Compared to the general population, persons with intellectual disability (ID) have a similar cancer rate, but cancer is often discovered at a later stage. Adults with ID show lower participation in organized screenings for breast, cervical, and colorectal cancer. Here we tested an intervention to increase cancer screening knowledge and intention to participate among persons with ID. An open-label cluster randomized controlled trial was co-constructed with people having ID. Participants with ID underwent interventions about cancer screening or oral hygiene, using PowerPoint presentations, booklets, dice games, workshops, films, and discussions. Both groups completed a questionnaire two weeks before the intervention and at 15 min, three months, and one year after the intervention, which evaluated their knowledge gain and intention to participate in cancer screenings. At 15 min, three months, and one year after the intervention, participants in the cancer group showed significantly improved cancer screening knowledge (p < 0.001). The intention to participate in screenings was increased on the intervention date (p < 0.001), but this change was non-significant three months later, and observed as a trend at one year (p = 0.068). A steering group of persons with ID gave advice regarding participant recruitment, conducting sessions, and modifying the film scenario, PowerPoint presentation, and questionnaire. Persons with ID co-constructed the booklet on cancer screening and acted in the film. Participation of persons with ID greatly improved the study efficacy. This research provides strong evidence supporting direct interventions for people with intellectual disability to increase their participation in organized cancer screening.

Background Cancer occurs in people with intellectual disability (ID) as frequently as in the general population. However, successful cancer treatment is less likely in people with ID, and the underlying reasons are not well-documented. Here we investigated the perspectives of health care professionals (HCPs) and family members regarding cancer care delivery and challenges for people with ID, with the aim of identifying the barriers and facilitators to care. Methods Semi-structured interviews were conducted with professionals and family members involved in cancer care for adults with ID. The obtained data were subjected to thematic analysis. Results Thirty-seven interviews were analyzed.Ten barriers to care were identified, four of which emerged from the participants'accounts.The main identified barriers to care were related to patients'limitations (psychological, physical, and treatment non-agreement), communication difficulties (i.e., with the patient, or between professionals or institutions), professionals' lack of knowledge, and advanced cancer stage at diagnosis. Facilitating circumstances were also identified-which included any presence of a proactive family member or professional caregiver, presence of a proactive family member or caregiver throughout the course of treatment, the patient having a confident and positive attitude, and tailored environment. Conclusion While barriers related to patient characteristics are unmodifiable, it may be possible to improve professionals' knowledge, communication skills, the patient's environment, and diagnostic delays. Thus, many obstacles that complicate cancer treatment for people with ID, and those who care for them, can be alleviated to potentially improve cancer prognosis in this vulnerable population.

Objective: We evaluate ovarian cancer (OC) in women with intellectual disability (ID). Methods: We reviewed the literature and added personal observations. The literature search included data from epidemiological studies on cancer incidence and mortality, institutional experiences, and case reports. We also used data from the Hérault Tumor Registry (HTR) in southern France. Results: A total of 72 articles met the inclusion criteria, which included 41 cases of OC. The review yielded 29 (74%) germ cell tumors, mainly in girls and young women, and only 4 (10%) ovarian carcinomas, all in adult women. In contrast, the HTR contained six cases of OC and one borderline tumor in adult women with ID aged > 45 years, but no cancer in children and adolescents with ID. These OC cases in adults were discovered at an advanced stage. We found that symptoms revealing OC in women with ID do not differ from those in the general population. However, diagnosis is more complicated in women with ID because they do not communicate easily and may express pain and unease in an unusual way, often through behavioral changes. Conclusion: OC could be as frequent in women with ID as in the general population and discovered at a late stage. The literature review indicates that girls and adolescents with ID develop mainly germ cell OC, and few carcinomas have been reported in women with ID. In contrast, the HTR was similar to the general population, with carcinomas in women with ID and no OC in children with ID.

