Assessing the TP53 marker type in patients treated with or without neoadjuvant chemotherapy for resectable colorectal liver metastases: a p53 Research Group study

Assessment and treatment considerations for patients with colorectal liver metastases: AHPBA consensus guideline and update for surgeons

BACKGROUND

Colorectal cancer most commonly metastasizes to the liver. While various treatment strategies have been developed, surgical management of these patients has vital implications on the prognosis and survival of this group of patients. There remains a need for a consensus guideline regarding the surgical evaluation and management of patients with colorectal liver metastases (CRLM).

METHODS

This review article is a consensus guideline established by the members of the AHPBA Professional Standards Committee, as an amalgamation of existent literature and a guide to surgeons managing this complex disease.

RESULTS

These guidelines reports the benefits and shortcomings of various diagnostic modalities including imaging and next-generation sequencing in the management of patients with CRLM. While surgery has established survival benefits in patients with resectable disease, this report notes the importance of treatment sequencing with non-surgical modalities as well as between colon and liver resection. Finally, the guidelines address the various treatment modalities for patients with unresectable disease, that may have significant impact on survival.

CONCLUSION

CRLM is a complex diagnosis which warrants multidisciplinary approach with early surgical involvement in both assessment and management of the disease, to optimize patient outcomes and survival.

The prognostic role of p53 mutations in metastatic colorectal cancer: A systematic review and meta-analysis

INTRODUCTION

P53 is one of the most frequently mutated genes in colorectal cancer (CRC). The present study was undertaken to provide a solid estimate of the prognostic value of p53 mutations in metastatic CRC patients.

METHODS

This meta-analysis was done in accordance to the Preferred Reporting Item For Systematic Reviews and Meta-Analysis 2020 guidelines. Studies in English published in the last ten years were searched through PubMed and Google Scholar. Final selection criteria were: 1) association with overall survival, 2) presence of Hazard Ratios (HRs) with 95% Confidence Intervals (CIs). The articles were evaluated for quality and risk of bias using the Newcastle-Ottawa Scale and QUIPS tool, respectively. The meta-analysis was conducted with random-effects model according to the Hartung-Knapp-Sidik-Jonkman method and results were depicted in classical Forest plots. Studies heterogeneity was determined by I2 and Tau2 statistics. The relationship between p53 mutation and clinic-pathological variables was examined using the χ2 test.

RESULTS

Nine articles met the eligibility criteria and went to the final analysis. Sample size ranged from 51 to 1043 patients. All studies were retrospective. The Newcastle Ottawa Scale score was > 6 in all studies, QUIPS risk of bias was low in 6, moderate in 3 studies. Only three studies analysed the entire p53 gene coding region. The DNA sequencing technological platforms varied from Sanger to NGS sequencing techniques. The p53 mutational frequencies ranged from 35.0 % to 73.0 %. A strong association (p < 0.0001) emerged between p53 alteration and left-sided CRC. The final pooled HR (p53 mutated vs p53 wild-type tumors) for overall survival was 1.30 (95 % CI: 0.75-2.25) at random-effects model.

CONCLUSIONS

The available evidence does not support a prognostic role for p53 in metastatic CRC patients. Prospective studies, with larger sample sizes and consistent and harmonized methodology, are needed to explore the prognostic role of p53 in metastatic CRC patients.

Presence of Concurrent TP53 Mutations Is Necessary to Predict Poor Outcomes within the SMAD4 Mutated Subgroup of Metastatic Colorectal Cancer

Simple Summary

Prior studies have resulted in conflicting conclusions on the value of SMAD4 mutations as a prognostic biomarker in metastatic colorectal cancer. In a cohort study of 433 patients with metastatic colorectal cancer, we showed that the presence of a coexisting mutation in TP53 is necessary to culminate in a negative overall survival impact in patients with SMAD4 mutations (multivariate HR = 2.5, 95% CI 1.44–4.36, p = 0.001). Our findings indicate that patients with concurrent SMAD4 and TP53 mutations represent a distinct poor-prognosis subgroup that may benefit from further translational studies.

