A 25-year-old woman presents for a new patient physical exam. Aside from occasional shin splints, she has a relatively unremarkable medical history. She takes oral contraceptive pills and a multivitamin daily. All of her age appropriate immunizations are up to date. Her periods have been regular, occurring once every 28 to 30 days with normal flow. She is sexually active with 2 partners, who use condoms routinely. Her prior pap smear was performed last year and was normal. Her mother has diabetes and coronary artery disease, and her father passed away at age 45 after being diagnosed with colon cancer at age 40. Her grand-aunt underwent bilateral mastectomies after being diagnosed with breast cancer at age 60. Her temperature is 36.7°C (98°F), blood pressure is 115/80 mmHg, pulse is 65/min, respirations are 12/min, and oxygen saturation is 100% on room air. Her physical exam is within normal limits. Which of the following is the most appropriate recommendation for this patient?
Mammogram now
Colonoscopy in 5 years
Colonoscopy in 10 years
Pap smear in 5 years
Colonoscopy in 5 years
This patient is presenting for a health evaluation with a family history significant for her father's death due to colon cancer at age 45. She should thus get a colonoscopy when she reaches the age 10 years prior to her father's age of diagnosis or in 5 years (at age 30).

The age threshold for colon cancer screening varies based on the patient's risk factors, including family history of colon cancer, inflammatory bowel disease, and/or genetic disorders. In the absence of significant risk factors, colonoscopies can be used for screening starting at age 45 and repeated every 10 years if results are normal. If there is family history of colon cancer (one or more first degree relatives, including parent, sibling, or child), colonoscopies should be recommended starting at age 40 or 10 years prior to the age of the family member's diagnosis, whichever is earlier. Polyps or grossly abnormal colon tissue may be biopsied for grading and guide further diagnostic imaging workup.

Aasma et al. review the clinical guidelines for colorectal cancer screening. They found that recent epidemiological data shows an increase in the incidence of colorectal cancer in individuals younger than 50 years. They recommend starting colonoscopy screening at 45 years of age in the average-risk adult population.

Incorrect Answers:
Answer B: Colonoscopy in 10 years is reasonable, but it is not the earlier of the 2 age thresholds mentioned above.

Answer C: Pap smear with HPV DNA screening for cervical cancer is indicated every 5 years for women aged 30 to 65 who wish to extend the screening interval from the 3 year interval for pap smear alone.

Answer D: Pap smear alone is indicated every 3 years for women of ages 21 to 65.

Answer E: Mammogram to screen for breast cancer is recommended every 2 years for women aged 50 to 74.

Bullet Summary:
For patients with a family history of colon cancer, screening should start at age 40 or 10 years prior to the age of the family member's diagnosis, whichever is earlier.