OBJECTIVE:People with intellectual disabilities (ID) have difficulty in accessing oral or written health information presented in a conventional manner what compromises prevention. This study aims to develop accessible information on breast, cervical and colorectal cancer screening for people with ID. METHOD:The instructional material has been developed collaboratively by a team involving representatives from different scientific disciplines (medical and psychoeducational) and people with ID. Five principles guided its elaboration, i.e. coconstruction, multimodality, phasing, socio-cognitivism and accessibility. RESULTS:The material created is a 5-component module including a 20-minute easy-toread and understand oral presentation with a slideshow, a workshop that encourages manipulation and discussion, a booklet to take away, a film to consolidate information and a questionnaire. CONCLUSION:Providing accessible information is considered a key action in reestablishing equality in access to cancer health care and preventing a cascade of consequences. The co-construction of the module ensures its social and ecological validity. An interventional study is underway to verify its efficacy. PRACTICAL IMPLICATION:The best practices for cancer prevention endorse spending enough time to discuss screening. This accessible module can be used to provide people with ID basic information about screening, increase their adherence, and facilitate the discussion on this issue.

Introduction. - The life expectancy of people with intellectual disabilities is increasing thanks to medical advances, and the risk of developing cancer in this population is high. Objectives. - This study focuses between oncology caregivers' training in intellectual disability and the impact this has on their daily practice, particularly in the assessment and treatment of painful symptomatology. Method. - Semi-structured interviews were conducted with 13 caregivers, all of whom had cared for intellectually disabled cancer patients at least once in their careers. Results. - Thematic content analysis revealed a lack of knowledge of intellectual disability on the part of caregivers, and a concern on the part of professionals to care for these patients. This lack of knowledge hampers the care given to these patients, and interferes with the assessment and treatment of pain. Conclusion. - This type of study enables us to understand the obstacles to care with this specific population, in particular the fear of caregivers of not recognizing pain and not being able to relieve it adequately due to difficulties in communicating with patients. Training for healthcare professionals would help develop their professional attitudes, enabling them to identify and respond to changes in patient behaviour.

BACKGROUND:Individuals with Down syndrome (DS) exhibit a distinct pattern of solid tumor occurrence. However, the incidence of specific solid tumors remains inconsistent. We aimed to assess the burden of solid tumors in individuals with DS and compare it to the general population. METHODS:We conducted a systematic literature search across PubMed, Scopus, Web of Science, and Google Scholar to identify cohort studies reporting the incidence of solid tumors in individuals with DS. Statistical analyses were performed using random-effects model, along with subgroup analyses, heterogeneity evaluation, publication bias, and sensitivity analyses. RESULTS:The systematic search identified 8049 records. Fourteen studies were included, representing 34,561 individuals with 452,409.72 person-years of follow-up. The pooled incidence rate of solid tumors in individuals with DS was 95 cases per 100,000 person-years (95% confidence interval [CI]: 42-170). Compared to the general population, individuals with DS exhibited a significantly lower incidence rate of solid tumors (standardized incidence ratio [SIR]: 0.69, 95% CI: 0.51-0.94), with significantly lower rates observed for female genital organ (SIR: 0.44, 95% CI: 0.20-0.99), breast (SIR: 0.35, 95% CI: 0.17-0.73), skin (SIR: 0.24, 95% CI: 0.11-0.50), and lung (SIR: 0.10, 95% CI: 0.02-0.62) cancers. In contrast, higher incidences were identified for testicular (SIR: 4.28, 95% CI: 2.61-7.03) and liver (SIR: 3.72, 95% CI: 1.09-12.75) tumors. CONCLUSIONS:This study provides a comprehensive overview of solid tumor epidemiology in individuals with DS, emphasizing the need for population-specific screening measures.

