Outcomes of Patients with Early Onset Colorectal Cancer Treated in a UK Specialist Cancer Center

Differences in Tumor-Associated T cell receptor repertoires between Early-Onset and Average-Onset colorectal cancer

The incidence of colorectal cancer (CRC) among individuals younger than age 50 (early onset CRC; EOCRC) has substantially increased, yet the etiology and molecular mechanisms underlying this alarming rise remain unclear. We compared tumor-associated T cell repertoires between EOCRC and average-onset CRC (AOCRC) to uncover potentially unique immune microenvironment-related features by age of onset. Our discovery cohort included 242 patients who underwent surgical resection at Cleveland Clinic from 2000 to 2020. EOCRC was defined as age < 50 years at diagnosis (N = 126), and AOCRC as age ≥ 60 years (N = 116). T cell receptor (TCR) abundance and clonality were measured by immunosequencing of tumors. Logistic regression models were used to evaluate the associations between TCR repertoire features and age of onset, adjusting for sex, race, tumor location, and stage. Findings were replicated in 152 EOCRC and 1,984 AOCRC cases from the Molecular Epidemiology of Colorectal Cancer Study. EOCRC tumors had significantly higher TCR diversity compared to AOCRC tumors in the discovery cohort (Odds Ratio (OR):0.44, 95% Confidence Interval (CI):0.32-0.61, p < .0001). This association was also observed in the replication cohort (OR : 0.74, 95% CI : 0.62-0.89, p = .0013). No significant differences in TCR abundance were observed between EOCRC and AOCRC in either cohort. Higher TCR diversity, suggesting a more diverse intratumoral T cell response, is more frequently observed in EOCRC than AOCRC. Further studies are warranted to investigate the role of T cell diversity and the adaptive immune response more broadly in the etiology and outcomes of EOCRC.

The health-related quality of life of early-onset colorectal cancer patients: an Australian cross-sectional study

AIM

Early-onset colorectal cancer (EOCRC) patients are more likely to have advanced disease and undergo more aggressive treatment modalities. However, current literature investigating the health-related quality of life (HRQoL) of EOCRC patients is scarce. This study aimed to determine the HRQoL of an Australian cohort of EOCRC patients including a subset who underwent pelvic exenteration (PE) or cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

METHOD

A cross-sectional study of EOCRC patients treated at the Royal Prince Alfred Hospital, Sydney Australia was performed. Patients were divided into groups based on the time interval from their index operation: ≤2 years and >2 years. HRQoL was evaluated using the SF-36v2 questionnaire.

RESULTS

A total of 50 patients were included. For patients ≤2 years from surgery, the median physical component summary (PCS) and mental health component summary (MCS) scores were 53.3 (36.4-58.9) and 47.3 (37.5-55.7). In the >2 years group, the median PCS and MCS scores were 50.6 (43.3-57.7) and 50.2 (39.04-56.2), respectively. Stage I (vs. stage II) disease and emergency (vs. elective) surgery conferred poorer PCS scores in patients ≤2 years from surgery. No other variables impacted PCS or MCS scores in EOCRC patients in either group.

CONCLUSIONS

HRQoL of EOCRC patients was equivocal to the Australian population. Having an earlier stage of diagnosis and emergency index operation was associated with poorer levels of physical functioning in patients ≤2 years from surgery. However, because of the limitations of this study, these findings require validation in future large-scale prospective research.

Risk factors, histopathological landscape, biomarkers, treatment patterns and survival of early-onset colorectal cancer: A narrative review

Early-onset colorectal cancer (EOCRC) incidence has increased in most Western countries over the last decade, with Australia at the forefront. Recent literature has thus focused on characterizing EOCRC from later-onset colorectal cancer (LOCRC). Earlier exposure to modifiable risk factors resulting in gut dysbiosis has been linked with EOCRC development. EOCRCs have more aggressive histopathological features with somatic mutations resulting in pro-inflammatory tumor microenvironments. There is a tendency to treat EOCRCs with multimodal chemotherapeutic regimens and more extensive surgery than LOCRCs with conflicting postoperative outcomes and survival data. Current research is limited by a lack of Australasian studies, retrospective study designs, and heterogeneous definitions of EOCRC. Future research should address these and focus on investigating the role of immunotherapies, establishing minimally invasive diagnostic biomarkers and nomograms, and evaluating the survival and functional outcomes of EOCRC.

