HER2 and BRAF mutation in colorectal cancer patients: a retrospective study in Eastern China

Systematic literature review and meta-analysis of HER2 amplification, overexpression, and positivity in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the second most common cause of cancer death globally. Recent clinical trials suggest an emerging role for HER2 as a potential clinically relevant biomarker in CRC. Testing for HER2 in CRC is not standard practice; consequently, the prevalence of HER2 positivity (HER2+) in patients with CRC remains uncertain.

METHODS

A systematic literature review and meta-analysis were conducted to generate estimates of proportions of patients with CRC with HER2 overexpression or HER2 amplification and HER2+ (either overexpression or amplification), overall and in patients with rat sarcoma virus (RAS) wild-type cancer. HER2+ was defined as 1) immunohistochemistry with a score of 3+, 2) immunohistochemistry with a score of 2+ and in situ hybridization+, or 3) next-generation sequencing positive.

RESULTS

Of 224 studies identified with information on HER2 in CRC, 52 studies used a US Food and Drug Administration-approved assay and were selected for further analysis. Estimated HER2+ rate was 4.1% (95% confidence interval [CI] = 3.4% to 5.0%) overall (n = 17 589). HER2+ rates were statistically higher in RAS wild-type (6.1%, 95% CI = 5.4% to 6.9%) vs RAS mutant CRC (1.1%, 95% CI = 0.3% to 4.4%; P < .0001). Despite limited clinical information, we confirmed enrichment of HER2+ CRC in patients with microsatellite stable and left-sided CRC.

CONCLUSION

This meta-analysis provides an estimate of HER2+ CRC and confirms enrichment of HER2 in microsatellite stable, left-sided, RAS wild-type CRC tumors. Our work is important given the recently described clinical efficacy of HER2-targeted therapies in HER2+ CRC and informs strategies for incorporation of HER2 testing into standard of care.

KRAS/NRAS Mutations Associated with Distant Metastasis and BRAF/PIK3CA Mutations Associated with Poor Tumor Differentiation in Colorectal Cancer

Background

The occurrence, progression, and prognosis of colorectal cancer (CRC) are regulated by EGFR-mediated signaling pathways. However, the relationship between the core genes (KRAS/NRAS/BRAF/PIK3CA) status in the signaling pathways and clinicopathological characteristics of CRC patients in Hakka population remains controversial.

Methods

Patients were genotyped for KRAS (codons 12, 13, 61, 117, and 146), NRAS (codons 12, 61, 117, and 146), BRAF (codons 600), and PIK3CA (codons 542, 545 and 1047) mutations. Clinical records were collected, and clinicopathological characteristic associations were analyzed together with mutations of studied genes.

Results

Four hundred and eight patients (256 men and 152 women) were included in the analysis. At least one mutation in the four genes was detected in 216 (52.9%) patients, while none was detected in 192 (47.1%) patients. KRAS, NRAS, BRAF, and PIK3CA mutation status were detected in 190 (46.6%), 11 (2.7%), 10 (2.5%), 34 (8.3%) samples, respectively. KRAS exon 2 had the highest proportion (62.5%). Age, tumor site, tumor size, lymphovascular invasion, and perineural invasion were not associated with gene mutations. KRAS mutations (adjusted OR 1.675, 95% CI 1.017-2.760, P=0.043) and NRAS mutations (adjusted OR 5.183, 95% CI 1.239-21.687, P=0.024) appeared more frequently in patients with distant metastasis. BRAF mutations (adjusted OR 7.224, 95% CI 1.356-38.488, P=0.021) and PIK3CA mutations (adjusted OR 3.811, 95% CI 1.268-11.455, P=0.017) associated with poorly differentiated tumor.

Conclusion

KRAS/NRAS mutations are associated with distant metastasis and BRAF/PIK3CA mutations are associated with poor tumor differentiation in CRC. And the results provided a better understanding between clinicopathological characteristics and gene mutations in CRC patients.

Dual HER2 Targeted Therapy With Pyrotinib and Trastuzumab in Refractory HER2 Positive Metastatic Colorectal Cancer: A Result From HER2-FUSCC-G Study

BACKGROUND

Dual-HER2 targeted therapy has led to a promising antitumor effect in HER2 positive cancers including gastrointestinal cancer. The present data focus on patients with HER2 positive colorectal cancer who received pyrotinib and trastuzumab after failure to standard second-line treatment.

