[Colorectal exfoliated cell in stool and its nuclear DNA quantitative analysis for diagnosis of colorectal cancer].
OBJECTIVE
Detection of colorectal exfoliated epithelial cells and their nuclear DNA content may provide another non-invasive way of screening and early diagnosis of colorectal cancer. This study was designed to analyze the roles of exfoliated cells in stool and its nuclear DNA content in diagnosis of colorectal cancer.


METHODS
1. One hundred and seventy nine individuals were selected, forty-six of them had pathological confirmation of colorectal carcinoma. The other 133 persons had no colonoscopic evidence of colorectal malignancy and therefore served as control. Exfoliated cells in the stool were isolated by elutriation, and the elutriation means was modified Iyengar's method. All individuals in the study had stool specimens for occult blood test(FOBT). 2. Nuclear DNA content and morphometric quantitative analysis in the exfoliated cells was performed on the 33 patients with colorectal cancer and 30 individuals served as control. The parameters selected in this study were DNA content, nuclear area, nuclear irregular index, and percent of > or = 5C cells.


RESULTS
1 Exfoliative cytology and FOBT: In 35 of 46 cases of colorectal malignancy(76.09%), cytology was positive: 5 cases demonstrated dysplastic cells, 4 cases indicated suspected carcinoma cells, 26 cases showed carcinoma cells. The positive rate of exfoliated cells had no significant relation to locations, sizes, histomorphologies, histological differentiations, Dukes stages, and lymph node metastases of the lesion(P > 0.05). Exfoliative cytology had a 98.50% (131/133) specificity for colorectal cancer in the study. The sensitivity for colorectal cancer was no significant difference between the two methods of exfoliative cytology and FOBT (76.09% vs 84.78%, P > 0.05), but the specificity for colorectal cancer, exfoliative cytology was significant higher than FOBT(98.50% vs 73.68%, P < 0.05). 2. DNA analysis of exfoliated cells nuclear, DNA content, nuclear area, nuclear irregular index and percent of > or = 5C cells in the stool were significant higher in colorectal cancer than in control group(P < 0.05). The percentage of > or = 5C cells were significantly associated with histological grade (P < 0.05).


CONCLUSIONS
1. Detection of exfoliated cells in stool plays an important role in diagnosis of colorectal cancer. Testing of FOBT and exfoliated cells sequentially hopes to be a new useful non-invasive test for screening of colorectal cancer. 2. DNA analysis of exfoliated cell in stool may provide an objective method of determining malignant grades and diagnosis of colorectal cancer.
Fan
Ru-ying
RY
Department of Gastroenterology, General Hospital of Peking Army Region, Chinese People's Liberation Army, Beijing 100700, P. R. China.
Li
Shi-rong
SR
Wu
Zi-tao
ZT
Wu
Xia
X
Chen
Zhi-min
ZM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000235:genetics; D004273:DNA, Neoplasm / Q000032:analysis*; D005243:Feces / Q000737:chemistry / Q000166:cytology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
D004273:DNA, Neoplasm