TP53 germline mutation may affect response to anticancer treatments: analysis of an intensively treated Li-Fraumeni family

Treatment and Response Evaluation Challenges in a Pregnant Woman With B-Cell Lymphoblastic Leukemia and Li-Fraumeni Syndrome

Li-Fraumeni syndrome (LFS) is a cancer predisposing syndrome caused by pathogenic germline TP53 gene mutations with important therapeutic and prognostic implications for many types of cancer. A small proportion of LFS patients develop B-cell lymphoblastic leukemia (B-ALL) in adult years. Standard treatment often proves inadequate, but immunotherapy has provided new treatment options. The current case report presents a pregnant woman with LFS and newly diagnosed B-ALL with hypodiploidy developed after treatment for early-onset breast cancer. We describe the treatment course, treatment-related complications and provide laboratory data crucial for evaluating and modifying treatment for this difficult clinical case. Our findings support the need for close collaboration between clinicians and experts on immunophenotyping. Through our report, we show that immunotherapy is feasible in patients with LFS and B-ALL, despite a poor initial response to induction therapy.

Germline TP53 pathogenic variants and breast cancer: A narrative review

Approximately 10% of breast cancers are associated with the inheritance of a pathogenic variant (PV) in one of the breast cancer susceptibility genes. Multiple breast cancer predisposing genes, including TP53, are responsible for the increased breast cancer risk. Tumor protein-53 (TP53) germline PVs are associated with Li-Fraumeni syndrome, a rare autosomal dominant inherited cancer predisposition syndrome associated with early-onset pediatric and multiple primary cancers such as soft tissue and bone sarcomas, breast cancer, brain tumors, adrenocortical carcinomas and leukemias. Women harboring a TP53 PV carry a lifetime risk of developing breast cancer of 80-90%. The aim of the present narrative review is to provide a comprehensive overview of the criteria for offering TP53 testing, prevalence of TP53 carriers among patients with breast cancer, and what is known about its prognostic and therapeutic implications. A summary of the current indications of secondary cancer surveillance and survivorship issues are also provided. Finally, the spectrum of TP53 alteration and testing is discussed. The optimal strategies for the treatment of breast cancer in patients harboring TP53 PVs poses certain challenges. Current guidelines favor the option of performing mastectomy rather than lumpectomy to avoid adjuvant radiotherapy and subsequent risk of radiation-induced second primary malignancies, with careful consideration of radiation when indicated post-mastectomy. Some studies suggest that patients with breast cancer and germline TP53 PV might have worse survival outcomes compared to patients with breast cancer and wild type germline TP53 status. Annual breast magnetic resonance imaging (MRI) and whole-body MRI are recommended as secondary prevention.

Molecular Characterization of the Tumor Microenvironment in Renal Medullary Carcinoma

Renal medullary carcinoma (RMC) is a highly aggressive disease associated with sickle hemoglobinopathies and universal loss of the tumor suppressor gene SMARCB1. RMC has a relatively low rate of incidence compared with other renal cell carcinomas (RCCs) that has hitherto made molecular profiling difficult. To probe this rare disease in detail we performed an in-depth characterization of the RMC tumor microenvironment using a combination of genomic, metabolic and single-cell RNA-sequencing experiments on tissue from a representative untreated RMC patient, complemented by retrospective analyses of archival tissue and existing published data. Our study of the tumor identifies a heterogenous population of malignant cell states originating from the thick ascending limb of the Loop of Henle within the renal medulla. Transformed RMC cells displayed the hallmarks of increased resistance to cell death by ferroptosis and proteotoxic stress driven by MYC-induced proliferative signals. Specifically, genomic characterization of RMC tumors provides substantiating evidence for the recently proposed dependence of SMARCB1-difficient cancers on proteostasis modulated by an intact CDKN2A-p53 pathway. We also provide evidence that increased cystine-mTORC-GPX4 signaling plays a role in protecting transformed RMC cells against ferroptosis. We further propose that RMC has an immune landscape comparable to that of untreated RCCs, including heterogenous expression of the immune ligand CD70 within a sub-population of tumor cells. The latter could provide an immune-modulatory role that serves as a viable candidate for therapeutic targeting.

