[Metastasis and its relation to cell kinetics in human colorectal cancers]

The difference of the cell kinetics between primary tumor and its metastasis was studied on six cases of human colorectal cancers (four cases at synchronous liver metastases and two metachronous) with migration chase method using flow cytometry in vivo. The bromodeoxyuridine labeling indices (LI), DNA synthesis time (Ts), and generation time (Tg) were measured in normal colonic mucosae, primary tumors, lymph node metastases, and liver metastases. The LI, Ts, and Tg were 4.9 +/- 2.2%, 11.6 +/- 1.4 hours, and 11.3 +/- 3.7 days, respectively, in normal mucosa. In cancer, they were 13.9 +/- 7.1%, 16.9 +/- 4.8 hours, and 6.0 +/- 2.5 days, respectively. LI was higher and Ts was longer in cancer than in normal mucosa. Tg was shorter in cancer than in normal mucosa. In lymph node metastases, LI, Ts, and Tg were 12.0 +/- 4.5%, 14.4 +/- 6.0 hours and 5.0 +/- 0.5 days, respectively. Ts was faster in lymph node metastases than in primary tumors. In liver metastases, they were 30.1 +/- 18.1%, 28.0 +/- 10.2 hours, and 4.8 +/- 2.1 days, respectively. LI was higher and Ts was longer in liver metastases than in primary tumors. In both metastatic lesions, Tg was shorter than in primary tumors. The proliferation rate correlated with LI/DNA index significantly (r = 0.7868, p less than 0.00001). From the results, it was revealed that the proliferation rate was higher in metastatic lesions than primary tumors in vivo. The application of this method for clinical and experimental use would be expected.