March is National Colorectal Cancer Awareness Month – an ideal time to educate and inform the population about the trends of colorectal cancer (CRC) incidence and mortality in the U.S. New data released by the American Cancer Society predict that of the 153,020 new CRC cases predicted in 2023, 13% (nearly 20,000) will be in individuals younger than 50 years (early-onset CRC). This means improving screening rates in the 45-49 population is even more important. Also important is  improving awareness of the signs and symptoms of CRC.

On March 1, 2023, the first day of Colorectal Cancer Awareness Month, the American Cancer Society released some alarming new statistics regarding early-onset colorectal cancer (CRC) diagnoses: in the U.S. population, people are increasingly being diagnosed with CRC at a younger age and with more advanced disease stage. Advanced-stage CRC diagnoses have risen by eight percent in the past two decades. Additionally, early onset diagnoses rose from one in ten individuals in 1995 to one in five in 2019. While CRC in the general population is declining, rates in younger people are on the rise. 

The complete report contains CRC incidence, mortality, and screening prevalence data that were derived from multiple national databases, including: 

  • National Cancer Institute
    • Surveillance, Epidemiology, and End Results (SEER) program
  • Center for Disease Control
    • National Program of Cancer Registries
    • Behavioral Risk Factor Surveillance System
    • National Center for Health Statistics
      • National Health Interview Survey
  • North American Association of Central Cancer Registries

The report projects that of the 153,020 expected CRC cases in 2023, 13% (nearly 20,000) will be in individuals younger than 50. Seven percent of projected CRC mortality will also be in individuals younger than 50. CRC mortality in individuals under the age of 50 is also on the rise, as the mortality rate in this population has risen one percent every year since 2004. 

Rising cancer trends in the younger U.S. population point to increased exposures to causal agents, and indicate the need for research that identifies newfound risk factors. The data from this report highlights the growing concern that is early-onset CRC incidence and mortality, pointing to a portion of the population that will need more research and funding in the CRC space. 

Efforts to improve screening rates at a health care center in New York City

Racial Disparity in CRC Incidence and Mortality

Racial disparities continue to exist in CRC incidence, mortality, and survival rates. Both incidence and mortality rates in the U.S. are highest among American Indian/Alaskan Native and non-Hispanic Black individuals. Alaskan Native individuals face the highest burden of CRC incidence than any other group (88.5 per 100,000 individuals). Risk factors that contribute to disparities in the Alaskan Native population are likely a combination of environmental factors (low sun exposure, diet low in fiber, smoking, and obesity) and low access to colon health care services. Alaskan Native individuals have the lowest screening rate in the U.S. 

Black Americans are more likely to be diagnosed with metastatic CRC than any other racial or ethnic group in the nation. Black patients also experience significant disparities in care, and are 21% less likely to receive colon cancer surgery and 28% less likely to receive rectal cancer surgery. Additionally, Black patients are more likely to develop right-sided tumors, which are correlated with a poorer prognosis. 

These updated data from the American Cancer Society point to the need for future research in early-onset incidence, racial disparities, and general risk factors for CRC. Scientists should aim to identify newfound risk factors that are contributing to the trend of CRC diagnoses under 50, and to identify factors specific to high-risk racial and ethnic groups as well.

You can learn more about the signs and symptoms of colorectal cancer on this page.

 

Emma Edwards is a Colorectal Cancer Prevention Intern with the Colon Cancer Foundation.

Biomarkers allow scientists to identify certain diseases from a simple biological sample like urine, breath, or even feces. Volatile organic compounds (VOCs) are the byproducts of metabolic processes associated with cancer, necrosis, or other metabolic changes. Scientists have now identified a new biomarker associated with both colorectal cancer (CRC) and adenoma (noncancerous tumor) that can be used for detection.

The cross-sectional study included 24 newly diagnosed CRC patients, 24 patients with adenomas, and 32 individuals who had a normal colonoscopy between July 2017 and July 2020. Individuals with normal colonoscopies and those with adenomas had fecal samples collected before and after their colonoscopy. Samples were requested from CRC patients 3-4 weeks after diagnosis and before treatment.