Introduction L’espérance de vie des personnes atteintes d’une déficience intellectuelle augmente grâce aux progrès de la médecine et les risques de développer un cancer, au sein de cette population, sont nombreux. Objectifs Cette étude se centre sur la formation des soignants en oncologie sur la déficience intellectuelle et l’impact sur leur pratique quotidienne, notamment dans l’évaluation et le traitement de la symptomatologie douloureuse. Méthode Des entretiens semi-structurés ont été réalisés auprès de 13 soignants ayant tous pris en charge, au moins une fois au cours de leur carrière, des patients déficients intellectuels atteints d’un cancer. Résultats L’analyse de contenu thématique met en évidence une méconnaissance de la déficience intellectuelle de la part des soignants et une inquiétude des professionnels à soigner ces patients. Cette méconnaissance entrave les soins prodigués à ces personnes et perturbe l’évaluation et le traitement de la douleur. Conclusion Ce type d’étude permet d’appréhender les obstacles aux soins avec cette population spécifique, notamment la peur des soignants de ne pas reconnaître la douleur et ne pas pouvoir la soulager de façon adéquate en raison d’une difficulté à communiquer avec les patients. Une formation des professionnels de santé permettrait de développer leurs attitudes professionnelles pour leur permettre un repérage adapté aux changements de comportements du patient.

Daniel Satgé, Sarah Habib-Hadef, Amaëlle Otandault, Emmanuelle Samalin, Brigitte Trétarre

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.

BACKGROUND:Few melanoma cases are reported in individuals with intellectual disability (ID), and prognostic factors at diagnosis are unknown in this population. This work was designed to investigate whether prognostic factors at diagnostic are different in patients with ID compared with a general population.METHODS:Melanoma cases retrieved from Hérault's Tumour Registry (HTR) from 1995 to 2015 were cross-referenced against a list of adult patients with ID, living in Hérault. Major prognostic factors were compared with those in non-ID melanoma patients included in HTR and in patients followed by Montpellier University Hospital and included in the Réseau pour la Recherche et l'Investigation Clinique sur le Mélanome (RIC-Mel) database.RESULTS:Ten melanoma cases in individuals with ID were identified and compared with 3804 non-ID melanoma cases in HTR and 1024 non-ID melanoma cases included in RIC-Mel. Mean Breslow thickness at diagnosis was 4.6 mm in melanoma cases among those with ID versus 1.89 mm in HTR (P = 0.109) and 2.36 mm in RIC-Mel (P = 0.156). Stage at diagnosis was superior to stage IIB in 42.9% of ID cases versus 11.4% of non-ID cases in HTR (P < 0.05) and 8.5% in RIC-Mel (P < 0.05).CONCLUSIONS:Melanomas in patients with ID had less favourable prognostic factors at diagnosis, including higher Breslow thickness and more advanced stage, than melanomas in non-ID patients. These adverse prognostic factors indicate a later diagnosis in this population, leading to a poorer prognosis. This work underlines the need to improve melanoma screening among individuals with ID.