METHODS

Patients diagnosed of HER2 positive refractory or metastatic colorectal cancer were enrolled to receive trastuzumab in combination with pyrotinib as third-line and beyond therapy. Trastuzumab was given as a loading dose at 8 mg/kg followed by 6mg/kg once every 3 weeks, and oral pyrotinib as 400 mg per day until progression. ORR was set as the primary endpoint. PFS and OS were set as a secondary endpoints. This trial is registered with Clinical Trial.gov, NCT04960943, and is ongoing.

RESULTS

Between February 2020 to December 2021, 16 patients including 14 with RAS wild-type status were enrolled in this cohort. ORR was 50.0% in the overall population, and 57.1% in RAS wild-type patients. At a median follow-up of 11.2 months, median PFS and OS were 7.53 and 16.8 months, respectively. The RAS/BRAF wild-type patients had prolonged survival (PFS: 7.53 vs. 1.63 months, P = .02; OS: NR vs.4.13 months, P = .001) compared with RAS/BRAF mutant patients. The most common treatment-emergent adverse event (TEAE) reported is diarrhea. Five (31.3%) patients reported grade 3 TEAEs, and no death was reported.

CONCLUSIONS

Trastuzumab in combination with pyrotinib demonstrated encouraging antitumor activity that translated to prolonged survival benefit in HER2 positive refractory or mCRC patients who are RAS wild-type with acceptable tolerance.

HER2 status is positively associated with vessel invasion of colorectal cancer: a retrospective large cohort study

PURPOSE

HER2-positive colorectal cancer was drawn increasing attention in recent years. Accumulating evidence showed HER2-positive metastatic colorectal cancer could benefit from HER2-targeted therapy. While HER2 expression and the relationship between HER2 status and clinicopathological characteristics of overall colorectal cancer remains largely unknown. The aim of this study was to evaluate HER2 expression in colorectal cancer and compare the clinicopathological features between HER2-positive and HER2-negative colorectal cancer.

METHODS

We retrospectively analyzed 3910 primary colorectal cancer patients treated in our institution from January 2016 to December 2019. Medical records and pathology reports after surgery were collected to provide information about HER2 status and other clinicopathological characteristics.

RESULTS

We identified 3347 HER2-negative and 79 HER2-positive colorectal cancer patients in our cohort. The chi-square test showed that vessel invasion was significantly more common in HER2-positive colorectal cancer patients. Crude analysis showed HER2 positive was associated with vessel invasion in colorectal cancer [OR and 95% CI 0.534 (0.341, 0.835), p = 0.006]. After adjusting for N stage, a significant association was still observed between HER2 status and vessel invasion in colorectal cancer [OR and 95% CI 0.550 (0.322, 0.941), p = 0.029]. Survival analysis showed that there was no significant difference in 3-year overall survival rate between HER2 positive and HER2 negative group (p = 0.603).

CONCLUSION

Our findings indicate that the rate of HER2 positivity in colorectal cancer was relatively low, and HER2 status was strongly associated with vessel invasion while having no significant influence on the 3-year overall survival rate in colorectal cancer patients.

A Systematic Review and Meta-analysis on the Occurrence of Biomarker Mutation in Colorectal Cancer among the Asian Population

Globally, colorectal carcinoma (CRC) is the third most common cancer and the third major cause of cancer-related death in both sexes. KRAS and BRAF mutations are almost mutually exclusively involved in the pathogenesis of CRC. Both are major culprits in treatment failure and poor prognosis for CRC. Method. A systematic review and meta-analysis of various research was done following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. This trial is registered with PROSPERO CRD42021256452. The initial search included 646 articles; after the removal of noneligible studies, a total of 88 studies was finally selected. Data analysis was carried out using OpenMeta Analyst and Comprehensive Meta-Analysis 3.0 (CMA 3.0) software to investigate the prevalence of KRAS and BRAF mutations among patients with CRC in Asia. Results. The meta-analysis comprises of 25,525 sample sizes from Asia with most being male 15,743/25525 (61.7%). Overall prevalence of KRAS mutations was (59/88) 36.3% (95% CI: 34.5-38.2) with I² = 85.54% (P value < 0.001). In 43/59 studies, frequency of KRAS mutations was majorly in codon 12 (76.6% (95% CI: 74.2–78.0)) and less in codon 13 (21.0% (95% CI: 19.1-23.0)). Overall prevalence of BRAF mutations was 5.6% (95% CI: 3.9-8.0) with I² = 94.00% (P value < 0.001). When stratified according to location, a higher prevalence was observed in Indonesia (71.8%) while Pakistan has the lowest (13.5%). Conclusion. Total prevalence of KRAS and BRAF mutations in CRC was 36.6% and 5.6%, respectively, and the results conformed with several published studies on KRAS and BRAF mutations.