Of the 60 VOCs identified, only 3 showed different peaks between CRC and the control groups: p-cresol, 1H-indole, and 3(4H)-DBZ. There was a statistically significant difference between p-cresol peak values in each group with the greatest difference between CRC and the control group. This was also the same for 3(4H)-DBZ. However, 1H-indole did not have a significant difference between the study groups.

After adjusting for sex, age, and body-mass index (BMI), the researchers found that only CRC was associated with increased p-cresol and 3(4H)-DBZ, and p-cresol seemed to be the best possible predictor of CRC. A combination of p-cresol and 3(4H)-DBZ “is also optimistic as a combined biomarker” according to the study authors.

p-cresol was also abundant among patients with adenomas compared to healthy controls. This was also the case after adjusting for age, sex, and BMI.

Although more work needs to be done to determine what processes produce these VOCs, these associations can launch a new set of studies to confirm its use in a clinical setting. Other biomarkers have been identified that can  predict CRC occurrence and mortality. Overall, the ability to better detect CRC and precancerous adenomas play an important role in global prevention efforts. A better understanding of the biological processes involved in these diseases is crucial for those efforts to be successful.

 

Kaylinn Escobar is a Colorectal Cancer Prevention Intern with the Colon Cancer Foundation.

Photo credit: National Cancer Institute on Unsplash

Interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-a) are inflammatory biomarkers that are capable of activating Janus kinase signaling pathways, nuclear factor signaling pathways, and C-reactive protein (CRP) transcription. CRP tests are commonly used in cancer care to predict prognosis, as activation of the Janus kinase and nuclear factor signaling pathways can  aid in tumor expansion and metastasis. Additionally, high-sensitivity CRP tests (hsCRP) are able to identify small amounts of CRP in blood samples.

One recent study assessed the association between these inflammatory biomarkers (IL-6, TNF-a, and hsCRP) with CRC recurrence and mortality in 1,494 stage III colorectal cancer (CRC) patients. This was the largest study assessing the relationship between these inflammatory biomarkers and CRC survival as of yet. 

While the study recruited a diverse sample of individuals, the final sample was overwhelmingly White (82.3%) and non-Hispanic (94.5%). Future studies should prioritize racial diversity to more accurately assess this association, as racial disparities exist in CRC diagnoses and outcomes. 

Researchers collected plasma samples from participants 3-8 weeks following their surgery but prior to chemotherapy. These plasma samples were then analyzed for IL-6, TNF-a, and hsCRP. The primary study outcome was disease-free survival and secondary outcomes were recurrence-free survival and overall survival. Participants who had higher concentrations of IL-6, TNF-a, and hsCRP were more likely to have CRC recurrence. High levels of these biomarkers were also found to be associated with an increased risk of mortality.

This study reveals that there is a significant association between inflammation following stage III diagnosis and poor CRC outcomes. Clinicians can utilize this information to better monitor their patients and improve CRC outcomes with evidence-based treatment solutions.

Emma Edwards is a Colorectal Cancer Prevention Intern with the Colon Cancer Foundation.

Social media is a powerful tool that can be used to spread important information at unprecedented speed. Many users of TikTok, the short-form video app that has taken the world by storm, have utilized the platform to share their experiences with colonoscopy screenings. Users upload “vlogs” (video blogs) to the platform that document their entire experience in detail and talk to their audience throughout the process. While this may seem like oversharing, the authentic nature of these vlogs has grown popular on TikTok, as videos that do well on the platform often contain genuine and unfiltered content. 

One example of this is @lucindabinney‘s three-part video series:

@lucindabinney

Colonoscopy Vloggy Part 1 🧻🧻🧻 #colonoscopy #gutissues

♬ Just a Cloud Away – Pharrell Williams

 

@lucindabinney

Colonoscopy Prep Part 2 🧻🧻🧻 #colonoscopy #gutissues

♬ original sound – lucinda

 

@lucindabinney

Colonoscopy Part 3 🧻🧻🚽🚽 #colonoscopy #guthealth #gutissues

♬ original sound – lucinda

Lucinda Binney walks her audience through her experience with colonoscopy prep in a humorous, unfiltered manner that is popular among many lifestyle influencers. She details her experience with a liquid diet (she includes jello) and the standard practice of taking laxatives to prepare her colon for screening. Through this three-part vlog, she demystifies this screening procedure for her 340,000 followers, coming clean about both her anxiety surrounding the experience and her surprise that the laxative drink didn’t taste as bad as she thought. 

