Patterns of Sociodemographic and Clinicopathologic Characteristics of Stages II and III Colorectal Cancer Patients by Age: Examining Potential Mechanisms of Young-Onset Disease

Changing epidemiology of colorectal cancer - birth cohort effects and emerging risk factors

Incidence and mortality of colorectal cancer (CRC) are increasing worldwide, suggesting broad changes in the epidemiology of CRC. In this Review, we discuss the changes that are becoming evident, including trends in CRC incidence and mortality by age and birth cohort, and consider the contributions of early-life exposures and emerging risk factors to these changes. Importantly, incidence of CRC has increased among people born since the early 1950s in nearly all regions of the world. These so-called birth cohort effects imply the involvement of factors that influence the earliest stages of carcinogenesis and have effects across the life course. Accumulating evidence supports the idea that early-life exposures are important risk factors for CRC, including exposures during fetal development, childhood, adolescence and young adulthood. Environmental chemicals could also have a role because the introduction of many in the 1950s and 1960s coincides with increasing incidence of CRC among people born during those years. To reverse the expected increases in the global burden of CRC, participation in average-risk screening programmes needs to be increased by scaling up and implementing evidence-based screening strategies, and emerging risk factors responsible for these increases need to be identified.

Trends in Colorectal Cancer Mortality in the United States, 1999 - 2020

Background

The United States faces a significant public health issue with colorectal cancer (CRC), which remains the third leading cause of cancer-related fatalities despite early diagnosis and treatment progress.

Methods

This investigation utilized death certificate data from the Centers for Disease Control and Prevention Wide-Ranging OnLine Data for Epidemiologic Research (CDC WONDER) database to investigate trends in CRC mortality and location of death from 1999 to 2020. Additionally, the study utilized the annual percent change (APC) to estimate the average annual rate of change over the specific time period for the given health outcome. Incorporating the location of death in this study served the purpose of identifying patterns related to CRC and offering valuable insights into the specific locations where deaths occurred.

Results

Between 1999 and 2020, there were 1,166,158 CRC-related deaths. The age-adjusted mortality rates (AAMRs) for CRC consistently declined from 20.7 in 1999 to 12.5 in 2020. Men had higher AAMR (18.8) than women (13.4) throughout the study. Black or African American patients had the highest AAMR (21.1), followed by White (15.4), Hispanic/Latino (11.8), American Indian or Alaska native (11.4), and Asian or Pacific Islanders (10.2). The location of death varied, with 41.99% at home, 28.16% in medical facilities, 16.6% in nursing homes/long-term care facilities, 7.43% in hospices, and 5.80% at other/unknown places.

Conclusion

There has been an overall improvement in AAMR among most ethnic groups, but an increase in AAMR has been observed among white individuals below the age of 55. Notably, over one-quarter of CRC-related deaths occur in medical facilities.

Early-Onset Cancer in the Gastrointestinal Tract Is on the Rise-Evidence and Implications

Epidemiologic data indicate a significant increase in the incidence of colorectal cancer in younger populations in the past three decades. Moreover, recent evidence also demonstrates a similar trend in gastric, pancreatic, and biliary tract cancers. A majority of these early-onset cases are sporadic and lack hereditary or familial background, implying a potential key role for behavioral, lifestyle, nutritional, microbial, and environmental factors. This review explores the current data on early-onset gastrointestinal cancer, exploring the etiology, unique treatment considerations for this population, future challenges, as well as implications for research and practice.

SIGNIFICANCE

The worrisome trend of an increasing incidence of early-onset gastrointestinal cancers appears to be correlated with nonhereditary etiologies in which behavioral, lifestyle, nutritional, microbial, and environmental factors, as well as host mechanisms, may play a key role. Further epidemiologic and pathogenetic research is urgently needed to better understand the underlying mechanisms and to develop preventive strategies and tailored early detection. Young patients with gastrointestinal cancer face unique challenges and unmet needs. These must be addressed in the future management of the disease to minimize treatment-related somatic morbidity and prevent psychosocial sequelae.

