Cancer screening in adults with down syndrome, a proposal

Unravelling single-cell DNA replication timing dynamics using machine learning reveals heterogeneity in cancer progression

Genomic heterogeneity has largely been overlooked in single-cell replication timing (scRT) studies. Here, we develop MnM, an efficient machine learning-based tool that allows disentangling scRT profiles from heterogenous samples. We use single-cell copy number data to accurately perform missing value imputation, identify cell replication states, and detect genomic heterogeneity. This allows us to separate somatic copy number alterations from copy number changes resulting from DNA replication. Our methodology brings critical insights into chromosomal aberrations and highlights the ubiquitous aneuploidy process during tumorigenesis. The copy number and scRT profiles obtained by analysing >119,000 high-quality human single cells from different cell lines, patient tumours and patient-derived xenograft samples leads to a multi-sample heterogeneity-resolved scRT atlas. This atlas is an important resource for cancer research and demonstrates that scRT profiles can be used to study replication timing heterogeneity in cancer. Our findings also highlight the importance of studying cancer tissue samples to comprehensively grasp the complexities of DNA replication because cell lines, although convenient, lack dynamic environmental factors. These results facilitate future research at the interface of genomic instability and replication stress during cancer progression.

The prevalence of solid tumors and hematologic malignancies among patients with Down syndrome: A systematic review and meta-analysis

BACKGROUND

Patients with Down syndrome (DS) have a unique genetic and clinical profile that may increase the risk of cancer.

METHODS

A literature search on PubMed, Scopus, Web of Science, and the Cochrane databases was conducted, focusing on studies to investigate the prevalence of solid and hematologic tumors in DS.

RESULTS

Fifteen studies were included, encompassing 62,121 individuals with Down syndrome (DS). The overall prevalence of cancer in DS was 2.02 % (95 % CI: 1.63-2.50 %). The analysis of hematological tumors revealed a prevalence of 1.18 % (95 % CI: 0.86 % - 1.62 %) for leukemia, 0.86 % (95 % CI: 0.73 % - 1.01 %) for acute lymphoblastic leukemia, and 0.51 % (95 % CI: 0.29 % - 0.90 %) for acute myeloid leukemia. Among solid tumors, testicular cancer had the highest prevalence, at 0.22 % (95 % CI: 0.12 % - 0.43 %).

CONCLUSIONS

Our results highlight the need for targeted screening strategies, prevention strategies and treatment protocols among those with Down syndrome.

Down syndrome-associated leukaemias: current evidence and challenges

Children with Down syndrome (DS) are at increased risk of developing haematological malignancies, in particular acute megakaryoblastic leukaemia and acute lymphoblastic leukaemia. The microenvironment established by abnormal haematopoiesis driven by trisomy 21 is compounded by additional genetic and epigenetic changes that can drive leukaemogenesis in patients with DS. GATA-binding protein 1 (GATA1) somatic mutations are implicated in the development of transient abnormal myelopoiesis and the progression to myeloid leukaemia of DS (ML-DS) and provide a model of the multi-step process of leukaemogenesis in DS. This review summarises key genetic drivers for the development of leukaemia in patients with DS, the biology and treatment of ML-DS and DS-associated acute lymphoblastic leukaemia, late effects of treatments for DS-leukaemias and the focus for future targeted therapy.

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.

