Genetic predisposition to colorectal cancer: new pieces in the pediatric puzzle

Clinicopathologic Profile and Treatment Outcomes of Colorectal Cancer in Young Adults: A Multicenter Study From India

PURPOSE

Colorectal cancer (CRC) in young adults is a rising concern in developing countries such as India. This study investigates clinicopathologic profiles, treatment patterns, and outcomes of CRC in young adults, focusing on adolescent and young adult (AYA) CRC in a low- and middle-income country (LMIC).

METHODS

A retrospective registry study from January 2018 to December 2020 involved 126 young adults (age 40 years and younger) with CRC. Patient demographics, clinical features, tumor characteristics, treatment modalities, and survival outcomes were analyzed after obtaining institutional ethics committees' approval.

RESULTS

Among 126 AYA patients, 62.70% had colon cancer and 37.30% had rectal cancer. Most patients (67%) were age 30-39 years, with no significant gender predisposition. Females had higher metastatic burden. Abdominal pain with obstruction features was common. Adenocarcinoma (65%) with signet ring differentiation (26%) suggested aggressive behavior. Limited access to molecular testing hindered mutation identification. Capecitabine-based chemotherapy was favored because of logistical constraints. Adjuvant therapy showed comparable recurrence-free survival in young adults and older patients. For localized colon cancer, the 2-year median progression-free survival was 74%, and for localized rectal cancer, it was 18 months. Palliative therapy resulted in a median overall survival of 33 months (95% CI, 18 to 47). Limited access to targeted agents affected treatment options, with only 27.5% of patients with metastatic disease receiving them. Chemotherapy was generally well tolerated, with hematologic side effect being most common.

CONCLUSION

This collaborative study in an LMIC offers crucial insights into CRC in AYA patients in India. Differences in disease characteristics, treatment patterns, and limited access to targeted agents highlight the need for further research and resource allocation to improve outcomes in this population.

Pediatric manifestations of Lynch Syndrome: A single center experience

Lynch syndrome is an autosomal dominant condition caused by a heterozygous variation in one of the DNA mismatch repair (MMR) genes that pre-disposes individuals to early onset colorectal cancers and other malignancies. Lynch syndrome is generally considered an adult-onset disorder, with malignancy rarely manifesting in childhood. Colorectal cancer is extremely rare in children, but hereditary syndromes including Lynch syndrome are an important cause. We aimed to assess the frequency and clinical course of children with Lynch syndrome associated pediatric colorectal cancers at our institution over the last 20 years.

In this retrospective study, we describe four cases of children with Lynch syndrome-associated colorectal cancers age 14–17 years at diagnosis. All patients were diagnosed with Lynch syndrome after diagnosis, despite three of them having family histories consistent with Lynch syndrome.

This series highlights a rare but important cause of pediatric malignancy and points to the need for early education on colorectal cancer warning symptoms and open discussion about this condition in affected families. It also illustrates the need for a thorough family history and a high level of suspicion for Lynch syndrome in children based on family background, as early detection may be key to improving cancer outcomes.

Management of Familial Adenomatous Polyposis in Children and Adolescents: Position Paper From the ESPGHAN Polyposis Working Group

Familial adenomatous polyposis (FAP) is a well-described inherited syndrome, characterized by the development of hundreds to thousands of adenomas in the colorectum, with implications in children and adolescents. Almost all adult patients will develop colorectal cancer if they are not identified and treated early enough. Identifying and screening for FAP commences in adolescence. The syndrome is inherited as an autosomal dominant trait and caused by mutations in the adenomatous polyposis (APC) gene. This European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) position paper provides a guide for diagnosis, assessment, and management of FAP in children and adolescents.This is the first position paper regarding FAP published by ESPGHAN. Literature from PubMed, Medline, and Embase was reviewed and in the absence of evidence, recommendations reflect the opinion of paediatric and adult experts involved in the care of polyposis syndromes. Because many of the studies that form the basis for the recommendations were descriptive and/or retrospective in nature, these of the recommendations are supported on expert opinion. This position paper will instruct on the appropriate management and timing of procedures in children and adolescents with FAP.

