High prevalence of deficient mismatch repair phenotype and the V600E BRAF mutation in elderly patients with colorectal cancer

Non-metastatic colon cancer: French Intergroup Clinical Practice Guidelines for diagnosis, treatments, and follow-up (TNCD, SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, ACHBT, SFP, AFEF, and SFR)

INTRODUCTION

This article is a summary of the French intergroup guidelines regarding the management of non-metastatic colon cancer (CC), revised in November 2022.

METHODS

These guidelines represent collaborative work of all French medical and surgical societies involved in the management of CC. Recommendations were graded in three categories (A, B, and C) according to the level of evidence found in the literature published up to November 2022.

RESULTS

Initial evaluation of CC is based on clinical examination, colonoscopy, chest-abdomen-pelvis computed tomography (CT) scan, and carcinoembryonic antigen (CEA) assay. CC is usually managed by surgery and adjuvant treatment depending on the pathological findings. The use of adjuvant therapy remains a challenging question in stage II disease. For high-risk stage II CC, adjuvant chemotherapy must be discussed and fluoropyrimidine monotherapy or oxaliplatin-based chemotherapy proposed according to the type and number of poor prognostic features. Oxaliplatin-based chemotherapy (FOLFOX or CAPOX) is the current standard for adjuvant therapy of patients with stage III CC. However, these regimens are associated with significant oxaliplatin-induced neurotoxicity. The results of the recent IDEA study provide evidence that 3 months of treatment with CAPOX is as effective as 6 months of oxaliplatin-based therapy in patients with low-risk stage III CC (T1-3 and N1). A 6-month oxaliplatin-based therapy remains the standard of care for high-risk stage III CC (T4 and/or N2). For patients unfit for oxaliplatin, fluoropyrimidine monotherapy is recommended.

CONCLUSION

French guidelines for non-metastatic CC management help to offer the best personalized therapeutic strategy in daily clinical practice. Each individual case must be discussed within a multidisciplinary tumor board and then the treatment option decided with the patient.

[Safety and efficacy of immune checkpoint inhibitors in elderly patients]

Immune checkpoint inhibitors (ICI) are the standard of care for many solid tumors with specific physiopathology mechanisms and adverse events. While the percentage of elderly patients increase from years to years, these patients are underrepresented in clinical trials. Immunosenescence and inflammaging, two main components of the aging of our immune system, and their consequences on the safety and the efficacy are today major focus of clinical research. However, there are still no risk assessment score specific to ICI in elderly patients. In this review we showed the global reassuring data on safety from several retrospective and subgroup analysis, in elderly patients. In summary, impairment of the general state is an independent factor of occurrence of adverse events treatment related whatever the age. Here, we highlight the necessity to use of geriatric evaluation screening test in clinic, the need of specific risk score ICI use in the erdely population and mostly the inclusion of elderly patients in clinical trial to generate specific data.

FOxTROT2: innovative trial design to evaluate the role of neoadjuvant chemotherapy for treating locally advanced colon cancer in older adults or those with frailty

Treating older adults with cancer is increasingly important in modern oncology practice. However, we currently lack the high-quality evidence needed to guide optimal management of this heterogeneous group. Principally, historic under-recruitment of older adults to clinical trials limits our understanding of how existing evidence can be applied to this group. Such uncertainty is particularly prevalent in the management of colon cancer (CC). With CC being most common in older adults, many patients also suffer from frailty, which is recognised as being strongly associated with poor clinical outcomes. Conducting clinical trials in older adults presents several major challenges, many of which impact the clinical relevance of results to a real-world population. When considering this heterogeneous group, it may be difficult to define the target population, recruit participants effectively, choose an appropriate trial design, and ensure participants remain engaged with the trial during follow-up. Furthermore, after overcoming these challenges, clinical trials tend to enrol highly selected patient cohorts that comprise only the fittest older patients, which are not representative of the wider population. FOxTROT1 was the first phase III randomised controlled trial to illustrate the benefit of neoadjuvant chemotherapy (NAC) in the treatment of CC. Patients receiving NAC had greater 2-year disease-free survival compared to those proceeding straight to surgery. Outcomes for older adults in FOxTROT1 were similarly impressive when compared to their younger counterparts. Yet, this group inevitably represents a fitter subgroup of the older patient population. FOxTROT2 has been designed to investigate NAC in a full range of older adults with CC, including those with frailty. In this review, we describe the key challenges to conducting a robust clinical trial in this heterogeneous patient group, highlight our strategies for overcoming these challenges in FOxTROT2, and explain how we hope to provide clarity on the optimal treatment of CC in older adults.