Case Report: A Novel Pathomechanism in PEComa by the Loss of Heterozygosity of TP53

Since the introduction of next-generation sequencing, the frequency of germline pathogenic TP53 variants and the number of cases with unusual clinical presentations have been increasing. This has led to the expansion of the classical Li–Fraumeni syndrome concept to a wider cancer predisposition syndrome designated as the Li–Fraumeni spectrum. Here, we present a case with a malignant, metastatic perivascular epithelioid cell tumor (PEComa) of the thigh muscle and a sinonasal carcinoma harboring a novel TP53 germline splice mutation (NM_000546.5:c.97-2A>C). The classical presentation of LFS in the long-since deceased mother and the presence of a germline TP53 variant in the proband suggested a possible familial TP53-related condition. Complex pathological, molecular, and clinical genetic analyses (whole exome sequencing of germline variants, multigene panel sequencing of tumor DNA, Sanger validation, an in vitro functional test on splicing effect, 3D protein modeling, p53 immunohistochemistry, and pedigree analysis) were performed. The in vitro characterization of the splice mutation supported the pathogenic effect that resulted in exon skipping. A locus-specific loss of heterozygosity in the PEComa but not in the sinonasal carcinoma was identified, suggesting the causative role of the splice mutation in the PEComa pathogenesis, because we excluded known pathogenetic pathways characteristic to PEComas (TSC1/2, TFE3, RAD51B). However, the second hit affecting TP53 in the molecular pathogenesis of the sinonasal carcinoma was not identified. Although PEComa has been reported previously in two patients with Li–Fraumeni syndrome, to the best of our knowledge, this is the first report suggesting a relationship between the aberrant TP53 variant and PEComa.

Avoidance or adaptation of radiotherapy in patients with cancer with Li-Fraumeni and heritable TP53-related cancer syndromes

The management of patients with cancer and Li-Fraumeni or heritable TP53-related cancer syndromes is complex because of their increased risk of developing second malignant neoplasms after genotoxic stresses such as systemic treatments or radiotherapy (radiosusceptibility). Clinical decision making also integrates the risks of normal tissue toxicity and sequelae (radiosensitivity) and tumour response to radiotherapy (radioresistance and radiocurability). Radiotherapy should be avoided in patients with cancer and Li-Fraumeni or heritable TP53 cancer-related syndromes, but overall prognosis might be poor without radiotherapy: radioresistance in these patients seems similar to or worse than that of the general population. Radiosensitivity in germline TP53 variant carriers seems similar to that in the general population. The risk of second malignant neoplasms according to germline TP53 variant and the patient's overall oncological prognosis should be assessed during specialised multidisciplinary staff meetings. Radiotherapy should be avoided whenever other similarly curative treatment options are available. In other cases, it should be adapted to minimise the risk of second malignant neoplasms in patients who still require radiotherapy despite its genotoxicity, in view of its potential benefit. Adaptations might be achieved through the reduction of irradiated volumes using proton therapy, non-ionising diagnostic procedures, image guidance, and minimal stray radiation. Non-ionising imaging should become more systematic. Radiotherapy approaches that might result in a lower probability of misrepaired DNA damage (eg, particle therapy biology and tumour targeting) are an area of investigation.

Brain Cancers in Genetic Syndromes

PURPOSE OF REVIEW

Although genetic conditions that cause primary central nervous system tumors are rare, their pathophysiology influences both treatment and surveillance. This article reviews the most frequently occurring genetic conditions associated with brain cancers and highlights the most recent therapeutic approaches in the treatment of Lynch syndrome (and other disorders of the mismatch repair system), neurofibromatosis 1, and Li-Fraumeni syndrome.