Kidney and urological involvement in Down syndrome: frequent, underestimated, but associated with impaired quality of life and risk of kidney failure

Patients with Down syndrome (DS) are at risk of multiorgan dysfunction; kidney and urological impairment are common. This is due to a likely increased risk of congenital kidney and urological malformations (odds ratio of 4.5 compared to the general population in one study), more frequent associated comorbidities at risk of kidney dysfunction (such as prematurity in 9-24% of children, intrauterine growth retardation or low birth weight in 20%, and congenital heart disease in 44%), and more frequent lower urinary tract dysfunction (reported in 27-77% of children with DS). If present, malformations and comorbidities at risk of kidney dysfunction warrant regular kidney monitoring in addition to their treatment. Serum creatinine in children with DS has been shown to be higher than in the general population and asymptomatic hyperuricemia is reported in 12-33% of children or young adults with DS. Moreover cryptorchidism and testicular cancer are also more common and should be detected by clinical examination. Thus, persons with DS at risk of presenting kidney and urological impairment should be identified by prenatal ultrasonography, comorbidities at risk of kidney sequelae considered, and during regular medical follow-up, clinically examined and questioned to diagnose testicular anomalies and lower urinary tract dysfunction. This is of importance as such kidney and urological impairments are associated with impaired quality of life and mental health, and risk of kidney failure.

From Churchill to Elephants: The Role of Protective Genes against Cancer

Richard Peto's paradox, first described in 1975 from an epidemiological perspective, established an inverse correlation between the probability of developing cancer in multicellular organisms and the number of cells. Larger animals exhibit fewer tumors compared to smaller ones, though exceptions exist. Mice are more susceptible to cancer than humans, while elephants and whales demonstrate significantly lower cancer prevalence rates than humans. How nature and evolution have addressed the issue of cancer in the animal kingdom remains largely unexplored. In the field of medicine, much attention has been devoted to cancer-predisposing genes, as they offer avenues for intervention, including blocking, downregulating, early diagnosis, and targeted treatment. Predisposing genes also tend to manifest clinically earlier and more aggressively, making them easier to identify. However, despite significant strides in modern medicine, the role of protective genes lags behind. Identifying genes with a mild predisposing effect poses a significant challenge. Consequently, comprehending the protective function conferred by genes becomes even more elusive, and their very existence is subject to questioning. While the role of variable expressivity and penetrance defects of the same variant in a family is well-documented for many hereditary cancer syndromes, attempts to delineate the function of protective/modifier alleles have been restricted to a few instances. In this review, we endeavor to elucidate the role of protective genes observed in the animal kingdom, within certain genetic syndromes that appear to act as cancer-resistant/repressor alleles. Additionally, we explore the role of protective alleles in conditions predisposing to cancer. The ultimate goal is to discern why individuals, like Winston Churchill, managed to live up to 91 years of age, despite engaging in minimal physical activity, consuming large quantities of alcohol daily, and not abstaining from smoking.

Down syndrome and leukemia: from basic mechanisms to clinical advances

Children with Down syndrome (DS, trisomy 21) are at a significantly higher risk of developing acute leukemia compared to the overall population. Many studies investigating the link between trisomy 21 and leukemia initiation and progression have been conducted over the last two decades. Despite improved treatment regimens and significant progress in iden - tifying genes on chromosome 21 and the mechanisms by which they drive leukemogenesis, there is still much that is unknown. A focused group of scientists and clinicians with expertise in leukemia and DS met in October 2022 at the Jérôme Lejeune Foundation in Paris, France for the 1st International Symposium on Down Syndrome and Leukemia. This meeting was held to discuss the most recent advances in treatment regimens and the biology underlying the initiation, progression, and relapse of acute lymphoblastic leukemia and acute myeloid leukemia in children with DS. This review provides a summary of what is known in the field, challenges in the management of DS patients with leukemia, and key questions in the field.

Incidence of urological tumors in Down's syndrome: a systematic review and meta-analysis

BACKGROUND

Some authors have estimated that the incidence of testicular germ cell tumors in individuals with trisomy 21 is more than fivefold higher than that in the general population.

OBJECTIVE

This systematic review aimed to estimate the incidence of urological tumors in patients with Down's syndrome.

STUDY DESIGN

We conducted a search strategy in MEDLINE (OVID), EMBASE, LILACS, and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to nowadays. We assessed the risk of bias and performed a meta-analysis. Also, the heterogeneity between trials was evaluated by the I2 test. We completed the subgroup analysis based on the type of urological tumor (testis, bladder, kidney, upper urological tract, penile, retroperitoneum).

