Resection of Colorectal Liver Metastases with Major Vessel Involvement

BACKGROUND

Treatment of CRLM with major vessel involvement is still challenging and valid data on outcomes are still rare. We analyzed our experience of hepatectomies with resection and reconstruction of major hepatic vessels with regard to operative and perioperative details, histopathological findings and oncological outcome.

METHODS

Data of 32 hepatectomies with major hepatic vessel resections and reconstructions were included. Results were correlated with perioperative and oncological outcome.

RESULTS

Out of 1236 surgical resections due to CRLM, we performed 35 major hepatic vessel resections and reconstructions in 32 cases (2.6%) during the study period from January 2008 to March 2023. The vena cava inferior (VCI) was resected and reconstructed in 19, the portal vein (PV) in 6 and a hepatic vein (HV) in 10 cases. Histopathological examination confirmed a vascular infiltration in 6/32 patients (VCI 3/17, HV 2/10 and PV 1/6). There were 27 R0 and 5 R1 resections. All R1 situations affected the parenchymal margin. Vascular wall margins were R0. Ninety-day mortality was 0. The median overall survival (OS) for the patient group with vascular infiltration (V1) was 21 months and for the V0 group 33.3 months.

CONCLUSION

Liver resections with vascular resection and reconstruction are rare and histological vessel infiltration occurs seldom. In cases with presumed vascular wall infiltration, liver resection combined with major vessel resection and reconstruction can be performed with low morbidity and mortality. We prefer a parenchymal sparing liver resection with vascular resection and reconstruction to achieve negative resection margins, but in technically difficult cases with higher risk for postoperative complications, tumor detachment from vessels without resection is a most reasonable surgical alternative.

A novel targeted NGS panel identifies numerous homologous recombination deficiency (HRD)-associated gene mutations in addition to known BRCA mutations

Deleterious mutations in the BRCA1 and BRCA2 genes have significant therapeutic relevance in clinical settings regarding personalized therapy approaches. BRCA1 and BRCA2 play a pivotal role in homologous recombination (HR) and thus are sensitive for PARP inhibitors (PARPi). Beyond the narrow scope of evaluating only the BRCA mutation status, PARPi can be beneficial for HR deficient (HRD) patients, who harbor mutations in other HR-associated genes. In the present retrospective study, a novel targeted HRD gene panel was validated and implemented for use with FFPE tissue. Samples of patients with ovarian, breast, pancreatic and prostate cancer were included. Variants were robustly detected with various DNA input amounts and the use of test samples showed complete concordance between previously known mutations and HRD panel results. From all the 90 samples included in this cohort, TP53 was the most frequently altered gene (73%). Deleterious BRCA1/2 mutations were found in 20 (22%) of all samples. New pathogenic or likely pathogenic mutations in additional HR-associated genes were identified in 22 (24%) patients. Taken together, the present study proves the feasibility of a new HRD gene panel with reliable panel performance and offers the possibility to easily screen for resistance mutations acquired over treatment time.Mutations in HR-associated genes, besides BRCA1/2, might represent promising potential targets for synthetic lethality approaches. Thus, a substantial number of patients may benefit from expanding the scope of therapeutic agents like PARPi.

Multistain deep learning for prediction of prognosis and therapy response in colorectal cancer

Although it has long been known that the immune cell composition has a strong prognostic and predictive value in colorectal cancer (CRC), scoring systems such as the immunoscore (IS) or quantification of intraepithelial lymphocytes are only slowly being adopted into clinical routine use and have their limitations. To address this we established and evaluated a multistain deep learning model (MSDLM) utilizing artificial intelligence (AI) to determine the AImmunoscore (AIS) in more than 1,000 patients with CRC. Our model had high prognostic capabilities and outperformed other clinical, molecular and immune cell-based parameters. It could also be used to predict the response to neoadjuvant therapy in patients with rectal cancer. Using an explainable AI approach, we confirmed that the MSDLM's decisions were based on established cellular patterns of anti-tumor immunity. Hence, the AIS could provide clinicians with a valuable decision-making tool based on the tumor immune microenvironment.

Cancer gene related characterization of patterns and point of recurrence after resection of colorectal liver metastases

Background

Outcome after resection of CRLM is hampered by a high rate of recurrence. There are little data about the role of cancer related genes and their mutations in this scenario. The aim of our analysis was to assess the predictive power of cancer-related genes and their mutations on risk for and distribution of recurrence and the time of occurrence after resection of colorectal liver metastases (CRLM).