A Comprehensive Review of Pediatric Tumors and Associated Cancer Predisposition Syndromes

An understanding of the role of inherited cancer predisposition syndromes in pediatric tumor diagnoses continues to develop as more information is learned through the application of genomic technology. Identifying patients and their relatives at an increased risk for developing cancer is an important step in the care of this patient population. The purpose of this review is to highlight various tumor types that arise in the pediatric population and the cancer predisposition syndromes associated with those tumors. The review serves as a guide for recognizing genes and conditions to consider when a pediatric cancer referral presents to the genetics clinic.

Syndrome-Associated Tumors by Organ System

Certain tumors suggest the possibility of a patient harboring a genetic syndrome, particularly in children. Syndrome-associated tumors of the gastrointestinal tract, genitourinary tract, gynecologic tract, heart, lungs, brain, eye, endocrine organs, and hematopoietic system will be briefly discussed.

Risk-reduction surgery in pediatric surgical oncology: A perspective

OBJECTIVE

A small percentage of pediatric solid cancers arise as a result of clearly identified inherited predisposition syndromes and nongenetic lesions. Evidence supports preemptive surgery for children with genetic [multiple endocrine neoplasia type 2 (MEN2), familial adenomatous polyposis syndrome (FAP), hereditary nonpolyposis colorectal cancer (HNPCC), and hereditary diffuse gastric cancer (HDGC) and nongenetic [thyroglossal duct cysts (TGDC), congenital pulmonary airway malformations (CPAM), alimentary tract duplication cysts (ATDC), and congenital choledochal cysts (CCC)] developmental anomalies. Our aim was to explore the utility of risk reduction surgery to treat and prevent cancer in children.

METHODS

A systematic review of the available peer-reviewed literature on PubMed was performed using a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) search strategy, where possible. Search items included "risk reduction surgery", "hereditary cancer predisposition syndrome", "multiple endocrine neoplasia type 2", "familial adenomatous polyposis", "hereditary nonpolyposis colorectal cancer", "hereditary diffuse gastric cancer", "thyroglossal duct cysts", congenital pulmonary airway malformations", "alimentary tract duplication cysts", "malignant transformation", and "guidelines".

RESULTS

We identified 67 articles that met the inclusion criteria describing the indications for prophylactic surgery in surgical oncology. For the genetic predisposition syndromes, 7 studies were related to professional endorsed guidelines, 7 were related to surgery for MEN2, 11 were related to colectomy for FAP, 6 were related to colectomy for HNPCC, and 12 related to gastrectomy for HDGC. Articles for the nongenetic lesions included 5 for techniques related to TGDC resection, 9 for surgery for CPAMs, and 10 for resection of ATDCs. Guidelines and strategies varied significantly especially related to the extent and timing of surgical intervention; the exception was for the timing of thyroidectomy in children with MEN2.

CONCLUSION

Current evidence supporting prophylactic surgery in the management of pediatric cancer predisposition syndromes and nongenetic lesions is best delineated for thyroidectomy to prevent medullary thyroid cancer in children with MEN2 (Strength of Recommendation Grade B/C). Despite the lack of pediatric specific evidence-based recommendations regarding the appropriate extent and timing for risk-reduction surgery for FAP, HNPCC, HDGC and nongenetic anomalies, our review represents an opportunity towards understanding the postgenomic development of these lesions and provides current indications and techniques for preemptive cancer prevention surgery in children.

Familial adenomatous polyposis in an adolescent with coexisting schizophrenia: treatment strategies and implications

Schizophrenia is associated with high mortality and morbidity. The etiology of schizophrenia remains unclear, studies implicate a multifactorial origin with genetic and environmental factors. The adenomatous polyposis coli (APC) gene has been associated with FAP (familial adenomatous polyposis), and studies have linked it to schizophrenia. However, there are few studies which examine the association between FAP and schizophrenia. Limited data exist regarding recommendations for genetic counseling of adolescents with comorbid psychiatric illness. A case of an adolescent with FAP who developed psychotic symptoms is presented. This case hopes to add to the literature about mental illness in those with FAP. A review of literature about the role of APC in schizophrenia as well as implications of genetic counseling on those who suffer with mental illness will be discussed.