RESULTS

We found 350 studies by the search strategy. After carefully reviewing, full-text studies were included. 16,248 individuals with Down's syndrome were included, and 42 patients presented with urological tumors. There was a total incidence of 0.1%, 95%CI (0.06-0.19), I2 61%. The most common urological tumor reported was testicular. We found six studies describing 31 events and an overall incidence of 0.19%, 95%CI (0.11-0.33), I2: 51%. Other studies reported kidney, penile, upper urinary tract, bladder, and retroperitoneum tumors with a very low incidence, 0.02%, 0.06%, 0.03%, 0.11%and 0.07%, respectively.

DISCUSSION

Regarding non-testicular urological tumors, we found incidences as low as 0.02% in kidney cancer or 0.03% in the upper-urothelial tract tumors. It is also lower than the general population. Compared to the age of onset of patients, it is also lower than the general population, perhaps related to a shorter life expectancy. As a limitation, we found a high heterogeneity and a lack of information regarding non-testicular tumors.

CONCLUSION

There was a very low incidence of urological tumors in people with Down's syndrome. Testis tumor was the most frequently described in all cohorts and within a normal distribution range.

Assessing cancer in people with profound and multiple disabilities

BACKGROUND

Cancers are as common in individuals with intellectual disabilities as in the general population (GP). For the subgroup of people with profound and multiple disabilities (PMD) who present with both severe intellectual disability and major motor disorders, the frequency and distribution of cancers are currently not known, preventing proper cancer surveillance.

METHODS

We carried out a systematic and synthetic review of the medical literature, including a focused search of Japanese data.

RESULTS

The total risk of cancer in individuals with PMD is thought to be lower than in the GP, possibly due to a shorter life expectancy. They have reduced exposure to cancer risk factors, such as alcohol, tobacco, sunlight, human papillomavirus infection, occupational toxins, and being overweight. On the other hand, individuals with PMD present a greater frequency of gastroesophageal reflux disease, Helicobacter pylori gastritis, chronic cystitis, and cryptorchidism, which increase the risk for cancer of the esophagus, stomach, urinary bladder, and testes. In addition, certain genetic disorders underlying compromised motor and cognitive functions are associated with higher risk of childhood cancers. An analysis of 135 cancers in persons with PMD in Japan suggested that they present a particular tumor profile, with certain cancers rarer than in the GP, whereas cancers of the digestive tract are frequent. Cancers of the digestive tract occurred significantly earlier than in the GP (colon: average age 48.3 years vs. 71.3 years in the GP, esophagus: 39 years vs. 72 years in the GP). An increasing number of therapeutic successes in children and adults with PMD have been reported in different countries when cancers are discovered early.

CONCLUSION

Individuals with PMD must be appropriately monitored for cancer. Screenings for breast and colon cancer, as well as regular monitoring of the esophagus, stomach, urinary bladder, and testicles, are necessary. Population-based epidemiological studies are needed to better understand risk factors, frequency, and distribution of cancers in the PMD population.

DNA methylation profiling in Trisomy 21 females with and without breast cancer

Background

Down Syndrome (DS) is the most common chromosome anomaly in humans and occurs due to an extra copy of chromosome 21. The malignancy profile in DS is unique, since DS patients have a low risk of developing solid tumors such as breast cancer however they are at higher risk of developing acute myeloid leukemia and acute lymphoblastic leukemia.

Methods

In this study, we investigated DNA methylation signatures and epigenetic aging in DS individuals with and without breast cancer. We analyzed DNA methylation patterns in Trisomy 21 (T21) individuals without breast cancer (T21-BCF) and DS individuals with breast cancer (T21-BC), using the Infinium Methylation EPIC BeadChip array.