While it is uncommon for people in their 20s to receive colonoscopies, as the U.S. Preventive Services Task Force does not recommend them until age 45 (a recent change from the previous age 50 guideline), individuals at high risk for colorectal cancer (CRC) may benefit from receiving a screening. CRC rates in the younger population have risen dramatically in the past two decades, with incidence jumping from 2.7 people per 100,000 in the year 2000 to 5.0 per 100,000 in 2019 in the 15-to-39 age group. While these incidence rates are still not high enough to warrant routine screenings in the general young adult population, they help make the case for increased screenings among those at higher-risk. 

Haddon Pantel, MD, of Yale Medicine recommends that people in their 20s and 30s seek CRC screening if they experience any sudden changes in bowel movements, rectal bleeding, or any weight loss, abdominal pain, or appetite changes that are not otherwise explained. For more information about the signs of CRC, check out this resource

Emma Edwards is a Colon Cancer Prevention Intern with the Colon Cancer Foundation.

Colorectal cancer (CRC) is a leading cause of cancer-related deaths in the U.S., and the incidence of early-age onset CRC (EAO-CRC)—when the disease is diagnosed in those younger than 50 years—is rising. In the Black population, EAO-CRC makes up nearly 10% of all new diagnoses. The incidence of EAO-CRC in the Black population (8.4 cases per 100,000 people in 2019) is slightly lower than that of the White population (8.9 cases per 100,000 people in 2019), but this is reversed when it comes to the mortality rate. The mortality rate of EAO-CRC in the Black population is 2.4 deaths per 100,000 people, while it is 1.8 deaths per 100,000 people in the White population. Between 2015-2019, 5,329 new EAO-CRC cases were diagnosed among Black Americans.

Studies have shown that Black individuals are more likely to be diagnosed with EAO-CRC at a younger age and a more advanced stage than White individuals: 22% of White Americans receive a metastatic diagnosis compared with 26% of Black Americans. 

 

 

While additional research is needed to discern the higher incidence of EAO-CRC in the Black population, certain socioeconomic and environmental factors likely play an important role. These include limited access to proper healthcare services, the prevalence of food deserts leading to poor nutrition, and living in areas with high pollution rates. Additional resources to support research, prevention, and treatment efforts of EAO-CRC in this population are critical.  

Empowering the population via awareness and education campaigns around the early warning signs of CRC and the importance of screening in the Black community would also go a long way. Early warning signs of CRC include changes in bowel movements, blood in stool, unexpected weight loss, and continuous abdominal discomfort. If you are experiencing these symptoms, speak with your doctor. 

Additional information on prevention, symptoms, and diagnosis of CRC can be found under ‘Resources’ on the Colon Cancer Foundation’s website.

 

Emma Edwards is a Colorectal Cancer Prevention Intern with the Colon Cancer Foundation.

Over 30% of patients with stage II or stage III colorectal cancer (CRC) and 60-70% of patients who undergo oligometastatic resection experience cancer recurrence. Stage II or III CRC is usually treated with surgery followed by adjuvant chemotherapy (ACT). However, patients with clinical and pathological risk factors only see a 10-15% decrease in cancer recurrence with standard ACT. 

Now, a new study proposes using circulating tumor DNA (ctDNA) as a predictive biomarker to guide chemotherapy treatment decisions in CRC patients. 

ctDNA is a minimally invasive biomarker that can help oncologists measure disease status and progression during cancer therapy, including the detection of molecular residual disease (MRD). In this study, researchers evaluated whether ctDNA following surgery could predict disease recurrence in early-stage CRC. 

The study enrolled 1,563 patients with:

  • Stage II or III CRC 
  • Surgically resectable stage IV CRC 
  • Recurrent CRC were prospectively enrolled in the study 

Blood samples were collected before and at predetermined time intervals after surgery (up to 18 months), and imaging was performed every six months until 18 months after surgery. MRD, defined as ctDNA positivity after surgery or therapy, is strongly associated with poor prognosis in patients with surgically resectable CRC. Of the 1,039 patients included in the ctDNA analysis, 18.0% were ctDNA positive four weeks after surgery.

