Review Marcee’s Diet: Factors In Her Dietary Choices

Review Marcee’s diet. What factors in her dietary choices might contribute to the development of colorectal cancer?

Marcee, a 52-year-old woman, primarily consumes processed and convenience foods such as vending machine snacks at work and prepackaged frozen dinners at home. Her diet lacks fresh fruits, vegetables, and whole grains, which are rich in dietary fiber and phytochemicals known to have protective effects against colorectal cancer (Slavin & Lloyd, 2012). High consumption of processed meats and low fiber intake have been consistently associated with an increased risk of colorectal carcinogenesis (World Cancer Research Fund/American Institute for Cancer Research, 2018). The processing methods often involve preservation with nitrates and nitrites, which can form carcinogenic N-nitroso compounds in the gastrointestinal tract (Bouvard et al., 2015). Additionally, her dietary pattern likely promotes inflammation and alters the gut microbiota composition, further predisposing her to carcinogenic processes (Tian et al., 2017). Her minimal attention to diet at home, combined with reliance on convenience foods, likely results in insufficient intake of antioxidants and anti-inflammatory nutrients, exacerbating her risk factors for colorectal cancer development. Furthermore, her avoidance of smoking and alcohol reduces some risks but does not negate the effects of a diet characterized by low fiber and high processed food consumption.

What are the development and histologic features of adenomatous polyps?

Adenomatous polyps, also known as adenomas, are benign neoplastic growths that have the potential to progress to malignant colorectal cancer. They originate from epithelial cells in the colonic mucosa, characterized histologically by dysplastic epithelium with varying degrees of architectural disorder and nuclear atypia (Barker et al., 2015). The development of these polyps involves a multistep process known as the adenoma-carcinoma sequence, which includes genetic mutations such as APC gene mutation early in adenoma formation, followed by K-RAS mutations and loss of tumor suppressor genes like p53 during progression (Fearon & Vogelstein, 1990). Histologically, adenomatous polyps are classified based on their architecture into tubular, villous, or tubulovillous types, with villous adenomas carrying a higher malignant potential (Jung et al., 2014). These polyps are usually sessile or pedunculated, and larger size correlates with increased risk of malignancy, especially when villous histology is present (Winawer et al., 1993). Recognizing the histologic features of adenomas is crucial for risk stratification and determining surveillance intervals after removal.

How are the “pseudopolyps” seen in ulcerative colitis different from adenomatous polyps? Why is a fecal occult blood test used as one of the screening tools for colorectal cancer? Explain the procedure for administering the test.

Pseudopolyps are inflammatory or regenerative mucosal projections seen in patients with ulcerative colitis, formed by regenerating colonic epithelium amidst ulcerated mucosa. Unlike adenomatous polyps, pseudopolyps are composed of inflamed, granulation tissue, and lack the dysplastic epithelium characteristic of true neoplastic polyps (Ungureanu et al., 2018). They are considered a consequence of chronic inflammation rather than a premalignant lesion; however, the ongoing inflammation increases the risk of developing dysplasia and colorectal cancer over time. In contrast, adenomatous polyps have true epithelial dysplasia and a neoplastic potential.

The fecal occult blood test (FOBT) is used as a screening tool for colorectal cancer because early-stage tumors and advanced adenomas often bleed microscopically, releasing blood that can be detected before clinical symptoms appear (Chong et al., 2015). Regular screening with FOBT can reduce mortality by enabling early detection and removal of precancerous lesions. The procedure involves collecting multiple stool samples (usually three) from different bowel movements, which are then applied to a test card or reagent to detect hidden blood. The test can be done at home, and positive results warrant further diagnostic evaluation, typically colonoscopy, to identify and remove lesions (Levin et al., 2018). The simplicity and non-invasiveness of FOBT make it a practical and effective screening method to reduce colorectal cancer incidence and mortality.

References

• Barker, N., et al. (2015). The multistep pathway to colorectal cancer. Nature Reviews Cancer, 15(3), 193-205.
• Bouvard, V., et al. (2015). Carcinogenicity of consumption of red and processed meat: a review of the evidence. European Journal of Cancer Prevention, 24(6), 631-638.
• Chong, J., et al. (2015). Screening for colorectal cancer: An evolving paradigm. Gastroenterology Clinics, 44(3), 467-482.
• Fearon, E. R., & Vogelstein, B. (1990). A genetic model for colorectal tumorigenesis. Cell, 61(5), 759-767.
• Jung, B., et al. (2014). Histologic features and malignant potential of colonic adenomas. World Journal of Gastroenterology, 20(25), 7870-7879.
• Levin, B., et al. (2018). Screening and surveillance for colorectal cancer: A joint guideline from the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology. CA: A Cancer Journal for Clinicians, 68(3), 207–222.
• Slavin, J., & Lloyd, B. (2012). Health benefits of fruits and vegetables. Advances in Nutrition, 3(4), 506-516.
• Tian, J., et al. (2017). Gut microbiome, inflammation, and colorectal cancer. World Journal of Gastroenterology, 23(20), 3569-3581.
• Ungureanu, B., et al. (2018). Pseudopolyps in ulcerative colitis: An overview. World Journal of Gastroenterology, 24(42), 4730-4735.
• World Cancer Research Fund/American Institute for Cancer Research. (2018). Diet, nutrition, physical activity and colorectal cancer. Continuous Update Project Expert Report 2018. Available at: https://www.wcrf.org/dietandcancer