Over the past 20 years, management of patients with metastatic colorectal cancer (mCRC) has improved considerably, leading to increased overall survival and more patients eligible for third- or later-line therapy. Currently, two oral therapies are recommended in the third-line treatment of mCRC, regorafenib and trifluridine/tipiracil. Selecting the most appropriate treatment in the third-line setting poses different challenges compared with treatment selection at earlier stages. Therefore, it is important for physicians to understand and differentiate between available treatment options and to communicate the benefits and challenges of these to patients. In this narrative review, practical information on regorafenib is provided to aid physicians in their decision-making and patient communications in daily practice. We discuss the importance of appropriate patient selection and adverse events management through close patient monitoring and dose adjustments to ensure patients stay on treatment for longer and receive as much benefit as possible. We also highlight key physician–patient communication points to facilitate shared decision-making.
Dominant collagen XII mutations cause a distal myopathy
AbstractObjectiveTo characterize the natural history and clinical features of myopathies caused by mono‐allelic, dominantly acting pathogenic variants in COL12A1.MethodsPatients with dominant COL12A1‐related myopathies were characterized by history and clinical examination, muscle imaging, and genetic analysis. Pathogenicity of the variants was assessed by immunostaining patient‐derived dermal fibroblast cultures for collagen XII.ResultsFour independent families with childhood‐onset weakness due to novel, dominantly acting pathogenic variants in COL12A1 were identified. Adult patients exhibited distal‐predominant weakness. Three families carried dominantly acting glycine missense variants, and one family had a heterozygous, intragenic, in‐frame deletion of exon 52 of COL12A1. All pathogenic variants resulted in increased intracellular retention of collagen XII in patient‐derived fibroblasts as well as loss of extracellular, fibrillar collagen XII deposition. Since haploinsufficiency for COL12A1 is largely clinically asymptomatic, we designed and evaluated small interfering RNAs (siRNAs) that specifically target the mutant allele containing the exon 52 deletion. Immunostaining of the patient fibroblasts treated with the siRNA showed a near complete correction of collagen XII staining patterns.InterpretationThis study characterizes a distal myopathy phenotype in adults with dominant COL12A1 pathogenic variants, further defining the phenotypic spectrum and natural history of COL12A1‐related myopathies. This work also provides proof of concept of a precision medicine treatment approach by proposing and validating allele‐specific knockdown using siRNAs specifically designed to target a patient’s dominant COL12A1 disease allele.
Centronuclear myopathy with cardiomyopathy due to recessive titinopathy
Pharmacogenetic Analysis of INT 0144 Trial: Association of Polymorphisms with Survival and Toxicity in Rectal Cancer Patients Treated with 5-FU and Radiation
ABSTRACTIntroduction: Recessive mutations in the anoctamin‐5 gene (ANO5) cause a spectrum of clinical phenotypes, including limb‐girdle muscular dystrophy (LGMD 2L), distal myopathy, and asymptomatic hyperCKemia. Methods: In this report we describe our clinical, electrophysiological, pathological, and molecular findings in a subject with anoctaminopathy‐5. Results: A 49‐year‐old Arabic man from a consanguineous family presented with a 5‐year history of myalgias, hyperCKemia and an episode of unprovoked rhabdomyolysis. Muscle biopsy showed mild myopathic changes and interstitial amyloid deposition. ANO5 analysis detected a novel homozygous deletion of approximately 11.9 kb encompassing exons 13–17, predicted to be pathogenic. Conclusions: Anoctaminopathy‐5 can manifest with a phenotype reminiscent of metabolic myopathy and should be considered as a potential cause of myalgia and myoglobinuria. Amyloid deposition in the muscle biopsy is helpful for the diagnosis. A novel homozygous ANO5 deletion was identified, suggesting that screening for common mutations may have low yield in non‐European subjects. Muscle Nerve 50: 610–613, 2014
DNAJB6 myopathy: A vacuolar myopathy with childhood onset
Background and purposeAnoctamin 5 (ANO5) is a putative intracellular calcium‐activated chloride channel. Recessive mutations in ANO5 cause primary skeletal muscle disorders (limb‐girdle muscular dystrophy 2L and distal muscular dystrophy), which are phenotypically similar to dysferlinopathy, a muscular dystrophy due to dysferlin‐encoding gene (DYSF) mutations.MethodsThis study reports the phenotype and genotype of seven unrelated patients with ANO5‐muscular dystrophy.ResultsThree patients had amyloid deposition in muscle and two had cardiac involvement. An additional patient without skeletal muscle amyloidosis had cardiac involvement with septal hypokinesis and supraventricular tachycardia requiring ablation. Amyloid subtyping using laser capture microdissection and mass spectrometry‐based proteomic analysis did not identify ANO5 or any fragment of ANO5 in the amyloid deposits, but detected other known amyloidogenic proteins. Three patients had myotonic discharges without clinical myotonia. Four ANO5 mutations are novel, including a heterozygous 0.4 Mb deletion involving the entire ANO5 gene.ConclusionsThe results of the present study suggest that ANO5 mutations can be associated with amyloid deposition in muscle, but the nature of the amyloid deposits remains indeterminate, as does their relationship with cardiac involvement. ANO5 analysis should be considered in cases of muscle amyloid deposition of indeterminate etiology. Electrical myotonia can accompany ANO5‐muscular dystrophy.