Polyposis syndromes in children and adolescents: a case series data analysis

BACKGROUND

Polyposis syndromes in children are distinct entities clinically and pathologically. These syndromes have multiple genetic characteristics, with development of polyps at various sites of the gastrointestinal (GI) tract, and are associated with an increased risk of colon cancer. They are relatively rare, and have mostly been characterized in the adult population, whereas little epidemiologic data have been reported in children.

AIMS

The aim of this study was to summarize the pediatric experience collected over a period of 11 years on polyposis syndromes in three major Israeli tertiary centers.

PATIENTS AND METHODS

Medical records of children below 18 years old and their families, diagnosed with polyposis syndromes between 1999 and 2010, were reviewed. The data included disease presentation, genetic profile, surveillance, and treatment.

RESULTS

Fifty patients with polyposis syndromes were identified. The most frequent syndrome was familial adenomatous polyposis (FAP) in 33 children (66%), of whom 25 children (75.7%) had a known mutation. The mean age at presentation was 10.6±3.9 years (range 4-17 years). Most children were examined because of a family history of a polyposis syndrome (42 children, 84%). Among symptomatic children (32 children), the most frequent complaint was rectal bleeding (42%), followed by abdominal pain (22%), intussusception (10%), and diarrhea (4%). The youngest symptomatic patient was 4 years old at presentation, with rectal bleeding.All patients underwent multiple colonoscopies and upper GI endoscopies according to specific guidelines. Thirteen children underwent colonic surgery (39%); nine children had FAP. Adenocarcinoma of the colon was diagnosed in a 12.5-year-old child.

CONCLUSION

In this cohort study, FAP was the most common type of polyposis syndrome diagnosed in this pediatric population. Colon cancer was present at the onset of symptoms in a 12.5-year-old patient with FAP. We therefore recommend strict adherence to the hereditary GI cancer guidelines to prevent morbidity and mortality in FAP and other inherited polyposis syndromes.

Delayed diagnosis of familial adenomatous polyposis in an adolescent patient with a coexisting eating disorder

Colorectal carcinoma in the population aged less than 20 years of age is rare but associated with poor prognosis, which is attributable to advanced disease at presentation and higher incidence of the unfavourable mucinous histology. Colorectal carcinoma commonly presents with non-specific gastrointestinal symptoms in conjunction with iron deficiency anaemia. Many of these symptoms can mimic eating disorders, which are common in adolescent women. We present the case of a 20-year-old woman with previously undiagnosed familial adenomatous polyposis and colorectal carcinoma who experienced a significant delay in diagnosis, given a coexisting eating disorder mimicking her symptoms. After confirmation of the diagnosis by colonoscopy and genetic testing, the patient underwent a successful proctocolectomy and experienced full recovery. This case is a reminder that underlying organic pathology should always be excluded prior to a diagnosis of an eating disorder.

Important considerations in treating children, adolescents and young adults with colorectal carcinoma

SUMMARY Colorectal carcinoma (CRC) in children, adolescents and young adults under 30 years of age is rare. When it occurs in these young people, is this just an ‘adult’ cancer occurring in a young patient or is it a different disease? How should these patients be managed? Here, we review what is known about the epidemiology and clinical presentation of CRC in children, adolescents and young adults, as well as the current model for CRC development to provide a framework for questioning whether CRC in these young patients is the same disease as that seen in their older adult counterparts. In addition, we will summarize the clinical options described in the peer-reviewed literature to provide a basis for management decisions of these young patients.

Management of colorectal carcinoma in children and young adults

Colorectal Carcinoma (CRC) is rare in patients less than 20 years of age. Although presenting symptoms are similar to adults, this diagnosis is rarely considered in the initial differential diagnosis of young patients. We will review what is published about the incidence, epidemiology, and clinical presentation of CRC in children, adolescents and young adults. Because of its rarity in this age group, few pediatric oncologists will have experience with CRC, and clinical trials will rarely be available. The treatment of CRC in adults is evolving rapidly and consultation with medical oncologists experience in treating adults with CRC is essential to develop the best treatment plan for a young patient diagnosed with CRC.

