At what age should a daughter start getting colonoscopies if her father was diagnosed with colon (colorectal) cancer at 45-50 years old?

From the Guidelines

If your father was diagnosed with colorectal cancer between ages 45-50, you should begin colonoscopy screening at age 40 or 10 years before your father's age at diagnosis, whichever comes first, as recommended by the most recent guidelines 1. In this case, you should start at age 35-40 (10 years before your father's diagnosis). The frequency of screening should typically be every 5 years, though your doctor might recommend more frequent screenings based on your personal risk factors. This recommendation is based on the understanding that first-degree relatives (parents, siblings, children) of individuals with colorectal cancer have a 2-3 times higher risk of developing the disease themselves. Early screening is crucial because colorectal cancer often develops slowly from precancerous polyps, which can be removed during colonoscopy before they become cancerous. Besides colonoscopies, maintain a healthy lifestyle with regular exercise, a diet rich in fruits and vegetables, limited red meat and processed foods, and avoid smoking and excessive alcohol consumption to further reduce your risk. Some key points to consider include:

• The American College of Gastroenterology and the National Comprehensive Cancer Network recommend starting screening at age 40 or 10 years before the earliest diagnosis of colorectal cancer in a first-degree relative 1.
• The US Multi-Society Task Force on Colorectal Cancer also recommends starting screening at age 40 or 10 years before the earliest diagnosis of colorectal cancer in a first-degree relative 1.
• It's essential to discuss your individual risk factors and family history with your doctor to determine the best screening schedule for you. Overall, prioritizing early screening and a healthy lifestyle can significantly reduce your risk of developing colorectal cancer.

From the Research

Colonoscopy Screening for Daughter with Family History of Colon Cancer

• The daughter's father was diagnosed with colon cancer at 45-50 years old, which puts her at a higher risk of developing colon cancer at a young age 2, 3, 4.
• According to the American Cancer Society and other organizations, first-degree relatives of individuals diagnosed with colorectal cancer before age 60 should start screening with colonoscopy at age 40 2, 5.
• Studies have shown that individuals with a family history of colon cancer have a higher prevalence of adenomas and colon cancer, especially if they have a first-degree relative diagnosed with colon cancer before age 60 3, 4.
• One study found that 36.4% of 40- to 50-year-old first-degree relatives of colon cancer patients had polypoid lesions, compared to 20.9% of controls 4.
• Another study recommended that all patients over 30 years of age with a family history of colorectal cancer undergo colonoscopy on presentation and, if clear, every four years thereafter, unless two first-degree relatives are affected, when it should be every two years 3.

Recommended Screening Age for Daughter

• Based on the evidence, it is recommended that the daughter start getting colonoscopies at age 40, given her family history of colon cancer 2, 5, 4.
• However, some studies suggest that screening may be beneficial even earlier, at age 30-39, especially if there are multiple first-degree relatives affected 3, 4.
• The daughter should discuss her individual risk factors and screening options with her healthcare provider to determine the best course of action 2, 5, 4.