Symptomatic Versus Asymptomatic Colorectal Cancer: Predictive Features at CT Colonography

Computed tomographic colonography (CTC) is a robust tool for evaluating colorectal lesions in both screening and diagnostic settings. The purpose of this study was to assess the relationship between colorectal cancer (CRC) tumor characteristics and patient symptomatology.

This is a retrospective analysis of all pathology-confirmed cases of CRC evaluated with CTC at our institution from October 2004 to October 2012. Cases were reviewed to determine tumor size, morphology, and degree of luminal narrowing. An electronic medical record review was performed to delineate specific patient symptomatology and determine depth of invasion.

A total of 55 patients (36 symptomatic and 19 asymptomatic) with a total of 63 CRCs were evaluated by CTC during the study time period. The most common symptoms were gastrointestinal (GI) bleeding/anemia (n = 26), followed by obstructive symptoms (n = 23), and constitutional symptoms (n = 5). Symptomatic cancers were more likely to have annular morphology (n = 30/43, 70% vs. n = 3/20, 15%; odds ratio [OR] = 13.1, P = 0.0003), whereas asymptomatic cancers were more likely to be polypoid (n = 11/20, 55% vs. n = 6/43, 14%, OR = 7.5, P = 0.001). Symptomatic cancers were also larger (46.1 ± 22.4 vs. 38.8 ± 18.4 mm, P = 0.005) and resulted in greater luminal narrowing (8.7 ± 8.5 mm vs. 35.8 ± 18.8 mm, P < 0.0001) with deeper invasion (n = 29/35 [invasion unknown for 8 cases], 83% vs. n = 6/20, 30%, OR = 11.3, P = 0.0003). Invasive cancers were more likely to have annular morphology (66%, 23/25, P = 0.002).

There is an intuitive and predictable relationship between tumor characteristics on CTC and patient symptoms. Annular morphology, tumor size, degree of luminal narrowing, and invasive disease all correlate with the presence of symptoms.