RECENT FINDINGS

Recent advances in molecular diagnostics have considerably improved the ability to diagnose genetic conditions in people with primary brain tumors. The common application of next-generation sequencing analyses of tissue increases the frequency with which clinicians are forced to address the possibility of an underlying genetic condition based on tissue molecular findings. Clinicians must be aware of the clinical presentation of genetic conditions predisposing to brain tumors in order to discern which patients are appropriate for germline genetic testing. Advances in therapeutics for specific genetic variants are increasingly available, and accurately diagnosing an underlying genetic condition may directly impact patient outcomes.

Childhood Cancer: Occurrence, Treatment and Risk of Second Primary Malignancies

Cancer represents the leading cause of disease-related death and treatment-associated morbidity in children with an increasing trend in recent decades worldwide. Nevertheless, the 5-year survival of childhood cancer patients has been raised impressively to more than 80% during the past decades, primarily attributed to improved diagnostic technologies and multiagent cytotoxic regimens. This strong benefit of more efficient tumor control and prolonged survival is compromised by an increased risk of adverse and fatal late sequelae. Long-term survivors of pediatric tumors are at the utmost risk for non-carcinogenic late effects such as cardiomyopathies, neurotoxicity, or pneumopathies, as well as the development of secondary primary malignancies as the most detrimental consequence of genotoxic chemo- and radiotherapy. Promising approaches to reducing the risk of adverse late effects in childhood cancer survivors include high precision irradiation techniques like proton radiotherapy or non-genotoxic targeted therapies and immune-based treatments. However, to date, these therapies are rarely used to treat pediatric cancer patients and survival rates, as well as incidences of late effects, have changed little over the past two decades in this population. Here we provide an overview of the epidemiology and etiology of childhood cancers, current developments for their treatment, and therapy-related adverse late health consequences with a special focus on second primary malignancies.

Breast Cancer Adjuvant Radiotherapy in BRCA1/2, TP53, ATM Genes Mutations: Are There Solved Issues?

BRCA1, BRCA2, TP53 and ATM gene mutations are the most studied tumour suppressor genes (TSGs) influencing the loco-regional approach to breast cancer (BC). Due to altered radio sensitivity of mutated cancer cells, mastectomy has always been advised in most patients with BC linked to TSGs mutations in order to avoid or minimize the use of adjuvant radiotherapy (ART). Whether ART is safe or not in these carriers is still debated. As a result, this issue has been widely discussed in the recent ASTRO and ASCO papers, yielding important and useful recommendations on the use of ART according to the mutational status. In this review, we have highlighted the impact of these mutations on local control, toxicities, second tumors, and contralateral breast cancers (CBCs) after ART to solve remaining doubts and encourage the safe use of ART when indicated.

Radiotherapy-induced malignancies in breast cancer patients with TP53 pathogenic germline variants (Li-Fraumeni syndrome)

The risk of radiotherapy-induced malignancies (RIMs) is a concern when treating Li-Fraumeni syndrome (LFS) or Li-Fraumeni Like (LFL) patients. However, the type of TP53 pathogenic germline variant may possibly influence this risk. TP53 p.R337H mutation is particularly prevalent in Brazil. We aimed to evaluate the outcomes of patients with pathogenic TP53 variants treated for localized breast cancer in a Brazilian cohort. We evaluated retrospectively a cohort of patients with germline TP53 pathogenic variants treated for localized breast cancer between December 1999 and October 2017. All patients were followed by the Hereditary Cancer Group of an academic cancer center. Our primary objective was to evaluate the occurrence of RIMs after adjuvant radiotherapy. Sixteen patients were evaluated; 10 (62.5%) had a germline TP53 p.R337H pathogenic variant. Median age was 39.8 years. Thirteen patients had invasive ductal carcinoma: 8 (61.5%) were hormone receptor-positive; 6 (46.1%), human epithelial growth factor receptor 2 (HER2)-amplified. Three patients had ductal carcinoma in situ. Most patients (N = 12/16, 75%) received adjuvant radiotherapy. After a median follow-up of 52.5 months, 2 patients (2/12, 16.6%) had RIMs. One had a fibrosarcoma and the other, a low-grade leiomyosarcoma. In the group treated with radiotherapy, one distant recurrence was diagnosed (1/12), and no loco-regional recurrence occurred. Among 4 patients who did not receive radiotherapy, 2 presented with loco-regional recurrence. In this cohort of patients with LFS enriched in TP53 p.R337H pathogenic variant, the incidence of RIMs after treatment of localized breast cancer was lower than previous literature. Nevertheless, rates of RIMs were still alarming. Early molecular diagnosis and careful evaluation of treatment risks and benefits are essential for these patients.

