Metastatic Colorectal Tumors Research Articles

Single-cell genomic and transcriptomic landscapes of primary and metastatic colorectal cancer tumors

BackgroundColorectal cancer (CRC) ranks as the second-leading cause of cancer-related death worldwide with metastases being the main cause of cancer-related death. Here, we investigated the genomic and transcriptomic alterations in matching adjacent normal tissues, primary tumors, and metastatic tumors of CRC patients.MethodsWe performed whole genome sequencing (WGS), multi-region whole exome sequencing (WES), simultaneous single-cell RNA-Seq, and single-cell targeted cDNA Sanger sequencing on matching adjacent normal tissues, primary tumors, and metastatic tumors from 12 metastatic colorectal cancer patients (n=84 for genomes, n=81 for exomes, n=9120 for single cells). Patient-derived tumor organoids were used to estimate the anti-tumor effects of a PPAR inhibitor, and self-renewal and differentiation ability of stem cell-like tumor cells.ResultsWe found that the PPAR signaling pathway was prevalently and aberrantly activated in CRC tumors. Blocking of PPAR pathway both suppressed the growth and promoted the apoptosis of CRC organoids in vitro, indicating that aberrant activation of the PPAR signaling pathway plays a critical role in CRC tumorigenesis. Using matched samples from the same patient, distinct origins of the metastasized tumors between lymph node and liver were revealed, which was further verified by both copy number variation and mitochondrial mutation profiles at single-cell resolution. By combining single-cell RNA-Seq and single-cell point mutation identification by targeted cDNA Sanger sequencing, we revealed important phenotypic differences between cancer cells with and without critical point mutations (KRAS and TP53) in the same patient in vivo at single-cell resolution.ConclusionsOur data provides deep insights into how driver mutations interfere with the transcriptomic state of cancer cells in vivo at a single-cell resolution. Our findings offer novel knowledge on metastatic mechanisms as well as potential markers and therapeutic targets for CRC diagnosis and therapy. The high-precision single-cell RNA-seq dataset of matched adjacent normal tissues, primary tumors, and metastases from CRCs may serve as a rich resource for further studies.

Guanylyl cyclase C as a diagnostic and therapeutic target in colorectal cancer.

Colorectal cancer remains a major cause of mortality in theUSA, despite advances in prevention and screening. Existing therapies focus primarily on generic treatment such as surgical intervention and chemotherapy, depending on disease severity. As personalized medicine and targeted molecular oncology continue to develop as promising treatment avenues, there has emerged a need for effective targets and biomarkers of colorectal cancer. The transmembrane receptor guanylyl cyclase C (GUCY2C) regulates intestinal homeostasis and has emerged as a tumor suppressor. Further, it is universally expressed in advanced metastatic colorectal tumors, as well as other cancer types that arise through intestinal metaplasia. In this context, GUCY2C satisfies many characteristics of a compelling target and biomarker for gastrointestinal malignancies.

Immunohistochemical expression of FAP and PCNA in neoplastic epithelial colonic lesions

Background Colorectal carcinoma is one of the leading causes of morbidity and mortality worldwide. Fibroblast-activation protein is expressed in cancer-associated fibroblasts and its expression is upregulated during the transformation of benign colorectal tissue into cancer. Proliferating-cell nuclear antigen expression was used as a marker of cell proliferation and is considered as a marker able to identify aggressive adenomas that may in turn become malignant. Aim To study the expression of fibroblast-activation protein and proliferating-cell nuclear antigen in neoplastic epithelial colonic lesions and their role in adenoma–carcinoma sequence. Patients and methods This retrospective study aimed to evaluate the expression of fibroblast-activation protein and proliferating-cell nuclear antigen in 80 cases of neoplastic epithelial colonic lesions. Results In malignant colorectal epithelial tumors, high fibroblast-activation protein expression was detected with an increase in histological grade, depth of invasion, vascular invasion, and lymph-node metastasis. No fibroblast-activation protein expression was detected in all benign cases. In included benign cases, there was a significant relation between proliferating-cell nuclear antigen labeling index and both histological type and grade of dysplasia. In the included malignant cases, there was a significant relation between proliferating-cell nuclear antigen labeling index with grade of tumor and the depth of invasion. Conclusions Both fibroblast-activation protein and proliferating-cell nuclear antigen labeling index suggested to have a role in early detection of malignant transformation and had a prognostic role in malignant cases.