Colorectal adenocarcinoma: a pediatric case review with a focus on mismatch repair gene mutations and E-cadherin expression

Colorectal adenocarcinoma (CRAC) is exceedingly rare in the pediatric population (fewer than 2 cases per 1 million children). There are 2 major categories of pediatric colorectal adenocarcinoma syndromes: polyposis-related and hereditary nonpolyposis colorectal cancer, also known as Lynch syndrome. Germ line mutations in DNA mismatch repair (MMR) genes (eg, MLH1, MSH2, PMS2, MSH6) have been established as the molecular genetic basis of Lynch syndrome. Another prognostic factor in adult CRAC is the reduced expression of epithelial cadherin (E-cadherin), which has been associated with poor outcome in some adult CRAC cases; however, its role in predicting prognoses in pediatric cases remains unclear. Seven pediatric patients with primary CRAC were reviewed. Available molecular genetic test results were evaluated, and immunohistochemical labeling for MMR proteins and E-cadherin were performed on 5 patients. Four of the 5 patients in our study with available paraffin blocks showed loss of MMR protein expression, consistent with Lynch syndrome. In cases stained for E-cadherin, 3 were strongly positive and 2 were weakly positive; however, with the small sample size and the relatively short follow-up period, an accurate correlation between E-cadherin and prognosis cannot be reached with any degree of certainty. Our findings highlight the importance of genetic testing for MMR gene mutations in children with colorectal cancer and suggest further investigation into the prognostic role of E-cadherin in pediatric CRAC.

Enhanced auditory brainstem response and parental bonding style in children with gastrointestinal symptoms

BACKGROUND

The electrophysiological properties of the brain and influence of parental bonding in childhood irritable bowel syndrome (IBS) are unclear. We hypothesized that children with chronic gastrointestinal (GI) symptoms like IBS may show exaggerated brainstem auditory evoked potential (BAEP) responses and receive more inadequate parental bonding.

METHODOLOGY/PRINCIPAL FINDINGS

Children aged seven and their mothers (141 pairs) participated. BAEP was measured by summation of 1,000 waves of the electroencephalogram triggered by 75 dB click sounds. The mothers completed their Children's Somatization Inventory (CSI) and Parental Bonding Instrument (PBI). CSI results revealed 66 (42%) children without GI symptoms (controls) and 75 (58%) children with one or more GI symptoms (GI group). The III wave in the GI group (median 4.10 interquartile range [3.95-4.24] ms right, 4.04 [3.90-4.18] ms left) had a significantly shorter peak latency than controls (4.18 [4.06-4.34] ms right, p = 0.032, 4.13 [4.02-4.24] ms left, p = 0.018). The female GI group showed a significantly shorter peak latency of the III wave (4.00 [3.90-4.18] ms) than controls (4.18 [3.97-4.31] ms, p = 0.034) in the right side. BAEP in the male GI group did not significantly differ from that in controls. GI scores showed a significant correlation with the peak latency of the III wave in the left side (rho = -0.192, p = 0.025). The maternal care PBI scores in the GI group (29 [26]-[33]) were significantly lower than controls (31 [28.5-33], p = 0.010), while the maternal over-protection PBI scores were significantly higher in the GI group (16 [12]-[17]) than controls (13 [10.5-16], p = 0.024). Multiple regression analysis in females also supported these findings.

CONCLUSIONS

It is suggested that children with chronic GI symptoms have exaggerated brainstem responses to environmental stimuli and inadequate parental behaviors aggravate these symptoms.

Evaluation of guidelines for management of familial adenomatous polyposis in a multicenter pediatric cohort

OBJECTIVE

To retrospectively assess, in a pediatric multicenter cohort, guidelines for the management of familial adenomatous polyposis (FAP).

METHODS

Ten centers from the French-speaking Pediatric Gastroenterology Hepatology and Nutrition Group provided follow-up data on patients up to 18 years of age. Clinical records, genetic test results, endoscopy with histopathology examination, and therapeutic modalities were reviewed.

RESULTS

A total of 70 children from 47 families were included. When initial consultation resulted from a surveillance program because of an affected family member, 12 of 59 children were already symptomatic. Among 11 patients whose initial consultation was based only on symptoms, families were unaware at the time of a familial FAP history for 7 children, whereas only 4 cases were sporadic. A panel of 27 different pathogenic adenomatous polyposis coli (APC) germ-line mutations and large genomic deletions were identified in 43 families. Extracolonic manifestations were found in half of the patients. As part of the standard practice for initial screening, the entire cohort underwent colonoscopy, which revealed adenoma above an intact rectosigmoid in 8 cases. Prophylactic colectomy was performed in 42 cases; high-grade dysplastic adenoma and 1 invasive carcinoma were detected in 6 children. For timing of surgery, indications were in accordance with recent international guidelines.

