36 research outputs found
H2AX promotes replication fork degradation and chemosensitivity in BRCA-deficient tumours
Histone H2AX plays a key role in DNA damage signalling in the surrounding regions of DNA double-strand breaks (DSBs). In response to DNA damage, H2AX becomes phosphorylated on serine residue 139 (known as γH2AX), resulting in the recruitment of the DNA repair effectors 53BP1 and BRCA1. Here, by studying resistance to poly(ADP-ribose) polymerase (PARP) inhibitors in BRCA1/2-deficient mammary tumours, we identify a function for γH2AX in orchestrating drug-induced replication fork degradation. Mechanistically, γH2AX-driven replication fork degradation is elicited by suppressing CtIP-mediated fork protection. As a result, H2AX loss restores replication fork stability and increases chemoresistance in BRCA1/2-deficient tumour cells without restoring homology-directed DNA repair, as highlighted by the lack of DNA damage-induced RAD51 foci. Furthermore, in the attempt to discover acquired genetic vulnerabilities, we find that ATM but not ATR inhibition overcomes PARP inhibitor (PARPi) resistance in H2AX-deficient tumours by interfering with CtIP-mediated fork protection. In summary, our results demonstrate a role for H2AX in replication fork biology in BRCA-deficient tumours and establish a function of H2AX separable from its classical role in DNA damage signalling and DSB repair
National approaches to managing cancer care: Responses of countries in the MENA region to the COVID-19 pandemic
Background: The coronavirus disease 2019 (COVID-19) pandemic presents serious challenges to cancer care because of the associated risks from the infection itself and the disruption of care delivery. Therefore, many professional societies have published recommendations to help manage patients with cancer during the current pandemic. The objective of our study is to assess the national responses of Middle East North Africa (MENA) countries in terms of publishing relevant guidelines and analyse various components of these guidelines. Methods: A survey based on the preliminary review of the literature regarding cancer care adaptations has been developed and then completed by a group of oncologists from the following Arab countries affected by the pandemic: Algeria, Egypt, Iraq, Jordan, Kuwait, Lebanon, Morocco, Oman, Saudi Arabia, Syria, Tunisia, United Arab Emirates and Yemen. The survey inquired about COVID-19 cases, national recommendations regarding general measures of COVID-19 prevention and patient care in oncology as well as their implementation about cancer care adaptations during the pandemic. Results: Analysis of the COVID-19 pandemic-related guidelines revealed at least 30 specific recommendations that we categorised into seven essential components. All included countries had national guidelines except one country. Estimated full compliances with all specific category recommendations ranged from 30% to 69% and partial compliance ranged from 23% to 61%. Conclusion: There is a very good response and preparedness in the Arab Middle East and North Africa region surveyed. However, there are inconsistencies in the various components of the guidelines across the region, which reflects the evolving status of the pandemic in each country as well as the lack of clear evidence-based guidelines for many of the issues in question. There is a need for a clear framework on essential components that should be included in these guidelines to assure providing the best guidance to the oncology community. Copyright: © the authors; licensee ecancermedicalscience. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Markers of subtypes in inflammatory breast cancer studied by immunohistochemistry: Prominent expression of P-cadherin
<p>Abstract</p> <p>Background</p> <p>Inflammatory breast cancer (IBC) is a distinct and aggressive form of locally-advanced breast cancer with high metastatic potential. In Tunisia, IBC is associated with a high death rate. Among the major molecular subtypes, basal breast carcinomas are poorly differentiated, have metastatic potential and poor prognosis, but respond relatively well to chemotherapy. The aim of this study was to determine the distribution of molecular subtypes in IBC and identify factors that may explain the poor prognosis of IBC.</p> <p>Methods</p> <p>To determine breast cancer subtypes we studied by immunohistochemistry the expression of 12 proteins in a series of 91 Tunisian IBC and 541 non-IBC deposited in tissue microarrays.</p> <p>Results</p> <p>We considered infiltrating ductal cases only. We found 33.8% of basal cases in IBC vs 15.9% in non-IBC (p < 0.001), 33.3% of ERBB2-overexpressing cases in IBC vs 14.5% in non-IBC (p < 0.001), and 29.3% of luminal cases in IBC vs 59.9% in non-IBC (p < 0.001). The most differentially-expressed protein between IBCs and non-IBCs was P-cadherin. P-cadherin expression was found in 75.9% of all IBC vs 48.2% of all non-IBC (p < 0.001), 95% of IBC vs 69% of non-IBC (p = 0.02) in basal cases, and 82% of IBC vs 43% of non-IBC (p < 0.001) in luminal cases. Logistic regression determined that the most discriminating markers between IBCs and non-IBCs were P-cadherin (OR = 4.9, p = 0.0019) MIB1 (OR = 3.6, p = 0.001), CK14 (OR = 2.7, p = 0.02), and ERBB2 (OR = 2.3, p = 0.06).</p> <p>Conclusion</p> <p>Tunisian IBCs are characterized by frequent basal and ERBB2 phenotypes. Surprisingly, luminal IBC also express the basal marker P-cadherin. This profile suggests a specificity that needs further investigation.</p
Ovarian cancer: Status of homologous recombination pathway as a predictor of drug response
Endometriosis-associated ovarian carcinomas: insights into pathogenesis, diagnostics, and therapeutic targets—a narrative review