Abstract

Prior studies have resulted in conflicting conclusions on the value of SMAD4 mutations as a prognostic biomarker in metastatic colorectal cancer. In this study, the impact of coexisting mutations with SMAD4 on overall survival was evaluated retrospectively in 433 patients with metastatic colorectal cancer. SMAD4 mutation was found in 16.2% (70/433) of tumors. A systemic univariate and multivariate survival analysis model including age, gender, sidedness of primary tumor, RAS, BRAF^V600E, APC, TP53 and SMAD4 status showed that SMAD4 mutations were not associated with worse prognosis (multivariate HR = 1.25, 95% CI 0.90–1.73, p = 0.18). However, coexisting mutations in SMAD4 and TP53 were significantly associated with worse overall survival (multivariate HR = 2.5, 95% CI 1.44–4.36, p = 0.001). The median overall survival of patients with coexisting SMAD4 and TP53 mutation was 24.2 months, compared to 42.2 months for the rest of the population (p = 0.002). Concurrent SMAD4 and TP53 defines a new subgroup of patients of metastatic colorectal cancer with poor clinical outcomes.

Association of genomic profiles and survival in early onset and screening‐age colorectal cancer patients with liver metastases resected over 15 years

BACKGROUND

This study explores whether genomic profiles of colorectal liver metastasis (CRLM) patients with early onset (EO, < 50 years old) and screening age (SA) primary diagnosis are associated with overall survival (OS).

METHODS

All patients undergoing hepatectomy between 2002 and 2017 were identified and tumor specimens with next-generation sequencing data were cataloged. Gene and signaling-level alterations were checked for association with OS from primary diagnosis accommodating for left-truncated survival.

RESULTS

Of 1822 patients, 333 were sequenced-127 (38%) EO-CRLM and 206 (62%) SA-CRLM patients. More aggressive features presented in EO-CRLM patients-synchronous metastatic presentation (83% vs. 75%, p < 0.001) and primary node-positive disease (71% vs. 61%, p < 0.001). The median OS from primary diagnosis was 11.8 years (95% confidence interval = 7.94-NA). Five-year OS did not differ by age (p = 0.702). On multivariable analysis, altered APC (EO-CRLM: [hazard ratio [HR] = 0.37, p = 0.018] vs. SA-CRLM:[HR = 0.61, p = 0.260]), BRAF (EO-CRLM:[HR = 4.38, p = 0.007] vs. SA-CRLM:[HR = 4.78, p = 0.032]), and RAS-TP53 (EO-CRLM:[HR = 2.82, p = 0.011] vs. SA-CRLM:[HR = 2.35, p = 0.003]) associated with OS.

CONCLUSIONS

Despite bearing more aggressive features, EO-CRLM patients had similar genomic profiles and survival as SA-CRLM patients. Better performance status in younger patients leading to increased treatment tolerance may partly explain this. As screening and treatment strategies from older patients are applied to younger patients, genomic predictors of biology identified historically in older cohorts could apply to EO patients.

Genetic mutations associated with sensitivity to neoadjuvant chemotherapy in metastatic colon cancer: A case report and review of literature

BACKGROUND

Colorectal liver metastases (CLM) occur in 15%-30% of patients with colorectal cancer (CRC). Advancements in next generation sequencing (NGS) can provide more precise prognoses for cancer patients and help guide clinical treatment. However, the genetic variants that predict high sensitivity to neoadjuvant chemotherapy remain unclear, especially in patients with CLM. The aim of this study was to identify the relevant genetic variants in a single CLM patient and to summarize the current evidence on mutations and single nucleotide polymorphisms (SNPs) that objectively predict sensitivity to neoadjuvant chemotherapy.

CASE SUMMARY

A 76-year-old male patient, who was diagnosed as stage IV colon cancer with liver metastases, was found to have APC/TP53/KRAS mutations. He showed a good therapeutic response to 12 courses of oxaliplatin regimens combined with Bevacizumab. Genetic analysis of the patient identified 5 genes with 7 detected SNPs that may be related to a better response to chemotherapy drugs. In addition, a critical literature review was performed based on a standardized appraisal form after selecting the articles. Ultimately, 21 eligible studies were appraised to assess the association between gene mutations and good prognosis. Mutations in KRAS, TP53, SMAD4, and APC were identified as being associated with a poor response to chemotherapy drugs, whereas mutations of CREBBP and POLD1 were associated with longer overall survival.

CONCLUSION

NGS can identify precise predictors of response to neoadjuvant chemotherapy, leading to improved outcomes for CRC patients.