Early-Onset Colorectal Cancer in Egypt: Pathological Characters, Patterns of Care, and Survival Compared to Average-Age Onset Colorectal Cancer: A Retrospective Multicenter Study

PURPOSE

Early-onset colorectal cancer (EOCRC) is a rising health problem. The incidence of EOCRC has increased over the past 2 decades all over the world. Reports from Egypt since the 1990s have reported a higher incidence among young populations with no identifiable risk factors. The aim of this study was to assess EOCRC in Egypt regarding incidence, characteristics, treatment pattern, and survival compared with average age onset and elderly patients.

MATERIALS AND METHODS

This was a retrospective, record-based, cohort study combining data from four different cancer centers in Egypt. We grouped patients according to age into three categories: the EOCRC group for patients age ≤45 years and the average age onset and elderly cancer group (for patients age ≥65 years).

RESULTS

The study included 1,310 patients with histopathologically proven colorectal cancer, representing four different geographical areas in Egypt. Patients with EOCRC represented 42.4% of the study population. Female patients were 50.6% among the EOCRC group and 52.5% among the average age group. Rectal tumors were significantly higher in EOCRC (54.7% v 40.6%; P < .001). There was no significant difference between both groups regarding the tumor stage at presentation, obstruction, or presence of metastases at presentation. Patients with EOCRC had a significantly higher rate of peritoneum/adnexa metastases than the average age ones (12.3% in EOCRC v 6.9% in the average age group; P < .001). No statistically significant differences between EOCRC and average age groups in both disease-free survival and overall survival were reported.

CONCLUSION

A comprehensive framework for the study of EOCRC is required in Egypt as well as a genomic analysis to identify possible underlying genetic alterations responsible for the high incidence of EOCRC.

Biological and clinical implications of early-onset cancers: A unique subtype

In recent years, the incidence of cancers is continuously increasing in young adults. Early-onset cancer (EOC) is usually defined as patients with cancers under the age of 50, and may represent a unique subgroup due to its special disease features. Overall, EOCs often initiate at a young age, present as a better physical performance but high degree of malignancy. EOCs also share common epidemiological and hereditary risk factors. In this review, we discuss several representative EOCs which were well studied previously. By revealing their clinical and molecular similarities and differences, we consider the group of EOCs as a unique subtype compared to ordinary cancers. In consideration of EOC as a rising threat to human health, more researches on molecular mechanisms, and large-scale, prospective clinical trials should be carried out to further translate into improved outcomes.

Patients younger than 40 years with colorectal cancer have a similar prognosis to older patients

PURPOSE

Colorectal cancer (CRC) is a leading cause of cancer-related deaths worldwide. In recent years, the proportion of patients diagnosed with CRC at younger ages has increased. The clinicopathological features and oncological outcomes in younger patients with CRC remain controversial. We aimed to analyze the clinicopathological features and oncological outcomes in younger patients with CRC.

METHODS

We examined 980 patients who underwent surgery for primary colorectal adenocarcinoma between 2006 and 2020. Patients were divided into two cohorts: younger (< 40 years old) and older (≥ 40 years old).

RESULTS

Of the 980 patients, 26 (2.7%) were under the age of 40 years. The younger group had more advanced disease (57.7% vs. 36.6%, p = 0.031) and more cases beyond the transverse colon (84.6% vs. 65.3%, p = 0.029) than the older group. Adjuvant chemotherapy was administered more frequently in the younger group (50% vs. 25.8%, p < 0.01). Relapse-free survival and overall survival were similar between the groups at all stages. Moreover, in stages II and III they were also comparable, regardless of the administration of adjuvant chemotherapy.

CONCLUSIONS

Younger patients with CRC have a prognosis equivalent to that of older patients. Further studies are needed to establish the optimal treatment strategies for these patients.