Results

Our results revealed several differentially methylated sites and regions in the T21-BC patients that were associated with changes in gene expression. The differentially methylated CpG sites were enriched for processes related to serine-type peptidase activity, epithelial cell development, GTPase activity, bicellular tight junction, Ras protein signal transduction, etc. On the other hand, the epigenetic age acceleration analysis showed no difference between T21-BC and T21-BCF patients.

Conclusions

This is the first study to investigate DNA methylation changes in Down syndrome women with and without breast cancer and it could help shed light on factors that protect against breast cancer in DS.

Breast Cancer Screening Among Women With Intellectual Disability in Denmark

IMPORTANCE

Breast cancer-specific mortality is increased among women with intellectual disability (ID), and knowledge about participation in breast cancer screening in this group is needed.

OBJECTIVE

To examine participation in the Danish national breast cancer screening program among women with ID compared with women without ID.

DESIGN, SETTING, AND PARTICIPANTS

This dynamic population-based cohort study assessed participation in the Danish national breast cancer screening program initiated in 2007, targeting women aged 50 to 69 years with a screening interval of 2 years. In all, 6357 women with ID born between 1941 and 1967 and eligible for the screening program were identified in national registers. Women entered the study between January 1, 2007, and December 31, 2017. Subsequently, 273 women were excluded due to a history of carcinoma in situ or breast cancer, and 489 due to registration errors in registers. Each woman was individually age-matched with 10 women without ID (reference group). All women were followed up until March 31, 2021, or censoring (due to death, carcinoma in situ, or breast cancer). Data were analyzed from December 1, 2021, to June 31, 2022.

EXPOSURES

Intellectual disability was defined as being registered with an ID diagnosis or a diagnosis most likely leading to ID or residing at an institution for persons with ID.

MAIN OUTCOMES AND MEASURES

Participation in breast cancer screening (fully, partly, and never).

RESULTS

A total of 5595 women with ID and 49 423 age-matched women in the reference group were included in the analysis. Of these, 2747 women with ID (49%) and 24 723 in the reference group (50%) were 50 years of age at study entry; for those older than 50 years, the median age was 51 years (IQR, 50-58 years) in both groups. In all, 1425 women with ID (25%) were fully screened according to guidelines for the Danish breast cancer screening program compared with 30 480 women in the reference group (62%). Women with ID had nearly 5 times higher odds of never being screened compared with the reference group (odds ratio, 4.90 [95% CI, 4.60-5.22]). In all, 2498 women with ID (45%) and 6573 in the reference group (13%) were never screened. The proportion of never-screened women increased with severity of ID, from 834 of 2287 (36%) among women with mild ID to 173 of 212 (82%) among women with profound ID.

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that women with ID are markedly less likely to participate in breast cancer screening compared with women without ID. These findings further suggest a need for tailored guidelines and approaches for breast cancer screening in this group of women.

Metastatic Testicular Seminoma in a Patient With Down Syndrome Presenting As Extensive Deep Venous Thrombosis

Testicular cancer, particularly seminoma, is associated with Down syndrome. In cognitively impaired patients, the typical presenting signs of testicular cancer may be missed, and atypical presenting features may be the only clue to the diagnosis. In this report, we present the case of a 38-year-old male who presented with extensive deep vein thrombosis in the setting of seminoma.

Ten Reasons Why People With Down Syndrome are Protected From the Development of Most Solid Tumors -A Review