Anatomic location of colorectal cancer presents a new paradigm for its prognosis in African American patients

Among all racial groups in the U.S., African Americans (AA) have the highest incidence of and mortality from colorectal cancer (CRC). Although socioeconomic factors, as the major contributors to racial disparity of CRC, have been widely investigated, there is a dearth of information germane to understanding its biological basis. To better elucidate the clinicopathologic features we extracted demographic, clinical, pathologic and molecular features of 500 consecutive cases of CRC diagnosed at our institution which has an AA-predominant patient population (75% of all patients). We compared data from our AA patients with those of white patients both from our institution and from SEER and the published literature for meaningful comparison. AA patients were more likely to be at an advanced disease stage (25.9% vs. 20.8%, p = 0.041), have low grade tumors (89.2% vs. 77.5%, p<0.001) in cecum (18.7% vs. 16.2%, p<0.001) and <60-years-old than white patients (31.8% vs. 26.3%, p = 0.015). The frequency of KRAS mutation was higher in AA patients than in white patients (56.8% vs. 20.7%, p<0.001). Amongst subtypes of KRAS tested in CRC, codon 12 mutation is more common in AA than white patients (85.2% vs. 68.9%, p = 0.020). Compared with other racial groups, we found AA patients to have worse disease-free survival (HR = 3.682, p = 0.035). Also, AA patients with CRC in distal (sigmoid and rectum) or proximal (cecum) colon have worse overall survival than those with CRC in middle colon (HR = 2.926, p = 0.014), a finding not observed in white patients. In both racial groups, advanced stage, perforation, and hypertension were independent prognostic factors for overall survival (p<0.05). Similarly, low body-mass index at presentation, mucinous adenocarcinoma, lymphovascular invasion, perineural invasion and KRAS mutations were independent factors significantly associated with poor disease-free survival. Collectively, our data provide new insights into the roles of clinicopathologic features, especially anatomic distribution, in predicting outcomes of CRC in AA population.

Survival in Young-Onset Metastatic Colorectal Cancer: Findings From Cancer and Leukemia Group B (Alliance)/SWOG 80405

BACKGROUND

The incidence of young-onset colorectal cancer (yoCRC) is increasing. It is unknown if there are survival differences between young and older patients with metastatic colorectal cancer (mCRC).

METHODS

We studied the association of age with survival in 2326 mCRC patients enrolled in the Cancer and Leukemia Group B and SWOG 80405 trial, a multicenter, randomized trial of first-line chemotherapy plus biologics. The primary and secondary outcomes of this study were overall survival (OS) and progression-free survival (PFS), respectively, which were assessed by Kaplan-Meier method and compared among younger vs older patients with the log-rank test. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated based on Cox proportional hazards modeling, adjusting for known prognostic variables. All statistical tests were 2-sided.

RESULTS

Of 2326 eligible subjects, 514 (22.1%) were younger than age 50 years at study entry (yoCRC cohort). The median age of yoCRC patients was 44.3 vs 62.5 years in patients aged 50 years and older. There was no statistically significant difference in OS between yoCRC vs older-onset patients (median = 27.07 vs 26.12 months; adjusted HR = 0.98, 95% CI = 0.88 to 1.10; P = .78). The median PFS was also similar in yoCRC vs older patients (10.87 vs 10.55 months) with an adjusted hazard ratio of 1.02 (95% CI = 0.92 to 1.13; P = .67). Patients younger than age 35 years had the shortest OS with median OS of 21.95 vs 26.12 months in older-onset patients with an adjusted hazard ratio of 1.08 (95% CI = 0.81 to 1.44; Ptrend = .93).

CONCLUSION

In this large study of mCRC patients, there were no statistically significant differences in survival between patients with yoCRC and CRC patients aged 50 years and older.

Racial and Ethnic Disparities in Germline Genetic Testing of Patients With Young-Onset Colorectal Cancer

BACKGROUND & AIMS

Up to 20% of younger patients (age <50 years) diagnosed with colorectal cancer (CRC) have germline mutations in cancer susceptibility genes. Germline genetic testing may guide clinical management and facilitate earlier intervention in affected relatives. Few studies have characterized differences in genetic testing by race/ethnicity.

METHODS

We identified young adults (age 18-49 years) diagnosed with CRC between 2009 and 2017 in 2 health systems in Dallas, TX. We evaluated referral to genetic counseling, attendance at genetic counseling appointments, and receipt of germline genetic testing by race/ethnicity.

