction of a transcriptome from long-read sequence data. Using the constructed transcriptome as a reference, we analyze RNA extracted from 22 clinical breast cancer specimens. We identify a comprehensive set of subtype-specific and differentially used isoforms, which extended our knowledge of isoform regulation to unannotated isoforms including a short form TNS3. We also find that the exon-intron structure of fusion transcripts depends on their genomic context, and we identify double-hop fusion transcripts that are transcribed from complex structural rearrangements. For example, a double-hop fusion results in aberrant expression of an endogenous retroviral gene, ERVFRD-1, which is normally expressed exclusively in placenta and is thought to protect fetus from maternal rejection; expression is elevated in several TCGA samples with ERVFRD-1 fusions. Our analyses provide direct evidence that full-length transcript sequencing of clinical samples can add to our understanding of cancer biology and genomics in general.

Anti-cancer activity of amorphous curcumin preparation in patient-derived colorectal cancer organoids

Despite its adverse effects, chemotherapy is generally used for the treatment of colorectal cancer (CRC). Development of supplement preparations targeting cancer stem cells (CSCs) that cause distant metastasis and drug resistance is required. Although curcumin is known to have anti-tumor, hepatoprotective, and hypoglycemic-like actions, its low water solubility, oral absorption, and bioavailability impede its therapeutic uses. Patient-derived organoid cultures can recapitulate heterogeneity, epithelial structures, and molecular imprints of their parental tissues. In the present study, anti-carcinogenic properties of amorphous curcumin (AC), a compound with improved solubility and bioavailability, were evaluated against human CRC organoids. Treatment with AC inhibited the cell viability of CRC organoids in a concentration-dependent manner. AC arrested the cell cycle of CRC organoids and induced apoptosis. AC inhibited phosphorylation of ERK. Expression of downstream signals of ERK, namely c-MYC and cyclin-D1, were inhibited. Expressions of CSC markers, CD44, LGR5, and CD133, were declined in the AC-treated CRC organoids. The combinational treatment of CRC organoids with AC and anti-cancer drugs, oxaliplatin, 5-FU, or irinotecan showed a synergistic activity. In vivo, AC decreased the tumor growth of CRC organoids in mice with the induction of necrotic lesions. In conclusion, AC diminished the cell viability of CRC organoids through the inhibition of proliferation-related signals and CSC marker expression in addition to arresting the cell cycle. Collectively, these data suggest the value of AC as a promising supplement that could be used in combination with anti-cancer drugs to prevent the recurrence and metastasis of CRC.

Laparoscopic Sutureless Rectopexy Using a Fixation Device for Complete Rectal Prolapse

BACKGROUND

Complete rectal prolapse (CRP) commonly affects the daily life of older people and has no established operative treatment approach. We describe our simple method of laparoscopic, sutureless rectopexy, involving rectal mobilization (along with its peritoneum bilaterally) and fixation to the sacral promontory using a fixation device. We also present an analysis of short-term outcomes in patients treated using this procedure.

MATERIALS AND METHODS

We retrospectively evaluated 62 patients with CRP, who underwent a laparoscopic rectopexy via tack fixation, between 2004 and 2017. The peritoneum was widely attached near the site of peritoneal reflection, as in rectal cancer surgery. The hypogastric nerve was carefully detached from the front of the sacrum. Keeping the nerve intact, we lifted and mobilized the dissected rectum cranially towards the promontory, and the rectal peritoneum was affixed to the sacrum by applying 2 to 3 fixed tacks bilaterally, using a fixation device.

RESULTS

The median age of the study group was 80 (10 to 91) years. All procedures were successful without serious intraoperative complications; only 1 patient required conversion to open surgery. Median values for operative duration, intraoperative blood loss, and postoperative period of hospitalization were 177 (125 to 441) minutes, 5 (0 to 275) mL, and 7 (3 to 17) days, respectively. Only 6 (9.7%) patients experienced recurrence during the follow-up period.

CONCLUSION

Laparoscopic tacking rectopexy performed using a fixation device for repairing CRP is a simple, safe, and sutureless procedure with no severe complications or mortality.

Pancreatic Cancer Stem-Like Cells With High Calreticulin Expression Associated With Immune Surveillance

OBJECTIVE

Pancreatic cancer stem-like cells (P-CSLCs) are thought to be associated with poor prognosis. Previously, we used proteomic analysis to identify a chaperone pro-phagocytic protein calreticulin (CALR) as a P-CSLC-specific protein. This study aimed to investigate the association between CALR and P-CSLC.

METHODS

PANC-1-Lm cells were obtained as P-CSLCs from a human pancreatic cancer cell line, PANC-1, using a sphere induction medium followed by long-term cultivation on laminin. To examine the cancer stem cell properties, subcutaneous injection of the cells into immune-deficient mice and sphere formation assay were performed. Cell surface expression analysis was performed using flow cytometry.

RESULTS

PANC-1-Lm showed an increased proportion of cell surface CALR-positive and side-population fractions compared with parental cells. PANC-1-Lm cells also had higher frequency of xenograft tumor growth and sphere formation than PANC-1 cells. Moreover, sorted CALRhigh cells from PANC-1-Lm had the highest sphere formation frequency among tested cells. Interestingly, the number of programmed death-ligand 1-positive cells among CALRhigh cells was increased as well, whereas that of human leukocyte antigen class I-positive cells decreased.

CONCLUSION

In addition to the cancer stem cell properties, the P-CSLC, which showed elevated CALR expression on the cell surface, might be associated with evasion of immune surveillance.

[Immune-Related Factors as Prognostic Markers for Resectable Colorectal Cancer]

BACKGROUND

Tumor infiltration of CD3 and CD8-positive T cells has been reported as a good prognostic marker for patients with colorectal cancer(CRC). To clarify the significance of CD4 and FOXP3-positive T cells in CRC for prognosis of intratumoral infiltration.

METHODS

CD3, CD8, CD4 and FOXP3-positive T cells were immunostained(IHC)from tissue specimens of 342 CRC patients who underwent curative resection to quantify the number of infiltrating cells in the tumor. Microsatellite instability(MSI)was also evaluated in 322 samples and the clinicopathological factors and survival were analyzed.

RESULTS

Highly infiltrated groups of CD3, CD4 and FOXP3-positive T cells were associated with improved relapse-free survival(RFS). Highly infiltrated groups of CD8, CD4 and FOXP3-positive T cells were associated with improved disease- specific survival(DSS). Invasion depth, vascular infiltration, and CD4-positive T cell density were independent prognostic factors for DSS. CD4 and FOXP3-positive T cell infiltration was not associated with the high-frequency microsatellite instability group, in contrast to CD3 and CD8-positive T cell infiltration.

CONCLUSIONS

Intratumoral CD4-positive T cell density and FOXP3-positive 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.

[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.