Age of first cancer diagnosis and survival in Bloom syndrome

Biological and therapeutic implications of the cancer-related germline mutation landscape in lung cancer

Although smoking is the primary cause of lung cancer, only about 15% of lifelong smokers develop the disease. Moreover, a substantial proportion of lung cancer cases occur in never-smokers, highlighting the potential role of inherited genetic factors in the cause of lung cancer. Lung cancer is significantly more common among those with a positive family history, especially for early-onset disease. Therefore, the presence of pathogenic germline variants might act synergistically with environmental factors. The incorporation of next-generation sequencing in routine clinical practice has led to the identification of cancer-predisposing mutations in an increasing proportion of patients with lung cancer. This Review summarises the landscape of germline susceptibility in lung cancer and highlights the importance of germline testing in patients diagnosed with the disease, which has the potential to identify individuals at risk, with implications for tailored therapeutic approaches and successful prevention through genetic counselling and screening.

Gastrointestinal Cancer Precursor Conditions and Their Detection

Gastrointestinal cancers are a leading cause of cancer morbidity and mortality. Many gastrointestinal cancers develop from cancer precursor lesions, which are commonly found in individuals with hereditary cancer syndromes. Hereditary cancer syndromes have advanced our understanding of cancer development and progression and have facilitated the evaluation of cancer prevention and interception efforts. Common gastrointestinal hereditary cancer syndromes, including their organ-specific cancer risk and surveillance recommendations, are reviewed in this article. The management of common gastroesophageal, pancreatic, and colonic precursor lesions is also discussed, regardless of their genetic background. Further research is needed to advance chemoprevention and immunoprevention strategies.

Bloom Syndrome Complicated by Low-Grade Lymphoma and Non-small Cell Lung Cancer: A Case Report

Bloom syndrome (BS) is a rare autosomal recessive genetic disorder characterized by photosensitivity, rashes on the nose and cheeks, short stature, and a predisposition to develop cancers. In this report, we discuss the diagnosis and management of a 34-year-old Canadian male BS patient, originally from Honduras, who developed B-cell lymphoma and a subsequent non-small cell lung carcinoma (NSCLC). Given the radiosensitivity of the patient due to his BS diagnosis and the early stage of the low-grade B-cell lymphoma, we relied on surveillance as the clinical approach to his management. The treatment for NSCLC was initiated in stage III of the disease and was palliative in intent. Chemotherapy (12 rounds of paclitaxel, with the dosage gradually increasing from 48 mg to 58 mg and finally to 72 mg) was employed to shrink the left upper lobe (LUL) lung mass. Subsequently, radiotherapy (3000 cGY in 20 fractions) was administered to improve symptoms further. The radiotherapy dose schedule was modified given the patient's BS diagnosis to avoid excessive toxicity. The palliative treatment course was well tolerated by the patient and resulted in symptom relief. However, his cancer progressed over the course of the treatment, ultimately resulting in his death 18 months after the initial diagnosis of NSCLC; no autopsy was performed. We believe this report will spur clinicians to engage in fruitful discussions about tailoring chemotherapy and radiation therapy regimens for treating cancer in BS patients.

Cancer risks related to intellectual disabilities: A systematic review

BACKGROUND

People with intellectual disabilities (ID) face barriers in cancer care contributing to poorer oncological outcomes. Yet, understanding cancer risks in the ID population remains incomplete.

AIM

To provide an overview of cancer incidence and cancer risk assessments in the entire ID population as well as within ID-related disorders.

METHODS

This systematic review examined cancer risk in the entire ID population and ID-related disorders. We systematically searched PubMed (MEDLINE) and EMBASE for literature from January 1, 2000 to July 15, 2022 using a search strategy combining terms related to cancer, incidence, and ID.

RESULTS

We found 55 articles assessing cancer risks in the ID population at large groups or in subgroups with ID-related syndromes, indicating that overall cancer risk in the ID population is lower or comparable with that of the general population, while specific disorders (e.g., Down's syndrome) and certain genetic mutations may elevate the risk for particular cancers.

DISCUSSION

The heterogeneity within the ID population challenges precise cancer risk assessment at the population level. Nonetheless, within certain subgroups, such as individuals with specific ID-related disorders or certain genetic mutations, a more distinct pattern of varying cancer risks compared to the general population becomes apparent.

CONCLUSION

More awareness, and personalized approach in cancer screening within the ID population is necessary.

Bloom syndrome patients and mice display accelerated epigenetic aging

Bloom syndrome (BSyn) is an autosomal recessive disorder caused by variants in the BLM gene, which is involved in genome stability. Patients with BSyn present with poor growth, sun sensitivity, mild immunodeficiency, diabetes, and increased risk of cancer, most commonly leukemias. Interestingly, patients with BSyn do not have other signs of premature aging such as early, progressive hair loss and cataracts. We set out to determine epigenetic age in BSyn, which can be a better predictor of health and disease over chronological age. Our results show for the first time that patients with BSyn have evidence of accelerated epigenetic aging across several measures in blood lymphocytes, as compared to carriers. Additionally, homozygous Blm mice exhibit accelerated methylation age in multiple tissues, including brain, blood, kidney, heart, and skin, according to the brain methylation clock. Overall, we find that Bloom syndrome is associated with accelerated epigenetic aging effects in multiple tissues and more generally a strong effect on CpG methylation levels.

Pathological variants in TOP3A cause distinct disorders of mitochondrial and nuclear genome stability

Topoisomerase 3α (TOP3A) is an enzyme that removes torsional strain and interlinks between DNA molecules. TOP3A localises to both the nucleus and mitochondria, with the two isoforms playing specialised roles in DNA recombination and replication respectively. Pathogenic variants in TOP3A can cause a disorder similar to Bloom syndrome, which results from bi-allelic pathogenic variants in BLM, encoding a nuclear-binding partner of TOP3A. In this work, we describe 11 individuals from 9 families with an adult-onset mitochondrial disease resulting from bi-allelic TOP3A gene variants. The majority of patients have a consistent clinical phenotype characterised by bilateral ptosis, ophthalmoplegia, myopathy and axonal sensory-motor neuropathy. We present a comprehensive characterisation of the effect of TOP3A variants, from individuals with mitochondrial disease and Bloom-like syndrome, upon mtDNA maintenance and different aspects of enzyme function. Based on these results, we suggest a model whereby the overall severity of the TOP3A catalytic defect determines the clinical outcome, with milder variants causing adult-onset mitochondrial disease and more severe variants causing a Bloom-like syndrome with mitochondrial dysfunction in childhood.

Photodermatoses: what's new

PURPOSE OF REVIEW

The purpose of this review is to summarize and highlight the recent literature in photodermatoses. In the past year, there have been many developments in this heterogeneous group of conditions.

RECENT FINDINGS

This review is divided by photodermatoses type, which include idiopathic photodermatoses, photodermatoses secondary to exogenous agents, photodermatoses secondary to endogenous agents (the porphyrias), and genodermatoses. The idiopathic photodermatoses section focuses on case series and reports highlighting new disease presentations or further disease characterization and new treatment strategies for these disorders. The second section discusses a unique case and has a brief update on photoallergens. Clinical, diagnostic, and treatment updates for porphyrias are discussed in Section 3. For genodermatoses, we discuss complications and neoplastic risk of xeroderma pigmentosum and a few highlights from other rare disorders. Finally, we conclude with a brief overview of photoprotection updates, from assessing sun-damaged skin to the most effective photoprotective agents.

SUMMARY

Up-to-date information will help providers identify and manage this rare group of disorders.