Preliminary tolerance analysis of adjuvant chemotherapy in older patients after resection of stage III colon cancer from the PRODIGE 34-FFCD randomized trial

BACKGROUND

Colon adenocarcinoma mainly occurs in older patients. Oxaliplatin-based adjuvant chemotherapy improved disease-free survival after stage III colon cancer resection, but this improvement was not demonstrated in older patients.

METHODS

The purpose of ADAGE-PRODIGE 34, randomized open phase III trial is to compare in patients over 70 years oxaliplatin plus fluoropyrimidine with fluoropyrimidine alone in fit patients (Group 1) and fluoropyrimidine with observation in frail patients (Group 2) after resection of stage III colon adenocarcinoma. We report a preliminary tolerance analysis on 50% of the first patients enrolled.

RESULTS

The analysis was conducted on 491 patients (378 in Group 1 and 113 in Group 2). Patients in Group 2 were older and showed more frailty criteria than those in Group 1. Cumulative grade 3-5 toxicities were more frequent in patients treated with oxaliplatin in Group 1 or with fluoropyrimidine in Group 2 than in patients treated with fluoropyrimidine in Group 1. At least one course was deferred in more than half of the patients in all groups. Early treatment cessation was more frequent in Group 2.

CONCLUSION

No safety concerns were raised for the continuation of accrual. The frailty criteria distribution suggests that the investigator's evaluation for group allocation was accurate.

Prevalence and prognosis of microsatellite instability in oesogastric adenocarcinoma, NORDICAP 16-01

BACKGROUND

The prevalence and prognosis association of microsatellite instability (MSI) in oesogastric junction and gastric adenocarcinoma (OGC) have been reported with conflicting results.

METHODS

Patients with OGC from 2010 to 2015 were enrolled in this retrospective multicenter study. MSI was determined by genotyping. MLH1 promoter methylation and BRAFV600E mutation were screened in the MSI tumors.

RESULTS

Among 315 tumors analyzed, 39 (12.4%) were of the MSI phenotype. Compared to MSS tumors, MSI tumors were more frequent in patients >70 years (17% vs 9%, p=0.048) and in gastric antral primary (20% versus 5% in junction tumor and 12% in fundus tumor. Among 29 MSI tumors analyzed, 28 had a loss of MLH1 protein expression and 27 had MLH1 promotor hypermethylation. None had a BRAF V600E mutation. The 4-year cumulative incidence of recurrence for patients with resected tumor was significantly lower in dMMR tumors versus pMMR tumors (17% versus 47%, p=0.01). For the patients with unresectable tumor the median overall survival was 11 months in MSS group and 14 months in MSI group (p=0.24).

CONCLUSION

MSI prevalence in OGC was 12.4%, associated with antral localization and advanced age. Patients with MSI tumors had a lower cumulative incidence of recurrence after surgery. MSI phenotype was mainly associated with loss of MLH1 protein expression, MLH1 promotor hypermethylation and had no BRAFV600E mutation.

Comparison of universal screening in major lynch-associated tumors: a systematic review of literature

Lynch syndrome (LS) is associated with an increased lifetime risk of several cancers including colorectal (CRC), endometrial (EC), ovarian (OC), urinary (UT) and sebaceous tumors (ST). The benefit for universal screening in CRC and EC is well known. However, this benefit in other major lynch-associated tumors is unclear. We performed a systematic review of all published articles in the MEDLINE database between 2005 to 2017 to identify studies performing universal screening for LS in unselected CRC, EC, OC, UT and ST. All cases with MSI-H (instability in two or more markers) or missing one or more proteins on IHC testing were considered screening positive. Cases with MLH1 promoter hypermethylation or BRAF mutation positive were considered to have somatic mutations. A total of 3788 articles were identified in MEDLINE yielding 129 study arms from 113 studies. The overall pooled yield of universal LS screening and germline mismatch gene mutation was significantly different across the major LS-associated tumors (Mann Whitney test, p < 0.001). The pooled screening yield was highest in ST [52.5% (355/676), 95% CI 48.74-56.26%] followed by EC [22.65% (1142/5041), 95% CI 21.54-23.86%], CRC [11.9% (5649/47,545), 95% CI 11.61-12.19%], OC [11.29% (320/2833), 95% CI 10.13-12.47%] and UT [11.2% (31/276), 95% CI 7.48-14.92%]. ST also had the highest pooled germline positivity for mismatch repair gene mutation [18.8%, 33/176, 95%CI 13.03-24.57], followed by EC [2.6% (97/3765), 95% CI 2.09-3.11], CRC [1.8% (682/37,220), 95% CI 1.66-1.94%], UT [1.8%(3/164), 95% CI - 0.24-3.83%] and OC [0.83%(25/2983), 95% CI 0.48-1.12%]. LS screening in EC yielded significantly higher somatic mutations compared to CRC [pooled percentage 16.94% [(538/3176), 95%CI 15.60-18.20%] vs. 5.23% [(1639/26,152), 95% CI 4.93-5.47%], Mann Whitney test, p < 0.0001. Universal LS testing should be routinely performed in OC, UT and STs in addition to CRC and EC. Our findings also support consideration for IHC and somatic mutation testing before germline testing in EC due to higher prevalence of somatic mutations as well as germline testing in all patients with ST. Our results have implications for future design of LS screening programs and further studies are needed to assess the cost effectiveness and burden on genetic counselling services with expanded universal testing for LS.