Human Epidermal Growth Factor Receptor 2 Overexpression and Amplification in Patients With Colorectal Cancer: A Large-Scale Retrospective Study in Chinese Population

Background

Cumulative evidence in colorectal cancer (CRC) suggests that patients with human epidermal growth factor receptor 2 (HER2) overexpression or amplification can benefit from anti-HER2 therapy. The purpose of our study was to evaluate HER2 status and its correlation with clinicopathological characteristics and survival according to currently utilized HER2 diagnostic criteria in a large cohort of Chinese CRC patients.

Methods

HER2 protein expression was tested by immunohistochemistry (IHC) in formalin-fixed, paraffin-embedded (FFPE) samples from 4,836 CRC patients in our institution. Breast cancer (BC) and gastroesophageal adenocarcinoma (GEA) criteria, as well as the HERACLES criteria, were used for the determination of HER2 status. Dual-color silver-enhanced in situ hybridization (DSISH) was performed in all IHC 2+~3+ cases determined by BC/GEA criteria.

Results

The HER2 expression rate of IHC (1+~3+) was 7.01% (339/4,836) and 6.02% (291/4,836) in CRCs based on the BC/GEA criteria and the HERACLES criteria, respectively, while combined DSISH results in the HER2 amplification/overexpression ratio of 3.39% (164/4,836) in our cohort. HER2 expression detected by IHC was positively correlated with the female gender, whereas the HER2 overexpression/amplification showed no correlation with any clinicopathological parameter. In addition, no significant correlation was found between HER2 statuses and either disease-free survival or overall survival regardless of the evaluation criterion used. However, patients with HER2 1+ CRC showed a tendency of having the shortest overall survival as compared with any other group of patients according to the HERACLES criteria, and this trend has always existed in the rectal location, T3 stage, and TNM stage II, medium differentiation, and perineural invasion stratified group. Furthermore, the HER2 protein expression was significantly negatively correlated with RAS/BRAF mutations according to the HERACLES criteria.

Conclusion

To our knowledge, this is the largest study of HER2 status in Asian patients with CRC. Our findings suggest that the current most commonly used HERACLES criteria might be too strict for patients with CRC. Future studies are needed to explore the most suitable criteria for screening CRC patients who could benefit from anti-HER2 therapy as much as possible.

Molecular Analysis of Colorectal Cancers Suggests a High Frequency of Lynch Syndrome in Indonesia

Simple Summary

The incidence of young people <50 years old who are diagnosed with colorectal cancer (CRC), termed as early onset colorectal cancer (EOCRC), accounted for nearly 30% of the total CRC patients in Indonesia, which is about three times higher than what is being reported in Europe, the UK and USA. Lynch syndrome (LS) is a hereditary type of CRC that is associated with a younger age of onset. Detecting LS has been long reported to be a cost-effective strategy to provide aid in the diagnosis or management of the individual or at-risk family members. The aim of this retrospective study was to screen for Lynch Syndrome in Indonesian CRC patients using simple and robust polymerase chain reaction (PCR)-based molecular testing, known as N_LyST (Nottingham Lynch Syndrome Test). To our knowledge, we are the first to study and observe a potentially higher frequency of LS (13.85%) among CRC patients in Indonesia (n = 231). This may partially contribute to the reported much higher rate of EOCRC found in the country.