Methods

We included 130 patients with 167 liver resections. The work-up consisted of the analysis of a total of 720 cancer-related genes by next-generation sequencing (NGS). Results were correlated with the patterns and time of recurrence and survival.

Results

At the time of analysis, 89/130 patients (68%) had developed recurrence. This included liver only recurrence in 52%, lung only recurrence in 11% and disseminated disease in 37% of cases. In univariate analysis, alterations in the RAS/RAF pathway and in the SMAD family had significant predictive power for the time of recurrence (P<0.0001) whereas single mutations did not reach statistical significance in multivariate analysis. Mutations of PIK3CA were associated with a better prognosis and a later occurrence of relapse. A recurrence risk score (r-RS) based on mutations in these cancer related genes is predictive of the time of recurrence.

Conclusions

In conclusion, mutations in the RAS/RAF pathway and the SMAD family are risk factors for early recurrence. Mutations of PIK3CA are associated with a lower risk for recurrence after resection of CRLM. Cancer related genes and their mutations do not correlate with patterns of recurrence but are predictive for the timely onset of recurrence.

[Hepatocellular carcinoma in an inflammatory adenoma with β-catenin mutation in a patient with hepatocellular adenomatosis due to germline mutation in HNF1α]

Hepatocyte nuclear factor 1 α (HNF1α) mutations cause maturity-onset diabetes of the young (MODY) type 3 and are associated with hepatocellular adenomatosis. Malignant transformation of HNF1α-mutated hepatocellular adenomas is rare. We report a case of a 28-year-old man with HNF1α-inactivated adenomatosis who developed an inflammatory adenoma with β catenin mutation with malignant transformation into a well-differentiated hepatocellular carcinoma (HCC).

Exome sequencing characterizes the somatic mutation spectrum of early serrated lesions in a patient with serrated polyposis syndrome (SPS)

Background

Serrated or Hyperplastic Polyposis Syndrome (SPS, HPS) is a yet poorly defined colorectal cancer (CRC) predisposition characterised by the occurrence of multiple and/or large serrated polyps throughout the colon. A serrated polyp-CRC sequence (serrated pathway) of CRC formation has been postulated, however, to date only few molecular signatures of serrated neoplasia (BRAF, KRAS, RNF43 mutations, CpG Island Methylation, MSI) have been described in a subset of SPS patients and neither the etiology of the syndrome nor the distinct genetic alterations during tumorigenesis have been identified.

Methods

To identify somatic point mutations in potential novel candidate genes of SPS-associated lesions and the involved pathways we performed exome sequencing of eleven early serrated polyps obtained from a 41 year-old female patient with clinically confirmed SPS. For data filtering and analysis, standard pipelines were used. Somatic mutations were identified by comparison with leukocyte DNA and were validated by Sanger sequencing.

Results

The BRAF p.V600E or KRAS p.G12D mutation was identified in six polyps (~50%) and not found in polyps from the distal colon. In addition, we found seven unique rare somatic alterations of seven different genes in four serrated tumours, all of which are missense variants. The variant in ABI3BP and CATSPERB are predicted to be deleterious. No established cancer gene or candidate genes related to serrated tumorigenesis were affected.

Conclusions

Somatic mutations seem to be rare events in early hyperplastic and serrated lesions of SPS patients. Neither frequently affected genes nor enrichment of specific pathways were observed. Thus, other alterations such as non-coding variants or epigenetic changes might be the major driving force of tumour progression in SPS.

Electronic supplementary material

The online version of this article (10.1186/s13053-017-0082-9) contains supplementary material, which is available to authorized users.

