The oncologist
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: The objective of this review is to describe existing data on breast cancer incidence and mortality in low- and middle-income countries (LMICs), in particular in sub-Saharan Africa; identify the limitations of these data; and review what is known about breast cancer control strategies in sub-Saharan African countries and other LMICs. Available estimates demonstrate that breast cancer incidence and mortality are rising in LMICs, including in Africa, although high-quality data from LMICs (and particularly from sub-Saharan Africa) are largely lacking. Case fatality rates from breast cancer appear to be substantially higher in LMICs than in high-income countries. Significant challenges exist to developing breast cancer control programs in LMICs, perhaps particularly in sub-Saharan Africa, and the most effective strategies for treatment and early detection in the context of limited resources are uncertain. High-quality research on breast cancer incidence and mortality and implementation research to guide effective breast cancer control strategies in LMICs are urgently needed. Enhanced investment in breast cancer research and treatment in LMICs should be a global public health priority. ⋯ The numbers of new cases of breast cancer, and breast cancer deaths per year, in low- and middle-income countries are rising. Engagement by the international breast cancer community is critical to reduce global disparities in breast cancer outcomes. Cancer specialists and institutions in high-income countries can serve as key partners in training initiatives, clinical care, protocol and program development, and research. This article provides an overview of what is known about breast cancer incidence, mortality, and effective strategies for breast cancer control in sub-Saharan Africa and identifies key gaps in the literature. This information can help guide priorities for engagement by the global cancer community.
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: The carcinoid syndrome represents a set of signs and symptoms associated with neuroendocrine tumors (NETs) that occur primarily when metastases are developed in the liver, resulting in the worsening of quality of life. Serotonin plays a central role in the physiology of carcinoid syndrome by promoting intestinal motility. Somatostatin analogs (SSAs) have widely demonstrated their efficacy as symptomatic relievers of carcinoid syndrome, but this control is ephemeral, being reduced by approximately 50% within the first year. The exact mechanisms of resistance to SSAs are not fully understood, but it is believed that serotonin might be involved. Patients with carcinoid syndrome present with a significant increase in serotonin plasma levels and, consequently, in the soluble urinary metabolite 5-hydroxyindole acetic acid. Telotristat etiprate is a potent inhibitor of tryptophan hydroxylase, a rate-limiting enzyme in the synthesis of serotonin, that has demonstrated in the phase III TELESTAR clinical trial a significant improvement in the control of bowel movements in patients with NETs who have carcinoid syndrome and who have progressed to an SSA. Based on these results, telotristat etiprate has emerged as a potential new option in the treatment algorithm of symptomatic control of functioning NETs. However, some issues need to be clarified, such as the safety profile of the drug outside clinical trials, the benefit in quality of life, and the possible impact on tumor growth, as well as its role within sequencing or combination treatment strategies with pre-existing drugs effective in NET treatment. ⋯ This article reviews the literature about carcinoid syndrome, which affects patients diagnosed with neuroendocrine tumors. Few articles have been published about this syndrome and its pathophysiology. Somatostatin analogs provide symptomatic relief; however, patients may become refractory to this strategy, usually within the first year of treatment. In this context, as an agent with an innovative mechanism of action, telotristat etiprate has demonstrated activity in a phase III trial, and findings may offer a path to an improve quality of life and prolonged survival for certain patients.
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Review
Clinical Application of Poly(ADP-Ribose) Polymerase Inhibitors in High-Grade Serous Ovarian Cancer.
: High-grade serous ovarian cancer is characterized by genomic instability, with one half of all tumors displaying defects in the important DNA repair pathway of homologous recombination. Given the action of poly(ADP-ribose) polymerase (PARP) inhibitors in targeting tumors with deficiencies in this repair pathway by loss of BRCA1/2, ovarian tumors could be an attractive population for clinical application of this therapy. PARP inhibitors have moved into clinical practice in the past few years, with approval from the Food and Drug Administration (FDA) and European Medicines Agency (EMA) within the past 2 years. The U.S. FDA approval of olaparib applies to fourth line treatment in germline BRCA-mutant ovarian cancer, and European EMA approval to olaparib maintenance in both germline and somatic BRCA-mutant platinum-sensitive ovarian cancer. In order to widen the ovarian cancer patient population that would benefit from PARP inhibitors, predictive biomarkers based on a clear understanding of the mechanism of action are required. Additionally, a better understanding of the toxicity profile is needed if PARP inhibitors are to be used in the curative, rather than the palliative, setting. We reviewed the development of PARP inhibitors in phase I-III clinical trials, including combination trials of PARP inhibitors and chemotherapy/antiangiogenics, the approval for these agents, the mechanisms of resistance, and the outstanding issues, including the development of biomarkers and the rate of long-term hematologic toxicities with these agents. ⋯ The poly(ADP-ribose) polymerase (PARP) inhibitor olaparib has recently received approval from the Food and Drug Administration (FDA) and European Medicines Agency (EMA), with a second agent (rucaparib) likely to be approved in the near future. However, the patient population with potential benefit from PARP inhibitors is likely wider than that of germline BRCA mutation-associated disease, and biomarkers are in development to enable the selection of patients with the potential for clinical benefit from these agents. Questions remain regarding the toxicities of PARP inhibitors, limiting the use of these agents in the prophylactic or adjuvant setting until more information is available. The indications for olaparib as indicated by the FDA and EMA are reviewed.