People with Down syndrome have unique characteristics as a result of the presence of an extra chromosome 21. Regarding cancer, they present a unique pattern of tumors, which has not been fully explained to date. Globally, people with Down syndrome have a similar lifetime risk of developing cancer compared to the general population. However, they have a very increased risk of developing certain tumors (e.g., acute leukemia, germ cell tumors, testicular tumors and retinoblastoma) and, on the contrary, there are some other tumors which appear only exceptionally in this syndrome (e.g., breast cancer, prostate cancer, medulloblastoma, neuroblastoma and Wilms tumor). Various hypotheses have been developed to explain this situation. The genetic imbalance secondary to the presence of an extra chromosome 21 has molecular consequences at several levels, not only in chromosome 21 but also throughout the genome. In this review, we discuss the different proposed mechanisms that protect individuals with trisomy 21 from developing solid tumors: genetic dosage effect, tumor suppressor genes overexpression, disturbed metabolism, impaired neurogenesis and angiogenesis, increased apoptosis, immune system dysregulation, epigenetic aberrations and the effect of different microRNAs, among others. More research into the molecular pathways involved in this unique pattern of malignancies is still needed.

Causes of death in patients with Down syndrome in 2014-2016: A population study in Japan

Despite the higher mortality rates in patients with Down syndrome compared with the general Japanese population, the life span has dramatically increased in Japan and other countries. We aimed to clarify recent causes of death in patients with Down syndrome in Japan. We calculated proportionate mortality and standardized mortality odds ratios (SMORs) among all deaths registered with Down syndrome as the cause of death (ICD‐10 code, Q90) in the Japanese National Death Registry Database in 2014–2016. In the study period, 762 in patients with Down syndrome died. The main causes of death were pneumonia/respiratory infections (20.5%), congenital malformations of the circulatory system (11.2%), other diseases of the circulatory system (9.2%), and aspiration pneumonia (8.4%). The SMORs (95% confidence intervals) were higher for natural death, defined as death of an elderly person with no other cause of death to be mentioned (55.73 [36.92–84.12]), early‐onset Alzheimer's disease, defined as Alzheimer's disease with onset <65 years of age (29.36 [16.44–52.44]), aspiration pneumonia (18.33 [14.03–23.96]), pneumonia/respiratory infections (8.11 [6.76–9.73]), congenital malformations of the circulatory system (8.07 [5.98–10.88]), and leukemia/lymphoma (2.16 [1.55–2.99]) but lower for malignant solid tumors (0.04 [0.02–0.06]) in patients with Down syndrome. Patients with Down syndrome had the greatest relative risk of dying from natural death, early‐onset Alzheimer's disease, and respiratory illnesses, highlighting the need for appropriate medical, health, and welfare services.

Role of long non-coding RNAs in Down syndrome patients: a transcriptome analysis study

Down syndrome (DS) is defined by the presence of a third copy of chromosome 21. Several comorbidities can be found in these patients, such as intellectual disability (ID), muscle weakness, hypotonia, congenital heart disease, and autoimmune diseases. The molecular mechanisms playing a role in the development of such comorbidities are still unclear. The regulation and expression of genes that map to chromosome 21 are dynamic and complex, so it is important to perform global gene expression studies with high statistical power to fully characterize the transcriptome in DS patients. This study was undertaken to evaluate mRNAs and lncRNA expression in patients with DS versus a matched cohort of healthy subjects. RNA sequencing was used to perform this transcriptome study. Differential expression analysis revealed 967 transcripts with padj ≤ 0.05. Among them, 447 transcripts were differentially expressed in patients with DS compared to controls. Particularly, 203 transcripts were down expressed (151 protein-coding mRNAs, 45 lncRNAs, 1 microRNA, 1 mitochondrial tRNA, 1 ribozyme, and 1 small nuclear RNA) and 244 were over expressed (210 protein-coding mRNAs and 34 lncRNAs). Interestingly, deregulated lncRNAs are involved in pathways that play a role in developmental disorders, neurological diseases, DNA replication and repair mechanisms, and cancer development in DS patients. In conclusion, these results suggest a role of lncRNAs in the phenotype of DS patients.