Dear Editors, Current guidelines for breast cancer screening in women with intellectual disability (WIDs) do not differ from those for women in the general population. However, research suggests that WIDs are younger and have more advanced disease at breast cancer diagnosis than women in the general population. Three studies conducted in France showed breast cancer appearing earlier (Table 1). A hospital survey in central France included 11 breast cancer cases in WIDs discovered at a mean age of 55.6 years, 7 years earlier than in the control cohort (62.4 years). Five of the 11 malignancies (45%) were discovered in women before the age of 50. The cases in WIDs however were at a more advanced stage than in the control cohort (American Joint Committee on Cancer: AJCC1, OR=3.2, p=0.010). A study including 1519 randomly selected institutions dedicated to disabled adults across the whole of France identified 13 breast cancer cases in WIDs (with age known). These were diagnosed at a mean age of 47.8 years, 15 years earlier than in the French population during the corresponding period, and eight (61%) were in women under 50 years at diagnosis. The third was a population-based study conducted in the south of France which analyzed breast cancers in 21 WIDs. The mean age at diagnosis was 7 years earlier (54.7 years vs 61.8 years) than for controls in the regional Cancer Registry. Seven tumors (33%) were diagnosed before 50 years of age. There was also a trend to greater tumor volume (more advanced T stage) (Jacot et al., article submitted). A literature search conducted by one of us (MN) on Japanese publication sources, using “Japan Medical Abstract Society” (ICHUSHI) which includes medical conference reports, with key words “breast cancer” and “intellectual disability” yielded five articles and abstracts published 2003–2018.Thefive Japanesewomen concerned were aged 38–61 (mean 46.6). According to the data of “Cancer Statistics”, Cancer Information Service, National Cancer Center, Japan (National Cancer Registry, Ministry of Health, Labor and Welfare)” in recent years (2016–2018), the mean age at diagnosis of female breast cancer in Japan is 62.4 years. Three of the five WIDs were younger than 50 years at diagnosis. In a US nationwide study of data collected during 2010, 384 breast cancers among 602 reproductive cancers in WIDs were treated almost seven years earlier, at a mean age of 61, compared to 67.8 years for women without intellectual disability. Mass screening is a precious opportunity to treat breast cancer early in WIDs. First, breast cancer which has a similar incidence compared to women in the general population is the most frequent malignancy in WIDs. Second, WIDs have greater risk factors such as being more frequently overweight or obese, less involved in physical exercise, more frequently nulliparous and rarely breast feeding. Third, many WIDs do not practice breast self-palpation and have difficulties expressing their pain and symptoms. Fourth, and importantly, breast cancer is discovered at a later stage in WIDs. The current age to begin breast cancer screening is 50 in most countries. Screening before this age has been considered less conclusive because breast cancer is less frequent before 50 in the general population. However, this may not be true for the particular subgroup of WIDs. Breast cancer diagnosis delay is associated with more advanced stages and lower survival. As life expectancy in WIDs is increasing, and as breast cancer incidence does not decrease after 50 years of age, a well-adapted surveillance strategy is urgently needed. We acknowledge that the current lack of data on absolute incidence of breast cancer in WIDs by age is a limitation of our message. This information should be established from large cohorts and different countries to evaluate if guidelines used for women in the general population are appropriate for this particular subgroup of vulnerable persons. Already, a greater breast awareness is necessary after the age of 40 years in this group of women.

Die Versorgungssituation für Menschen mit geistiger Behinderung und Krebserkrankung in Deutschland ist bisher weitgehend unbekannt. Daten aus dem europäischen und außereuropäischen Ausland legen nahe, dass – bei im Vergleich zu Menschen ohne geistige Behinderung gleicher Erkrankungshäufigkeit – teils erhebliche onkologische Versorgungsdefizite für diese vulnerable Gruppe bestehen. Es ist davon auszugehen, dass das deutsche Gesundheitssystem auf die speziellen Bedarfslagen von an Krebs erkrankten Patient*innen mit geistiger Behinderung ähnlich unzureichend ausgelegt ist, wie dies für das europäische und außereuropäische Ausland bereits beschrieben wurde. Eine systematische Aufbereitung des Sachstands wird angesichts der Datenlage auch in Zukunft nicht möglich sein, sofern Gesundheitspolitik und Forschungsförderung nicht zeitnah gegensteuern. Dies ist angesichts der absehbar steigenden Krankheitslast aufgrund der insgesamt steigenden Zahl von Menschen mit geistigen Behinderungen, die ein höheres Lebensalter erreichen, allerdings dringend erforderlich. Für die Quantifizierung der vermuteten Versorgungslücke ist die fehlende Verfügbarkeit von Basisdaten zur Zielpopulation eine relevante Hürde. Beispielsweise liegen keine Informationen zur Gesamtzahl der in Deutschland lebenden Menschen mit geistiger Behinderung im Sinne der WHO-Definition (ICD F70–F79) vor. Zugleich handelt es sich bei Menschen mit geistiger Behinderung um eine sehr heterogene Population mit unabhängig von einer Krebserkrankung unterschiedlichen und häufig unbekannten Bedarfen und Bedürfnissen. Wir umreißen hier kurz das Problem, stellen den internationalen Forschungsstand und die (limitierte) Datenlage in Deutschland dar und skizzieren aus Sicht der Autor*innen erforderliche Forschungsschritte und Empfehlungen für die Praxis. Hierzu gehören u. a. die bessere Erfassung von Menschen mit geistiger Behinderung zur Abbildung epidemiologischer Kennzahlen, bessere Früherkennungsroutinen zur Vermeidung verspäteter Diagnosen, Kommunikationsschulungen für Behandelnde und die Integration spezialisierter Krebsversorgung mit bestehenden Angeboten spezialisierter Versorgung für Menschen mit geistiger Behinderung.