Abstract 5134: Biomarker concordance between matched primary and metastatic colorectal tumors

Abstract Background: Distant metastasis accounts for ~90% of deaths from colorectal cancer (CRC). The use of biomarkers for targeted therapy in metastatic CRC is well-established, requiring genetic testing of primary or metastatic biopsies. Here we aimed to assess the concordance of actionable alterations in matched primary and metastatic colorectal tumors. Methods: Hybrid capture-based next-generation sequencing (NGS) were performed in a CAP/CLIA-approved laboratory (3DMed). NGS testing for SNV, InDel, CNV, MSI and TMB were performed on 19 primary tumors and 23 matched metastatic biopsies. Results: 42 matched primary and metastatic tumor samples from 19 CRC patients were analyzed. 68.4% of the patients had only liver metastases, 5.3% ovarian metastases, 5.3% peritoneal metastases and 10.5% of the patients had more than one metastatic site. Mutational landscape showed that the primary samples and the metastases shared 80% of top 20 mutations. Biomarker concordance for KRAS was 89.5% (17/19), NRAS was 89.5% (17/19), BRAF was 94.7% (18/19), EGFR was 89.5% (17/19), BRCA2 was 94.7% (18/19) and MS status was 100% (19/19). Inconsistent RAS/BRAF status was found in two liver metastases and one ovarian metastasis. The frequencies of SRC amplification (P = 0.08) and ACVR2A mutation (P = 0.31) seem to be higher in the primary tumors, although these were not statistically significant. Conversely, mutations of NRAS, EGFR and MAP2K4 were detected only in the metastases. One patient harbored EGFR amplification in the ovarian metastasis, while this variant was not present in liver and primary sites. Copy number loss of MAP2K4 was found in the metastatic biopsies of two patients. Tumor mutation burden was comparable between the primary tumors and metastases (3.12 vs 2.17muts/Mb, P=0.29). Conclusions: Our results demonstrates high concordance across multiple biomarkers between the primary and paired metastatic colorectal tumors. Molecular features of ovarian metastasis is more prone to inconsistent with primary sites than liver metastasis, which remains to be further verified in a large population. Citation Format: Yun Yang, Ying Xin, Jianning Song, Chao Jing, Baoyi Zhao, Depei Huang, Wei Deng. Biomarker concordance between matched primary and metastatic colorectal tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5134.

Abstract 3842: Versican proteolysis is a predictive biomarker of tumor infiltrating lymphocytes within primary and metastatic colorectal cancer tumors

Abstract Background: A major roadblock to immune-therapy response in many solid malignancies is the lack of tumor-infiltrating lymphocytes (TILs) found within their immune micro-environments. These immunologically cold tumors have lower response rates to immune-based therapies and among all colorectal cancers (CRC), only about six percent of patients have an objective response to immune checkpoint blockade (ICB). Versican (VCAN) accumulation has been found to be negatively correlated with TILs and its proteolysis into versikine (Vkine) correlates with higher TILs. In this study we analyze the association between VCAN accumulation/proteolysis and TILs in CRC from patients with both resectable primary CRCs and matched liver metastases. Methods: VCAN, Vkine, and TIL abundance were assessed via immunohistochemistry, with VCAN and Vkine being measured using an intensity binning system ranging from 0-3+ and TILs counted at 40X magnification for each tumor. Tumors were then designated as high (2 or 3+) or low (0 or 1) for both VCAN and Vkine. Tumors that were designated VCAN low and Vkine high are considered VCAN proteolytic predominant (VPP) and all other combinations are considered VCAN proteolytic weak (VPW). Results: 53% of both primary and metastatic tumors were designated VCAN low and 47% VCAN high. 59% of metastases from patients with VCAN-high primary tumors were also designated VCAN high, whereas 43% of metastases from patients with VCAN low primary tumors were designated VCAN high. When assessing proteolysis, it was found that 37% of primary tumors were designated VPP but only 26% of metastases were found to be VPP. When comparing proteolysis in a pairwise fashion, it was found that only 37% of VPP primaries had a VPP metastasis. An inverse correlation was again found between VCAN accumulation and TILs within primary CRCs. Tumors containing high levels of VCAN had an average of three TILs/high powered field (HPF), whereas tumors with low levels of VCAN had an average of 16 TILs/HPF (p=0.007). VPW tumors had an average of three TILs/HPF and VPP cores had an average of 21 TILs/HPF (p=0.009). VPW metastatic tumors had an average of eight TILs/HPF, whereas those that were VPP had an average of 15 TILs/HPF (p=0.01). Conclusion: Overall, these data confirm the inverse correlations between VCAN accumulation and TILs in primary CRCs. Additionally, VCAN proteolysis correlates with TILs in primary tumors and metastases. The potential for different VCAN accumulation/proteolysis in the primary tumor and metastatic disease will be an important consideration when studying VCAN further as a potential biomarker of immunotherapy response. Citation Format: Sean G. Kraus, Kristina A. Matkowskyj, Philip B. Emmerich, Wei Zhang, Linda Clipson, Cheri A. Pasch, Dustin A. Deming. Versican proteolysis is a predictive biomarker of tumor infiltrating lymphocytes within primary and metastatic colorectal cancer tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3842.