Perioperative care of adults with Down syndrome: a narrative review

Because of enhanced life expectancy due to medical and surgical therapeutic advances, it is estimated that there are more adults than children living with Down syndrome (DS), or trisomy 21, in the United States. Therefore, DS can no longer be considered a syndrome limited to the pediatric population. These patients are presenting for surgery and anesthesia in adult care settings, where anesthesiologists will encounter these patients more frequently. As these patients age, their commonly associated co-morbidities not only progress, but they also develop other cardiac, respiratory, gastrointestinal, and neurologic conditions. The manifestations and consequences of chronic disease can present new challenges for the anesthesiologist and require expertise and judgement to minimize patient risk. The purpose of this narrative review is to describe the common pediatric co-morbidities associated with DS and discuss the age-acquired manifestations. Additionally, considerations for anesthetic care of the adult with DS will be presented, including the preoperative assessment, intraoperative management, and postoperative care.

Prevalence of Common Disease Conditions in a Large Cohort of Individuals With Down Syndrome in the United States

Purpose

Given the current life expectancy and number of individuals living with Down syndrome (DS), it is important to learn common occurrences of disease conditions across the developmental lifespan. This study analyzed data from a large cohort of individuals with DS in an effort to better understand these disease conditions, inform future screening practices, tailor medical care guidelines, and improve utilization of health care resources.

Methods

This retrospective, descriptive study incorporated up to 28 years of data, compiled from 6078 individuals with DS and 30,326 controls matched on age and sex. Data were abstracted from electronic medical records within a large Midwestern health system.

Results

In general, individuals with DS experienced higher prevalence of testicular cancer, leukemias, moyamoya disease, mental health conditions, bronchitis and pneumonia, gastrointestinal conditions, thyroid disorder, neurological conditions, atlantoaxial subluxation, osteoporosis, dysphagia, diseases of the eyes/adnexa and of the ears/mastoid process, and sleep apnea, relative to matched controls. Individuals with DS experienced lower prevalence of solid tumors, heart disease conditions, sexually transmitted diseases, HIV, influenza, sinusitis, urinary tract infections, and diabetes. Similar rates of prevalence were seen for lymphomas, skin melanomas, stroke, acute myocardial infarction, hepatitis, cellulitis, and osteoarthritis.

Conclusions

While it is challenging to draw a widespread conclusion about comorbidities in individuals with Down syndrome, it is safe to conclude that care for individuals with DS should not automatically mirror screening, prevention, or treatment guidelines for the general U.S. population. Rather, care for those with DS should reflect the unique needs and common comorbidities of this population.

Transcriptomic study in women with trisomy 21 identifies a possible role of the GTPases of the immunity-associated proteins (GIMAP) in the protection of breast cancer

BACKGROUND

People with trisomy 21 (T21) are predisposed to developing hematological tumors, but have significantly lower-than-expected age-adjusted incidence rates of having a solid tumor.

MATERIAL AND METHODS

To identify novel genetic factors implicated in the lower breast cancer (BC) frequency observed in women with T21 than in the general population, we compared the transcriptome pattern of women with a homogeneous T21, aged more than 30 years, with or without BC, and tumoral BC tissue of control women with a normal karyotype from the study of Varley et al. (2014).

RESULTS

Differential analysis of gene expression between the 15 women in the T21 without BC group and BC patients in the other groups (two women with T21 and fifteen control women, respectively) revealed 154 differentially expressed genes, of which 63 were found to have similar expression profile (up- or downregulated). Of those 63 genes, four were in the same family, namely GIMAP4, GIMAP6, GIMAP7 and GIMAP8, and were strongly upregulated in the T21 without BC group compared to the other groups. A significant decrease in mRNA levels of these genes in BC tissues compared to non-tumor breast tissues was also noted.

CONCLUSION

We found that the expression of some GIMAPs is significantly higher in women with T21 without BC than in patients with sporadic BC. Our findings support the hypothesis that GIMAPs may play a tumor-suppressive role against BC, and open the possibility that they may also have the same role for other solid tumors in T21 patients. The search for new prognostic factors and hopefully new therapeutic or preventive strategies against BC are discussed.