Early Onset Metastatic Colorectal Cancer: Current Insights and Clinical Management of a Rising Condition

Despite a recent overall decrease in colorectal cancer (CRC) incidence and mortality, there has been a significant rise in CRC diagnoses in young adults. Early onset colorectal cancer (EOCRC) is defined as CRC diagnosed before the age of 50. Possible predisposing conditions include not only genetic syndromes but also other risk factors, such as microbiome alteration, antibiotic exposure, obesity, diabetes mellitus, and inflammatory bowel disease. EOCRC tends to be diagnosed later than in the older counterpart because of a lack of awareness and the fact that screening for CRC usually starts at the age of 50. Furthermore, CRC in young adults seems to be related to unique molecular features and more aggressive clinical behavior. This paper aims to provide an in-depth review of this poorly understood subject, with a comprehensive review of the state of the art and considerations for future perspectives.

Impact of the COVID-19 pandemic in the early-onset colorectal cancer

The COVID19 pandemic has affected the spectrum of cancer care worldwide. Early onset colorectal cancer (EOCRC) is defined as diagnosis below the age of 50. Patients with EOCRC faced multiple challenges during the COVID19 pandemic and in some institutions it jeopardized cancer diagnosis and care delivery. Our study aims to identify the clinicopathological features and outcomes of patients with EOCRC in our Centre during the first wave of the pandemic in comparison with the same period in 2019 and 2021.

Patients with EOCRC visited for the first time at Vall d'Hebron University Hospital in Spain from the 1st March to 31st August of 2019, 2020 and 2021 were included in the analysis. 177 patients with EOCRC were visited for the first time between 2019 and 2021, of which 90 patients met the inclusion criteria (2019: 30 patients, 2020: 29 patients, 2021: 31 patients). Neither differences in frequency nor in stage at diagnosis or at first visit during the given periods were observed. Of note, indication of systemic therapy in the adjuvant or metastatic setting was not altered. Days to treatment initiation and enrollment in clinical trials in this subpopulation was not affected due to the COVID-19 outbreak.

Comparison of the short- and long-term prognosis of early-onset colorectal cancer compared with later-onset colorectal cancer: A systematic review and meta-analysis

Background and Aims

The annual incidence of early-onset colorectal cancer (EOCRC) is increasing at an alarming rate. The prognosis of EOCRC remains controversial, and whether the early onset is a risk factor for colorectal cancer remains unclear.

Methods

We searched four electronic bibliographic databases from database inception to April 25, 2022 for studies that included both early- and later-onset patients and performed a prognostic analysis. Random-effects models were used to summarize the prognostic information extracted by the investigators, including overall survival (OS), cancer-special survival (CSS), and disease-free survival (DFS). Network meta-analysis (NMA) was used to compare patients' long-term prognoses in different age subgroups.

Results

After 694 reports were screened, 13 studies were included in the final analysis, with a total of 448,781 CRC cases. In the meta-analysis of the 5-year OS, EOCRC had a better prognosis compared to LOCRC (hazard ratio [HR] 0.87, 95% confidence interval [CI], 0.74-0.99; relative risk [RR] 0.83, 95% CI, 0.78-0.89). No difference in prognosis was found between the two groups in terms of 5-year CSS (RR 0.99, 95% CI, 0.93-1.05), 5-year DFS (RR 0.90, 95% CI, 0.74-1.09), and short-term OS. In the NMA, patients aged <30 years had the worst outcome (surface under the cumulative ranking curve [SUCRA], 15.8%) in 5-year OS; consistent results were observed in the analysis of 5-year CSS (<30 years, SUCRA 4.5%), but the difference was not statistically significant.

Conclusion

Although patients with early-onset CRC had better OS than those with later-onset CRC, there was no difference in the CSS. Meanwhile, the trend for survival was worse in younger patients, especially in those ages 18-29 years. Thus, more attention should be paid to early diagnosis and treatment of EOCRC.

Systematic Review and Meta‐Analysis Registration

The systematic review and Meta-analysis protocol was registered with PROSPERO (registration number CRD42022334697).