Exome Sequencing Identifies Biallelic MSH3 Germline Mutations as a Recessive Subtype of Colorectal Adenomatous Polyposis

In ∼30% of families affected by colorectal adenomatous polyposis, no germline mutations have been identified in the previously implicated genes APC, MUTYH, POLE, POLD1, and NTHL1, although a hereditary etiology is likely. To uncover further genes with high-penetrance causative mutations, we performed exome sequencing of leukocyte DNA from 102 unrelated individuals with unexplained adenomatous polyposis. We identified two unrelated individuals with differing compound-heterozygous loss-of-function (LoF) germline mutations in the mismatch-repair gene MSH3. The impact of the MSH3 mutations (c.1148delA, c.2319-1G>A, c.2760delC, and c.3001-2A>C) was indicated at the RNA and protein levels. Analysis of the diseased individuals' tumor tissue demonstrated high microsatellite instability of di- and tetranucleotides (EMAST), and immunohistochemical staining illustrated a complete loss of nuclear MSH3 in normal and tumor tissue, confirming the LoF effect and causal relevance of the mutations. The pedigrees, genotypes, and frequency of MSH3 mutations in the general population are consistent with an autosomal-recessive mode of inheritance. Both index persons have an affected sibling carrying the same mutations. The tumor spectrum in these four persons comprised colorectal and duodenal adenomas, colorectal cancer, gastric cancer, and an early-onset astrocytoma. Additionally, we detected one unrelated individual with biallelic PMS2 germline mutations, representing constitutional mismatch-repair deficiency. Potentially causative variants in 14 more candidate genes identified in 26 other individuals require further workup. In the present study, we identified biallelic germline MSH3 mutations in individuals with a suspected hereditary tumor syndrome. Our data suggest that MSH3 mutations represent an additional recessive subtype of colorectal adenomatous polyposis.

Activating ERBB2/HER2 mutations indicate susceptibility to pan-HER inhibitors in Lynch and Lynch-like colorectal cancer

OBJECTIVE

Microsatellite instability (MSI) is detected in approximately 15% of all colorectal cancers (CRC) and virtually in all cases with Lynch syndrome. The MSI phenotype is caused by dysfunctional mismatch repair (MMR) and leads to accumulation of DNA replication errors. Sporadic MSI CRC often harbours BRAF(V600E); however, no consistent data exist regarding targeted treatment approaches in BRAF(wt) MSI CRC.

DESIGN

Mutations and quantitative MSI were analysed by deep sequencing in 196 formalin fixed paraffin embedded (FFPE) specimens comprising Lynch and Lynch-like CRCs from the German Hereditary Nonpolyposis Colorectal Cancer registry. Functional relevance of recurrent ERBB2/HER2 mutations was investigated in CRC cell lines using reversible and irreversible HER-targeting inhibitors, EGFR-directed antibody cetuximab, HER2-directed antibody trastuzumab and siRNA-mediated ERBB2/HER2 knockdown.

RESULTS

Quantification of nucleotide loss in non-coding mononucleotide repeats distinguished microsatellite status with very high accuracy (area under curve=0.9998) and demonstrated progressive losses with deeper invasion of MMR-deficient colorectal neoplasms (p=0.008). Characterisation of BRAF(wt) MSI CRC revealed hot-spot mutations in well-known oncogenic drivers, including KRAS (38.7%), PIK3CA (36.5%), and ERBB2 (15.0%). L755S and V842I substitutions in ERBB2 were highly recurrent. Functional analyses in ERBB2-mutated MSI CRC cell lines revealed a differential response to HER-targeting compounds and superiority of irreversible pan-HER inhibitors.

CONCLUSIONS

We developed a high-throughput deep sequencing approach for concomitant MSI and mutational analyses in FFPE specimens. We provided novel insights into clinically relevant alterations in MSI CRC and a rationale for targeting ERBB2/HER2 mutations in Lynch and Lynch-like CRC.

MDM2 gene amplification in esophageal carcinoma

Esophageal cancer (EC) is one of the most common malignancies diagnosed in the Western world with an increasing incidence noted for esophageal adenocarcinoma (EAC). Despite improvements in staging, surgical procedures and postoperative treatments, the overall survival of patients with EC remains low. Murine double minute‑2 (MDM2) acts as an oncogene by inducing the degradation of the tumor‑suppressor protein TP53. In order to evaluate the MDM2 gene amplification status in EAC and squamous cell carcinoma (SCC), we established a quantitative PCR (qPCR) assay, screening a total of 127 esophageal carcinoma cases for MDM2 amplification. Esophageal carcinoma cases with enhanced MDM2 gene copy numbers were further analyzed by fluorescence in situ hybridisation (FISH) and MDM2 immunostaining. Among a total of 23 specimens (18%), identified by qPCR to possess elevated MDM2 gene copy numbers, one third (6.3%) showed a cluster‑like fluorescence pattern by FISH analyses and marked MDM2 protein immunostaining. MDM2 gene amplifications did not correlate with the occurrence of TP53 mutations. Due to the high therapeutic relevance of MDM2 overexpression, but the high cost of FISH, we suggest a primary screening of MDM2 copy number variations by qPCR, followed by detailed FISH analysis of the identified ECs.

