Volume 1, Issue 2

 

VEXING ISSUES IN COLORECTAL CANCER SCREENING

August 2, 2010

Background

Colonoscopy is the gold standard test for prevention and early detection of Colorectal Cancer (CRC).  The United States Preventive Services Task Force (USPSTF) recommends against routine screening for colorectal cancer (CRC) in adults over 75 years of age. There are limited studies on CRC screening in elderly population and minorities are often under-represented.

Guidelines from multiple societies have recommended surveillance intervals for repeat colonoscopy for colorectal cancer (CRC) screening based on findings on index examination. There are no guidelines for surveillance interval in subjects with unsatisfactory bowel preparation

Objectives

  1. To evaluate the outcome of screening colonoscopy in elderly African American, Hispanics and Asian Americans.
  2. To evaluate the outcomes of repeat colonoscopy at different surveillance intervals in patients with unsatisfactory preparation and complete colon examination on index colonoscopy,.
  3. To determine factors associated with positive outcomes [Advanced Adenomas (AAd) or  CRC] during colonoscopic examinations.

Methods

10,908 subjects who had colonoscopy during the study period 2005-2009 were included in the retrospective cohort study.

Demographics, colonoscopy characteristics and histopathology findings were reviewed. 

 Colonoscopy for Colorectal Cancer (CRC) screening in  elderly African Americans, Hispanics and Asian Americans

Study Design

Inclusion criteria: Subjects ≥ 75 years with colonoscopy done for screening, surveillance or evaluation of symptoms. Exclusion criteria: Colonoscopies with incomplete records.

Results:

1496 subjects met the inclusion criteria. Mean Age 82 years (Range 75-105 years)

 

  Outcome in Screening Group (N=510)              Outcome in Symptomatic Group (N=986)

Predictor of Advanced Adenomas: •Anemia (odds ratio [OR] 1.34 [95% CI, 0.8-2.0], P < .05).  Predictors of Colorectal Cancers: •Presence of anemia (OR 1.01 [95% CI, 0.5-1.9], P < .05) •Abnormal CT scan (OR 4.2 [95% CI, 2-8.9], P < .001).

Conclusions:

  •  Advanced Adenoma and Colorectal Cancer detection rates are higher in:
    • Subjects with prior history of advanced adenomas
    • African Americans in comparison to Hispanics.
  •  Screening of Symptomatic (SOS) can be a helpful approach for CRC screening in elderly (age ≥ 75 years).
  •  Presence of anemia is a predictor for both advanced adenoma and CRC, while abnormal CT scan is a strong predictor of CRC.

  Impact of bowel preparation on surveillance colonoscopy interval for Colorectal Cancer screening Study Design:  

Inclusion Criteria:

1. Patients who had a repeat colonoscopy.

2. Index exam with suboptimal /fair/poor bowel prep.

3. Examination completed to cecum.

Exclusion Criteria:

History of inflammatory bowel disease, polyposis and colorectal cancer.

Results:

297 patients met the inclusion criteria. Mean Age 68 years (Range 51-95 years). 54.8% females and 45.2% males.

Repeat Colonoscopy indications:

Evaluation of symptoms 150/297 (50.5%) and CRC screening 147/297 (49.5%).

 

 

  Conclusions:

• ADR is low in repeat colonoscopies done at surveillance interval < 3 years for subjects having an index colonoscopy with suboptimal bowel prep and complete colon examination

 • A surveillance interval of 3 years can be reasonable for above subset of patients presenting for CRC screening

• Colonoscopy should be repeated earlier in:

 •Patients with advanced adenoma on index exam •Patients presenting with hematochezia and/or anemia