CONCLUSIONS

Defining optimal screening and therapeutic modalities in pediatric FAP cohorts is a challenge. Specific advice for genetic screening, endoscopy surveillance, and type of surgery based on recent guidelines is recommended.

Colorectal cancer in the young: trends, characteristics and outcome

BACKGROUND

Colorectal cancer (CRC) in young patients is associated with a poor outcome due to advanced stage at diagnosis and poor differentiation.

AIM

The aim of this study is to compare clinicopathological characteristics, overall survival (OS) and disease-free survival (DFS) of young (≤40 years) and older patients with CRC.

METHODS

A total of 2,538 patients including 59 young patients (age ≤40 years) with CRC were identified over 20 years. The clinicopathological variables of young patients were compared with a group of consecutive older patients (n = 416) spanning both decades. Survival analysis was done using Kaplan-Meier, log-rank and Cox regression models.

RESULTS

The frequency in young patients increased from 1.4% to 3.0% from first to second decade (overall -2.3%, p = 0.006). There was a higher frequency of tumours with poor differentiation (43% vs. 16%, p = < 0.001), T4 stage (47% vs. 30%, p = 0.005) and vascular invasion (VI; 38% vs. 29%, p = 0.13) in younger group. There was no significant difference in OS (p = 0.116) and DFS (p = 0.261) between the two groups. Node-negative young patients had a significantly better OS (p = 0.046). Young patients with VI had significantly reduced OS (p = 0.043), whereas young patients without VI had significantly better OS (p = 0.012). Multivariate analysis showed T4 status (p = 0.001) and vascular invasion (p = 0.002) as independent prognostic factors for OS and T4 status (p = 0.004) as independent factor influencing DFS.

CONCLUSION

The frequency of CRC in young patients increased significantly. Vascular invasion is the single most important prognostic factor in young CRC. Along with vascular invasion, high proportion of T4 status in young patients increases the chances of recurrence and negates any survival advantage in young patients.

Familial adenomatous polyposis in children and adolescents

BACKGROUND

Familial adenomatous polyposis (FAP) is the most common inherited polyposis syndrome characterized by the development of hundreds of colorectal adenomatous polyps. The aim of this study was to review cases of FAP diagnosed at The Children's Hospital of Philadelphia in a 16-year period.

METHODS

Medical records of patients diagnosed as having FAP between 1990 and 2005 were reviewed. The collected data included disease presentation, genetic profile, extraintestinal manifestations, surveillance, and treatment.

RESULTS

We identified 12 patients with FAP. The age range at presentation was 7 to 18 years. Seven (68%) patients presented due to symptoms, the most common of which was rectal bleeding (6 patients, 86%). The youngest age at which polyps were detected was 7 years. Eight patients (67%) had positive family history. Three patients had Gardner syndrome and 1 presented in infancy with hepatoblastoma. Four patients had adenomatous polyposis coli gene mutation identified. One patient was diagnosed as having rectal carcinoma in situ. Six patients (50%) had gastric fundic gland polyposis and 6 had duodenal adenomatous changes. Capsule endoscopy was performed in 3 patients; 1 had multiple polyps in the duodenum and the jejunum. Seven patients (58%) underwent total colectomy with no serious complications.

CONCLUSIONS

FAP is a rare condition but with significant risk of cancer and comorbidity. In this series, patients commonly presented to medical attention due to their symptoms. The youngest patient with polyps detected was 7 years old. We identified 1 patient with rectal cancer in situ and high proportion of patients with duodenal adenomatous lesions. Majority of patients underwent early colectomy.

The gastrointestinal phenotype of germline biallelic mismatch repair gene mutations

OBJECTIVES

A novel cancer syndrome associated with biallelic mismatch repair (MMR) mutations has been described recently. Patients presenting with childhood-onset gastrointestinal (GI) cancers may carry biallelic MMR mutations and have a distinct phenotype from classic Lynch syndrome. The aim of this study was to characterize patients with GI small bowel and/or colorectal cancers (CRCs) who have germline biallelic MMR mutations.

