The present study was designed to assess the chemosensitivity profile of freshly separated
colorectal cancer cells and to screen effective agents for the design of new combination regimens. The
DNA synthesis and chemosensitivity (% inhibition of
DNA synthesis by the
anticancer agent) were successfully assessed in 184 samples (107 primary and 77 metastatic or recurrent lesions) from 152 patients with
colorectal cancer using an 3H-thymidine incorporation assay, and the correlations between these two measures and various clinicopathological factors were analysed.
DNA synthesis was highest in nodal
metastasis followed by malignant effusion, primary lesion, liver
metastasis, and local recurrence.
DNA synthesis liver
metastasis and local recurrence were significantly lower than in other lesions. The results of the chemosensitivity assay are as follows:
5-FU seems to be the most beneficial for primary
colorectal cancer;
carboquone (CQ),
etoposide (VP-16),
5-FU, and
mitomycin-C (MMC) for nodal
metastasis; CQ,
cisplatin (CDDP),
5-FU,
adriamycin (ADR) and
VP-16 for malignant effusion; and
VP-16, CDDP and CQ for liver
metastasis. However, the present results showing the chemosensitivity profiles in different lesions suggest that regimens including
5-FU with
VP-16 and CQ in addition to MMC or ADR may be applicable for all kinds of
colorectal cancer lesions. These results demonstrated the heterogeneity in the chemosensitivity of
colorectal cancer, which suggests not only the necessity of patient-specific
chemotherapy dependent on the sensitivity assay, but also the usefulness of the present results in the choice of agents for widely applicable combination regimens for
colorectal cancer.