RESULTS

Of 385 patients with young-onset CRC (median age at diagnosis 44.4 years), 176 (45.7%) were Hispanic, 98 (25.4%) non-Hispanic Black, and 111 (28.8%) non-Hispanic White. Most patients (76.9%) received immunohistochemistry (IHC) for mismatch repair proteins, and there was no difference in receipt of IHC by race/ethnicity. However, a lower proportion of Black patients were referred to genetic counseling (50.0% vs White patients 54.1% vs Hispanic patients 65.9%; P = .02) and attended genetic counseling appointments (61.2% vs 81.7% White patients vs 86.2% Hispanic patients; P < .01). Of 141 patients receiving genetic testing, 38 (27.0%) had a pathogenic or likely pathogenic variant in a cancer susceptibility gene. An additional 33 patients (23.4%) had variants of uncertain significance, of which 84.8% occurred in racial/ethnic minorities.

CONCLUSIONS

In a diverse population of patients diagnosed with young-onset CRC, we observed racial/ethnic differences in referral to and receipt of germline genetic testing. Our findings underscore the importance of universal genetic testing to address racial/ethnic disparities in young-onset CRC.

Trends in the incidence of early-onset colorectal cancer in all 50 United States from 2001 through 2017

BACKGROUND

The rate of change in the incidence of colorectal cancer (CRC) among persons younger than 50 years in the United States appears to vary by demographics, tumor location, and geography. This study analyzed data from all 50 states to examine recent changes in the incidence of CRC among persons younger than 50 years and to identify key subgroups with disproportionate risk.

METHODS

Annual incidence rates for CRC, colon cancer, and rectal cancer in persons aged 20 to 49 years were extracted from the US Cancer Statistics for the period 2001-2017. Secular trends were examined overall and by age group, sex, race/ethnicity, stage, and state. Joinpoint regression was used to compute annual percent changes and average annual percent changes (AAPCs) as well as corresponding 95% confidence intervals (95% CIs).

RESULTS

The incidence of CRC increased by 1.27% (95% CI, 0.95%-1.60%) annually from 2001 to 2012 and by 3.00% (95% CI, 2.06%-3.95%) annually from 2012 to 2017. AAPCs for the period 2001-2017 were higher among persons aged 20 to 24 years (AAPC, 6.62%; 95% CI, 3.86%-9.45%) in comparison with other age groups and higher among non-Hispanic Whites (AAPC, 2.38%; 95% CI, 1.98%-2.79%) in comparison with other racial/ethnic groups. In 2001-2002, only 1 state had an age-standardized incidence rate > 13.0 per 100,000, but this number increased to 32 states by 2016-2017.

CONCLUSIONS

CRC rates among US adults aged 20 to 49 years increased from 2001 to 2017, with the fastest increases observed from 2012 to 2017. Increases were observed among the youngest age groups, among non-Hispanic Whites, and in states in the West, Midwest, and Rocky Mountain regions. Increasing rates across all tumor stages suggest a real increase in CRC incidence.

Young-Onset Colon Cancer and Recurrence Risk by Gene Expression

The incidence and mortality from colorectal cancer in younger adults (younger than 55 years) is increasing. We reviewed the complete database of a gene-expression test, Oncotype DX Colon Recurrence Score test, to determine age-related differences in recurrence score (RS) and single-gene results (7 cancer-related of the 12-gene assay). We included 20 478 stage II and III A and B colon cancer patients submitted to Genomic Health. RS results were grouped by low-, intermediate-, and high-risk groups. Single-gene scores were described using median and interquartile range. Of all patients 72.5% and 72.6% of those younger than 40 years had low-risk RS. Comparing older with younger patients, RS or single-gene expression did not differ by age group or stage. Young-onset colon cancer does not differ by expression of the RS component genes. Most patients with stage II and III colon cancer have low-risk disease as measured by the 12-gene assay, regardless of age.