Early-Onset GI Cancers: Rising Trends, Genetic Risks, Novel Strategies, and Special Considerations

Cancers in young adults (commonly described as early-onset [EO] cancer) represent a group of malignancies that have unique and challenging biology and genetic, treatment, social, and psychological implications. Even more concerning is a rising trend of EO cancers in multiple tumor types. Research and investigation in EO cancers will help elucidate mechanisms of carcinogenesis, differences in biology and response to treatment, and the need for multidisciplinary care to ensure comprehensive treatment and support for young patients.

Serum IgG N-glycans enable early detection and early relapse prediction of colorectal cancer

Colorectal cancer (CRC) develops mainly from colorectal advanced adenomas (AA), which are considered precancerous lesions. Novel early diagnostic biomarkers are urgently needed to distinguish CRC and AA from healthy control (HC). Alternative glycosylation of serum IgG has been shown to be closely associated with CRC. We aimed to explore the potential of IgG N-glycan as biomarkers in the early differential diagnosis of CRC. The study population was strictly matched to the exclusion criteria process. Serum IgG N-glycan profiles were analyzed by a robust and reliable relative quantitative method based on ultra-performance liquid chromatography (UPLC). Relative quantification and classification performance of IgG N-glycans were evaluated by Mann-Whitney U tests and ROC curve based on directly detected and derived glycan traits, respectively. Six and 14 directly detected glycan traits were significantly changed in AA and CRC, respectively, compared with HC. GP1 and GP3 were able to accurately distinguish AA from HC for early precancerous lesions screening. GP4 and GP14 provided a high value in discriminating CRC from HC. A novel combined index named GlycoF, including GP1, GP3, GP4, GP14 and CEA was developed to provide a potential early diagnostic biomarker in discriminating simultaneously AA (AUC = 0.847) and CRC (AUC = 0.844) from HC. GlycoF also demonstrated a superior CRC detection rate across CRC all stages and conspicuous prediction ability of risk of relapse. Serum IgG N-glycans analysis provided powerful early screening biomarkers that can efficiently differentiate CRC and AA from HC.

Young Patients With Colorectal Cancer Have Higher Early Mortality but Better Long-Term Survival

INTRODUCTION

To define the prognosis of colorectal cancer (CRC) in young patients and to compare their postoperative treatment with that of older patients.

METHODS

This multicenter study enrolled 5,457 patients with primary CRC who underwent surgical resection. The overall survival (OS), clinicopathologic characteristics, and postoperative treatment of 253 young patients aged 18-44 years and 5,204 older patients aged 44-80 years were analyzed.

RESULTS

The OS rate was 77.1% for young and 74.2% for older patients (P = 0.348). Landmark analysis showed a significant difference in survival between young and older patients, with 63.8% of deaths among young patients being within 25 months of surgery compared with 42.4% among older patients (P = 0.002). Among those who survived more than 25 months, young patients had significantly better survival than older patients (P = 0.009). Multivariable analysis of young patients revealed that the tumor location, perineural invasion, and stage were associated with poor survival within 25 months; after this period, stage was the only prognostic marker. Young patients were more likely to receive chemotherapy, particularly multiagent regimens. For young patients, no significant difference in OS was found based on the chemotherapy regimen, regardless of disease stage (II, III, or IV, all P > 0.05). In addition, unlike in older patients, no difference in OS was found in young patients regardless of the drug regimen administered (all P > 0.05).

DISCUSSION

Young-onset CRC may have a unique disease biology that warrants further research and therapy development.

Young-onset colorectal cancer: Insights from an English population-based study

AIM

Young colorectal cancer (CRC) patients are reported to have more aggressive disease, an advanced stage at diagnosis and conflicting survival outcomes. The aim of this study was to analyse the demographics, clinicopathological features and prognosis of young CRC at a population-based level in England.

METHOD

This is a retrospective review of all CRC patients using data from Public Health England collated from regional cancer registries in England between 2010 and 2014. Those aged 40 years and below were classified as young and those over 40 were classified as older.