Comparison of Patient Susceptibility Genes Across Breast Cancer: Implications for Prognosis and Therapeutic Outcomes

Hereditary breast cancer syndromes affect a small (10–15% of cases) but significant group of patients. BRCA1 and BRCA2 are the most familiar and well-studied genes associated with inherited breast cancer. However, mutations in the high-penetrance genes, TP53, PTEN, CDH1, MSH1, MLH1, MSH6, PMS2, PALB2, and STK11, and in the moderate-penetrance genes, CHEK2, ATM, and BRIP1, also correlate with high lifetime risks of breast cancer and other malignancies as well. Advances in breast cancer genetics have led to an improved perception of diagnosis and screening strategies. The specific considerations and challenges involved in treating this unique population have become a fertile ground for research. Indeed, these genes and downstream molecular pathways have now become potential therapeutic targets in breast cancer patients, including those with BRCA1 or BRCA2 mutations. This review describes the variety of hereditary breast cancer genes, from their molecular origins to the prognosis and multidisciplinary clinical decision-making processes. Key publications and other reported recent clinical trials and guidelines are provided.

Radiation Biology and Its Role in the Canadian Radiation Protection Framework

The linear no-threshold (linear-non-threshold) model is a dose-response model that has long served as the foundation of the international radiation protection framework, which includes the Canadian regulatory framework. Its purpose is to inform the choice of appropriate dose limits and subsequent as low as reasonably achievable requirements, social and economic factors taken into account. The linear no-threshold model assumes that the risk of developing cancer increases proportionately with increasing radiation dose. The linear no-threshold model has historically been applied by extrapolating the risk of cancer at high doses (>1,000 mSv) down to low doses in a linear manner. As the health effects of radiation exposure at low doses remain ambiguous, reducing uncertainties found in cancer risk dose-response models can be achieved through in vitro and animal-based studies. The purpose of this critical review is to analyze whether the linear no-threshold model is still applicable for use by modern nuclear regulators for radiation protection purposes, or if there is sufficient scientific evidence supporting an alternate model from which to derive regulatory dose limits.

Challenges in the introduction of next-generation sequencing (NGS) for diagnostics of myeloid malignancies into clinical routine use

Given the vast phenotypic and genetic heterogeneity of acute and chronic myeloid malignancies, hematologists have eagerly awaited the introduction of next-generation sequencing (NGS) into the routine diagnostic armamentarium to enable a more differentiated disease classification, risk stratification, and improved therapeutic decisions. At present, an increasing number of hematologic laboratories are in the process of integrating NGS procedures into the diagnostic algorithms of patients with acute myeloid leukemia (AML), myelodysplastic syndromes (MDS), and myeloproliferative neoplasms (MPNs). Inevitably accompanying such developments, physicians and molecular biologists are facing unexpected challenges regarding the interpretation and implementation of molecular genetic results derived from NGS in myeloid malignancies. This article summarizes typical challenges that may arise in the context of NGS-based analyses at diagnosis and during follow-up of myeloid malignancies.

