Objective: To study the methodology and significance of flow cytometry in detecting lymph node micrometastasis of colorectal cancer.
Methods: One hundred sixty-two cellular suspensions were prepared with lymph nodes which were resected radically on 25 patients with colorectal cancer and in which no cancer cells were found by HE staining. Different concentrations of cultured Lovo colorectal cancer cells were added into the celular suspension prepared from lymph node tissue of persons without colorectal cancer in order to prepare a control model. Dual staining with CK/FTTC and PI was made to the sedimetns from those 2 kinds of suspension. Flow cytometry was used to detect cancer cells.
Results: An ideal correlation was obtained between the detection value and the theoretical value of cancer cells in the specimen suspensions and control models (r = 0.097 6) with a sensitivity rate of 10/10(5). Cancer cells were detected from 7 out of the 25 patients and 30 of the 162 cellular suspensions. The detection rate was correlated with the size and infiltrating depth of the cancer.
Conclusion: Flow cytometry is a reliable, rapid, and quantitative method for detecting lymph node micrometastasis in colorectal cancer.