A 45-year-old male presents to the clinic with a family history of colorectal cancer. He reports no significant symptoms but expresses concerns about his risk of developing the disease due to his family’s medical history. Upon further investigation, it is revealed that his father was diagnosed with colorectal cancer at the age of 50, and his paternal grandfather also had a history of the disease.
What is the most common cause of large bowel cancer syndrome in individuals with a family history of colorectal cancer?
A) Familial adenomatous polyposis
B) Peutz Jeghers syndrome
C) Gardner syndrome
D) Lynch syndrome
The most common cause of large bowel cancer syndrome in individuals with a family history of colorectal cancer is
D. Lynch syndrome.[1]
Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer (HNPCC), is the most common cause of large bowel cancer syndrome in individuals with a family history of colorectal cancer. [1]
This syndrome is characterized by an autosomal dominant inheritance pattern, meaning that individuals with one copy of the mutated gene have a significantly higher risk of developing colorectal cancer and other cancers, including endometrial, ovarian, gastric, urinary tract, and small bowel cancers.
Lynch syndrome is caused by germline mutations in DNA mismatch repair (MMR) genes, including MLH1, MSH2, MSH6, PMS2, and EPCAM.
Individuals with Lynch syndrome typically develop colorectal cancer at a younger age compared to sporadic cases, and they often have a family history of multiple cancers across different generations.
Familial adenomatous polyposis (A), Peutz Jeghers syndrome (B), and Gardner syndrome (C) are also hereditary syndromes associated with an increased risk of colorectal cancer, but they are less common than Lynch syndrome and typically present with distinct clinical features.