Abstract 20: Cancer incidence in the U.S. military: An updated analysis

Abstract Background: Active duty military service members and the general US population differ in several ways related to cancer occurrence. This study aimed to update and expand our previous study which compared incidence of six cancers between the U.S. military and general populations. Methods: Cancers included in this study were pathologically confirmed malignant lung, colorectal, testicular, prostate, cervical and breast tumors diagnosed 1990-2013. The study populations were men and women aged 20-59 in the US active duty military and the population in nine areas covered by the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) cancer registry program. Military data were from the Department of Defense’s Automated Central Tumor Registry (ACTUR) and Defense Manpower Data Center. Age adjusted rates in ACTUR and SEER and incidence rate ratios (IRR) and 95% confidence intervals (95% CI) comparing ACTUR to SEER were calculated. Comparisons were made by sex, race, and cancer stage. Results: Age adjusted incidence rates of colorectal cancer were significantly lower in ACTUR than SEER among White (IRR 0.78; 95% CI 0.72-0.84) and Black men (IRR 0.86; 95% CI 0.74-1.00), respectively. Lung cancer incidence was lower in ACTUR than SEER among White (IRR 0.55; 95% CI 0.49-0.62) and Black men (IRR 0.34; 95% CI 0.26-0.42) and White women (IRR 0.74; 95% CI 0.53-0.98). Whites in ACTUR had significantly lower incidence of testicular cancer (IRR 0.92; 95% CI 0.88-0.96). Lower incidence of cervical cancer in ACTUR was observed among both Whites (IRR 0.82; 95% CI 0.69-0.97) and Blacks (IRR 0.39; 95% CI 0.27-0.54). Incidence of prostate cancer was higher in ACTUR than SEER among both Whites (IRR 2.31; 95% CI 2.18-2.45) and Blacks (IRR 2.35; 95% CI 2.13-2.58). Results by tumor stage showed similar results between the ACTUR and SEER populations for regional and distant tumors, while no differences between the two were observed for localized tumors, except in the case of prostate cancer. Incidence of localized and regional prostate tumors was higher in ACTUR than SEER, while there was no significant difference in distant tumors. Conclusion: Active duty service members had lower age adjusted incidence rates of colorectal, lung, testicular, and cervical cancers, but higher rates of prostate cancer than the general US population. While these findings may result from the combined effects of many factors, the lower incidence in the military may be associated with healthier status of service members. In addition, universal health care for active duty military may lead to earlier diagnosis of some tumors, such as prostate cancer, in the military. Disclaimer: The contents of this publication are the sole responsibility of the authors and do not necessarily reflect the views, opinions or policies of USUHS, HJF, the DoD or the Departments of the Army, Navy or Air Force. Mention of trade names, commercial products or organizations does not imply endorsement by the US Government. Citation Format: Julie A. Bytnar, Katherine A. McGlynn, Craig D. Shriver, Kangmin Zhu. Cancer incidence in the U.S. military: An updated analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 20.

Abstract 1210: Resolving clonal substructure from single cell genomic data in primary and metastatic tumors using CopyKit

Abstract Advances in single cell copy number sequencing technologies have enabled the generation of data on hundreds to thousands of cells in parallel. Despite the rapid development in these technologies, there is a significant bottleneck for the analysis of the resulting large-scale datasets. Here we present CopyKit, a comprehensive and user-friendly toolkit for the analysis of single cell copy number data. CopyKit provides a suite of tools for pre-processing, QC, copy number inference, and subclone clustering to delineate the clonal diversity of tumors. We performed single cell copy number sequencing of 2977 cells from two breast tumor liver metastasis. CopyKit identified 4 and 12 subclonal populations, including amplification of PDGFRA, KRAS, and MYC as well as losses of PTEN, FOXO1, RB1, and BRCA1, many of which were spatially segregated in the tumor mass of the two tumors. Additionally, we applied CopyKit to study metastatic dissemination from a primary ER+ breast tumor with two matched metastatic sites and two colorectal carcinomas with matched liver metastatic tissues. This analysis demonstrated that the breast metastatic tumors selected for subclones that were lacking ERBB2 amplification in the primary site. Furthermore, the liver metastasis had deletions of chromosomes 18, 19, and 20p and a focal gain of FGFR1, while the pleural effusion acquired two additional focal gains on chromosome 8, including MYC. The colorectal metastatic tumors diverged from the primary tumor with copy number events affecting important cancer genes such as gain of SOX4, MYC, CDK8 and deletions of FHIT, CHEK1, and CHEK2. Collectively, this study shows that CopyKit provides a comprehensive set of tools for resolving clonal substructure from single cell copy number data for diverse applications in cancer biology. Citation Format: Darlan Conterno Minussi, Junke Wang, Aislyn Schalck, Yun Yan, Hua-Jun Wu, Cheng Peng, Min Hu, Emi Sei, Mary Edgerton, Hui Chen, Alejandro Contreras, David Hui, Senthil Damodaran, Scott Kopetz, Bora Lim, Nicholas Navin. Resolving clonal substructure from single cell genomic data in primary and metastatic tumors using CopyKit [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1210.

