COLORECTAL CANCER (Syllabus: GS Paper 3 – Sci and Tech)

Context: In a new study, a group of researchers from the Fred Hutchinson Cancer Center in the U.S. has identified a distinct subtype of the bacterium that’s found in relatively greater quantities in colorectal cancer (CRC) tumours.

Colorectal Cancer (CRC)

• Definition: Colorectal cancer is a disorder affecting the colon or rectum caused by abnormal growth of glandular cells.
• Types of CRC: There are three main types: sporadic, hereditary, and colitis-associated.
• Symptoms: Hemorrhoids, diarrhea, infection, or irritable bowel syndrome.
• Risk Factors: Both environmental and genetic factors play a role, with increased risk for those with long-standing ulcerative colitis or Crohn's disease.
• Inflammation: Studies show diet, lifestyle, family history, and chronic inflammation are risk factors.
• Alarming Rise in Young Adults: While overall CRC incidence might be declining, early-onset CRC is increasing significantly, especially in people under 30.
• India Specific: CRC is the seventh most common cancer in India, with a 20% case increase from 2004 to 2014.

Fusobacterium nucleatum and Colon Cancer

• About: Fusobacterium nucleatum, a bacterium normally found in the mouth, is surprisingly present in colon and rectal cancer tumors.
• Aiding Cancer Spread: The bacteria's presence in tumors helps cancer cells evade the immune system and metastasize (spread) to other organs.
• Genetic Link to Cancer: Studies suggest specific genetic factors in Fusobacterium might enhance its ability to associate with gut cancers.