[Site-specific colorectal cancer; how is it different?]

Area of Science:

• Oncology
• Gastroenterology
• Cancer Research

Context:

• Colorectal cancer (CRC) presents significant differences between proximal (right-sided colon cancer, RCC) and distal (left-sided colon cancer, LCC) disease.
• RCC shows unique epidemiological patterns, including higher prevalence in women and older patients, with notable age disparities compared to LCC.
• Colonoscopy offers less protection against RCC, highlighting a critical clinical concern.

Purpose:

• To challenge the traditional dichotomous view of the colon in CRC.
• To propose a shift towards a colorectal continuum model for understanding CRC.
• To advocate for tailored preventive and therapeutic strategies based on this new model.

Summary:

• For decades, the left and right colon have been viewed as distinct entities in CRC based on molecular, histopathological, epidemiologic, and clinical data.
• Recent evolutionary data suggest a linear progression from the rectum to the ascending colon, supporting a colorectal continuum model over the traditional two-colon concept.
• This continuum hypothesis encompasses molecular features and site-specific clinicopathological differences, moving beyond a simple right-left dichotomy.

Impact:

• Facilitates a deeper understanding of the complex etiology of colorectal carcinogenesis.
• Enables the development of personalized preventive measures and therapeutic interventions for CRC.
• Supports the implementation of individualized CRC screening programs for improved patient outcomes.