Colorectal Cancer Awareness Month: Overcoming Barriers to Early Detection

Charles Meakin, MD, MHA

The Current Colorectal Cancer (CRC) Landscape

March is CRC Awareness Month. CRC is currently the third most common cancer diagnosed in both men and women and the third most common cause of cancer-related deaths in the United States.¹ Further, CRC is estimated to be the fourth most commonly diagnosed cancer in the United States among men and women aged 30 to 39. More than 151,000 new cases of colon and rectal cancer are estimated for 2022.²

There are several risk factors for CRC, including being older, having a personal or family history of colorectal polyps or cancer, Lynch syndrome or familial polyposis syndrome, inflammatory bowel disease, type 2 diabetes,³ smoking, and alcohol use.⁴ African Americans have the highest incidence and mortality rates of CRC of any ethnic group in the United States and are more often diagnosed with CRC at an earlier age and with more advanced disease.⁵

With early detection and intervention, CRC may be one of the most preventable types of cancer. Early localized CRC has a 91% 5-year survival.² If the cancer has metastasized at the time of diagnosis, the 5-year survival rate is 15%. However, about a third of people who are eligible to get screened for CRC are not doing so,⁶ even though there are now multiple screening options available. The pandemic has worsened the situation; there was an 80% decline in colorectal screenings from March to May 2020 because of COVID-19.⁷

It is well known by physicians that the traditional method to screen for CRC is through colonoscopy, beginning at age 45, if the person has no family history of CRC, polyps, inflammatory bowel disease, or certain genetic syndromes.⁸ Other methods of screening include stool and imaging tests, such as fecal occult blood tests, sigmoidoscopies, digital rectal exams, and liquid biopsies.⁹

Innovations in CRC Detection

The connection between early detection of CRC and increased survival rates is clear. However, challenges remain in increasing both disease awareness and screening. Liquid biopsies are a more recent innovation in CRC detection that may be key to increasing screening rates. These tests only require a person to have a single sample of blood taken, which can be used to screen for molecular signatures of CRC. Current liquid biopsies for CRC detection may analyze circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), circulating tumor RNA, and/or exosomes in peripheral blood.¹⁰ In addition to CTCs, ctDNA and circulating free DNA derived from tumors, it has also been demonstrated that RNA profiles generated from circulating blood can be used to identify patients with a number of conditions.^11,12 These minimally invasive and low-risk blood tests can sometimes find cancers before standard methods, informing people if they should seek further evaluation with colonoscopy or other diagnostics.

Clinical research has shown that liquid biopsies can provide information on the molecular status of CRC at any disease stage of the tumor. These tests may also help oncologists in treatment guidance, specifically in identifying abnormalities leading to cancer initiation, treatment decisions, and predicting patient response to treatment.¹³

One important benefit to liquid biopsies in CRC screening is increasing adherence—many people prefer getting a blood test as opposed to more invasive diagnostics. A study published in Cancer Management and Research in 2020 found that while people had limited understanding of cancer-specific blood-based biomarkers, 90% preferred liquid over tissue biopsies to assess biomarkers.¹⁴

Detecting CRC at an early stage based on liquid biopsy can be an effective strategy in reducing patient mortality and in increasing overall survival in affected patients.¹³ Although there are currently no liquid biopsies for CRC that are FDA-approved, various liquid biopsies are available and offer a promising screening option as a first step for many patients.

Improving Patient Screening and Follow-Up Care

More accessible testing options alone are often not enough to increase colorectal screening rates. A concerted effort is needed to ensure eligible patients are screened for CRC and receive appropriate evaluation and intervention. Screening for CRC is a multistep process that requires communication and coordination across different levels of the healthcare system, including the individual, clinical team, healthcare institution, and community setting.¹⁵

Physician recommendation of CRC screening is a critical facilitator of screening completion. If physicians provide people with a choice of screening options, that may also increase their likelihood of getting screened. In a study evaluating the effectiveness of both physician and patient intervention in relation to CRC screenings, a physician-patient intervention—one where patients were shown an educational video with information on CRC and the importance of screening and screening options prior to an appointment with their physician—increased rates of screening discussions. However, the same study noted that these physician-patient discussions overwhelmingly focused solely on colonoscopy. There is evidence that limiting physician recommendation to colonoscopy can result in lower CRC screening completion rates compared with providing a recommendation for fecal occult blood test or a choice between the 2.¹⁶ This further underscores the importance of providing patients with a variety of options when discussing CRC screening.

