Objectives: Although colonoscopy is effective in screening for colorectal cancer, its high cost and low compliance rates have encouraged a search for different methods. Our study was designed to evaluate the feasibility of rectal cancer detection using a nonlinear tuneable oscillator (TRIMprob), a recently developed device for detecting differences in electromagnetic properties of cancerous and normal tissues.
Methods: We tested 228 patients (115 male and 113 female) between March and September 2006: 114 patients with rectal cancer diagnosed on colonoscopy and 114 patients with negative colonoscopy results. The TRIMprob probe was moved over the surface of the pelvic area from the back and the front, with the patient standing, normally dressed, between the operator and the system receiver. The signal variation of three spectral lines, for 465-MHz, 930-MHz, and 1395-MHz frequencies was recorded for each of six probe positions.
Results: Analysis of resonance values showed that only the 465-MHz frequency differentiated patients with rectal cancer from those without cancer at all six probe positions (P < 0.001). With a cutoff value of 50 arbitrary units, the area under the receiver operating characteristic curve was 0.94 (specificity, 85 percent; sensitivity, 94 percent).
Conclusions: The TRIMprob test discriminates well between patients with normal rectal tissue and those with malignant lesions. These preliminary results confirm that electromagnetic detection of rectal cancer is possible and suggest this method of extracorporeal scanning may be useful as a first-level screening tool.