The absence of cumulative bone marrow toxicity in patients with recurrent adenocarcinoma of the ovary receiving dose-intense taxol and granulocyte colony stimulating factor

Taxanes: their impact on gynecologic malignancy

The use of taxanes in the treatment of gynecologic malignancies has expanded tremendously over the past 30 years. Both paclitaxel and docetaxel have unique microtubule stabilizing, antiangiogenic and radiation sensitizing properties that endow them with remarkable activity as chemotherapeutic agents. As research into the appropriate dose, timing, treatment interval, and response rates have been studied, they have emerged as one of the most active agents available in the treatment of gynecologic cancer. The body of research on taxanes continues to expand especially with regard to the use of taxanes in alternative formulations and in combination with newer treatments or routes of treatment. This review focuses on the development of taxanes as an effective therapy in the treatment of gynecologic cancers and data currently available in the literature regarding their efficacy. Future directions of taxane-based chemotherapy with regards to ovarian, uterine, and cervical cancers are also addressed. There is little doubt that taxane-based chemotherapy will remain an integral part of the treatment of gynecologic cancer for the foreseeable future.

Treatment of relapsed carcinoma of the ovary with single-agent paclitaxel following exposure to paclitaxel and platinum employed as initial therapy

OBJECTIVES

The aim of this study was to evaluate the ability of paclitaxel to achieve a second clinical response in patients with recurrent epithelial ovarian carcinoma who responded to standard therapy with platinum and paclitaxel in the initial setting.

METHODS

Thirty-four patients with epithelial ovarian who demonstrated a complete response to paclitaxel and platinum in the initial treatment setting were retreated with paclitaxel as a single agent for relapse of their disease. Paclitaxel was given at a dose of 135-175 mg/m(2) over 3 h at 21-day intervals. Fifteen patients had platinum-resistant disease and 19 had potentially platinum-sensitive disease. Response was documented by physical examination, serial serum CA125 measurement, or radiologic evaluation.

RESULTS

An objective response to paclitaxel retreatment was demonstrated in 15 patients (44%), with a median progression-free interval (PFI) of 8.6 months (range 4-17 months). An additional 14 patients (41%) demonstrated disease stabilization, with a median PFI of 7.4 months (range 3-13 months). Overall, retreatment with paclitaxel was well tolerated, with minimal cumulative toxicities, despite repetitive dosing.

CONCLUSION

These results demonstrate that patients with ovarian cancer who relapse after initial treatment with paclitaxel often have disease that is still responsive to the agent. Given its relative lack of cumulative toxicity, retreatment with paclitaxel as a single agent is a reasonable therapeutic option for patients with recurrent ovarian cancer.

Future directions with taxane therapy

The potential biochemical and genetic mechanisms by which a cell might experience a decreased sensitivity to taxanes and other drugs of this class are discussed in the first part of this article. The use of taxanes in the current gynecologic-oncologic clinical setting is reviewed with special consideration given to the pharmacokinetics of taxane in relation to dose intensity and length of administration.

The impact of disease severity on the informed consent process in clinical research

PURPOSE

To assess the efficacy of informed consent in subjects differing in disease severity, ranging from those with immediately life-threatening disease to healthy volunteers.

SUBJECTS AND METHODS

A total of 127 subjects, enrolled in four types of clinical research protocols, were tested. Subjects completed questionnaires before entry into the protocol, within 24 hours of signing the primary protocol's consent document, and 4 to 6 weeks after entry.

RESULTS

Healthy volunteers retained the most information about risks and side effects, and severely ill Phase I subjects retained the least (P <0.0001). Phase I and II subjects had the best long-term retention of information about procedures, whereas Phase III subjects and healthy volunteers retained the least (P <0.001). Information about the scientific purpose and confidentiality of data were retained best by symptom-free, Phase III subjects (P <0.05). Phase I subjects entered the study primarily for treatment purposes, and the consent document was rated less useful by subjects with more advanced disease (P <0.05).

CONCLUSIONS

Subjects with differing disease processes and illness severities focused on and retained different aspects of experimental protocols for dissimilar reasons. During the informed consent process, research staff should inquire of potential subjects' personal goals for participating in experimental protocols and develop means for ensuring subjects' understanding of the inherent risks and alternative interventions available.

Taxanes: a new class of antitumor agents

Taxanes belong to a new group of antineoplastic agents with a novel mechanism of action for a cytotoxic drug. They promote microtubule assembly and stabilize the microtubules. Paclitaxel, the first agent in this group to become available, was isolated from the Pacific yew, Taxus brevifolia, in 1971. In preclinical and clinical studies, paclitaxel and its semisynthetic analog docetaxel exhibit significant antitumor activity. This review deals with the physicochemical properties, pharmacology, and results of preclinical and clinical trials of the taxanes.

Clinical, toxicological and pharmaceutical aspects of the antineoplastic drug taxol: a review

Taxol, a diterpene alkaloid isolated from the bark of Taxus brevifolia, has a unique mechanism of action. The drug promotes the formation of microtubule polymers in a cell, by reversibly and specifically binding the beta-subunit of tubulin. Taxol is administered intravenously by a 3-24-hour infusion at 3-week intervals. Myelosuppression, especially neutropenia, appears to be the dose limiting toxicity in solid tumours at 200-250 mg/m2. Furthermore, side effects such as sensory neurotoxicity (with typical numbness, tingling and painful paraesthesiae in the extremities), diarrhoea and alopecia appear frequently. Mucositis appears to be the non-haematological dose limiting side effect at 390 mg/m2 that has been determined in patients with leukaemia. Hypersensitivity reactions, which have been fatal in individual cases, might be schedule dependent. Furthermore, antiallergic prophylaxis must be given, although this precaution might not be considered to be fully protective. Phase I studies performed with combinations of taxol and cisplatin, doxorubicin or cyclophosphamide have indicated the feasibility of these regimens and show promise for future investigations. Addition of granulocyte-colony stimulating factor (G-CSF), aimed at modulating myelosuppressive toxicity, showed in Phase I studies that the taxol dose could be increased to 250 mg/m2, with peripheral neuropathy as the dose limiting toxicity. In Phase II studies, taxol has been shown to be effective, including producing complete tumour remission, in advanced drug refractory ovarian carcinoma (19%-36% response rate), previously treated patients with metastatic breast carcinoma (27%-62% response rate), advanced non-small lung cancer (21%-24% response rate), advanced small cell lung cancer (37% response rate) and advanced head and neck cancer (34% response rate).(ABSTRACT TRUNCATED AT 250 WORDS)