Abstract

There is about three times higher incidence of young patients <50 years old with colorectal cancer, termed EOCRC, in Indonesia as compared to Europe, the UK and USA. The aim of this study was to investigate the frequency of Lynch Syndrome (LS) in Indonesian CRC patients. The previously described Nottingham Lynch Syndrome Test (N_LyST) was used in this project. N_LyST is a robust high-resolution melting (HRM)-based test that has shown 100% concordance with standard reference methods, including capillary electrophoresis and Sanger sequencing. The test consisted of five mononucleotide microsatellite markers (BAT25, BAT26, BCAT25, MYB, EWSR1), BRAF V600E mutation and MLH1 region C promoter for methylation (using bisulphite-modified DNA). A total of 231 archival (2016–2019) formalin-fixed, paraffin-embedded (FFPE) tumour tissues from CRC patients collected from Dr. Sardjito General Hospital Yogyakarta, Indonesia, were successfully tested and analysed. Among those, 44/231 (19.05%) were MSI, 25/231 (10.82%) were harbouring BRAF V600E mutation and 6/231 (2.60%) had MLH1 promoter methylation. Almost all—186/197 (99.45%)—MSS cases were MLH1 promoter unmethylated, while there were only 5/44 (11.36%) MSI cases with MLH1 promoter methylation. Similarly, only 9/44 (20.45%) of MSI cases were BRAF mutant. There were 50/231 (21.65%) EOCRC cases, with 15/50 (30%) regarded as MSI, as opposed to 29/181 (16.02%) within the older group. In total, 32/231 patients (13.85%) were classified as “Probable Lynch” (MSI, BRAF wildtype and MLH1 promoter unmethylated), which were enriched in EOCRC as compared to older patients (24% vs. 11.05%, p = 0.035). Nonetheless, 30/50 (76.00%) cases among the EOCRC cases were non-LS (sporadic) and were significantly associated with a left-sided tumour. The overall survival of both “Probable Lynch” and non-LS (sporadic) groups (n = 227) was comparable (p = 0.59), with follow up period of 0–1845 days/61.5 months. Stage, node status, histological grading and ECOG score were significantly associated with patient overall survival (p < 0.005), yet only ECOG was an independent factor for OS (HR: 4.38; 95% CI: 1.72–11.2; p = 0.002). In summary, this study is the first to reveal a potentially higher frequency of LS among CRC patients in Indonesia, which may partially contribute to the reported much higher number of EOCRC as compared to the incidence in the West.

The role of multiple metabolic genes in predicting the overall survival of colorectal cancer: A study based on TCGA and GEO databases

The recent advances in gene chip technology have led to the identification of multiple metabolism-related genes that are closely associated with colorectal cancer (CRC). Nevertheless, none of these genes could accurately diagnose or predict CRC. The prognosis of CRC has been made by previous prognostic models constructed by using multiple genes, however, the predictive function of multi-gene prognostic models using metabolic genes for the CRC prognosis remains unexplored. In this study, we used the TCGA-CRC cohort as the test dataset and the GSE39582 cohort as the experimental dataset. Firstly, we constructed a prognostic model using metabolic genes from the TCGA-CRC cohort, which were also associated with CRC prognosis. We analyzed the advantages of the prognostic model in the prognosis of CRC and its regulatory mechanism of the genes associated with the model. Secondly, the outcome of the TCGA-CRC cohort analysis was validated using the GSE39582 cohort. We found that the prognostic model can be employed as an independent prognostic risk factor for estimating the CRC survival rate. Besides, compared with traditional clinical pathology, it can precisely predict CRC prognosis as well. The high-risk group of the prognostic model showed a substantially lower survival rate as compared to the low-risk group. In addition, gene enrichment analysis of metabolic genes showed that genes in the prognostic model are enriched in metabolism and cancer-related pathways, which may explain its underlying mechanism. Our study identified a novel metabolic profile containing 11 genes for prognostic prediction of CRC. The prognostic model may unravel the imbalanced metabolic microenvironment, and it might promote the development of biomarkers for predicting treatment response and streamlining metabolic therapy in CRC.