Researchers discovered that patients with high-risk stage II, stage III, and stage IV CRC, who were ctDNA-positive four weeks after surgery, benefited from ACT. ctDNA was identified as the most significant risk factor for CRC recurrence in these patients, and ctDNA positivity is an important predictor of ACT benefit. 

Regardless of the pathological stage of CRC, patients with a higher risk of recurrence based on ctDNA status may benefit from ACT, while those with negative ctDNA status may be able to avoid unnecessary ACT. These findings can guide clinicians in making evidence-based treatment decisions for CRC patients.

 

Sahar Alam is a Colorectal Cancer Prevention Intern with the Colon Cancer Foundation.

Cancer screening remains a powerful tool. Even limited screening has long-term benefits compared to no screening  and can lower the risk of cancer and related deaths. A recent study by researchers at the CDC compared data on adults who reported they had not received a colorectal cancer (CRC) screening test between 2012 and 2020 using information from the Behavioral Risk Factor Surveillance System (BRFSS). The study identified various trends, most notably that 22 states did not meet the CDC’s Healthy People 2020 goal of 70.5% adults screened for CRC.

The sample was limited to adults aged 50 to 75 years, with up to date screenings defined as one of the following:

  • Home stool-blood test within the past year
  • Sigmoidoscopy within five years with fecal occult blood test or within one year with fecal immunochemical test
  • Colonoscopy within ten years

The ‘never screened’ numbers were a composite of those who answered no to being screened or those who were not up to date. Those who declined to answer or reported uncertainty were excluded. Overall, the study identified:

  • A 5.8% decrease in unscreened adults between 2012 and 2020 
  • States with the largest improvements were also those with the largest unscreened population in 2012 

 

Despite these improvements, CRC screening goals have yet to be met and may be difficult to meet with the new Healthy People 2030 standards. The target of 74.4% screened may have been a challenge to meet, possibly further exacerbated by the COVID-19 pandemic.

Researchers noted that including just two more questions on the BRFSS in 2020, the percentage of up to date screenings increased to 71.6%. These two questions enquired about:

  • Stool DNA testing
  • Computerized tomographic colonography

It is important to note that the National Colorectal Cancer Roundtable—a membership organization established by the CDC and the American Cancer Society—has set its goal to 80% screening rates across the country.

Study authors recognized recall bias and an inability to distinguish between screening versus diagnostic tests as major study limitations. Additionally, social desirability bias and a low response rate may have also affected the results. However, financial factors and health disparities may also describe the differences between states.

Following implementation of the Affordable Care Act, researchers at the American Cancer Society found that CRC screening among low-income adults across the U.S. increased by up to 8%, with the greatest increases observed in early Medicaid expansion states. They also noted that a majority of those who were never screened also lived in a state without expansion (South Dakota). 

Nonfinancial factors such as health disparities were studied in a mixed-methods analysis conducted at the Virginia Commonwealth University’s School of Medicine. Here, researchers noted that participants of gender-specific and race-specific focus groups brought forth nuanced concerns regarding screening. This included lack of awareness of both the disease and the screening, lack of physician recommendation that is clear and rational, and fear of being diagnosed and complications associated with testing. These concerns, if unaddressed, may limit others from seeking out CRC screening.

To read more about the Healthy People 2030 CRC screening standards and the current progress, visit Healthy People 2030.

 

Kaylinn Escobar is a Colorectal Cancer Prevention Intern with the Colon Cancer Foundation. 

Mismatch repair–deficient (dMMR) or microsatellite instability–high (MSI-H) colorectal cancer (CRC) is an advanced form of CRC that is highly responsive to treatment with immunotherapy, especially PD-1 inhibitors. Preliminary research results demonstrate that PD-1 inhibitors are significantly effective cancer treatments, with high response rates and sustained progression-free survival. 

A new study investigated the treatment impact of neoadjuvant PD-1 inhibitors on the long-term survival of dMMR CRC patients. The study found that PD-1 inhibitor treatment before surgery was significantly effective among patients with dMMR/MSI-H CRC.

