Loss of skeletal muscle area and fat-free mass during dabrafenib/trametinib and vemurafenib/cobimetinib treatments in patients with BRAF-mutant metastatic malignant melanoma

Combating chemoresistance: Current approaches & nanocarrier mediated targeted delivery

Chemoresistance, a significant challenge in effective cancer treatment needs clear elucidation of the underlying molecular mechanism for the development of novel therapeutic strategies. Alterations in transporter pumps, oncogenes, tumour suppressor genes, mitochondrial function, DNA repair processes, autophagy, epithelial-mesenchymal transition (EMT), cancer stemness, epigenetic modifications, and exosome secretion lead to chemoresistance. Despite notable advancements in targeted cancer therapies employing both small molecules and macromolecules success rates remain suboptimal due to adverse effects like drug efflux, target mutation, increased mortality of normal cells, defective apoptosis, etc. This review proposes an advanced nanotechnological technique precisely targeting molecular determinants of chemoresistance which holds promise for enhancing cancer treatment efficacy. Further, the review explores various cancer hallmarks and pathways implicated in chemoresistance, current therapeutic modalities, and their limitations. It advocates the combination of nanoparticle-conjugated conventional drugs and natural compounds to specifically target molecular pathways that can potentially reverse or minimize chemoresistance incidences in cancer patients.

Comprehensive assessment of pretreatment sarcopenia impacts on patients with EGFR-mutated NSCLC treated with afatinib

BACKGROUND

This study aimed to comprehensively evaluate the efficacy and toxicity of afatinib in patients with sarcopenia, an important prognostic factor for treatment efficacy and toxicity in patients with cancer.

METHODS

The clinical features of patients with advanced NSCLC treated with frontline afatinib between 2014 and 2018 at a medical center in Taiwan were retrospectively reviewed. Sarcopenia was evaluated based on the total cross-sectional area of skeletal muscles assessed by computed tomography (CT) imaging at the L3 level. Baseline characteristics, response rates, survival rates, and adverse events (AEs) were compared between sarcopenic and nonsarcopenic patients.

RESULTS

A total of 176 patients evaluated for sarcopenia by CT and treated with afatinib were enrolled in the current study. Sarcopenia was significantly associated with good performance status, low body mass index (BMI), low body surface area (BSA), and low total mass area (TMA). Sarcopenia did not influence the response rate (69.2% vs. 72.0%, p = 0.299), progression-free survival (median 15.9 vs. 14.9 months, p = 0.791), or overall survival (median 26.5 vs. 27.2 months, p = 0.441). However, BSA ≤ 1.7 and the 40 mg afatinib dose were associated with dose reduction. TMA was the only independent factor for afatinib discontinuation due to AEs.

CONCLUSION

Sarcopenia was not associated with treatment efficacy or toxicity among patients with NSCLC harboring common mutations treated with afatinib, indicating sarcopenic patients should not be excluded from afatinib treatment. Other factors, such as BSA and TMA, were associated with dose reduction and afatinib discontinuation, respectively, which may require additional evaluations in future studies.

Cellular and Molecular Mechanisms of MEK1 Inhibitor-Induced Cardiotoxicity

Background

Trametinib is a MEK1 (mitogen-activated extracellular signal-related kinase kinase 1) inhibitor used in the treatment of BRAF (rapid accelerated fibrosarcoma B-type)-mutated metastatic melanoma. Roughly 11% of patients develop cardiomyopathy following long-term trametinib exposure. Although described clinically, the molecular landscape of trametinib cardiotoxicity has not been characterized.

Objectives

The aim of this study was to test the hypothesis that trametinib promotes widespread transcriptomic and cellular changes consistent with oxidative stress and impairs cardiac function.

Methods

Mice were treated with trametinib (1 mg/kg/d). Echocardiography was performed pre- and post-treatment. Gross, histopathologic, and biochemical assessments were performed to probe for molecular and cellular changes. Human cardiac organoids were used as an in vitro measurement of cardiotoxicity and recovery.