Beyond this, 2 of the most effective interventions to increase screening of CRC are outreach and navigation. Outreach is the active dissemination of screening outside of the primary care setting. This can also include contacting patients at home to schedule screening procedures. Navigation is when trained personnel such as nurses, laypeople, or peers assist the individual through the process of screening, including performing the test, obtaining results, and undergoing a colonoscopy or further testing if the initial screening indicates the presence of molecular signatures of CRC. Outreach and navigation, combined with other interventions, can further increase screening uptake.¹⁵

Additional studies are needed on successful interventions to increase adherence to follow-up colonoscopy after a positive screening. Failing to complete a diagnostic colonoscopy increases mortality up to threefold;¹⁷ however, rates of follow-up colonoscopy for abnormal screening tests vary from 30% to 82%.¹⁸

Providing patients with clinical support through screening, diagnosis, treatment, and beyond is critical for the early detection and intervention of this cancer. Increasing awareness and education around the risks of CRC and providing multiple options for screening with innovations such as liquid biopsies can help overcome barriers to early CRC detection. The hope is that ongoing and expanded efforts to detect and treat CRC at earlier stages will improve outcomes for people impacted by this disease.

_References:

_{1. Key statistics for colorectal cancer. American Cancer Society. Updated January 12, 2022. Accessed March 7, 2022. https://bit.ly/3IaCSbk}

_{2. Colorectal cancer: statistics. ASCO Cancer.Net. Updated February 2022. Accessed March 7, 2022. https://bit.ly/3t8GB4S}

_{3. Ma Y, Yang W, Song M, et al. Type 2 diabetes and risk of colorectal cancer in two large U.S. prospective cohorts. Br J Cancer. 2018;119(11):1436-1442. doi:10.1038/s41416-018-0314-4}

_{4. Colorectal cancer risk factors. American Cancer Society. Updated June 29, 2020. Accessed March 7, 2022. https://bit.ly/3IclqDl}

_{5. Augustus GJ, Ellis NA. Colorectal cancer disparity in African Americans: risk factors and carcinogenic mechanisms. Am J Pathol. 2018;188(2):291-303. doi:10.1016/j.ajpath.2017.07.023}

_{6. Colorectal cancer screening. Centers for Disease Control and Prevention. Updated 2020. Accessed March 7, 2022. https://bit.ly/3CJ4J15}

_{7. AACR report on the impact for COVID-19 on cancer research and patient care. American Association for Cancer Research. Published on February 9, 2022. Accessed March 7, 2022. https://bit.ly/3IbVdVd}

_{8. Colorectal (colon) cancer: What should I know about screening? Centers for Disease Control and Prevention. Updated February 17, 2022. Accessed March 7, 2022. https://bit.ly/3q3QNtx}

_{9. Colorectal cancer screening (PDQ®)–health professional version. NIH National Cancer Institute. Updated June 30, 2021. Accessed March 7, 2022. https://bit.ly/36itHZ9}

_{10. Ding Y, Li W, Wang K, Xu C, Hao M, Ding L. Perspectives of the application of liquid biopsy in colorectal cancer. Biomed Res Int. 2020;2020:6843180. doi:10.1155/2020/6843180}

_{11. Dempsey A, Howard Tripp J, Chao S et al. Aristotle: A single blood test for pan-cancer screening. J Clin Oncol. 2020;38:(suppl 15). doi:10.1200/JCO.2020.38.15_suppl.e15037}

_{12. Olmos D, Brewer D, Clark J, et al. Prognostic value of blood mRNA expression signatures in castration-resistant prostate cancer: a prospective, two-stage study. Lancet Oncol. 2012;13(11):1114-1124. doi:10.1016/S1470-2045(12)70372-8}

_{13. Mazouji O, Ouhajjou A, Incitti R, Mansour H. Updates on clinical use of liquid biopsy in colorectal cancer screening, diagnosis, follow-up, and treatment guidance. Front Cell Dev Biol. 2021;9:660924. doi:10.3389/fcell.2021.660924}

_{14. Lee MJ, Hueniken K, Kuehne N, et al. Cancer patient-reported preferences and knowledge for liquid biopsies and blood biomarkers at a comprehensive cancer center. Cancer Manag Res. 2020;12:1163-1173. doi:10.2147/CMAR.S235777}

_{15. Inadomi JM, Issaka RB, Green BB. What multilevel interventions do we need to increase the colorectal cancer screening rate to 80%? Clin Gastroenterol Hepatol. 2021;19(4):633-645. doi:10.1016/j.cgh.2019.12.016}

_{16. Dolan NC, Ramirez-Zohfeld V, Rademaker AW, et al. The effectiveness of a physician-only and physician-patient intervention on colorectal cancer screening discussions between providers and African American and Latino patients. J Gen Intern Med. 2015;30(12):1780-1787. doi:10.1007/s11606-015-3381-8}

_{17. Lee YC, Fann JC, Chiang TH, et al. Time to colonoscopy and risk of colorectal cancer in patients with positive results from fecal immunochemical tests. Clin Gastroenterol Hepatol. 2019;17(7):1332-1340.e3. doi:10.1016/j.cgh.2018.10.041}

_{18. Issaka RB, Avila P, Whitaker E, Bent S, Somsouk M. Population health interventions to improve colorectal cancer screening by fecal immunochemical tests: A systematic review. Prev Med. 2019;118:113-121. doi:10.1016/j.ypmed.2018.10.021}