Background and methods: Colonoscopic 1-year control of polyps of less than 10 mm left in situ was carried out in 103 (89%) of 116 originally examined patients.
Results: Analysis showed an 85% recovery: 91% and 81% for polyps of 5-9 mm and < 5 mm, respectively. The recovery was significantly related to size and localization, whereas the growth rate was inversely correlated to the originally measured diameter. A linear relationship was demonstrated between anus-to-polyp distances 1 year apart, with a normalized agreement index of 0.70. In only 1 of 189 polyps, an increase of diameter to > 10 mm was demonstrated. The 79 new polyps in 52 (50%) of the patients were significantly smaller, more often right-sided, and related to multiplicity of polyps at the initial examination but not to growth of recovered polyps or cleansing status.
Conclusion: An acceptable recovery and growth rate of polyps < 10 mm seems to justify the continuation of the study for the remaining 2 years.