Occult blood testing in asymptomatic patients previously resected for colorectal cancer

Hemoccult testing was carried out in 100 patients who had previously undergone surgical resection for colorectal cancer. Of the 15 Hemoccult-positive patients detected, endoscopic examination revealed polypoid formations in six (one with invasive carcinoma) and local recurrent tumors in three. Eighteen polypoid lesions were endoscopically detected in 10 Hemoccult-negative patients. Patient acceptance was good (above 90%) for Hemoccult testing especially when compared to the significantly lower compliance to endoscopic examination (66% in Hemoccult-negative patients). The results suggest that a significant number of lesions may be missed if the Hemoccult test is heavily relied upon exclusively for follow-up of patients previously resected for colorectal cancer.