Systems-level biomarkers identification and drug repositioning in colorectal cancer

Colorectal cancer (CRC) is the most commonly diagnosed fatal cancer in both women and men worldwide. CRC ranked second in mortality and third in incidence in 2020. It is difficult to diagnose CRC at an early stage as there are no clinical symptoms. Despite advances in molecular biology, only a limited number of biomarkers have been translated into routine clinical practice to predict risk, prognosis and response to treatment. In the last decades, systems biology approaches at the omics level have gained importance. Over the years, several biomarkers for CRC have been discovered in terms of disease diagnosis and prognosis. On the other hand, a few drugs are being developed and used in clinics for the treatment of CRC. However, the development of new drugs is very costly and time-consuming as the research and development takes about 10 years and more than $1 billion. Therefore, drug repositioning (DR) could save time and money by establishing new indications for existing drugs. In this review, we aim to provide an overview of biomarkers for the diagnosis and prognosis of CRC from the systems biology perspective and insights into DR approaches for the prevention or treatment of CRC.

The Role of p53 Dysfunction in Colorectal Cancer and Its Implication for Therapy

Colorectal cancer (CRC) is one of the most common and fatal cancers worldwide. The carcinogenesis of CRC is based on a stepwise accumulation of mutations, leading either to an activation of oncogenes or a deactivation of suppressor genes. The loss of genetic stability triggers activation of proto-oncogenes (e.g., KRAS) and inactivation of tumor suppression genes, namely TP53 and APC, which together drive the transition from adenoma to adenocarcinoma. On the one hand, p53 mutations confer resistance to classical chemotherapy but, on the other hand, they open the door for immunotherapy, as p53-mutated tumors are rich in neoantigens. Aberrant function of the TP53 gene product, p53, also affects stromal and non-stromal cells in the tumor microenvironment. Cancer-associated fibroblasts together with other immunosuppressive cells become valuable assets for the tumor by p53-mediated tumor signaling. In this review, we address the manifold implications of p53 mutations in CRC regarding therapy, treatment response and personalized medicine.

Prognostic and Predictive Molecular Biomarkers for Colorectal Cancer: Updates and Challenges

Colorectal cancer (CRC) is a leading cause of death among cancer patients. This heterogeneous disease is characterized by alterations in multiple molecular pathways throughout its development. Mutations in RAS, along with the mismatch repair gene deficiency, are currently routinely tested in clinics. Such biomarkers provide information for patient risk stratification and for the choice of the best treatment options. Nevertheless, reliable and powerful prognostic markers that can identify “high-risk” CRC patients, who might benefit from adjuvant chemotherapy, in early stages, are currently missing. To bridge this gap, genomic information has increasingly gained interest as a potential method for determining the risk of recurrence. However, due to several limitations of gene-based signatures, these have not yet been clinically implemented. In this review, we describe the different molecular markers in clinical use for CRC, highlight new markers that might become indispensable over the next years, discuss recently developed gene expression-based tests and highlight the challenges in biomarker research.

Gene mutation and surgical technique: Suggestion or more?

Advancements in chemotherapy and molecular targeted therapy have improved long-term outcomes for patients with resectable colorectal liver metastases (CLM). RAS mutation status was an original focus as a molecular biomarker as it predicted treatments response to anti-epidermal growth factor receptor agents. More recently, studies have incorporated somatic mutation data in analyses pertaining to surgical outcomes and prognosis. This evidenced-based review covers the implications of somatic mutations in patients undergoing resection of CLM.

Deleterious Effect of RAS and Evolutionary High-risk TP53 Double Mutation in Colorectal Liver Metastases

OBJECTIVE

To assess the impact of somatic gene mutations on survival among patients undergoing resection of colorectal liver metastases (CLM).

BACKGROUND

Patients undergoing CLM resection have heterogeneous outcomes, and accurate risk stratification is necessary to optimize patient selection for surgery.

METHODS

Next-generation sequencing of 50 cancer-related genes was performed from primary tumors and/or liver metastases in 401 patients undergoing CLM resection. Missense TP53 mutations were classified by the evolutionary action score (EAp53)-a novel approach that dichotomizes mutations as low or high risk.

RESULTS

The most frequent somatic gene mutations were TP53 (65.6%), followed by KRAS (48.1%) and APC (47.4%). Double mutation in RAS/TP53, identified in 31.4% of patients, was correlated with primary tumor location in the right colon (P = 0.006). On multivariable analysis, RAS/TP53 double mutation was an independent predictor of shorter overall survival (hazard ratio 2.62, 95% confidence interval 1.41-4.87, P = 0.002). In patients with co-mutated RAS, EAp53 high-risk mutations were associated with shorter 5-year overall survival of 12.2%, compared with 55.7% for TP53 wild type (P < 0.001). The negative prognostic effects of RAS and TP53 mutations were limited to tumors harboring mutations in both genes.

CONCLUSIONS

Concomitant RAS and TP53 mutations are associated with decreased survival after CLM resection. A high EAp53 predicts a subset of patients with worse prognosis. These preliminary analyses suggest that surgical resection of liver metastases should be carefully considered in this subset of patients.