Disparities in Early-Onset Colorectal Cancer

The incidence and mortality of early-onset colorectal cancer (CRC) are increasing in the United States (US) and worldwide. In the US, there are notable disparities in early-onset CRC burden by race/ethnicity and geography. African Americans, Hispanic/Latinos, and populations residing in specific regions of the Southern U.S. are disproportionately affected with CRC diagnosed at younger ages, while less is known about disparities in other countries. Reasons for these disparities are likely multi-factorial and potentially implicate differences in health determinants including biology/genetics, diet/environment, individual health behaviors, and access to high-quality health services, as well as social and policy factors. This review summarizes current understanding of early-onset CRC disparities and identifies specific research areas that will inform evidence-based interventions at individual, practice, and policy levels to reduce the global burden of this disease.

Risk Factors for Early-Onset Colorectal Cancer

BACKGROUND & AIMS

Colorectal cancer (CRC) incidence and mortality are increasing among persons younger than 50 years old in the United States, but risk factors associated with early-onset CRC (EOCRC) have not been widely studied.

METHODS

We conducted a case-control study of US veterans 18 to 49 years old who underwent colonoscopy examinations from 1999 through 2014. EOCRC cases were identified from a national cancer registry; veterans who were free of CRC at their baseline colonoscopy through 3 years of follow-up were identified as controls. We collected data on age, sex, race/ethnicity, body weight, body mass index (BMI), diabetes, smoking status, and aspirin use. Multivariate-adjusted EOCRC odds were estimated for each factor, with corresponding 95% confidence interval (CI) values.

RESULTS

Our final analysis included 651 EOCRC cases and 67,416 controls. Median age was 45.3 years, and 82.3% were male. Higher proportions of cases were older, male, current smokers, nonaspirin users, and had lower BMIs, compared with controls (P < .05). In adjusted analyses, increasing age and male sex were significantly associated with increased risk of EOCRC, whereas aspirin use and being overweight or obese (relative to normal BMI) were significantly associated with decreased odds of EOCRC. In post hoc analyses, weight loss of 5 kg or more within the 5-year period preceding colonoscopy was associated with higher odds of EOCRC (odds ratio 2.23; 95% CI 1.76-2.83).

CONCLUSIONS

In a case-control study of veterans, we found increasing age and male sex to be significantly associated with increased risk of EOCRC, and aspirin use to be significantly associated with decreased risk; these factors also affect risk for CRC onset after age 50. Weight loss may be an early clinical sign of EOCRC. More intense efforts are required to identify the factors that cause EOCRC and signs that can be used to identify individuals at highest risk.

Colorectal cancer risk based on extended family history and body mass index

Family history and body mass index (BMI) are well-known risk factors for colorectal cancer (CRC), however, their joint effects are not well described. Using linked data for genealogy, self-reported height and weight from driver's licenses, and the Utah Surveillance, Epidemiology, and End-Results cancer registry, we found that an increasing number of first-degree relatives (FDR) with CRC is associated with higher standardized incidence ratio (SIR) for overweight/obese probands but not for under/normal weight probands. For probands with two CRC-affected FDRs, the SIR = 1.91 (95% CI [0.52, 4.89]) for under/normal weight probands and SIR = 4.31 (95% CI [2.46, 7.00]) for overweight/obese probands. In the absence of CRC-affected FDRs, any number of CRC-affected SDRs did not significantly increase CRC risk for under/normal weight probands, but for overweight/obese probands with at least three CRC-affected SDRs the SIR = 2.68 (95% CI [1.29, 4.93]). In the absence of CRC-affected FDRs and SDRs, any number of CRC-affected third-degree relatives (TDRs) did not increase risk in under/normal weight probands, but significantly elevated risk for overweight/obese probands with at least two CRC-affected TDRs was observed; SIR = 1.32 (95% CI [1.04, 1.65]). For nonsyndromic CRC, maximum midlife BMI affects risk based on family history and should be taken into account for CRC risk communication when possible.

Nomogram predicting cancer-specific mortality in early-onset rectal cancer: a competing risk analysis

BACKGROUND

The incidence of rectal cancer has meaningfully increased in young patients. However, quantitative evaluation for the competing data of early-onset rectal cancer is lacking. So, we performed a competing risk analysis to calculate the cumulative incidence of death for patients with early-onset rectal cancer and developed a nomogram to predict the probability of cancer-specific mortality for these patients.