Seventy-three patients with dMMR/MSI-H CRC who had previously been treated with PD-1 inhibitors were included in a retrospective review. The most common locations of primary tumors were in the rectum (24.7%) and ascending colon (24.7%). 79.5% of patients were treated with PD-1 inhibitor alone. The study found:

  • Nearly all patients involved in the study benefited from neoadjuvant PD-1 inhibitors, with 25% experiencing complete response.
  • 84.9% of patients experienced an objective response, with 61.6% achieving a partial response. 
  • The two-year tumor-specific overall survival and disease-free survival rates for patients who underwent surgery after PD-1 blockade were both 100%.

These findings are promising for patients with nonmetastatic dMMR/MSI-H CRC, including those with locally advanced disease. Dustin A. Deming, MD, University of Wisconsin Carbone Cancer Center, stated in an NCCN newsletter, “The treatment of mismatch repair deficient locally-advanced colorectal cancer is a highly active area of research. This retrospective analysis highlights the potential for significant treatment responses with limited toxicities for these patients treated with immune checkpoint inhibitors. It will be exciting to see how these results, and other completed and ongoing studies, will be utilized to incorporate anti-PD1 treatments into the standard-of-care for locally-advanced colorectal cancers.”

To read more about types of immunotherapy drugs and their impact on cancer care, visit Understanding Cancer Immunotherapy Research

 

Sahar Alam is a Colorectal Cancer Prevention Intern with the Colon Cancer Foundation.

Colorectal cancer (CRC), the third most common cancer and the third leading cause of cancer-related deaths in the U.S., is preventable with regular screening. In addition to routine screening, other modifiable risk factors, such as diet, play an important role in lowering the risk of CRC. For example, red and processed meats are associated with an increased risk for CRC, while diets rich in dietary fiber reduce the risk of CRC. 

A recent prospective cohort study discovered that plant-based diets rich in healthy plant foods were associated with a lower risk of CRC in men, and varied based on race, ethnicity, and tumor location. These findings signify the importance of incorporating healthy plant foods into diets and reducing meat consumption to lower the risk of CRC. 

The multiethnic cohort study included 79,952 men and 93,475 women. Three plant-based diet scores were investigated to determine the incidence of invasive CRC:

  • Overall plant-based diet index (PDI)
  • Healthful plant-based diet index (hPDI)
  • Unhealthful plant-based diet index (uPDI)

The participants completed a food frequency questionnaire with over 180 food items. PDI, hPDI, and uPDI were calculated based on scoring methods and defined food groups that included:

  • Healthy plant foods, such as whole grains, fruits, vegetables, vegetable oils, nuts, legumes, tea, and coffee.
  • Less healthy plant foods, such as refined grains, fruit juices, potatoes, and added sugars.
  • Animal foods, such as animal fat, dairy, eggs, fish and seafood, and meat. 

Each food group was associated with specific scores. 

  • High PDI scores demonstrated greater consumption of all types of plant foods. 
  • High hPDI foods showed greater consumption of healthy plant foods and lower consumption of less healthy plant foods. 
  • Higher uPDI scores demonstrated lower consumption of healthy plant foods and greater consumption of less healthy plant foods. 

The study found that a plant-based diet that includes natural, rather than processed, plant-based foods is associated with a reduced risk of CRC in men. For women, however, none of the plant-based diets were significantly associated with CRC risk. For both men and women, the average scores of PDI and hPDI were highest among Japanese Americans and lowest among Native Hawaiians. The mean uPDI was highest in Native Hawaiian men and lowest in African American men and white women. Men with higher scores for PDI and hPDI had a 24% and 21% lower risk of CRC than men with lower scores for those diets, respectively. Furthermore, no significant association was found between risk for CRC and uPDI for men.

These analyses highlight the potential significance of plant-based diets in preventing CRC and suggest that the benefits of plant-based diets can vary based on sex and race/ethnicity. The findings underscore the importance of increasing healthy and less-processed plant foods in our diet and reducing meat consumption to lower the risk of CRC.

 

Sahar Alam is a Colorectal Cancer Prevention Intern with the Colon Cancer Foundation.