Molecular and Immunohistochemical Markers with Prognostic and Predictive Significance in Liver Metastases from Colorectal Carcinoma

Despite the significant recent achievements in the diagnosis and treatment of colorectal cancer (CRC), the prognosis of these patients has currently plateaued. During the past few years, the opportunity to consider multiple treatment modalities (including surgery and other locoregional treatments, systemic therapy, and targeted therapy) led to the research of novel prognostic and predictive biomarkers in CRC liver metastases (CRCLM) patients. In this review, we seek to describe the current state of knowledge of CRCLM biomarkers and to outline impending clinical perspectives, in particular focusing on the cutting-edge tools available for their characterization.

TP53 is not a prognostic marker-clinical consequences of a generally disregarded fact

Technological progress within the last 15-20 years has significantly increased our knowledge about the molecular basis of cancer development, tumor progression, and treatment response. As a consequence, a vast number of biomarkers have been proposed, but only a small fraction of them have found their way into clinical use. The aim of this paper is to describe the specific demands a clinically relevant biomarker should meet and how biomarkers can be tested stepwise. We name this procedure the "triple-R principle": robustness, reproducibility, and relevance. The usefulness of this principle is illustrated with the marker TP53. Since it is mutated in a broad spectrum of cancer entities, TP53 can be considered a very promising marker. Thus, TP53 has been studied in detail but there is still no explicit consensus about its clinical value. By considering our own experience and reviewing the literature, we demonstrate that a major problem of current biomarker research is disregard of whether the biomarker is prognostic or predictive. As an example, it is demonstrated that TP53 is not a prognostic marker, but rather a purely predictive marker, and that disregard of this fact has made this otherwise strong biomarker appear as not being clinically useful so far.

Colorectal Liver Metastases: Does the Future of Precision Medicine Lie in Genetic Testing?

Colorectal liver metastases (CRLM) present an important clinical challenge in both surgical and medical oncology. Despite improvements in management, survival among patients undergoing resection of CRLM is still very variable and there is a paucity of clinical trial data and reliable biomarkers that could guide prognostic forecasts, treatment selection, and follow-up. Fortunately, recent advances in molecular biology and tumor sequencing have identified a number of critical genetic loci and proliferation markers that may hold the key to understanding the biologic behavior of CRLM; specifically, mutations of KRAS, BRAF, TP53, PIK3CA, APC, expression of Ki-67, and the presence of microsatellite instability appear to have a decisive impact on prognosis and response to treatment in patients with CRLM. While the applicability of genetic biomarkers in everyday clinical practice remains conditional on the development of inexpensive bedside sequencing, targeted therapies, and the conduct of appropriate clinical trials, the promise of personalized treatment may be closer to realization than ever before.

• Pancho trial (p53-adapted neoadjuvant chemotherapy for resectable esophageal cancer) completed-mutation rate of the marker higher than expected

Background

In operable esophageal cancer patients, neoadjuvant therapy benefits only those who respond to the treatment. The • Pancho trial represents the first prospective randomized trial evaluating the relevance of the mark53 status for predicting the effect of two different neoadjuvant chemotherapies.

Method

Biomarker analysis was conducted using the mark53 analysis. Calculation of patient number needed was based on a 60% rate of marker positivity, deduced from the results of a phase II pilot study.

Results

From 2007–2012, the • Pancho trial recruited 235 patients with operable esophageal cancer in Austria. A total of 181 patients were eligible and could be subjected to mark53 analysis and randomization. After randomizing 74 patients, the overall TP53 mutation rate was 79%. However, due to the high prevalence of marker positivity, the number of projected patients was increased to 181 patients in order to ensure a sufficient number of marker-negative patients. After completion of the trial, the overall TP53 mutation rate was 77.9%.

Conclusion

Due to high medical need, the recruitment for the academic trial was excellent. Mark53 analysis clearly detected more mutations in the TP53 gene as compared to the cancer-specific p53 literature. Final analysis examining the interaction between the mark53 status and the effect of chemotherapies applied in the • Pancho trial is now awaited.

PDXliver: a database of liver cancer patient derived xenograft mouse models

BACKGROUND

Liver cancer is the second leading cause of cancer-related deaths and characterized by heterogeneity and drug resistance. Patient-derived xenograft (PDX) models have been widely used in cancer research because they reproduce the characteristics of original tumors. However, the current studies of liver cancer PDX mice are scattered and the number of available PDX models are too small to represent the heterogeneity of liver cancer patients. To improve this situation and to complement available PDX models related resources, here we constructed a comprehensive database, PDXliver, to integrate and analyze liver cancer PDX models.