Tissue Content and Pattern of Expression of Claudin-3 and Occludin in Normal and Neoplastic Tissues in Patients with Colorectal Cancer

BackgroundMetastasis is the worst prognostic variable of patients with colorectal cancer (CRC). For the development of metastases, it is necessary that cancer cells detach from the primary tumor, migrate into the angiolymphatic system, and invade the tissue where they will develop. The breakdown of the tight junctions (TJs) plays an important role in colorectal metastatic tumors. Claudin-3 and occludin are the main component proteins of TJs. AimTo analyze the expression and tissue content of claudin-3 and occludin in normal and neoplastic tissues of patients with metastatic CRC. MethodsFifty-seven consecutive patients with stage III and IV CRC were included. Fragments of neoplastic tissue were collected from the tumor margins, and samples of the normal tissue were collected from the same patient in a standardized distance of 10 cm from the cranial margin of the tumor. Immunohistochemistry technique was used to identify the tissue staining of claudin-3 and occludin. To measure the content of both proteins in cellular membranes of normal and cancer cells, a validated immunoscore was used. ResultsClaudin-3 and occludin in normal tissues are in the apical and lateral membranes of cells, while in the neoplastic, in cytoplasm. The mean of the tissue content of claudin-3 in the normal tissue was 2.57 ± 0.16, while in the neoplastic tissue was 1.03 ± 0.13. The contents of occludin were 2.77±0.1 in normal tissue, while in the neoplastic were 1.08 ± 0.14. ConclusionThere is a reduction in the content of the claudin-3 and occludin in the cell membranes of the neoplastic tissue in patients with CRC.

High Expression of a tRNAPro Derivative Associates with Poor Survival and Independently Predicts Colorectal Cancer Recurrence.

Colorectal cancer (CRC) is the second most lethal cause of cancer-related deaths in Europe. Fragments of tRNAPro are conserved among vertebrates, characterized by pleiotropic regulatory functions and have been found to discriminate colorectal tumors from normal colorectal mucosa. In the current study, we investigated the prognostic utility of 5′-tiRNA-ProTGG levels in CRC. For this purpose, total RNA was extracted from 155 malignant colorectal tumors and 74 adjacent non-cancerous tissue specimens, polyadenylated and reverse-transcribed using an oligo-dT adapter as primer. Real-time quantitative PCR (qPCR) was used to assess the levels of 5′-tiRNA-ProTGG. Kaplan-Meier survival analysis demonstrated that high 5′-tiRNA-ProTGG levels predict both poor disease-free survival (DFS) and overall survival (OS) of CRC patients. Of note, high 5′-tiRNA-ProTGG levels retain their unfavorable prognostic value in patients with rectal cancer and/or moderately differentiated CRC (grade II). More importantly, multivariate cox regression analysis highlighted that the overexpression of 5′-tiRNA-ProTGG constitutes an adverse prognostic factor predicting short-term relapse of CRC patients independently of the established prognosticators in CRC. Finally, bioinformatics analysis unveiled a potentially critical role of 5′-tiRNA-ProTGG regarding the maintenance of cellular homeostasis, signaling, cell communication, and cellular motility.

Immune Profile of BRAF-Mutated Metastatic Colorectal Tumors with Good Prognosis after Palliative Chemotherapy.

Simple SummaryThe present study demonstrated that the distinct subgroup of BRAF-MT CRC showed a good response after palliative chemotherapy. Based on the immune profile analysis, higher PD-L1 expression and CD8-positive cell infiltration were shown in this study population. Furthermore, the assessment of the immune profile of BRAF-MT tumors can be helpful to better understand tumor biology and the different clinical outcomes of BRAF-MT CRC. Background: BRAF-mutated colorectal cancers (BRAF-MT CRCs) are known to have poor prognoses. BRAF-MT CRC was reported to be possibly related to the immune-activated phenotype. Objectives: This study aimed to investigate the association between the immune microenvironment and prognosis of BRAF-MT CRC. Methods: We evaluated clinical outcomes and investigated the immune profile of the BRAF-MT CRC tumors using the multiplex immunohistochemistry of immune-related markers: cytokeratin, programmed death ligand-1 (PD-L1), programmed cell death protein-1 (PD-1), and a cluster of differentiation 8 (CD8). Results: Out of 2313 tumors, 123 were BRAF-MT tumors. Among them, 86 tumors with available tissue were included. Out of 86 patients, 75 patients were non-good responders (GR), whereas 11 patients were GR. Median progression-free survival after first-line chemotherapy (4.6 vs. 12.4 months, p = 0.008) and overall survival (11.8 vs. 45.0 months) were longer in the GR group (p < 0.001). Median CD8+ T cell (254.29 vs. 656.0, p = 0.092), PD-L1+ tumor cell (0.95 vs.15.56, p = 0.050), PD-L1+ stromal cell (3.17 vs. 72.38, p = 0.025), PD-L1+ tumor and stromal cell (5.08 vs. 74.92, p = 0.032), and PD-1+ stromal cell (45.08 vs. 325.40, p = 0.046) counts were greater in the GR group. Conclusion: The clinical outcomes of unselected patients with BRAF-MT CRC were generally similar to those in previous studies. Based on the immune profile analysis, higher PD-L1 expression and CD8-positive cell infiltration were observed in BRAF-MT tumors with a good prognosis.

