[Sample targeting under stereomicroscopy can raise the detection rate of early colorectal cancer]

To establish a set of pathological diagnosis method to raise the detection rate of early colorectal cancer.

All patients with colorectal tumor underwent ordinary electron enteroscopy in 2005. The lesions larger than 10 mm underwent indigo carmine staining and magnifying electron enteroscopy to observe the pit pattern. Endoscopic mucosal resection (EMR) or endoscopic piecemeal resection (EPMR) was performed on the suspected cases of cancer, such as laterally spreading tumor (LST). The resected specimens were stained with cresyl violet and observed by stereomicroscopy to determine the pit patterns. The parts showing the pit patterns associated with early colorectal cancer were targeted and biopsy specimens collected here to undergo pathohistological examination. Routine pathological examination was conducted on the other parts of the same specimen as control. The results of these specimens were compared with those of the specimens collected by ordinary methods from the patients with colorectal tumor in 2004.

In 2005 40 patients with colorectal tumor were suspected as with cancer and underwent EMR or EPMR of which 16 were confirmed to be with early stage colorectal cancer, including severe dysplasia by sampling targeting (40%). And the routine pathohistological examination of the randomly collected parts from these same specimens showed 15 cases of mild or moderate dysplasia and only one case of severe dysplasia, with a detection rate of 2.5%, significantly lower than that of the result of sample targeting under stereomicroscopy (P < 0.01). In 2004, out of the 54 patients suspected to be with colorectal cancer only 4 cases of early cancer, including severe dysplasia were detected with a detection rate of 7.4%, significantly than that of the year 2005 (P < 0.01).

Sample targeting and localized biopsy under stereomicroscopy raises the detection rate of early colorectal cancer.