METHODS

We abstracted data of patients with early-onset rectal cancer between 2004 and 2016 by using the Surveillance, Epidemiology, and End Results program database. The cumulative incidence function was used to calculate the crude cancer-specific mortality of early-onset rectal cancer. Fine and Gray's proportional sub-distribution hazard model was adopted to explore the risk factors of cancer-specific death. Then, we establish a nomogram to predict their 3-, 5-, and 10-year probabilities.

RESULTS

We identified 9917 patients with early-onset rectal cancer, and they were randomly divided into training (n = 6941) and validation (n = 2976) cohorts. In the training cohort, the 3-, 5-, and 10-year cumulative incidences of cancer-specific death after diagnosis for early-onset rectal cancer were 11.4%, 19.9%, and 28.8%, respectively. Fine and Gray's model showed that sex, race, marital status, histology, T stage, N stage, M stage, examined lymph nodes, and pretreatment carcinoembryonic antigen were independently associated with cancer-specific mortality. Such factors were selected to develop a prognostic nomogram.

CONCLUSION

The competing risk nomogram has an ideal performance for predictive cancer-specific mortality in early-onset rectal cancer.

Epidemiology and Mechanisms of the Increasing Incidence of Colon and Rectal Cancers in Young Adults

In contrast to the decreasing incidence of colorectal cancer (CRC) in older populations, the incidence has nearly doubled in younger adults since the early 1990s. Approximately 1 in 10 new diagnoses of CRC are now made in individuals 50 years or younger. Patients' risk of CRC has been calculated largely by age and family history, yet 3 of 4 patients with early-onset CRC have no family history of the disease. Rapidly increasing incidence rates in younger people could result from generational differences in diet, environmental exposures, and lifestyle factors. We review epidemiologic trends in CRC, data on genetic and nongenetic risk factors, and new approaches for determining CRC risk. These may identify individuals likely to benefit from early screening and specialized surveillance.

Incidence and characteristics of young-onset colorectal cancer in the United States: An analysis of SEER data collected from 1988 to 2013

BACKGROUND

The incidence of colorectal cancer (CRC) has significantly increased in adults < 50 years old who are below the screening age.

OBJECTIVES

The primary objective was to evaluate the age-standardized incidence (ASI) of young-onset CRC from 1988 to 2013. The secondary objective was to assess factors associated with cancer-specific death (CSD).

METHODS

We accessed data of 64,854 CRC patients (20-49 years old) from the United States Surveillance, Epidemiology, and End Results Program (SEER) database.

RESULTS

A gradual increase in the ASI of CRC in the study population was found: from 3.59/100,000 males in 1988 to 5.21/100,000 males in 2013, and from 3.15/100,000 females in 1988 to 4.45/100,000 females in 2013. ASI adjusted by race revealed a relatively pronounced increase in the white population compared to African American and other races, with an increase from 3.07/100,000 persons in 1988 to 4.79/100,000 persons in 2013. Males had a 19% higher likelihood of CRC-related death compared to females [hazard ratio (HR) = 1.19, 95% confidence interval (CI): 1.16-1.23], and African American had a 1.34-fold higher likelihood of CRC-related death compared to whites (95% CI: 1.28-1.39). CRC-related death was significantly higher in patients with signet ring-cell histology (HR = 1.56, 95% CI: 1.45-1.68), compared to patients with adenocarcinoma. Male gender, and advanced stage predicted a higher likelihood of CRC-related death in African Americans compared to the whole population. Signet ring-cell histology, advanced stage, and advanced grade were significantly associated with CRC-related death in African-American patients.

CONCLUSION

This study corroborates emerging data that the (ASI) of young-onset CRC is increasing. It also identified factors associated with cancer-specific death in this population that may aid in targeting screening strategies for adults < 50 years old.

Colorectal cancer incidence among Hispanics and non-Hispanic Whites in the United States

PURPOSE

Colorectal cancer (CRC) incidence has declined over the past two decades; however, these declines have not occurred equally in all populations. To better understand the impact of CRC among Hispanics, we examined incidence trends by age and Hispanic ethnicity.