Results

Long-term administration of trametinib was associated with significant reductions in survival and left ventricular ejection fraction. Histologic analyses of the heart revealed myocardial vacuolization and calcification in 28% of animals. Bulk RNA sequencing identified 435 differentially expressed genes and 116 differential signaling pathways following trametinib treatment. Upstream gene analysis predicted interleukin-6 as a regulator of 17 relevant differentially expressed genes, suggestive of PI3K/AKT and JAK/STAT activation, which was subsequently validated. Trametinib hearts displayed elevated markers of oxidative stress, myofibrillar degeneration, an 11-fold down-regulation of the apelin receptor, and connexin-43 mislocalization. To confirm the direct cardiotoxic effects of trametinib, human cardiac organoids were treated for 6 days, followed by a 6-day media-only recovery. Trametinib-treated organoids exhibited reductions in diameter and contractility, followed by partial recovery with removal of treatment.

Conclusions

These data describe pathologic changes observed in trametinib cardiotoxicity, supporting the exploration of drug holidays and alternative pharmacologic strategies for disease prevention.

CT-based assessment of body composition and skeletal muscle in melanoma: A systematic review

BACKGROUND/OBJECTIVES

Sarcopenia (low skeletal muscle index) and myosteatosis (low skeletal radiodensity) have been associated with poor outcomes in melanoma. This systematic review was performed to summarize and critically evaluate current literature surrounding body composition in melanoma.

METHODS

MEDLINE and Embase databases were searched for studies of melanoma patients with computed tomography (CT) based body composition analysis from 2000 to 2020. Outcomes of interest were survival, including overall survival (OS), progression-free survival (PFS), and disease-free survival (DFS), as well as treatment-related adverse events (AEs).

RESULTS

Nine studies of 914 patients were included in the final review. The majority of studies were of metastatic melanoma patients treated with immunotherapy. Studies demonstrated a variety of CT analysis techniques and cut-offs to define sarcopenia and myosteatosis. Associations of sarcopenia or myosteatosis with survival (OS, PFS, DFS) or risk of treatment-related AEs were conflicting. Multiple studies had low quality of evidence due to small sample sizes, use of non-validated CT measures, and lack of multivariable analyses.

CONCLUSIONS

Due to methodologic heterogeneity and low quality of evidence, impacts of CT-derived body composition parameters on outcomes in melanoma are unclear. Further research should be conducted to elucidate impacts of body composition in melanoma.

Low skeletal muscle mass is a predictor of treatment related toxicity in oncologic patients. A meta-analysis

BACKGROUND & AIMS

The purpose of this meta-analysis was to summarize the published data regarding associations between occurrence of severe treatment related toxicity and low skeletal muscle mass (LSMM) in oncologic patients and to perform a meta-analysis based on a large sample.

METHODS

MEDLINE, Cochrane, and SCOPUS databases were screened for associations between LSMM and treatment related toxicity in oncologic patients up to June 2021. Overall, 48 studies met the inclusion criteria. The following data were extracted: authors, year of publication, study design, number of patients, influence of LSMM on treatment toxicity (odds ratios and confidence intervals). The methodological quality of the involved studies was checked according to the QUADAS instrument. The meta-analysis was undertaken by using RevMan 5.4 software. DerSimonian and Laird random-effects models with inverse-variance weights were used to account for the heterogeneity between the studies.

RESULTS

The included 48 studies comprised 4803 patients with different malignant diseases. LSMM occurred in 1966 patients (40.9%). LSMM was associated with therapy toxicity (simple logistic regression) with an odds ratio OR = 2.19, CI95%= (1.78-2.68). LSMM was associated with DLT in patients underwent curative treatment (16 studies, 2381 patients) with OR = 2.48, CI95%= (1.77-3.48). LSMM predicted DLT in patients underwent palliative chemotherapy (30 studies, 2337 patients)with OR = 2.06, CI95%= (1.56-2.74). In the subgroups received different palliative therapies, relationships between LSMM and DLT were as follows: conventional chemotherapies (7 studies, 600 patients) OR = 2.14, CI95%= (1.38-3.31); different kinases inhibitors (13 studies, 906 patients) OR = 3.08, CI95%= (1.87-5.09); checkpoint inhibitors (7 studies, 557 patients) OR = 1.30, CI95%= (0.79-2.11).

CONCLUSIONS

LSMM is an essential factor of treatment toxicity in oncologic patients. Association between LSMM and DLT is strongest in patients received therapy with kinases inhibitors. The influence of LSMM on DLT is lowest in patients underwent treatment with checkpoint inhibitors. The presence of LSMM should be included into radiological reports and provided to oncologists to optimize chemotherapy. LSMM should be included into dose calculation for chemotherapy.