RESULTS

Overall, 167,501 patients had CRC. Of these, 3757 patients (2.2%) were young. Right-sided cancers were more common in younger patients (48.2% vs. 32.9%, p < 0.001). Favourable histological grade (well or moderately differentiated) was present in 83.1% and 73.5% of young and older patients, respectively. The percentage of young and older patients being diagnosed at an early stage (Stages 1 and 2) was similar at 40.6% vs. 42.9%. The 5-year age- and gender-adjusted relative survival (cancer specific) was significantly better for young patients when compared with older patients diagnosed with CRC. Additionally, overall 5-year survival was better for younger patients (71.6% and 47.2%, p < 0.001 in young and older CRC patients respectively).

CONCLUSION

The increased right-sided colon cancer in young CRC patients in England warrants attention. Contrary to previous reports, they do not present at later stage. Young CRC patients have better overall and relative survival than older patients with CRC.

Trends, clinicopathological features, surgical treatment patterns and prognoses of early-onset versus late-onset colorectal cancer: A retrospective cohort study on 34067 patients managed from 2000 to 2021 in a Chinese tertiary center

BACKGROUND

In recent decades, the incidence of early-onset colorectal cancer (EOCRC) has reportedly increased in several developed countries, whereas that of late-onset colorectal cancer (LOCRC) has decreased continuously. The trends, clinicopathological features, surgical treatment patterns, and prognoses of EOCRC and LOCRC in China remain unclear.

MATERIALS AND METHODS

This retrospective cohort study was performed in China using data from our pathology registry collected in 2000-2021. Pathologically confirmed cases of colorectal cancer (CRC) were analyzed. The average annual percentage change (AAPC) was estimated to quantify the secular trends. Clinicopathological features, surgical treatment patterns, and prognoses were compared between the two groups. Multivariate Cox regression analyses were performed for disease-free survival and overall survival.

RESULTS

A total of 34,067 cases of CRC were included, with 6,369 cases of EOCRC and 27,698 cases of LOCRC. Overall, the numbers of EOCRC (AAPC = 8.4%), LOCRC (AAPC = 11.6%), and CRC (AAPC = 11.0%) cases increased significantly from 2000 to 2021. Compared to the LOCRC group, the EOCRC group had fewer men, comorbidities, concomitant cancers, polyps, and KRAS mutations; more symptoms, rectal cancers, multiple primary CRCs, deficient mismatch repair tumors, poorly differentiated, mucinous adenocarcinoma or signet ring cell carcinoma, advanced TNM stage, vascular invasion, perineural invasion; less laparoscopic surgery and sphincter-preserving surgery; more extended radical resection, perioperative chemoradiotherapy and targeted therapy; and similar disease-free and overall survival rates.

CONCLUSION

The numbers of EOCRC and LOCRC cases have continuously increased over the last two decades. The EOCRC group has more aggressive features, advanced TNM stage, intensified surgical treatment and perioperative treatment than the LOCRC group, but similar disease-free and overall survival rates. More CRC screening programs are recommended for younger adults to combat the rapidly increasing trend of EOCRC.

Upregulated long intergenic non-protein coding RNA 1094 (LINC01094) is linked to poor prognosis and alteration of cell function in colorectal cancer

Colorectal cancer (CRC) showed high cancer-related mortality in recent years partly due to the absence of an effective prognostic predictor. This research intended to evaluate the prognostic value and potential role of long intergenic non-protein coding RNA 1094 (LINC01094) in CRC. In this work, we evaluated the LINC01094 level in 122 CRC patients’ tissues and in human CRC cell lines. We explored the ability of LINC01094 in overall survival and progression-free survival estimate. The effect of LINC01094 dysregulation on the CRC cells was investigated. LINC01094 is highly expressed in CRC tissues and cells than normal ones. This high expression was correlated with absent vascular invasion, positive lymph node metastasis, and advanced TNM stage. With the result of Kaplan-Meier analysis and multivariate Cox’s proportional hazard analysis, LINC01094 was an effective biomarker for CRC overall survival. Downregulation of LINC01094 impeded the malignant biological behavior (proliferation, invasion, and migration) of CRC cells, while overexpression of LINC01094 boosted that maybe by sponging miR-1266-5p. LINC01094 might function as an oncogene in CRC and allowed the discovery of a new biomarker for prognosis and therapy of CRC.

