Gemcitabine--a major advance?

Non-toxic and short treatment with gemcitabine inhibits in vitro migration of HT-1080 cells

Gemcitabine has demonstrated clinical activity in solid tumors. Several in vitro studies were carried out regarding its metabolism, toxicity and cell cycle effects, but none was done on the anti-metastasis potential of the drug. We sought to determine the effect of gemcitabine concentrations on migration velocity of HT-1080 cells at concentrations which do not alter cell cycle progression and proliferation. Cells were treated for 1 or 5 h at IC10-70 of gemcitabine in order to estimate its effects on viability, proliferation and migration capacity using flow cytometry and microscopy imaging, respectively. The gemcitabine treatment for 1 h had no effect on cell proliferation, viability, cycle or migration on HT-1080 cells. Even though the 5 h of exposure at IC10, IC20 and IC50 concentrations did not affect cell viability, proliferation and cell cycle repartition, the mean velocity of HT-1080 dramatically decreased by 50 and 30%, respectively. Gemcitabine at IC70 concentrations for 5 h of exposure first induced a time course inhibition of proliferation, together with a decrease in viability and altered cell morphology, and then inhibited cell migration by 50%. These data suggest the possibility to couple the anti-migratory property of gemcitabine with the known anti-tumoral effect in the treatment of tumors with high metastatic potential.

Examining quality of life issues in relation to endocrine therapy for breast cancer

With the development of highly effective, well-tolerated third-generation aromatase inhibitors (AIs), these drugs will probably play an increasingly important role in all phases of breast cancer treatment. As a result, the impact of such hormonal agents on patients' quality of life bears rigorous investigation. In a randomized, multicenter, single-blind cross-over study, the AIs letrozole and anastrozole were evaluated for quality of life, toxicity, and patient preference. A total of 72 patients were enrolled and were treated with each drug for a 4-week period, with a 1-week drug-free washout period before cross-over to the alternate agent. Assessments included the FACT-ES, toxicity, and patient preference. The FACT-ES is a validated questionnaire designed to measure quality of life of women with breast cancer who are being treated with endocrine therapies. Letrozole was superior to anastrozole with respect to both quality of life and toxicity evaluations. In addition, at the conclusion of the trial, reduced nausea, hot flashes, and abdominal discomfort caused almost twice as many patients to prefer to continue with letrozole therapy than with anastrozole. Data from this recent trial indicate that letrozole is better tolerated and provides better quality of life than anastrozole for women with metastatic breast cancer.

Cell cycle effects of gemcitabine

Gemcitabine (2',2'-difluoro-2'-deoxycytidine, or dFdC) is a promising anticancer agent with demonstrated clinical activity in solid tumours currently undergoing clinical trials. Despite extensive studies on the biochemical mechanism of action, cell cycle perturbations induced by dFdC have not yet been thoroughly investigated, apart from the expected inhibition of DNA synthesis. The aim of our study was to clarify whether cell population kinetics is a vital factor in the cytotoxicity of dFdC in single or repeated treatments and in the dFdC-cisplatin combination. Ovarian cancer cells growing in vitro were treated with dFdC for 1 hr in a range of concentrations from 10 nM to 10 microM. Cell kinetics was investigated by DNA-bromodeoxyuridine flow cytometry, using different experimental protocols to measure either the time course of DNA-synthesis inhibition or the fate of cells in G(1), S or G(2)M at the time of dFdC treatment or 24 hr later. A modified sulforhodamine B test was used to assess the growth inhibition caused by dFdC given alone or with cisplatin. Although dFdC promptly inhibited DNA synthesis, cytotoxicity on proliferating cells was not specific for cells initially in the S phase. DNA synthesis was restored after a G(1) block of variable, dose-dependent length, but recycling cells were intercepted at the subsequent checkpoints, resulting in delays in the G(2)M and G(1) phases. The activity of repeated treatment with dFdC + dFdC or dFdC + cisplatin was highly dependent on the interval length between them. These results suggest that the kinetics of cell recycling from a first dFdC treatment strongly affects the outcome of a second treatment with either dFdC itself or cisplatin.

Gemcitabine in the treatment of refractory Hodgkin's disease: results of a multicenter phase II study

PURPOSE

To explore the use of gemcitabine for the treatment of patients with relapsing or refractory Hodgkin's disease.

PATIENTS AND METHODS

Eligible patients had measurable disease and more than one previous chemotherapy regimen. Patients previously treated with high-dose chemotherapy with autologous bone marrow or peripheral stem-cell support were not included. Gemcitabine, 1,250 mg/m(2), was administered as a 30-minute intravenous infusion on days 1, 8, and 15 of each 28-day cycle of therapy. The dosing schedule remained fixed, and any dose of gemcitabine that could not be given on time was omitted. Patients who had not experienced any hematologic or nonhematologic toxicity after one complete cycle of therapy were permitted to have subsequent doses increased by 20%: that is, from 1, 250 mg/m(2) to 1,500 mg/m(2).

RESULTS

Of the 23 enrolled patients, 22 were assessable for response; all 23 patients were included in the efficacy analysis. Disease status for two patients (9%) reached a state of complete remission, and seven patients (30%) achieved a partial response, for an overall response rate of 39% (95% confidence interval, 19.7% to 61.5%). The likelihood of achieving a response was not influenced by a patients' main pretreatment characteristics or by their response to their last prior chemotherapy. The median duration of response was 6.7 months (range, 2 to 33+ months), and the median overall survival time was 10.7 months (range, 4 to 34.7+ months). In general, toxicities were mild; no treatment-related deaths occurred, and only one life-threatening adverse event was reported for this study.

CONCLUSION

Gemcitabine was shown to be active in heavily pretreated patients with Hodgkin's disease, producing a response rate of 39%. Additionally, drug-related toxicities were mild, which thus suggests the possible inclusion of gemcitabine in an earlier phase of treatment.