Drug Sensitivity of Different Tumor Lesions from the Same Patient Evaluated by a Short-Term Assay

Evidence of tumor heterogeneity in cervical cancers and lymph node metastases as determined by flow cytometry

BACKGROUND

The incidence and significance of tumor heterogeneity in primary tumors and metastatic lymph nodes were investigated in Stage IB-IIA cervical cancers.

METHODS

Paraffin-embedded tissues from 96 radical hysterectomy specimens were dewaxed, disaggregated, and subjected to dual parameter flow cytometry. Three-dimensional histograms were generated to delineate different tumor populations. A DNA index difference of at least +/- 0.15 was used to define tumor heterogeneity.

RESULTS

Mean DNA index difference of various tumor populations was 0.29 +/- 0.13. Among 69 patients with normal lymph nodes, there were 12 patients (incidence, 17.4%) with tumor heterogeneity in the primary tumors. Of 27 patients with metastatic lymph nodes, 5 (incidence, 18.5%) had evidence of tumor heterogeneity in the primary tumor, and 18 of 47 (incidence, 38.3%) had tumor heterogeneity in metastatic lymph nodes. When using DNA index to determine clonal origin of metastatic lymph nodes, as many as 60% of the metastases could not be traced to the primary tumor. Tumor heterogeneity was associated with a 40% reduction in median survival time. However, because of the small number of patients with tumor heterogeneity, statistical analyses did not show prognostic significance.

CONCLUSIONS

Tumor heterogeneity appeared to be a common characteristic of early cervical carcinoma. Additional study is needed to fully evaluate its prognostic value.

The use of ATP bioluminescence assays in selecting a drug screen panel for chemosensitivity testing of uterine cancer cell lines

The ATP bioluminescence assay has demonstrated a strong potential to become a clinical assay for chemosensitivity testing. Currently, chemotherapy of gynecologic cancers remains controversial and empirical. To optimize the patient's chance of survival and to justify related toxicities, the chemoregimen should be individualized and based on the patient's chemosensitivity profiles. This study was performed to identify a panel of active drugs against uterine cancer cell lines for possible use in future chemosensitivity testing. We used the ATP chemosensitivity assays to screen 12 common cytotoxic agents against six uterine cancer cell lines. Drug concentrations required for a 50% surviving fraction were defined as IC50s. When using an IC50 of 0.21 PPC (peak plasma concentration) as a cutoff value for sensitivity, the following 8 drugs were considered effective for uterine cancer cell lines: actinomycin D, Adriamycin, vinblastine, etoposide, 5-fluorouracil, methotrexate, cytosine arabinoside, and mitomycin-C. Meanwhile, 4 drugs, cisplatin, 4OH-Cytoxan, bleomycin, and Alkeran with mean IC50s of 2.1 +/- 0.7, 0.8 +/- 0.1, greater than 5.0, and 0.75 +/- 0.36 PPC, respectively, were considered inactive or partially active with higher IC50s than peak plasma concentrations. In conclusion, the above panel of promising drugs can be further tested in animal models or human cancer specimens for possible use in chemosensitivity testing of uterine cancer patients.

Chemosensitivity correlation between the primary tumors and simultaneous metastatic lymph nodes of patients evaluated by DNA synthesis inhibition assay

The chemosensitivities of primary tumors (PT) and simultaneous metastatic lymph nodes (MN) to mitomycin C (MMC), 5-fluorouracil (5-FU), Adriamycin (ADR) (doxorubicin; Adria Laboratories, Columbus, OH), carboquone (CQ), or cisplatin (CDDP) were assessed in a group of 29 patients (11 gastric, 8 colorectal, 4 breast, and 6 other cancers) by a DNA synthesis (3H-thymidine incorporation) inhibition assay. PT and MN from the same patient showed heterogeneity in chemosensitivity. MN were more sensitive to the agents than PT. PT were sensitive to 5-FU, whereas MN were sensitive to CDDP. An analysis of the sensitivity correlations showed that the sensitivities of PT to MMC, 5-FU, CQ, and CDDP correlated with each other, but ADR sensitivity correlated with only CQ sensitivity. The sensitivities of MN correlated with each other, except for those to ADR and CDDP. In contrast, MMC, ADR, or CQ sensitivity showed a correlation between PT and MN. These results suggest that patients should be treated according to the sensitivity of the target lesion. However, if the sensitivity assay is not available, the sensitivity correlation may be useful when choosing the agent. It also may be important that ADR sensitivity does not correlate with the sensitivities of other agents.