Epidemiology and biology of early onset colorectal cancer

Colorectal cancer (CRC) is the third leading cause of cancer-related mortality in men or women in the United States. Average-risk screening that begins at age 50 years has reduced incidence and mortality of CRC in those over 50 years of age, whereas CRC incidence in those under age 50 years (early onset colorectal cancer (eoCRC)) has recently and dramatically increased. In this review, we summarize the recent literature including risk factors for eoCRC, differences in clinicopathologic presentation and outcomes in eoCRC, and emerging evidence regarding the molecular pathways that are altered in eoCRC compared to later onset CRC (loCRC). Epidemiologic studies of eoCRC show predominance in distal colon and rectum, and association with several modifiable risk factors, including diabetes, obesity, diet, sedentary time, alcohol consumption and smoking. Data regarding potential risk factors of prior antibiotic exposure and microbiome alterations or direct carcinogen exposure are still emerging. Aggressive clinicopathologic features of eoCRC at presentation may be due to delay in diagnosis or more aggressive tumor biology. EoCRC outcomes are similar to loCRC when matched for stage, but overall mortality is greater due to higher frequency of advanced disease at a younger presentation, with more life-years lost. There are only few molecular evaluations of eoCRC to date, with findings of potential increase in TP53 and CTNNB1 somatic mutation and decrease in APC, KRAS and BRAF somatic mutation, compared to loCRC. Other findings include LINE-1 hypomethylation, absence of microsatellite instability (MSI-H), presence of chromosomal instability (CIN) or microsatellite and chromosomal stability (MACS). These studies are only now emerging and have not yet identified a specific molecular signature defining eoCRC. Further research evaluating genetic and molecular differences as well as environmental triggers for eoCRCs should provide a clearer understanding to inform targeted screening for pre-symptomatic at-risk younger individuals.

Updates on Age to Start and Stop Colorectal Cancer Screening: Recommendations From the U.S. Multi-Society Task Force on Colorectal Cancer

This document is a focused update to the 2017 colorectal cancer (CRC) screening recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer, which represents the American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy. This update is restricted to addressing the age to start and stop CRC screening in average-risk individuals and the recommended screening modalities. Although there is no literature demonstrating that CRC screening in individuals under age 50 improves health outcomes such as CRC incidence or CRC-related mortality, sufficient data support the U.S. Multi-Society Task Force to suggest average-risk CRC screening begin at age 45. This recommendation is based on the increasing disease burden among individuals under age 50, emerging data that the prevalence of advanced colorectal neoplasia in individuals ages 45 to 49 approaches rates in individuals 50 to 59, and modeling studies that demonstrate the benefits of screening outweigh the potential harms and costs. For individuals ages 76 to 85, the decision to start or continue screening should be individualized and based on prior screening history, life expectancy, CRC risk, and personal preference. Screening is not recommended after age 85.

Updates on Age to Start and Stop Colorectal Cancer Screening: Recommendations From the U.S. Multi-Society Task Force on Colorectal Cancer

This document is a focused update to the 2017 colorectal cancer (CRC) screening recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer, which represents the American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy. This update is restricted to addressing the age to start and stop CRC screening in average-risk individuals and the recommended screening modalities. Although there is no literature demonstrating that CRC screening in individuals under age 50 improves health outcomes such as CRC incidence or CRC-related mortality, sufficient data support the U.S. Multi-Society Task Force to suggest average-risk CRC screening begin at age 45. This recommendation is based on the increasing disease burden among individuals under age 50, emerging data that the prevalence of advanced colorectal neoplasia in individuals ages 45 to 49 approaches rates in individuals 50 to 59, and modeling studies that demonstrate the benefits of screening outweigh the potential harms and costs. For individuals ages 76 to 85, the decision to start or continue screening should be individualized and based on prior screening history, life expectancy, CRC risk, and personal preference. Screening is not recommended after age 85.