Immune checkpoints programmed death 1 ligand 1 and cytotoxic T lymphocyte associated molecule 4 in gastric adenocarcinoma

Remarkable efficacy of immune checkpoint inhibition has been reported for several types of solid tumors and early studies in gastric adenocarcinoma are promising. A detailed knowledge about the natural biology of immune checkpoints in gastric adenocarcinoma is essential for clinical and translational evaluation of these drugs. This study is a comprehensive analysis of cytotoxic T lymphocyte associated molecule 4 (CTLA-4) and programmed death 1 ligand 1 (PD-L1) expression in gastric adenocarcinoma. PD-L1 and CTLA-4 were stained on tumor sections of 127 Caucasian patients with gastric adenocarcinoma by immunohistochemistry (IHC) and somatic mutation profiling was performed using targeted next-generation sequencing. Expression of PD-L1 and CTLA-4 on lymphocytes in tumor sections, tumor-draining lymph nodes (TDLN) and peripheral blood were studied by flow-cytometry and immune-fluorescence microscopy in an additional cohort. PD-L1 and CTLA-4 were expressed in 44.9% (57/127) and 86.6% (110/127) of the analyzed gastric adenocarcinoma samples, respectively. Positive tumor cell staining for PD-L1 or CTLA-4 was associated with inferior overall survival. Somatic mutational analysis did not reveal a correlation to expression of PD-L1 or CTLA-4 on tumor cells. Expression of PD-1 (52.2%), PD-L1 (42.2%) and CTLA-4 (1.6%) on tumor infiltrating T cells was significantly elevated compared to peripheral blood. Of note, PD-1 and PD-L1 were expressed far higher by tumor-infiltrating lymphocytes than CTLA-4. In conclusion, specific immune checkpoint-inhibitors should be evaluated in this disease and the combination with molecular targeted therapies might be of benefit. An extensive immune monitoring should accompany these studies to better understand their mode of action in the tumor microenvironment.

Molecular and clinical evidence for an ARMC5 tumor syndrome: concurrent inactivating germline and somatic mutations are associated with both primary macronodular adrenal hyperplasia and meningioma

CONTEXT

Primary macronodular adrenal hyperplasia (PMAH) is a rare cause of Cushing's syndrome, which may present in the context of different familial multitumor syndromes. Heterozygous inactivating germline mutations of armadillo repeat containing 5 (ARMC5) have very recently been described as cause for sporadic PMAH. Whether this genetic condition also causes familial PMAH in association with other neoplasias is unclear.

OBJECTIVE

The aim of the present study was to delineate the molecular cause in a large family with PMAH and other neoplasias.

PATIENTS AND METHODS

Whole-genome sequencing and comprehensive clinical and biochemical phenotyping was performed in members of a PMAH affected family. Nodules derived from adrenal surgery and pancreatic and meningeal tumor tissue were analyzed for accompanying somatic mutations in the identified target genes.

RESULTS

PMAH presenting either as overt or subclinical Cushing's syndrome was accompanied by a heterozygous germline mutation in ARMC5 (p.A110fs*9) located on chromosome 16. Analysis of tumor tissue showed different somatic ARMC5 mutations in adrenal nodules supporting a second hit hypothesis with inactivation of a tumor suppressor gene. A damaging somatic ARMC5 mutation was also found in a concomitant meningioma (p.R502fs) but not in a pancreatic tumor, suggesting biallelic inactivation of ARMC5 as causal also for the intracranial meningioma.

CONCLUSIONS

Our analysis further confirms inherited inactivating ARMC5 mutations as a cause of familial PMAH and suggests an additional role for the development of concomitant intracranial meningiomas.