Panel gene profiling of small bowel adenocarcinoma: Results from the NADEGE prospective cohort

Small bowel adenocarcinoma (SBA) is a rare tumour. Large genomic analyses with prognostic assessments are lacking. The NADEGE cohort has enrolled 347 patients with all stage SBA from 2009 to 2012. Next-generation sequencing investigates the presence of 740 hotspot somatic mutations in a panel of 46 genes involved in carcinogenesis. The mismatch repair (MMR) status was assessed by immunochemistry. We have collected 196 tumour samples and 125 had conclusive results for mutation analysis. The number of mutations was 0 in 9.6% of tumours, only 1 in 32.0%, 2 in 26.4% and ≥3 in 32.0%. Overall, at least one genomic alteration was observed in 90.4% of tumour. The most frequent genomic alteration was in KRAS (44.0%), TP53 (38.4%), PIK3CA (20.0%), APC (18.4%), SMAD4 (14.4%) and ERBB2 (7.2%) genes. KRAS mutations were more frequent in synchronous metastatic tumours than in localised tumours (72.7% vs 38.2%, P = .003). There was no significant difference in the mutation rates according to primary location for the most frequently altered gene. ATM, FGFR3 and FGFR1 gene alterations were associated with Lynch syndrome and IDH1 mutations with Crohn disease. dMMR tumours were associated with younger age, localised tumours, less KRAS but more SMARCB1 mutations. No genomic alteration was associated with overall survival. There is a trend for better survival in patient with dMMR tumours. In conclusion, there is a different genomic alteration profile in SBA according to predisposing diseases. No association between genomic alterations and prognoses was observed except for a trend of better prognoses associated with dMMR.

Worldwide variation in lynch syndrome screening: case for universal screening in low colorectal cancer prevalence areas

To perform a systematic assessment of universal Lynch syndrome (LS) screening yield in colorectal cancer (CRC) patients around the world. Universal screening for LS is recommended in all CRC patients. However, the variation in yield of LS screening in the setting of significant global variation in CRC prevalence is unknown. A systematic review of articles in the MEDLINE database was performed to identify studies performing universal screening for LS. All cases with microsatellite instability (MSI-H) or missing one or more proteins on immunohistochemistry (IHC) were considered screening positive. The overall pooled yield of universal LS screening in 97 study arms from 89 identified studies was 11.9% (5649/47545) and the overall pooled percentage of confirmed LS patients was 1.8% (682/37220). LS screening positivity varied significantly based on geographic region (Kruskal Wallis test, p < 0.001) and reported 5-year CRC prevalence in the country (Fisher's exact, p < 0.001). Significant inverse correlation was found between LS screening positivity and 5-year CRC prevalence (Pearson correlation, r =  - 0.56, p < 0.001). The overall yield of LS screening was 15.00% (382/2553) and rate of confirmed LS was 7.7% (113/1475) in LS screening done in patients ≤ 50 years (16 studies). There is significant geographic variation in LS screening positivity with higher yield in countries with lower prevalence of CRC. Our results highlight the importance of universal LS screening in younger patients and low CRC prevalence countries.

Effect of Aspirin on Cancer Incidence and Mortality in Older Adults

Background

ASPirin in Reducing Events in the Elderly, a randomized, double-blind, placebo-controlled trial of daily low-dose aspirin (100 mg) in older adults, showed an increase in all-cause mortality, primarily due to cancer. In contrast, prior randomized controlled trials, mainly involving younger individuals, demonstrated a delayed cancer benefit with aspirin. We now report a detailed analysis of cancer incidence and mortality.

Methods

19 114 Australian and US community-dwelling participants aged 70 years and older (US minorities 65 years and older) without cardiovascular disease, dementia, or physical disability were randomly assigned and followed for a median of 4.7 years. Fatal and nonfatal cancer events, a prespecified secondary endpoint, were adjudicated based on clinical records.

