Should a 74-year-old patient undergo a colonoscopy, Dual-Energy X-ray Absorptiometry (DEXA) scan, and Abdominal Aortic Aneurysm (AAA) ultrasound?

Screening Recommendations for a 74-Year-Old Patient

For a 74-year-old patient, colonoscopy is not routinely recommended, but DEXA scan may be appropriate, and AAA ultrasound screening is recommended for men with smoking history but not for women who have never smoked.

Abdominal Aortic Aneurysm (AAA) Screening

Recommendations:

• For men aged 65-75 years with smoking history: One-time screening with ultrasound is strongly recommended (Grade B) 1
• For men aged ≥75 years: May be considered regardless of smoking history 1
• For women aged ≥75 years: May be considered only if they are current smokers or hypertensive 1
• For women who have never smoked: Screening is not recommended (Grade D) 1

AAA screening with ultrasound effectively reduces rupture-related mortality in high-risk populations, particularly male smokers. The risk-benefit analysis shows clear benefit for men with smoking history, but minimal benefit and potential harm for women who have never smoked.

Colorectal Cancer Screening

Recommendations:

• For adults aged 45-75 years: Regular screening with either stool-based tests or structural examinations is recommended 1
• For adults aged 76-85 years: Screening decisions should be individualized based on:
  • Life expectancy
  • Health status
  • Prior screening history 1
• For adults >85 years: Screening should be discouraged 1

At age 74, the benefits of colonoscopy diminish compared to younger populations. Research shows that in the 70-74 age group, screening colonoscopy provides only a modest absolute risk reduction of 0.42% for colorectal cancer over 8 years, with even smaller benefits (0.14% risk reduction) in the 75-79 age group 2. Additionally, the risk of adverse events increases with age, with 5.6 events per 1000 individuals in the 70-74 age group and 10.3 per 1000 in the 75-79 age group 2.

DEXA Scan for Bone Density

While specific guidelines for DEXA scanning were not provided in the evidence, standard practice suggests:

• DEXA scanning is appropriate for:
  • Women aged 65 and older
  • Men aged 70 and older
  • Younger individuals with risk factors for osteoporosis

At age 74, a DEXA scan would be appropriate to assess bone density and fracture risk, especially if the patient has not had one previously or has risk factors for osteoporosis.

Decision Algorithm

1. AAA Ultrasound:

   • If male with smoking history: Recommend one-time screening
   • If male without smoking history: Consider based on other risk factors (hypertension, family history)
   • If female with smoking history and hypertension: Consider screening
   • If female without risk factors: Do not recommend screening

2. Colonoscopy:

   • Assess previous screening history:
     • If never screened or >10 years since last colonoscopy: Consider benefits vs. risks
     • If screened within last 10 years with normal results: Likely unnecessary
   • Evaluate overall health status and life expectancy:
     • If life expectancy <10 years: Not recommended
     • If significant comorbidities: Not recommended due to increased procedural risks

3. DEXA Scan:

   • Recommend if:
     • No previous DEXA scan
     • Previous DEXA scan showed osteopenia/osteoporosis requiring monitoring
     • Risk factors for fractures present

Important Considerations

• Colonoscopy risks increase with age: Complications, poor bowel preparation, and incomplete examinations are more common in elderly patients 3, 4
• Life expectancy impact: The potential increase in life expectancy from screening colonoscopy is significantly reduced in patients over 75 3
• Diagnostic yield: While colonoscopy in the elderly has high diagnostic yield (20% cancer detection rate in those ≥80 years vs. 7.4% in younger patients), the mortality benefit must be weighed against risks 5
• Comorbidities: The presence of AAA and colorectal cancer together presents special management challenges, with increased risk of AAA rupture following colorectal surgery 6