Radiogenomic Predictors of Adverse Effects following Charged Particle Therapy

Radiogenomics is the study of genomic factors that are associated with response to radiation therapy. In recent years, progress has been made toward identifying genetic risk factors linked with late radiation-induced adverse effects. These advances have been underpinned by the establishment of an international Radiogenomics Consortium with collaborative studies that expand cohort sizes to increase statistical power and efforts to improve methodologic approaches for radiogenomic research. Published studies have predominantly reported the results of research involving patients treated with photons using external beam radiation therapy. These studies demonstrate our ability to pool international cohorts to identify common single nucleotide polymorphisms associated with risk for developing normal tissue toxicities. Progress has also been achieved toward the discovery of genetic variants associated with radiation therapy-related subsequent malignancies. With the increasing use of charged particle therapy (CPT), there is a need to establish cohorts for patients treated with these advanced technology forms of radiation therapy and to create biorepositories with linked clinical data. While some genetic variants are likely to impact toxicity and second malignancy risks for both photons and charged particles, it is plausible that others may be specific to the radiation modality due to differences in their biological effects, including the complexity of DNA damage produced. In recognition that the formation of patient cohorts treated with CPT for radiogenomic studies is a high priority, efforts are underway to establish collaborations involving institutions treating cancer patients with protons and/or carbon ions as well as consortia, including the Proton Collaborative Group, the Particle Therapy Cooperative Group, and the Pediatric Proton Consortium Registry. These important radiogenomic CPT initiatives need to be expanded internationally to build on experience gained from the Radiogenomics Consortium and epidemiologists investigating normal tissue toxicities and second cancer risk.

• 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.

National cancer database analysis of outcomes in pediatric glioblastoma

Glioblastoma in children is an aggressive disease with no defined standard therapy. We evaluated hospital‐based demographic and survival patterns obtained through the National Cancer Database to better characterize children with glioblastoma. Our study identified 1173 patients from 0 to 19 years of age between 1998 and 2011. Comparisons were made among demographics, clinical characteristics, treatment, and survival variables. Fifty‐four percent of patients were over 10 years of age. Approximately 80% of patients underwent either partial or complete resection. Adjuvant therapy was used variably, and its use increased with patient age. Forty‐eight percent of patients received the combination of surgery, radiation, and chemotherapy, and 4% did not receive any treatment. As expected, patients ≤5 years of age had better 5‐year survival than those ages 6–10 (P = 0.01) or 11–19 years (P = 0.0077). Other factors associated with poor survival included black race and central tumor location. Better outcomes were associated with treatment that included surgery, radiotherapy, and chemotherapy compared to any other treatment combinations. Radiotherapy had no impact on survival in the 0 to 10‐year‐old age group, but was associated with improved survival for patients 11–19 years. We report an extensive demographic and survival analysis of pediatric glioblastoma. The observed differences likely reflect variances in tumor biology and likelihood of treatment receipt. Improved survival was associated with the use of surgery, radiotherapy, and chemotherapy. Radiation therapy was not associated with survival in patients younger than 10 years of age.

The landscape of genomic alterations across childhood cancers

Pan-cancer analyses that examine commonalities and differences among various cancer types have emerged as a powerful way to obtain novel insights into cancer biology. Here we present a comprehensive analysis of genetic alterations in a pan-cancer cohort including 961 tumours from children, adolescents, and young adults, comprising 24 distinct molecular types of cancer. Using a standardized workflow, we identified marked differences in terms of mutation frequency and significantly mutated genes in comparison to previously analysed adult cancers. Genetic alterations in 149 putative cancer driver genes separate the tumours into two classes: small mutation and structural/copy-number variant (correlating with germline variants). Structural variants, hyperdiploidy, and chromothripsis are linked to TP53 mutation status and mutational signatures. Our data suggest that 7-8% of the children in this cohort carry an unambiguous predisposing germline variant and that nearly 50% of paediatric neoplasms harbour a potentially druggable event, which is highly relevant for the design of future clinical trials.