Results

981 cancer events occurred in the aspirin and 952 in the placebo groups. There was no statistically significant difference between groups for all incident cancers (hazard ratio [HR] = 1.04, 95% confidence interval [CI] = 0.95 to 1.14), hematological cancer (HR = 0.98, 95% CI = 0.73 to 1.30), or all solid cancers (HR = 1.05, 95% CI = 0.95 to 1.15), including by specific tumor type. However, aspirin was associated with an increased risk of incident cancer that had metastasized (HR = 1.19, 95% CI = 1.00 to 1.43) or was stage 4 at diagnosis (HR = 1.22, 95% CI = 1.02 to 1.45), and with higher risk of death for cancers that presented at stages 3 (HR = 2.11, 95% CI = 1.03 to 4.33) or 4 (HR = 1.31, 95% CI = 1.04 to 1.64).

Conclusions

In older adults, aspirin treatment had an adverse effect on later stages of cancer evolution. These findings suggest that in older persons, aspirin may accelerate the progression of cancer and, thus, suggest caution with its use in this age group.

JSCO-ESMO-ASCO-JSMO-TOS: international expert consensus recommendations for tumour-agnostic treatments in patients with solid tumours with microsatellite instability or NTRK fusions

A Japan Society of Clinical Oncology (JSCO)-hosted expert meeting was held in Japan on 27 October 2019, which comprised experts from the JSCO, the Japanese Society of Medical Oncology (JSMO), the European Society for Medical Oncology (ESMO), the American Society of Clinical Oncology (ASCO), and the Taiwan Oncology Society (TOS). The purpose of the meeting was to focus on what we have learnt from both microsatellite instability (MSI)/deficient mismatch repair (dMMR) biomarkers in predicting the efficacy of anti-programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) immunotherapy, and the neurotrophic tyrosine receptor kinase (NTRK) gene fusions in predicting the efficacy of inhibitors of the tropomyosin receptor kinase (TRK) proteins across a range of solid tumour types. The recent regulatory approvals of the anti-PD-1 antibody pembrolizumab and the TRK inhibitors larotrectinib and entrectinib, based on specific tumour biomarkers rather than specific tumour type, have heralded a paradigm shift in cancer treatment approaches. The purpose of the meeting was to develop international expert consensus recommendations on the use of such tumour-agnostic treatments in patients with solid tumours. The aim was to generate a reference document for clinical practice, for pharmaceutical companies in the design of clinical trials, for ethics committees in the approval of clinical trial protocols and for regulatory authorities in relation to drug approvals, with a particular emphasis on diagnostic testing and patient selection.

Prevalence of BRAF gene mutation in samples of primary and metastatic colorectal cancer: A meta-analysis

INTRODUCTION

Understanding the prevalence and biology of BRAF gene can improve the treatment methods of cancerous patients. This study aims to estimate the prevalence of BRAF gene mutation in samples of primary and metastatic colorectal cancer using meta-analysis method.

METHODS

We searched PubMed, Scopus, ScienceDirect, Ovid and Google Scholar motor engine using MeSH terms of relevant keywords. During the screening phase, titles, abstracts and full texts were reviewed and risk of bias was assessed for all selected papers based on Newcastle-Ottawa Scale (NOS) checklist. The results of the primary studies were combined using meta-analysis.

RESULTS

Of 95 eligible studies entered into the meta-analysis, prevalence of BRAF gene mutation had been assessed among 19,484 primary tumour samples as well as 12,256 metastatic samples. The total prevalence of BRAF gene mutation among primary tumour samples was estimated as of 10.16% (8.09-12.22) in the world, 0.41% (0-1.89) in EMRO region, 10.06% (7.54-12.59) in EURO region, 10.33% (7.24-13.43) in SEARO region and 11.33% (7.29-15.37) in WPRO region. The pooled estimates for BRAF gene mutation in metastatic samples were 6.53% (5.09-7.96), 8.07% (5.57-10.56), 5.38% (3.75-7.02) and 5.55% (1.72-9.38) for all regions, EURO, WPRO and PAHO regions respectively.

CONCLUSION

Our results showed evidences of BRAF gene mutation in one-tenth of primary colorectal tumour samples in EURO, PAHO, SEARO and WPRO regions which was considerably higher than that of the EMRO region.