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: The field of cancer immunotherapy has rapidly progressed in the past decade as several therapeutic modalities have entered into the clinic. One such immunotherapy that has shown promise in the treatment of cancer is the use of chimeric antigen receptor (CAR)-modified T lymphocytes. CARs are engineered receptors constructed from antigen recognition regions of antibodies fused to T-cell signaling and costimulatory domains that can be used to reprogram a patient's T cells to specifically target tumor cells. CAR T-cell therapy has demonstrated sustained complete responses for some patients with advanced leukemia, and a number of CAR therapies are being evaluated in clinical studies. CAR T-cell therapy-associated toxicities, including cytokine release syndrome, macrophage activation syndrome, and tumor lysis syndrome, have been observed and effectively managed in the clinic. In patients with significant clinical responses, sustained B-cell aplasia has also been observed and is a marker of CAR T-cell persistence that might provide long-term disease control. Education on CAR T-cell therapy efficacy and safety management is critical for clinicians and patients who are considering this novel type of treatment. In the present report, the current landscape of CAR T-cell therapy, the effective management of patients undergoing treatment, and which patients are the most suitable candidates for current trials are discussed. ⋯ The present report describes the current status of chimeric antigen receptor (CAR) T lymphocytes as an immunotherapy for patients with relapsed or refractory B-cell malignancies. CAR T cells targeting CD19, a protein expressed on many B-cell malignancies, typically induce high complete response rates in patients with B-cell leukemia or lymphoma who have very limited therapeutic options. Recent clinical trial results of CD19 CAR T-cell therapies and the management of CAR T-cell-associated adverse events are discussed. The present report will therefore inform physicians regarding the efficacy and safety of CAR T cells as a therapy for B-cell malignancies.
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Molecular therapies targeting epidermal growth factor receptor (EGFR) have had a profound impact on the management of advanced non-small cell lung cancer (NSCLC). EGFR inhibition with EGFR tyrosine kinase inhibitors (EGFR-TKIs) and anti-EGFR monoclonal antibodies (mAbs) in squamous NSCLC (sqNSCLC) remains controversial in patients whose tumors are not known to harbor EGFR mutations. Recent meta-analyses of EGFR-inhibition randomized trials that are adequately powered for histological subgroup analysis and anti-EGFR trials limited to patients with squamous histology afford the opportunity to revisit EGFR treatment in sqNSCLC. In unselected patients with sqNSCLC who are not eligible for chemotherapy, EGFR-TKI therapy is a valid treatment option over placebo or best supportive care, with improved progression-free survival noted in randomized controlled trials in both the first- and second-line setting and improved overall survival (OS) in the second-line setting. In patients eligible for chemotherapy, first-line combination regimens with anti-EGFR mAbs have been shown to improve OS over chemotherapy alone in patients with squamous histology in meta-analysis and more recently in the SQUIRE sqNSCLC trial (chemotherapy with and without necitumumab). In sqNSCLC patients who respond to induction chemotherapy, maintenance therapy with erlotinib delays disease progression and may improve the survival of patients with stable disease. In the second-line setting, survival outcomes are comparable between chemotherapy and EGFR-TKIs in meta-analysis, with the latter being more tolerable as a second-line therapy. Newer-generation EGFR-TKI therapies may further benefit patients with sqNSCLC who have failed first-line chemotherapy, given the positive trial results from LUX-Lung 8 (afatinib vs. erlotinib). EGFR is a valid therapeutic target in unselected/EGFR wild-type patients with squamous cell carcinoma of the lung. With the recent approval of immune checkpoint inhibitors in the second-line management of advanced sqNSCLC and their adoption as a new standard of care, there exists an opportunity for novel combination therapies to increase therapeutic efficacy and durable tumor control. As more targeted agents are approved, combination regimens that include an anti-EGFR agent should be evaluated, and the optimal sequencing of targeted therapies should be defined. ⋯ Anti-epidermal growth factor receptor (EGFR) therapies remain controversial in unselected/wild-type EGFR squamous non-small cell lung cancer (NSCLC). Recent meta-analyses and squamous-only NSCLC EGFR-inhibition trials have overcome the power limitations of early trials and can now inform the management of squamous NSCLC with anti-EGFR therapies. With the approval of immunotherapeutics in the second-line management of squamous NSCLC, there exists an opportunity for novel combination therapies to improve efficacy and durable tumor control. The optimal timing and sequencing of available second-line targeted therapies, however, have yet to be defined. This review analyzes randomized clinical trials of EGFR inhibition in NSCLC and meta-analyses of these trials, with a focus on patients with squamous histology.