Genetic predisposition in children with cancer - affected families' acceptance of Trio-WES

A considerable percentage of childhood cancers are due to cancer predisposition syndromes (CPS). The ratio of CPSs caused by inherited versus de novo germline mutations and the risk of recurrence in other children are unknown. We initiated a prospective study performing whole-exome sequencing (WES) of parent-child trios in children newly diagnosed with cancer. We initially aimed to determine the interest in and acceptance of trio WES among affected families and to systematically collect demographic, medical, and family history data to analyze whether these point to an underlying CPS. Between January 2015 and December 2016, 83 (88.3%) of 94 families participated; only 11 (11.7%) refused to participate. Five (6.0%) children presented with congenital malignancies and three (3.6%) with tumors with a high likelihood of an underlying CPS. Two (2.5%) families showed malignancies in family members < 18 years, 11 (13.8%) showed relatives < 45 years with cancer, 37 (46.3%) had a positive cancer history, and 14 (17.5%) families had > 1 relative with cancer.

CONCLUSIONS

Genetic testing in pediatric oncology is of great interest to the families, and the vast majority opts for investigation into potentially underlying CPSs. Trio sequencing provides unique insights into CPS in pediatric cancers and is increasingly becoming a common approach in modern oncology, and thus, trio sequencing needs also to be integrated routinely into the practice of pediatric oncology. What is Known: • A considerable percentage of childhood cancers are due to cancer predisposition syndromes (CPS). What is New: • Knowing about an underlying CPS and, thus, the risk of recurrence in other children is of great interest to affected families.

Pattern of p53 protein expression is predictive for survival in chemoradiotherapy-naive esophageal adenocarcinoma

Introduction

TP53 mutations are considered to be the driving factor in the initiation of esophageal adenocarcinoma (EAC). However, the impact of this gene and its encoded protein as a prognostic marker has not been definitely established yet.

Methods

In total, 204 chemoradiotherapy (CRT)-naive patients with EAC were included for p53 protein expression evaluation by immunohistochemistry (IHC) on the resection specimens, categorized as overexpression, heterogeneous or loss of expression, and correlated with disease free survival (DFS) and overall survival (OS) using multivariable Cox regression analysis. In a subset representing all three IHC subgroups mutational status of selected candidate genes (n=33) and high throughput methylation profiling (n=16) was assessed.

Results

Compared to heterogeneous p53 expression, loss and overexpression were both independently predictive for adverse DFS and OS. TP53 mutational status significantly correlated with the IHC categories (p=0.035). Most of the EAC with loss- or overexpression harbored TP53 mutations (18/20, representing nonsense and missense mutations respectively). In contrast, 6/13 EAC with heterogeneous expression were TP53 wild type, of which two demonstrated MDM4 or MDM2 amplification. Combined genomic hypomethylation and high frequency of intra-chromosomal breaks was found in a selection of EAC without p53 overexpression.

Conclusion

P53 expression pattern is prognostic for DFS and OS in this historical cohort of CRT-naive EAC. P53 IHC is an informative readout for TP53 mutational status in EAC with either loss- or overexpression, but not in case of a heterogeneous p53 pattern. Different EAC pathogenesis might exist, related to p53 and other candidate gene status, DNA hypomethylation and intrachromosomal breaks.

Medulloblastoma: Molecular Classification-Based Personal Therapeutics

Recent advances in cancer genomics have revealed 4 distinct subgroups of medulloblastomas, each with unique transcription profiles, DNA alterations and clinical outcome. Molecular classification of medulloblastomas improves predictions of clinical outcome, allowing more accurate matching of intensity of conventional treatments with chemotherapy and radiation to overall prognosis and setting the stage for the introduction of targeted therapies.

Breast cancer in patients with Li-Fraumeni syndrome - a case-series study and review of literature

Background

Li–Fraumeni Syndrome (LFS) is a rare disease with autosomal dominant inheritance linked to germline mutations of tumor suppressor gene TP53. These patients are predisposed to malignancies such as sarcoma, breast cancer, leukemia, and other malignancies. Breast cancer, the most common malignancy in adult patients with LFS, has an early-onset presentation and is usually treated as per the guidelines for the general population due to the limited literature about breast cancer in LFS. We aimed to describe our institutional experience treating patients with breast cancer and LFS to contribute to literature about this entity.

Design

Retrospective single-institution case-series study. We searched for cases with LFS and breast cancer from 01/01/2000 to 12/31/2015 with treatment received at our institution.