METHODS

Using data from the National Program of Cancer Registries and the Surveillance, Epidemiology, and End Results Program, we estimated CRC incidence rates during the period 2001-2014, and across all 50 U.S. states. We estimated incidence rates in younger (age < 50 years) and older (age ≥ 50 years) adults by anatomic subsite and stage at diagnosis, separately for non-Hispanic Whites and Hispanic Whites.

RESULTS

CRC incidence rates declined among older (age ≥ 50 years) Whites and Hispanics, but Whites experienced a greater decline (31% vs. 27% relative decline among Hispanics). In contrast to older adults, there were continued increases in CRC incidence from 2001 to 2014 among younger (age 20-49 years) adults. The largest relative increases in incidence occurred in Hispanics aged 20-29 years (90% vs. 50% relative increase among Whites).

CONCLUSIONS

Opposing incidence trends in younger versus older Hispanics may reflect generational differences in CRC risk by birth cohort, as well as environmental exposures and lifestyle-related risk factors associated with immigration and acculturation.

Cancer screening in the United States, 2018: A review of current American Cancer Society guidelines and current issues in cancer screening

Each year, the American Cancer Society publishes a summary of its guidelines for early cancer detection, data and trends in cancer screening rates from the National Health Interview Survey, and select issues related to cancer screening. In this 2018 update, we also summarize the new American Cancer Society colorectal cancer screening guideline and include a clarification in the language of the 2013 lung cancer screening guideline. CA Cancer J Clin 2018;68:297-316. © 2018 American Cancer Society.

Excessive risk of second primary cancers in young-onset colorectal cancer survivors

With an increasing trend of patients with young-onset colorectal cancer (CRC), risks of second primary cancers (SPCs) among them become a concerning issue. We aimed to define the detailed risk and site-distributed patterns of SPCs in young CRC individuals (age ≤50). A population-based cohort were identified from the Surveillance, Epidemiology, and End Results database between 1973 and 2013. Standardized incidence ratios (SIRs) and absolute excess risk (AER) were calculated to assess the risk for SPCs compared with the general population. A total of 44,106 patients, including 3245 (7.4%) the young and 40,861 (92.6%) the old, developed 50,679 secondary malignancies subsequently. With increased age, the risk of secondary cancers gradually decreased. A significant 44% excess risk of SPCs was observed in the young (SIR = 1.44, AER = 34.23), while a slightly increased risk was noted in the old (SIR = 1.02, AER = 4.29). For young survivors, the small intestine (SIR = 8.49), bile ducts (SIR = 3.77), corpus, and uterus (SIR = 2.45) were the most common sites of SPCs. Significantly, excess SIRs in the young were persisted regardless of other factors. For the young, secondary cancer-related deaths were responsible for 51.2% of overall deaths and secondary stomach, liver and bile, pancreas cancers were top three causes. An excessive risk of SPCs existed in young CRC survivors, and this trend was consistent among different subgroups. We hope our findings may inform future targeted screening strategies among young-onset CRC survivors.

Colorectal Cancer in the Young

PURPOSE OF REVIEW

Colorectal cancer incidence has been rapidly rising in those under the age of 50 over the last 20 years. This paper will review the epidemiology, clinicopathologic, molecular features, proposed risk factors, and prevention/treatment approach for early onset CRC (EOCRC) patients.

RECENT FINDINGS

EOCRC appears to have a different spectrum of clinical, pathologic, and molecular presentation compared to CRC diagnosed in older individuals. EOCRCs are disproportionately located in the distal colon; these patients tend to present with symptoms, and there is a longer interval between symptoms and diagnosis. There may be a distinct molecular signature, including progression through the microsatellite and chromosomal stable (MACS) pathway and LINE-1 hypomethylation for a subset of EOCRCs. The majority of EOCRCs are sporadic without clear risk factors that would have made the patient eligible for earlier screening. There is an acute need for educational efforts aimed at both providers and patients to raise awareness about CRC in the young. Improving adherence to screening in young patients eligible for screening and emphasizing early evaluation of symptoms are important steps to decreasing the burden of CRC in younger patients. Modeling and empiric data are needed to determine whether our current screening approach should be modified and whether causation and treatment options may be different in a molecular subset EOCRCs.