The aim of the present prospective study was to evaluate the prediction accuracy of electromagnetic detection of rectal cancer (RC). Eligible subjects were consecutively enrolled in the investigators' Institute and subjected to electromagnetic detection followed by colonoscopy and histopathologic analysis of biopsies. A putative RC carrier status was attributed to subjects showing an electromagnetic signal < 50 units (U).

Eligibility criteria: Gastrointestinal disease or clinical symptoms related to colorectal cancer risk. Exclusion criteria consisted of age younger than 18 years, history of psychiatric illness, and preoperative radiotherapy.

Outcome measures: RC screening was carried out using a Tissue Resonance InterferoMeter probe (TRIMprobe) electromagnetic detector (Galileo Avionica, Turin, Italy), which consists of a nonlinear oscillator placed in a cylindrical probe about 30 cm long, a radiofrequency spectrum analyzer, and dedicated computer software. Detection of RC is based on the decrease of the electromagnetic signal compared to the mean signal obtained in healthy subjects. The test was performed while the patient stood 120 cm from the receiver. The operator was on the opposite side of the examined pelvis. No metallic objects were allowed on the patient and no electronic devices were admitted in the test area. The detector was kept at close contact to the pelvis surface and was moved through six planes, to obtain a scan of the whole pelvis volume. Based on the investigators previous study, we used the electromagnetic detection system at 465 MHz frequency, in a scale from 0 to 255 arbitrary U. The device lets the examination limited to the pelvis and we regarded the rectum cutoff within 15 cm from the anal verge.

Inclusion Criteria:

• Gastrointestinal disease or clinical symptoms related to colorectal cancer risk.

Exclusion Criteria:

• Age younger than 18 years, history of psychiatric illness, and preoperative radiotherapy.