Novel Anti-LY6G6D/CD3 T-Cell-Dependent Bispecific Antibody for the Treatment of Colorectal Cancer.

New therapeutics and combination regimens have led to marked clinical improvements for the treatment of a subset of colorectal cancer. Immune checkpoint inhibitors have shown clinical efficacy in patients with mismatch-repair-deficient or microsatellite instability-high (MSI-H) metastatic colorectal cancer (mCRC). However, patients with microsatellite-stable (MSS) or low levels of microsatellite instable (MSI-L) colorectal cancer have not benefited from these immune modulators, and the survival outcome remains poor for the majority of patients diagnosed with mCRC. In this article, we describe the discovery of a novel T-cell-dependent bispecific antibody (TDB) targeting tumor-associated antigen LY6G6D, LY6G6D-TDB, for the treatment of colorectal cancer. RNAseq analysis showed that LY6G6D was differentially expressed in colorectal cancer with high prevalence in MSS and MSI-L subsets, whereas LY6G6D expression in normal tissues was limited. IHC confirmed the elevated expression of LY6G6D in primary and metastatic colorectal tumors, whereas minimal or no expression was observed in most normal tissue samples. The optimized LY6G6D-TDB, which targets a membrane-proximal epitope of LY6G6D and binds to CD3 with high affinity, exhibits potent antitumor activity both in vitro and in vivo. In vitro functional assays show that LY6G6D-TDB-mediated T-cell activation and cytotoxicity are conditional and target dependent. In mouse xenograft tumor models, LY6G6D-TDB demonstrates antitumor efficacy as a single agent against established colorectal tumors, and enhanced efficacy can be achieved when LY6G6D-TDB is combined with PD-1 blockade. Our studies provide evidence for the therapeutic potential of LY6G6D-TDB as an effective treatment option for patients with colorectal cancer.

Impact of Neoadjuvant Chemotherapy on SATB2 Expression in Colorectal Carcinomas: SATB2 Positivity is Preserved in Most Cases, but Down-Expressed in Effective Cases of Chemotherapy.

Special AT-rich sequence-binding protein 2 (SATB2) is a novel, diagnostically useful, and highly sensitive immunohistochemical marker for both primary and metastatic colorectal or appendiceal tumors. In the present study, we aimed to assess the impact of neoadjuvant chemotherapy on SATB2 expression in primary colorectal carcinomas and their corresponding liver metastases. Forty-four patients with colorectal carcinomas who received neoadjuvant chemotherapy were included. SATB2 expression in specimens of biopsy, resected primary colorectal carcinomas, and resected metastatic foci were examined by immunohistochemistry and compared to caudal-type homeobox transcription factor 2 (CDX2). Using a modified H-score, expressions were scored semiquantitatively for both staining intensity and tumor cell proportion with nuclear staining. SATB2 was positive in 43/44 cases (98%) in biopsy specimens, 42/44 cases (96%) in resected colorectal carcinomas with neoadjuvant chemotherapy, and 9/9 cases (100%) with liver metastases. However, these expressions were variably decreased, and the H-score was lower in resected colorectal carcinomas (158 ± 69) than in biopsy specimens (174 ± 60) (p < 0.01). The proportion of SATB2-positive area of colorectal carcinoma was 93% in metastatic foci, while the CDX2-positive area was 78%. When categorized by histopathological tumor regression, the most effective tumors of chemotherapy showed the lowest H-score in resected colorectal carcinomas among the three groups (p < 0.01). SATB2 is a useful marker for both primary colorectal carcinoma and corresponding liver metastases, even with neoadjuvant chemotherapy. However, caution should be exercised when performing needle biopsy for metastatic foci with neoadjuvant therapy because expressions could be decreased, especially in chemotherapy-effective cases, and show immunohistochemically negative results.

Comparison of Mortality Rates in Patients Waiting for Liver Transplant and Patients With Colorectal Metastatic Tumors.