Clinicopathologic features and prognostic value of KRAS, NRAS and BRAF mutations and DNA mismatch repair status: A single-center retrospective study of 1,834 Chinese patients with Stage I-IV colorectal cancer

Mutations of KRAS, NRAS, BRAF and DNA mismatch repair (MMR) status have become an important part of the assessment of patients with colorectal cancer (CRC), while respective clinicopathologic features and prognostic significance in specific stages and related detection strategies remain unclear. We retrospectively analyzed clinicopathologic features and prognosis of 1,834 patients with Stage I–IV colorectal adenocarcinoma. Mutations in KRAS, NRAS and BRAF and DNA MMR status were determined. The mutation rates of KRAS, NRAS and BRAF were 46.4, 3.2 and 3.5%, respectively, and the mismatch repair gene deletion (dMMR) rate was 5.6%. In a multivariate analysis, female, advanced age, tumor type histology, mucinous carcinoma and positive tumor deposits were associated with a high KRAS mutation rate. A high BRAF mutation rate was associated with female, poor differentiation, lymphovascular invasion and positive tumor deposits. Factors associated with high dMMR rates included low age, large tumor size, poor differentiation, Stages I–III. Tumor site was independently associated with KRAS mutation, BRAF mutation and dMMR. KRAS and BRAF mutations were independent risk factors for shorter overall survival (OS) in Stage IV tumors but not in Stage I–III tumors. NRAS mutation was an independent risk factor for shorter OS in Stage I–II tumors. dMMR was independently associated with longer OS in Stage III tumors.

What's new?

Mutations in KRAS, NRAS, BRAF and DNA mismatch repair (MMR) status are important biomarkers in the assessment of patients with colorectal cancer (CRC). However, the clinicopathologic features associated with these mutations—and their impact on prognosis—are unclear, especially at earlier stages of CRC. In this large Chinese study, the authors analyzed variables such as gender, age, tumor histology, lymphovascular invasion, etc., that were associated with particular oncogene mutations and overall survival. These results should provide guidance for improved clinical strategies and enhance the usefulness of these biomarkers.

Genetic and immunological biomarkers predict metastatic disease recurrence in stage III colon cancer

Background

Even though the post-operative outcome varies greatly among patients with nodal positive colon cancer (UICC stage III), personalized prediction of systemic disease recurrence is currently insufficient. We investigated in a retrospective setting whether genetic and immunological biomarkers can be applied for stratification of distant metastasis occurrence risk.

Methods

Eighty four patients with complete resection (R0) of stage III colon cancer from two clinical centres were analysed for genetic biomarkers: microsatellite instability, oncogenic mutations in KRAS exon2 and BRAF exon15, expression of osteopontin and the metastasis-associated genes SASH1 and MACC1. Tumor-infiltrating CD3 and CD8 positive T-cells were quantified by immunocytochemistry. Results were correlated with outcome and response to 5-FU based adjuvant chemotherapy, using Cox’s proportional hazard models and integrative two-step cluster analysis.

Results

Distant metastasis risk was significantly correlated with oncogenic KRAS mutations (p = 0.015), expression of SASH1 (p = 0.016), and the density of CD8-positive T-cells (p = 0.007) in Kaplan-Meier analysis. Upon multivariate Cox-regression analysis, KRAS mutation (p = 0.008) and density of CD8-positive TILs (p = 0.009) were retained as prognostic parameters for metachronous distant metastasis. Integrative two-step cluster analysis was used to combine all genetic markers, allowing stratification of patient subgroups. Post-operative distant metastasis risk ranged from 31% (low-risk) to 41% (intermediate), and 57% (high-risk) (p = 0.032). Increased expression of osteopontin (p = 0.019) and low density of CD8-positive T-cells (p = 0.043) were significantly associated with unfavourable response to 5-FU.

Conclusions

Integrative biomarker analysis allows stratification of stage III colon cancer patients for the risk of metastatic disease recurrence and may indicate response to 5-FU. Thus, biomarker analysis might facilitate the use of adjuvant therapy for high risk patients.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4940-2) contains supplementary material, which is available to authorized users.

Colorectal cancer care in elderly patients: Unsolved issues

Colorectal cancers are common in elderly patients. However, cancer screening is poorly used after 75. Elderly patients form a heterogeneous population with specific characteristics. Standards of care cannot therefore be transposed from young to elderly patients. Tumour resection is frequently performed but adjuvant chemotherapy is rarely prescribed as there are no clearly established standards of care. In a metastatic setting, recent phase III studies have demonstrated that doublet front-line chemotherapy provided no survival benefit. Moreover, several studies have established the benefit of bevacizumab in association with chemotherapy. There is a lack of evidence for the efficacy of anti-epidermal growth factor antibodies in elderly patients. Geriatric assessments could help to select the adequate treatment strategy for individual patients. Geriatric oncology is now the challenge we have to face, and more specific trials are needed.