BACKGROUND:Cancer occurrence among older people with intellectual disability (ID) is poorly documented, so we investigated the frequency and distribution of cancer in older people with ID compared with the general population.METHOD:People with ID who were ≥55years old and alive at the end of 2012 (n = 7936; ID cohort) were identified through a national register of people with ID who received social services in Sweden to optimise the individual's opportunity for good living conditions in daily life. An equally large reference cohort from the general population (gPop cohort) was matched by year of birth and sex. Cancer diagnoses registered in inpatient and outpatient specialist care were collected for 2002-2012 from the ID cohort and compared with diagnoses in the gPop cohort.RESULTS:A lower total cancer frequency was observed in the ID cohort, which contained 555 cancers, compared with 877 cancers in the gPop cohort [odds ratio (OR): 0.63; 95% confidence interval (CI): 0.57-0.70]. Women accounted for 60% of cancers in the ID cohort. Breast and gynaecological organ cancers had similar or slightly lower frequencies in the ID cohort than in the general population, with breast OR of 0.95, uterine corpus OR of 1.00 and ovary OR of 0.73. Surprisingly, cancer frequency of the digestive organs (OR: 0.67), including the colon (OR: 0.82), was lower than in the general population. Cancers of the prostate (OR: 0.25), urinary tract (OR: 0.42) and lung were less frequent than in the general population.CONCLUSIONS:Cancer was diagnosed less frequently in the ID cohort than in the gPop cohort. However, cancers of the breast and colon-rectum remain frequent in people with ID and therefore warrant prevention policies, monitoring and screening similar to those of the general population.

Background: The specific distribution of cancers in Down syndrome (DS) calls into question the validity of screening policies for cancer surveillance as implemented for the general population. Methods: We performed a literature review of cancer screening opportunities for adults with DS, taking account of the tumor profile in this specific population. Results: In DS, solid tumors in adults are at most half as common as in the overall group of persons with intellectual disabilities, who have a frequency similar to that of the general population. In women with DS, breast cancer is rare, the frequency of colorectal cancer is poorly described, and cervical cancer is rarely reported, although sometimes observed at an advanced stage. Young men have an increased risk of testicular cancer. Discussion: We propose that adults with DS should participate in colon cancer screening. For women with DS, breast cancer screening is not recommended, but annual clinical monitoring should be conducted, with the option to perform ultrasound or MRI examination in suspect cases. For cervical cancer, screening could be proposed to women who are sexually active beginning at age 25 years. Annual surveillance for testicular cancer via palpation by a health professional is preferable from ages 15 to 45. In case of additional genetic predisposition in a person with DS, a surveillance similar to other family members is recommended. Conclusion: The specific tumor profile in DS warrants an adapted screening program for breast, colon, cervical and testicular neoplasia.