Updates on age to start and stop colorectal cancer screening: recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer

This document is a focused update to the 2017 colorectal cancer (CRC) screening recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer, which represents the American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy. This update is restricted to addressing the age to start and stop CRC screening in average-risk individuals and the recommended screening modalities. Although there is no literature demonstrating that CRC screening in individuals under age 50 improves health outcomes such as CRC incidence or CRC-related mortality, sufficient data support the U.S. Multi-Society Task Force to suggest average-risk CRC screening begin at age 45. This recommendation is based on the increasing disease burden among individuals under age 50, emerging data that the prevalence of advanced colorectal neoplasia in individuals ages 45 to 49 approaches rates in individuals 50 to 59, and modeling studies that demonstrate the benefits of screening outweigh the potential harms and costs. For individuals ages 76 to 85, the decision to start or continue screening should be individualized and based on prior screening history, life expectancy, CRC risk, and personal preference. Screening is not recommended after age 85.

Screening and prevention of colorectal cancer

Mortality from colorectal cancer is reduced through screening and early detection; moreover, removal of neoplastic lesions can reduce cancer incidence. While understanding of the risk factors, pathogenesis, and precursor lesions of colorectal cancer has advanced, the cause of the recent increase in cancer among young adults is largely unknown. Multiple invasive, semi- and non-invasive screening modalities have emerged over the past decade. The current emphasis on quality of colonoscopy has improved the effectiveness of screening and prevention, and the role of new technologies in detection of neoplasia, such as artificial intelligence, is rapidly emerging. The overall screening rates in the US, however, are suboptimal, and few interventions have been shown to increase screening uptake. This review provides an overview of colorectal cancer, the current status of screening efforts, and the tools available to reduce mortality from colorectal cancer.

The Emergence of Immune-checkpoint Inhibitors in Colorectal Cancer Therapy

Immunotherapy has revolutionized the treatment landscape in a number of solid tumors. In colorectal cancer, evidence suggests that microsatellite high (MSI-H) tumors are the most responsive to immune checkpoint blockade due to increased neo-antigen load and a favorable tumor microenvironment. Indeed, Pembrolizumab now represents a first-line option in such patients. However, MSI-H tumors represent the minority and a proportion of patients' progress despite initially responding. Trials are investigating different immunotherapy combinatorial strategies to enhance immune response in less immunogenic colorectal tumors. Such strategies include dual immune checkpoint blockade, combining immune checkpoint inhibitors with other treatment modalities such as radiotherapy, chemotherapy or other biological or targeted agents. Moreover, there is an increasing drive to identify biomarkers to better select patients most likely to respond to immunotherapy and understand intrinsic and acquired resistance mechanisms. Apart from MSI-H tumors, there is a strong rationale to suggest that tumors with alterations in DNA polymerase epsilon and DNA polymerase delta are also likely to respond to immunotherapy and trials in this subpopulation are underway. Other strategies such as priming O6-methylguanineDNA methyltransferase silenced tumors with alkylating agents to make them receptive to immune checkpoint blockade are also being investigated. Here we discuss different colorectal subpopulations together with their likelihood of response to immune checkpoint blockade and strategies to overcome barriers to a successful clinical outcome. We summarize evidence from published clinical trials and provide an overview of trials in progress whilst discussing newer immunotherapy strategies such as adoptive cell therapies and cancer vaccines.

Care Patterns and Overall Survival in Patients With Early-Onset Metastatic Colorectal Cancer

PURPOSE

Colorectal cancer (CRC) incidence in patients younger than 50 years of age, commonly defined as early-onset (EO-CRC), is rising. EO-CRC often presents with distinct clinicopathologic features. However, data on prognosis are conflicting and outcomes with modern treatment approaches for metastatic disease are still limited.

MATERIALS AND METHODS

We prospectively enrolled patients with metastatic CRC (mCRC) to a biobanking and clinical data collection protocol from 2014 to 2018. We grouped the cohort based on age at initial diagnosis: < 40 years, 40-49 years, and ≥ 50 years. We used regression models to examine associations among age at initial diagnosis, treatments, clinicopathologic features, and survival.