We aimed to identify outcomes of liver surgery in patients with hepatocellular carcinoma and colorectal cancer, which result in primary and secondary liver tumors. Our study included 51 patients with colorectal cancer and liver metastases and 63 patients with hepatocellular carcinoma who were prepared for liver transplant due to cirrhosis who underwent hepatic resection or local ablation treatments; patients were seen between January 2011 and December 2021. Most patients with colorectal cancer were men (58.8%). Mean age was 65.76 ± 13.818 years (range, 27-88 y). Most patients had planned, elective surgery (86.3%). Neoadjuvant chemotherapy was administered to 58.8% of patients. The most common location of metastasis in the liver was in the right lobe (43.1%), and the most common surgery was low anterior resection (17 patients). During simultaneous liver surgery, 31 patients required metastasectomy and 7 patients required radiofrequency ablation plus metastasectomy. No deaths occurred in the early posttransplant period, and cumulative survival was 82.624 ± 7.962 months. Disease-free survival was 45.2 ± 7.495 months. Most patients with hepatocellular carcinoma were men (82.5%). Mean age was 58.73 ± 17.428 years. Hepatocellular carcinoma lesions were mostly located in both the right and left lobes (23.8%). In the hepatocellular cancer group, 60.3% had transarterial chemoembolization and 42.9% had radiofrequency ablation. The primary surgical resection was metastasectomy (17.9%) because of multiple localized lesions. Median follow-up was 22 months (range, 1-126 mo). Overall survival was 101.898 ± 7.169 months, with 10-year overall survival of 38%. Disease-free survival was 74.081 ± 8.732 months, with 1-year and 5-year disease-free survival of 90.5% and 54%. Better survival was shown in patients with hepatocellular carcinoma than in patients with colorectal cancer.Therefore, more aggressive treatment options, as used in hepatocellular carcinoma, including liver transplant, may be options for patients with colorectal cancer.

SGNTUC-019: Phase 2 basket study of tucatinib and trastuzumab in previously treated solid tumors with HER2 alterations—Urothelial cancer cohort (trial in progress).

TPS586 Background: Tucatinib, a highly selective HER2-directed tyrosine kinase inhibitor approved in multiple regions for HER2+ metastatic breast cancer, is being investigated as a novel therapy for metastatic colorectal cancer, gastric cancer, and other GI tumors. In xenograft models of HER2+ and HER2-mutated tumors, dual targeting of HER2 with tucatinib and trastuzumab showed superior activity to either alone (Kulukian 2020; Peterson 2020 ). Despite development of several new therapies for metastatic urothelial cancer, most patients do not respond to subsequent therapies, and majority of patients succumb to the disease, highlighting the need for additional therapeutic approaches. Given 20%-30% of metastatic urothelial cancers have molecular alterations of the ErbB family, tucatinib + trastuzumab warrants further evaluation. SGNTUC-019 (NCT04579380) is a multi-cohort, open-label, international Phase 2 study evaluating tucatinib + trastuzumab in patients with previously treated solid tumors displaying HER2+ or HER2-mutated solid tumors, including a cohort with locally advanced or metastatic urothelial cancer (UC). Methods: Eligible patients must have HER2+ or HER2-mutated locally advanced or metastatic solid tumors, with progression on or after the last systemic therapy for advanced disease. Additionally, patients must have an ECOG PS ≤1, adequate hepatic, hematologic, renal, and cardiac function, and no prior exposure to HER2-directed therapy in the UC cohort. For eligibility, HER2 alterations can be demonstrated by HER2 overexpression/amplification in tumor tissue by prior IHC/ISH, or by HER2 amplification/mutation in prior or pre-screening NGS assay of ctDNA or prior tissue NGS assay. The HER2 overexpression/amplification UC cohort will enroll 12 response-evaluable patients per RECIST 1.1. If ≥2 responses are observed, the cohort will be expanded to 30. Patients with HER2-mutated UC will be enrolled into a cohort of 30 patients with HER2-mutated solid tumors (except breast and non-squamous non-small cell lung cancers). The primary objective is antitumor activity, with confirmed ORR as the primary endpoint, and disease control rate, duration of response, PFS, and OS as secondary efficacy endpoints. Patients will receive tucatinib 300 mg orally twice daily and trastuzumab 8 mg/kg intravenous on Cycle 1 Day 1 and 6 mg/kg q21 days from Cycle 2 Day 1. Disease assessments per RECIST 1.1 will occur q6 weeks for 24 weeks, then q12 weeks. Trough concentrations of tucatinib will be evaluated in Cycles 2-6, with a peak concentration sampled in Cycle 3. Quality of life will be evaluated q2 cycle using EQ-5D-5L. Sites are currently enrolling within the US, EU, and Asia Pacific. Clinical trial information: NCT04579380.

Anastomosis technique and leakage rates in minimally invasive surgery for right-sided colon cancer. A retrospective national cohort study.