Changing histopathological diagnostics by genome-based tumor classification

Traditionally, tumors are classified by histopathological criteria, i.e., based on their specific morphological appearances. Consequently, current therapeutic decisions in oncology are strongly influenced by histology rather than underlying molecular or genomic aberrations. The increase of information on molecular changes however, enabled by the Human Genome Project and the International Cancer Genome Consortium as well as the manifold advances in molecular biology and high-throughput sequencing techniques, inaugurated the integration of genomic information into disease classification. Furthermore, in some cases it became evident that former classifications needed major revision and adaption. Such adaptations are often required by understanding the pathogenesis of a disease from a specific molecular alteration, using this molecular driver for targeted and highly effective therapies. Altogether, reclassifications should lead to higher information content of the underlying diagnoses, reflecting their molecular pathogenesis and resulting in optimized and individual therapeutic decisions. The objective of this article is to summarize some particularly important examples of genome-based classification approaches and associated therapeutic concepts. In addition to reviewing disease specific markers, we focus on potentially therapeutic or predictive markers and the relevance of molecular diagnostics in disease monitoring.

The SNP rs6441224 influences transcriptional activity and prognostically relevant hypermethylation of RARRES1 in prostate cancer

Epigenetic aberrations are frequent in prostate cancer and could be useful for detection and prognostication. However, the underlying mechanisms and the sequence of these changes remain to be fully elucidated. The tumor suppressor gene RARRES1 (TIG1) is frequently hypermethylated in several cancers. Having noted changes in the expression of its paralogous neighbor gene LXN at 3q25.32, we used pyrosequencing to quantify DNA methylation at both genes and determine its relationship with clinicopathological parameters in 86 prostate cancer tissues from radical prostatectomies. Methylation at LXN and RARRES1 was highly correlated. Increasing methylation was associated with worse clinical features, including biochemical recurrence, and decreased expression of both genes. However, expression of three neighboring genes was unaffected. Intriguingly, RARRES1 methylation was influenced by the genotype of the rs6441224 single-nucleotide polymorphism (SNP) in its promoter. We found that this SNP is located within an ETS-family-response element and that the more strongly methylated allele confers lower activity in reporter assays. Concomitant methylation of RARRES1 and LXN in cancerous tissues was also detected in prostate cancer cell lines and was shown to be associated with repressive histone modifications and transcriptional downregulation. In conclusion, we found that genotype-associated hypermethylation of the ETS-family target gene RARRES1 influences methylation at its neighbor gene LXN and could be useful as a prognostic biomarker.

DNA methylation changes in prostate cancer

Epigenetic alterations contribute significantly to the development and progression of prostate cancer, the most prevalent malignant tumor in males of Western industrialized countries. Here, we review recent research on DNA methylation alterations in this cancer type. Hypermethylation of several genes including GSTP1 is well known to occur in a consistent and apparently coordinate fashion during the transition from intraepithelial neoplasia to frank carcinoma. These hypermethylation events have shown promise as biomarkers for detection of prostate carcinoma. Many other individual genes have been shown to undergo hypermethylation, which is typically associated with diminished expression. These investigations indicate additional candidates for biomarkers; in particular, hypermethylation events associated with progression can be employed to identify more aggressive cases. In addition, some of genes silenced by aberrant methylation in prostate have been shown to exhibit properties of tumor suppressors, revealing insights into mechanisms of carcinogenesis. Whereas most studies in the past have used candidate gene approaches, new techniques allowing genome-wide screening for altered methylation are increasingly employed in prostate cancer research and have already yielded encouraging results.

Immune response to non-O157 Vero toxin-producing Escherichia coli in patients with hemolytic uremic syndrome

The incidence and time course of the immune response to Vero toxin-producing Escherichia coli (VTEC) other than O157 (O26, O55, O111, O128) were determined in 107 children with enteropathic hemolytic uremic syndrome (HUS) by ELISA and compared to antibody profiles of 125 healthy pediatric controls and 100 children with community-acquired uncomplicated diarrhea. Six of 8 HUS patients with non-O157 VTEC isolates exhibited a serologic response to the homologous lipopolysaccharide antigen similar to that of patients infected with E. coli O157. In addition, elevated IgM or IgG antibodies were demonstrated in 7 of 19 culture- and O157 serology-negative HUS patients. Serogroup-specific antibodies decreased below cutoff levels within several months after convalescence. Anti-non-O157 antibodies were found in 14% of the diarrheic controls. Unexpectedly, a high proportion (27/82) of anti-O157 lipopolysaccharide antibody-positive HUS samples reacted with LPS from E. coli O55:B5, suggesting shared epitopes with endemic VTEC O157 strains.