METHODS

A search of a Canadian GI cancer registry and literature review to identify patients with biallelic MMR was conducted.

RESULTS

The database identified 237 patients with intestinal cancer diagnosed before the age of 35 years. Five (2.1%) patients had biallelic MMR mutations. Overall, 32 individuals, from 29 families, with biallelic MMR gene mutations and GI cancers were identified by the registry and literature review. Among the 29 patients with CRCs, the mean age of first cancer diagnosis was 16.4 years (range: 5-28). More than one-third of patients had multiple colorectal adenomas (>10 polyps). Six individuals with biallelic MMR gene mutations have been reported with small bowel adenocarcinoma (mean age 20 years (range: 11-41)). Café-au-lait (CAL) macules were reported in 72% and, based on mutation analysis, consanguinity was suspected in 52% of kindred. Of the 29 kindred, 19 (66%) had PMS2 mutations, 6 (21%) had MSH6 mutations, 3 (10%) had MLH1 mutations, and 1 (3%) had MSH2 mutation.

CONCLUSIONS

Biallelic MMR mutations are an underrecognized cause of small bowel and colonic cancers in children and young adults. This distinct phenotype includes multiple adenomatous polyps and CAL skin lesions. It is important to identify such patients, so that families can be referred for genetic testing and counseling.

Inherited cancer syndromes in children and young adults

Geneticists estimate that 5% to 10% of all cancers diagnosed in the pediatric age range occur in children born with a genetic mutation that directly increases their lifetime risk for neoplasia. However, despite the fact that only a fraction of cancers in children occur as a result of an identified inherited predisposition, characterizing genetic mutations responsible for increased cancer risk in such syndromes has resulted in a profound understanding of relevant molecular pathways involved in carcinogenesis and/or resistance to neoplasia. Importantly, because most cancer predisposition syndromes result in an increased risk of a small number of defined malignancies, personalized prophylactic surveillance and preventive measures can be implemented in affected patients. Lastly, many of the same genetic targets identified from cancer-prone families are mechanistically involved in the majority of sporadic cancers in adults and children, thereby underscoring the clinical relevance of knowledge gained from these defined syndromes and introducing novel therapeutic opportunities to the broader oncologic community. This review highlights the clinical and genetic features of many of the known constitutional genetic syndromes that predispose to malignancy in children and young adults.

Colonic polyps in children and adolescents

Colonic polyps most commonly present with rectal bleeding in children. The isolated juvenile polyp is the most frequent kind of polyp identified in children. 'Juvenile' refers to the histological type of polyp and not the age of onset of the polyp. Adolescents and adults with multiple juvenile polyps are at a significant risk of intestinal cancer. The challenge for adult and pediatric gastroenterologists is determining the precise risk of colorectal cancer in patients with juvenile polyposis syndrome. Attenuated familial adenamatous polyposis (AFAP) can occur either by a mutation at the extreme ends of the adenomatous polyposis coli gene or by biallelic mutations in the mutY homologue (MYH) gene. The identification of MYH-associated polyposis as an autosomal recessive condition has important implications for screening and management strategies. Adult and pediatric gastroenterologists need to be aware of the underlying inheritance patterns of polyposis syndromes so that patients and their families can be adequately evaluated and managed. Colonic polyps, including isolated juvenile polyps, juvenile polyposis syndrome, FAP, AFAP and MYH-associated polyposis, are discussed in the present review.

Pediatric adenomatous polyposis syndromes: an update

Juvenile polyps are a common finding in the pediatric population. In contrast, colon adenomas, which are viewed as dysplastic precancerous lesions, are found sporadically in late adulthood. Adenomas in children and young adults are highly unusual and suggest one of several forms of inherited colorectal cancer. These disorders show a predilection to early adenoma formation and can present in childhood. Familial adenomatous polyposis and Lynch syndrome are autosomal dominant, often with involvement of multiple family members, or can be seen in an individual arising from a de novo mutation. The most recently described adenomatous polyposis syndrome, MutYH-associated polyposis, is autosomal recessive, requiring an inherited mutation from each parent. All three adenomatous polyposis disorders can display tremendous variation in expression, even within the same family, and can have a common overlapping phenotype. These disorders require regular medical care to minimize cancer risk in the digestive tract and in other organ systems.