The aim of this study was to describe the different techniques currently used in Denmark to construct right-sided ileocolic anastomoses in minimally invasive surgery, and investigate, compare and analyse the anastomotic configurations and their anastomotic leakage (AL) rates. This was a retrospective register-based, study design using prospectively collected data from the Danish Colorectal Cancer Group (DCCG) database. All patients aged 18years or older with a malignant colorectal tumour in Denmark in the period of 1 February 2015 until 31 December 2019, and who had an elective, curative, minimally invasive right hemicolectomy (MIRH) with ileocolic anastomosis, were included. Three thousand three hundred ninety-eight patients were included. The most commonly used anastomotic approach was the extracorporeal (EC) hand-sewn anastomosis (HA) with end-to-end configuration (59%) and the second most used was the EC stapled anastomosis (SA) side-to-side configuration (20%). The latter had a higher AL rate compared with the hand-sewn technique (3.8% vs. 1.3%), and had significantly higher odds ratio (OR) (OR: 2.85, 95% CI: 1.56-4.92, p < 0.0001) for AL in the adjusted regression model. The least used technique was the end-to-side HA which also had a significantly higher OR (OR: 3.05, 95% CI: 1.30-7.15, p = 0.010) compared with the end-to-end HA. Smoking was an independent factor associated with higher OR for AL. The ileocolic end-to-end HA was the most commonly used technique and had the lowest AL rate in MIRH for colon cancer. The EC SA technique and tobacco smoking were independent risk factors for leakage of the ileocolic anastomosis.

Immunomolecular Investigation of Human Papillomavirus Genotypes (16, 18) and P63 Expression in Patients with Malignant and Non-malignant Colorectal Tumors.

Cancer of the colon (colorectal cancer, or CRC) is the third most frequent malignancy in the world and the fourth leading cause of cancer-related death. Recent research has focused on the link between high-risk human papillomavirus (HPV) infections and the onset/development of several different types of cancer in humans. As a result, scientists are now paying more attention to HPV and CRC. In a variety of malignant tumors, P63 is overexpressed. This includes non-Hodgkin lymphoma and breast carcinoma, as well as lung, bladder, and prostate cancers. However, in accordance with the existence of many P63 isoforms in malignant tumors, the actions of P63 in these malignancies remain a source of debate. P63 immunohistochemistry expression in CRC tissues is being investigated as a possible etiological link between high-risk HPV types and CRC. This retrospective study intended to investigate if there was an etiological link between high-risk HPV types and CRC. It has utilized 92 chosen formalin-fixed and paraffin-embedded tissue block samples. The collected samples were divided into 62 blocks of colorectal adenocarcinoma mass tissues and 30 non-malignant colorectal tissues used as a control group. Chromogenic in situ hybridization (CISH) was employed to discover HPV DNA16/18 in colorectal tissues. The overall proportion of positive HPV16/18 DNA- CISH detection in the mass CRC group was 44.4%, whereas HPV16/18 DNA was obtained at 80.0% in the non-malignant control group. The overall proportion of positive P63-ISH detection in the CRC group was also 70.4%, whereas P63 was 73.3% in the non-malignant control group. The link between HPV infection and P63 expression in CRC might point to the importance of these molecules in the progression of CRC.

SGNTUC-019: Phase 2 basket study of tucatinib and trastuzumab in previously treated solid tumors with HER2 alterations—Biliary tract cancer cohort.

TPS489 Background: Tucatinib (TUC), a highly selective HER2-directed TKI approved in multiple regions for HER2+ metastatic breast cancer, is being investigated as a novel therapy for patients (pts) with metastatic colorectal cancer, gastric cancer, and other GI tumors. Preclinical and clinical data have shown HER2-targeted agents may improve clinical outcomes. In xenograft models of HER2+ and HER2-mutated tumors, dual targeting of HER2 with TUC + trastuzumab (Tras) showed superior activity to either agent alone (Kulukian 2020). Interim results from the MOUNTAINEER study have shown promising activity for TUC + Tras in HER2+ colorectal cancer. In 23 response-evaluable pts, an objective response rate (ORR) of 52% was observed with a median progression-free survival (PFS) of 8.1 months (mo) (Strickler 2019). The prognosis for pts with biliary tract cancers (BTCs) remain poor, and treatment options are limited. Given that approximately 12%-15% of BTC pts are HER2+, and 1%-8% have HER2 mutations, TUC + Tras warrants further evaluation in this patient population. The SGNTUC-019 basket study (NCT04579380) is evaluating TUC + Tras in pts with previously treated, locally advanced, unresectable or metastatic solid tumors including BTC that display HER2 overexpression/amplification or activating mutations. We describe the design of the BTC cohort. Methods: SGNTUC-019 is a multi-cohort, open-label, international Phase 2 study. Pts must be ≥18 years old; have an ECOG PS of ≤1; have adequate hepatic, hematological, renal, and cardiac functions; and have no previous exposure to HER2-directed therapy. BTC pts must have progressed on or after ≥1 previous line of treatment. The HER2+ BTC cohort will enroll 12 response-evaluable pts. If &gt;2 responses are observed, the cohort will be expanded to 30 pts. HER2-mutated BTC patients may also be enrolled in a 30 pts cohort for other HER2-mutated solid tumors. The primary objective is antitumor activity with confirmed ORR as the primary endpoint. Secondary efficacy endpoints include disease control rate, duration of response, PFS, and OS. For eligibility, HER2 alterations can be demonstrated by HER2 overexpression/amplification in tumor tissue by prior IHC/ISH, or by HER2 amplification/mutation in a prior or on-study NGS assay of ctDNA or prior tissue NGS assay. Pts will receive TUC 300 mg orally twice a day and Tras 8 mg/kg intravenously on Cycle 1 Day 1 then 6 mg/kg every 21 days from Cycle 2 Day 1. Disease assessments per RECIST 1.1 are every 6 weeks for the first 24 weeks, then every 12 weeks. Quality of life will be evaluated every 2 cycles using EQ-5D-5L. Sites are currently enrolling within the US, EU and Asia-Pacific. Clinical trial information: NCT04579380.