RESULTS

We identified 466 patients with mCRC (45 [10%] age < 40 years, 109 [23%] age 40-49 years, and 312 [67%] age ≥ 50 years). Patients < 40 years of age were more likely to have received multiple metastatic resections (odds ratio [OR], 3.533; P = .0066) than their older counterparts. Patients with EO-CRC were more likely to receive triplet therapy than patients > 50 years of age (age < 40 years: OR, 6.738; P = .0002; age 40-49 years: OR, 2.949; P = .0166). Patients 40-49 years of age were more likely to have received anti-EGFR therapy (OR, 2.633; P = .0016). Despite differences in care patterns, age did not predict overall survival.

CONCLUSION

Despite patients with EO-CRC receiving more intensive treatments, survival was similar to the older counterpart. However, EO-CRC had clinical and molecular features associated with worse prognoses. Improved biologic understanding is needed to optimize clinical management of EO-CRC. The cost-benefit ratio of exposing patients with EO-CRC to more intensive treatments has to be carefully evaluated.

Early age onset colorectal cancer

The incidence and mortality associated with colorectal cancer (CRC) diagnosed in patients under the age of 50 have been steadily increasing. The exact etiology of these epidemiologic trends is unclear. This chapter will provide a comprehensive review on the topic of early age onset colorectal cancer (EAO-CRC), defined as colorectal cancer (CRC) diagnosed in patients under the age of 50. Topics reviewed will include the epidemiology of EAO-CRC around the world, clinical and pathological features of EAO-CRC in contrast to later age onset CRC (CRC diagnosed on those over the age of 50) and the observed molecular and somatic characteristics. This chapter will review the etiologies to EAO-CRC and the established, as well as proposed risk factors for disease. Evidence-based approaches to prevention, early detection, treatment and survivorship will be presented.

Non-anaemic iron deficiency should be investigated with the same priority as iron deficiency anaemia in fast track colorectal clinics-retrospective cohort study

Background

Since year 2000 the diagnostic criterion for fast track (FT) referrals for patients with suspected colorectal cancer (CRC) is used in the UK. Iron deficiency anaemia (IDA) is one of the diagnostic criteria. There is a strong evidence in the literature which suggests that Iron deficiency (ID) alone has a strong relationship with CRC. Non-anaemic Iron deficiency (NAID) and all other types of anaemia are investigated outside the scope of FT clinics. We postulated that patients with ID regardless of degree of anaemia have an increased risk of CRC. By confirming this hypothesis, we can broaden the scope of the diagnostic criterion for referral that can help to increase diagnostic yield of FT CRC services.

Methods

A retrospective observational cohort study was conducted from a dedicated data for FT clinics from 2016-2018. Association between CRC and different forms of anaemia, Iron deficiency alone and bowel symptoms was determined.

Results

Patients with iron deficiency (low MCV, MCH and ferritin) regardless of degree of anaemia were found more likely to have CRC. Factors like age, gender, family history and bowel symptoms (except abdominal mass) showed a very weak association with CRC in patients with ID.

Conclusions

ID without anaemia has a strong relationship with CRC and should be investigated with the same priority as IDA is investigated.

Colorectal Cancer in Persons Under Age 50: Seeking Causes and Solutions

Early onset colorectal cancer (EOCRC) refers to colorectal cancer (CRC) in individuals under age 50. Although the incidence and mortality due to later onset CRC (≥50 years) has been declining over several decades, both are increasing in those under 50. EOCRC is more likely to occur in the distal colon and rectum. There are some unique pathologic and genetic features to these tumors; they are not usually associated with a germline mutation in a gene that predisposes to cancer, and at least some may have a distinct pathogenesis. Initiating CRC screening at an earlier age (40-45 years of age) would presumably detect more early stage and asymptomatic EOCRCs, but this would imply a major additional health care burden. The understanding of EOCRC and the optimal management approach to this problem are unsolved problems.