Circulating Biomarkers of Colorectal Cancer (CRC)-Their Utility in Diagnosis and Prognosis

The global burden of colorectal cancer (CRC) is expected to increase, with 2.2 million new cases and 1.1 million annual deaths by 2030. Therefore, the establishment of novel biomarkers useful in the early diagnosis of CRC is of utmost importance. A number of publications have documented the significance of the overexpression of several specific proteins, such as inflammatory mediators, in CRC progression. However, little is known about the potential utility of these proteins as circulating blood tumor biomarkers of CRC. Therefore, in the present review we report the results of our previous original studies as well as the findings of other authors who investigated whether inflammatory mediators might be used as novel biomarkers in the diagnosis and prognosis of CRC. Our study revealed that among all of the tested proteins, serum M-CSF, CXCL-8, IL-6 and TIMP-1 have the greatest value in the diagnosis and progression of CRC. Serum TIMP-1 is useful in differentiating between CRC and colorectal adenomas, whereas M-CSF and CRP are independent prognostic factors for the survival of patients with CRC. This review confirms the promising significance of these proteins as circulating biomarkers for CRC. However, due to their non-specific nature, further validation of their sensitivity and specificity is required.

Clinicopathological and molecular features of colorectal cancer with synchronous adenoma

OBJECTIVE

To investigate the clinicopathological and molecular features of colorectal cancer (CRC) with synchronous adenoma and to describe features of synchronous adenomas in CRC patients.

METHODS

Single-centre retrospective cohort of 180 patients were included. The clinicopathological and endoscopic data were collected. The expression mismatch repair (MMR) proteins were detected by immunohistochemistry. The determination of microsatellite instability (MSI) was performed by multiple fluorescence PCR, and the mutations of genes were detected by real-time PCR.

RESULTS

Among all cases, 49 were diagnosed as CRC with synchronous adenoma, and 131 were diagnosed as solitary CRC. Some of the differences between the groups are: higher incidence was found in male (71.4 vs. 52.6%, p = .023) and in patients with habit drinking (34.7 vs. 14.5%, p = .030) and with other neoplastic diseases (42.7 vs. 26%, p = .028). Less tumors in the synchronous group were diagnosed as stage III and IV than in the solitary group (28.6 vs. 45%, p = .045). One and four mutant subtypes of KRAS gene mutations were detected insynchronous group and solitary group respectively.The prevalence of BRAF mutations in solitary group was higher than that in the synchronous group (7.4 vs. 0%, p = .045). A total of 123 adenomas were found in synchronous group and they tend to be smaller than 10 mm (74%).

CONCLUSION

Gender, a habit of drinking and other neoplastic diseases are risk factors for the development of a synchronous adenoma. With a low rate of BRAF mutations, the responses to monoclonal antibody and prognosis of patients with synchronous adenomas may be better than that of solitary CRC.

Differential Expression of HER2 and SKP2 in Benign and Malignant Colorectal Lesions

Background:

Colorectal cancer (CRC) is the fourth most common cancer worldwide. Both HER2 and SKP2 have a carcinogenic role in CRC making them attractive targets for tailored treatment. This work aims to correlate HER2 and SKP2 protein expression as well as HER2 gene amplification with clinicopathological parameters aiming at identifying potential candidates for targeted therapy.

Methods:

This Study was conducted on 127 paraffin-embedded tissue samples of different colorectal lesions [controls, chronic colitis, ulcerative colitis (UC), hyperplastic polyps (HPs), adenomas and CRCs] to investigate HER2 and SKP2 expression by immunohistochemistry (IHC), Selected CRC cases [equivocal (2+) and positive (3+) by IHC] were further evaluated by ISH (CISH and SISH ) to assess HER2 gene amplification.

Results:

Chronic colitis, UC, HPs and adenomas were HER2-negative. HER2 positivity (scores 2+ and 3+) was found only in15% of CRCs. Both SISH and CISH showed the same results with high concordance as 66.7% of equivocal and 100% of positive cases showed amplification of HER2 gene. SKP2 positivity was detected in 26.7% and 45% of adenomas and CRCs respectively, while other studied groups were negative. A significant correlation was noted between HER2 and SKP2 expression.

Conclusion:

A small percent of CRCs exhibited HER2 gene amplification, which would be potential candidates for anti HER2 therapy whereas IHC could be a primary screening test for patient selection. A potential carcinogenic role of SKP2 was suggested by the findings that SKP2 expression was undetectable in normal colonic mucosa but significantly increases from adenoma to carcinoma, hoping adenoma patients to get benefit from targeted therapy.