Très peu de cas de mélanomes sont publiés chez les patients déficients intellectuels (DI). Les facteurs pronostiques au diagnostic n’ont jamais été étudiés dans cette population. L’objectif de ce travail était d’évaluer si le diagnostic est fait à un stade plus tardif dans cette population, pouvant entraîner un pronostic plus défavorable. Les cas de mélanomes extraits du Registre des Tumeurs de l’Hérault de 1995 à 2015 ont été croisés avec une liste de patients adultes DI résidant dans l’Hérault, permettant d’identifier les cas de mélanomes dans la population DI. Les facteurs pronostiques principaux de ces patients ont été comparés aux données des patients du Registre des Tumeurs de l’Hérault et aux données de la file active de mélanomes pris en charge au centre hospitalo-universitaire de Montpellier, inclus dans la base de données Réseau pour la Recherche et l’Investigation Clinique sur le Mélanome (RIC-Mel). Dix cas de mélanomes chez des patients DI ont été inclus et comparés aux 3804 cas du Registre des Tumeurs de l’Hérault et aux 1024 patients inclus dans la base RIC-Mel par Montpellier pour la période considérée. L’indice de Breslow moyen au diagnostic était de 7,49 mm, comparé à 1,89 mm dans le Registre (p = 0,0063) et 2,36 mm dans la base RIC-Mel (p = 0,0234) ; 28,6 % des tumeurs étaient ulcérées par rapport à 20,9 % dans le Registre et 26,3 % dans la base RIC-Mel. Le stade au diagnostic était supérieur au stade IIB pour 57,1 % des patients DI ; dans le Registre, cette proportion était de 11,4 % (p = 0,0369) et dans la base RIC-Mel, de 27,4 % (p = 0,0965). Chez les patients DI étudiés, les facteurs pronostiques au diagnostic sont plus défavorables : un indice de Breslow plus élevé et un stade plus avancé que les patients non DI, mais une proportion comparable de tumeurs ulcérées. Ces facteurs péjoratifs témoignent d’un diagnostic plus tardif dans cette population. Peu de données sont connues sur l’association mélanome et DI. Chez les patients porteurs d’un syndrome de Down, l’incidence du mélanome est plus faible que dans la population générale. Ce phénomène pourrait s’expliquer par une exposition solaire plus faible, mais aussi par des facteurs génétiques. Cependant, cette étude n’évalue pas l’incidence du mélanome chez les patients DI mais uniquement les facteurs pronostiques. Ce travail souligne également la nécessité d’améliorer le dépistage dans cette population. Chez les patients DI, le mélanome est diagnostiqué à un stade plus avancé que chez les patients atteints de mélanome en général, conduisant à un pronostic plus défavorable.

People with intellectual disabilities (PWIDs) are now living longer; thus, the incidence of cancer within this population is increasing. Available data indicate an excess of digestive tract cancers in PWIDs, but colorectal cancer has rarely been specifically studied and has not been extensively reviewed. This is despite risk factors such as being overweight, obesity, and lack of exercise being more frequent in PWIDs. In this article, we examine the literature on the frequency, screening, and treatment of colorectal cancer in PWIDs by as sessing 4 databases, Medline, EBSCO-CINHL, ASSIA, and PsychLIT, from 1970 to February 2017. Findings indicate that the frequency trends slightly higher than that found in the general population. Screening presents a unique opportunity to discover early colorectal cancer, but is underused in PWIDs compared to the general population. Furthermore, the clinical presentation is frequently masked, particularly by challenging behaviours, and colorectal cancer is therefore often diagnosed late, making treatment difficult due to the advanced stage of these tumours. To improve the care of PWIDs, we need more resources to support them and their caregivers, and to increase awareness of the risk factors and signs and symptoms of colorectal cancer.

The immune surveillance theory of cancer posits that the body's immune system detects and destroys randomly occurring malignant cells. This theory is based on the observation of the increased frequency of malignancies in primary and secondary immunodeficiencies, and is supported by the successful demonstration of immune augmentation in current oncological immune therapy approaches. We review this model in the context of Down syndrome (DS), a condition with a unique tumor profile and various immune defects. Children and adults with DS are more prone to infections due to anatomical reasons and a varying degree of T- and B-cell maturation defects, NK cell dysfunction, and chemotactic or phagocytic abnormalities. However, despite an increased incidence of lymphoblastic and myeloblastic leukemia of infants and children with DS, individuals with DS have a globally decreased incidence of solid tumors as compared to age-adjusted non-DS controls. Additionally, cancers that have been considered "proof of immune therapy principles," such as renal carcinoma, small cell lung carcinoma, and malignant melanoma, are less frequent in adults with DS compared to the general population. Thus, despite the combination of an increased risk of leukemia with detectable immune biological abnormalities and a clinical immunodeficiency, people with DS appear to be protected against many cancers. This observation does not support the immune surveillance theory in the context of DS and indicates a potential tumor-suppressive role for trisomy 21 in non-hematological malignancies.