DESCRIPTION

Currently, PDXliver contains 116 PDX models from Chinese liver cancer patients, 51 of them were established by the in-house PDX platform and others were curated from the public literatures. These models are annotated with complete information, including clinical characteristics of patients, genome-wide expression profiles, germline variations, somatic mutations and copy number alterations. Analysis of expression subtypes and mutated genes show that PDXliver represents the diversity of human patients. Another feature of PDXliver is storing drug response data of PDX mice, which makes it possible to explore the association between molecular profiles and drug sensitivity. All data can be accessed via the Browse and Search pages. Additionally, two tools are provided to interactively visualize the omics data of selected PDXs or to compare two groups of PDXs.

CONCLUSION

As far as we known, PDXliver is the first public database of liver cancer PDX models. We hope that this comprehensive resource will accelerate the utility of PDX models and facilitate liver cancer research. The PDXliver database is freely available online at: http://www.picb.ac.cn/PDXliver/.

AA-NAT, MT1 and MT2 Correlates with Cancer Stem-Like Cell Markers in Colorectal Cancer: Study of the Influence of Stage and p53 Status of Tumors

The characterization of colon cancer stem cells (CSCs) may help to develop novel diagnostic and therapeutic procedures. p53 loss increases the pool of CSCs in colorectal cancer (CRC). Recent reports suggest that the oncostatic effects of melatonin could be related to its ability to kill CSCs. Although there are no data linking the loss of p53 function and melatonin synthesis or signaling in cancer, melatonin does activate the p53 tumor-suppressor pathway in this disease. In this work, we analyze whether the expression of melatonin synthesis and signaling genes are related to the expression of CSC markers and the implication of p53 status in samples from patients with CRC. Arylalkylamine N-acetyltransferase (AA-NAT), MT1, and MT2 expression decreased in tumor samples versus normal mucosa samples in mutated p53 (mtp53) tumors versus those with wild-type p53 (wtp53). Further, AA-NAT and MT2 expression were lower in advanced stages of the disease in wtp53 tumors. On the contrary, CD44 and CD66c expression was higher in tumor versus normal mucosa in wtp53 tumors. Additionally, CD44 expression was higher in advanced stages of the disease regardless of the p53 status. Patients with CD44_highCD66c_high and wtp53 tumors in advanced stages showed low expression of AA-NAT and MT2 in wtp53 tumors. These results could indicate a possible interaction of these pathways in CRC.

Current and future biomarkers in the treatment of colorectal cancer

Colorectal cancer (CRC) is a leading cause of cancer deaths worldwide. CRC develops as a consequence of genomic instability, characterized by various genetic and epigenetic alterations. Its molecular heterogeneity explains the large variability in patient prognosis and treatment response, emphasizing the need for development of accurate prognostic and predictive biomarkers. This article delineates the different pathways of colorectal carcinogenesis and its molecular subtype classification. With this review, we aim to provide a comprehensive overview of the current and future biomarkers guiding clinical decision-making and CRC treatment.

TP53 Mutational Status and Prediction of Benefit from Adjuvant 5-Fluorouracil in Stage III Colon Cancer Patients

We investigated the hypothesis that the varying treatment efficacy of adjuvant 5-fluorouracil (5FU) in stage III colon cancer is linked to the TP53 mutational status. ABCSG-90 was a prospective randomized trial in which effect of adjuvant 5FU was studied in stage III colon cancer patients. Tumor material of 70% of these patients (389/572) was available for analysis of the biomarker TP53 using a TP53-gene-specific Sanger sequencing protocol. Median follow-up was 88 months. TP53 mutation frequency was 33%. A significant interaction between TP53 status, outcomes and nodal category was found (P = 0.0095). In the N1 category, TP53 wildtype patients had significantly better overall survival than TP53 mutated (81.0% vs. 62.0% overall survival at 5 years; HR = 2.131; 95% CI: 1.344-3.378; P = 0.0010). In the N2 category, the TP53 status did not affect survival (P = 0.4992). In TP53 wildtype patients, the prognostic significance of N category was significantly enhanced (P = 0.0002). In TP53 mutated patients, survival curves of N1 and N2 patients overlapped and nodal category was no longer prognostic. The biomarker TP53 independently predicted effect of adjuvant 5FU in N1 colon cancer patients. TP53 was not predictive in N2 patients, in whom 5FU is known to have no effect.