Endometriosis is a benign gynecologic condition affecting up to one woman out of ten of reproductive age. It is defined by the presence of endometrial-like tissue in localizations outside of the uterine cavity. It often causes symptoms such as chronic pain, most frequently associated with the menstrual cycle, and infertility, but may also be oligo- or asymptomatic. There is evidence that some ovarian carcinoma (OC) histotypes, mainly the ovarian clear cell (OCCC) and endometrioid (EnOC) carcinoma, may arise from endometriosis. The most frequent genomic alterations in these carcinomas are mutations in the AT-rich interacting domain containing protein 1A (ARID1A) gene, a subunit of the SWI/SNF chromatin remodeling complex, and alterations in the phosphatidylinositol 3-kinase (PI3K)/AKT/mTOR pathway, which frequently co-occur. In ARID1A deficient cancers preclinical experimental data suggest different targetable mechanisms including epigenetic regulation, cell cycle, genomic instability, the PI3K/AKT/mTOR pathway, inflammatory pathways, immune modulation, or metabolic alterations as potential precision oncology approaches. Most of these strategies are relying on the concept of synthetic lethality in which tumors deficient in ARID1A are more sensitive to the different compounds. Some of these approaches are currently being or have recently been investigated in early clinical trials. The remarkably frequent occurrence of these mutations in endometriosis-associated ovarian cancer, the occurrence in a relatively young population, and the high proportion of platinum-resistant disease certainly warrants further investigation of precision oncology opportunities in this population. Furthermore, advanced knowledge about oncogenic mutations involved in endometriosis-associated ovarian carcinomas may be potentially useful for early cancer detection. However, this approach may be complicated by the frequent occurrence of somatic mutations in benign endometriotic tissue as recent studies suggest. In this narrative review of the current literature, we will discuss the data available on endometriosis-associated ovarian carcinoma, with special emphasis on epidemiology, diagnosis and molecular changes that could have therapeutic implications and clinical applicability in the future
Changes of health-related quality of life 6 months after high-risk oncological upper gastrointestinal and hepatobiliary surgery: a single-centre prospective observational study (ChangeQol Study)
Introduction Postoperative health-related quality of life (HRQoL) is an essential outcome in oncological surgery, particularly for elderly patients undergoing high-risk surgery. Previous studies have suggested that, on average, HRQoL returns to premorbid normal levels in the months following major surgery. However, the averaging of effect over a studied cohort may hide the variation of individual HRQoL changes. The proportions of patients who have a varied HRQoL response (stable, improvement, or a deterioration) after major oncological surgery is poorly understood. The study aims to describe the patterns of these HRQoL changes at 6 months after surgery, and to assess the patients and next-of-kin regret regarding the decision to undergo surgery.Methods and analysis This prospective observational cohort study is carried out at the University Hospitals of Geneva, Switzerland. We include patients over 18 years old undergoing gastrectomy, esophagectomy, pancreas resection or hepatectomy. The primary outcome is the proportion of patients in each group with changes in HRQoL (improvement, stability or deterioration) 6 months after surgery, using a validated minimal clinically important difference of 10 points in HRQoL. The secondary outcome is to assess whether patients and their next-of-kin may regret their decision to undergo surgery at 6 months. We measure the HRQoL using the EORTC QLQ-C30 questionnaire before and 6 months after surgery. We assess regret with the Decision Regret Scale (DRS) at 6 months after surgery. Key other perioperative data include preoperative and postoperative place of residence, preoperative anxiety and depression (HADS scale), preoperative disability (WHODAS V.2.0), preoperative frailty (Clinical Frailty Scale), preoperative cognitive function (Mini-Mental State Examination) and preoperative comorbidities. A follow-up at 12 months is planned.Ethics and dissemination The study was first approved by the Geneva Ethical Committee for Research (ID 2020-00536) on 28 April 2020. The results of this study will be presented at national and international scientific meetings, and publications will be submitted to an open-access peer-reviewed journal.Trial registration number NCT04444544
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Prognostic significance and predictors of the neutrophil-to-lymphocyte ratio in ovarian cancer
Objective: To investigate the neutrophil-to-lymphocyte ratio (NLR) from peripheral blood, a general measure of inflammation, in ovarian cancer. Methods: White cell counts and CA125 levels before treatment, tumor features, and questionnaire data on 519 women with ovarian cancer at two Boston hospitals were recorded. Counts were log-transformed and effects on these by tumor features and epidemiologic variables assessed by analysis of variance and generalized linear models. Cox proportional hazards models were used to assess effects on overall survival. Results: Greater NLR was associated with higher tumor stage and grade, presence of ascites, and bilateral disease and correlated with risk factors including Jewish ethnicity, taller height, more ovulatory cycles, and family history of cancer in premenopausal women and talc use in all women. CA125 was positively correlated with neutrophil count, monocyte count, and NLR and inversely correlated with lymphocyte count. In a multivariate adjusted analysis, high NLR predicted poorer survival and high lymphocyte count better survival. Conclusion: An elevated NLR before treatment signals more aggressive disease and correlates with risk factors for ovarian cancer. CA125 directly correlates with neutrophils which may reflect secretion of both CA125 and neutrophilic growth factors by the tumor. CA125 inversely correlates with lymphocytes which may reflect the ability of some neutrophilic factors to induce lymphopenia and/or binding of CA125 to lymphocytes removing CA125 from the serum pool. Links between NLR, CA125, and epidemiologic factors may provide new clues about the pathogenesis and progression of ovarian cancer