Results

We identified 4 cases (2 African Americans, 1 Indian, and 1 Hispanic) in 4 different families, who were diagnosed with LFS after presenting with breast cancer. Three cases were triple-negative disease and 1 case was ER+, HER2 positive disease. They were treated with mastectomy and a third-generation breast chemotherapy regimen and/or trastuzumab-containing regimen. Radiation therapy was used in 2 patients. Breast cancer recurrence was seen in 1 patient, while three other malignancies were identified after breast cancer treatment (1 breast sarcoma, 1 leiomyosarcoma, and 1 myelodysplastic syndrome). A patient, who underwent surveillance with a positron emission tomography-computed tomography scan, was found to have a stage I leiomyosarcoma and was treated with surgical resection, but then developed metastatic disease requiring cytotoxic chemotherapy.

Conclusion

Breast cancer among patients with LFS needs a multidisciplinary treatment approach. Surgical management follows the guidelines for the general population. Risk–benefit assessment of chemotherapy and radiotherapy needs to be performed carefully in a case-by-case approach. Patients should undergo multimodality cancer surveillance, preferably in the context of a clinical trial.

Mutant p53 Gain of Function and Chemoresistance: The Role of Mutant p53 in Response to Clinical Chemotherapy

PURPOSE

To review mechanisms underlying mutant p53 (mutp53) gain of function (GOF) and mutp53-induced chemoresistance, and to investigate the role of mutp53 in response to clinical chemotherapy.

METHODS

We searched the PubMed database for clinical studies from the past decade, including data evaluating the impact of mutp53 in clinical chemotherapy response.

RESULTS

Interactions between mutp53 and transcriptional factors, proteins or DNA structures, as well as epigenetic regulation, contribute to mutp53 GOF. Major mechanisms of mutp53-induced chemoresistance include enhanced drug efflux and metabolism, promoting survival, inhibiting apoptosis, upregulating DNA repair, suppressing autophagy, elevating microenvironmental resistance and inducing a stem-like phenotype. Clinically, mutp53 predicted resistance to chemotherapy in diffuse large B-cell lymphoma, and esophageal and oropharyngeal cancers, but its impact on chronic lymphocytic leukemia was unclear. In bladder cancer, mutp53 did not predict resistance, whereas in some breast and ovarian cancers, it was associated with sensitivity to certain chemotherapeutic agents.

CONCLUSION

mutp53 has an intricate role in the response to clinical chemotherapy and should not be interpreted in isolation. Furthermore, when predicting tumor response to chemotherapy based on the p53 status, the drugs used should also be taken into consideration. These concepts require further investigation.

Treatment-related toxicities in children with acute lymphoblastic leukaemia predisposition syndromes

Although most children with acute lymphoblastic leukaemia (ALL) do not harbor germline mutations that strongly predispose them to development of this malignancy, large syndrome registries and detailed mapping of exomes or whole genomes of familial leukaemia kindreds have revealed that 3-5% of all childhood ALL cases are due to such germline mutations, but the figure may be higher. Most of these syndromes are primarily characterized by their non-malignant phenotype, whereas ALL may be the dominating or even only striking manifestation of the syndrome in some families. Identification of such ALL patients is important in order to adjust therapy and offer genetic counseling and cancer surveillance to mutation carriers in the family. In the coming years large genomic screening projects are expected to reveal further hitherto unrecognised familial ALL syndromes. The treatment of ALL cases harboring cancer predisposing mutations can be challenging for both the physician and the patient due to their preexisting symptoms, their reduced tolerance to radio- and/or chemotherapy with enhanced risk of life-threatening organ toxicities, and the paucity of data from ALL patients with the same or similar syndromes being treated by contemporary protocols. Recent studies clearly indicate that many of these patients stand a good chance of cure, and that they should be offered chemotherapy with the intention to cure. Some of these syndromes are characterized by reduced tolerance to radiotherapy and/or specific anticancer agents, while others are not. This review summarises our current knowledge on the risk of acute toxicities for these ALL patients and provides guidance for treatment adjustments.