Judgment of benign and early malignant colorectal tumors from ultrasound images with deep multi-View fusion

Background and objective: Colorectal cancer (CRC) is currently one of the main cancers world-wide, with a high incidence in the elderly. In the diagnosis of CRC, endorectal ultrasound plays an important role in judging benign and early malignant tumors. However, malignant tumors in the early-stage are not easy to identify visually and experts usually seek help from multi-view images, which increases the workload and also exists a certain probability of misdiagnosis. In recent years, with the widespread use of deep learning methods in the analysis of medical images, it becomes necessary to design an effective computer-aided diagnosis (CAD) system of CRC based on multi-view endorectal ultrasound images. Method: In this study, we proposed a CAD system for judging benign and early malignant colorectal tumors, and constructed the first multi-view ultrasound image dataset of CRC to validate our algorithm. Our system is an end-to-end model based on a deep neural network (DNN) which includes a feature extraction module based on dense blocks, a multi-view fusion module, and a Multi-Layer Perception-based classifier. A center loss was used for the first time in CAD tasks, to optimize our model. Result: On the constructed dataset, the proposed system surpasses expert diagnosis in accuracy, sensitivity, specificity, and F1-score. Compared with the popular deep classification networks and other CAD methods, the algorithm has reached the best performance. Comparative experiments using different feature extraction methods, different view fusion strategies, and different classifiers verify the effectiveness of each part of the algorithm. Conclusion: We propose a CAD system for judging benign and early malignant colorectal tumors based on DNN, which combines information of ultrasound images from different views for comprehension. On the first CRC multi-view ultrasound image dataset which we constructed, our method outperforms expert diagnosis results and all other methods, and the effectiveness of each part of the system has been verified. Our system has application value in future medical practice on early diagnosis of CRC.

Regorafenib: A narrative drug review

The process of angiogenesis is a complex balance of positive and negative regulators, and vascular endothelial growth factor (VEGF) is one of the most important proangiogenic factors involved in tumor angiogenesis. One of the drugs targeting this process is regorafenib, a multi-kinase inhibitor. It inhibits VEGF receptors 1, 2, and 3; rearranged during transfection (RET); receptor tyrosine kinase (KIT); platelet-derived growth factor receptor (PDGFR) alpha and beta; fibroblast growth factor receptor (FGFR) 1 and 2; angiopoietin-1 receptor (Tie2); discoidin domain-containing receptor 2 (DDR2); Ephrin type-A receptor 2 (Eph 2A); tropomyosin receptor kinase A (TrkA); rapidly accelerated fibrosarcoma (RAF-1); v-RAF murine sarcoma viral oncogene homolog B1 (BRAF); stress-activated protein kinase-2 (SAPK2); protein tyrosine kinase 5 (PTK5); and Abelson murine leukemia virus (Abl). Regorafenib has been approved for patients with metastatic colorectal cancer (CRC), locally advanced or metastatic gastrointestinal stromal tumor (GIST), and hepatocellular carcinoma (HCC). We present a review of regorafenib which includes the history, basic chemistry, pharmacology, pharmacokinetics, clinical indications, drug interactions, and safety profile. We performed a search in PubMed and other sources using the search terms “CRC,” “GIST,” “HCC,” “osteosarcoma,” and “regorafenib” and searched for full-text articles published in the past 10 years. Out of the total 65 studies identified, we included 46 studies. We combined all the abstracts and conference proceedings to generate a comprehensive review.

Anorectal malignant melanoma, a diagnostic challenge.

Malignant anorectal melanoma is an extremely rare cause of rectal neoplasia, accounting for less than 1% of all melanomas and about 4% of all malignant colorectal neoplasms. We present the endoscopic and pathological images of a case in our clinical practice.