Paclitaxel (Taxol) induces cumulative mild neurotoxicity

Neurological monitoring of neurotoxicity induced by paclitaxel/cisplatin chemotherapy

To evaluate the neurotoxicity of paclitaxel/cisplatin chemotherapy, we studied neurological and electrophysiological functions in 14 patients who had been treated with 1-7 courses of paclitaxel/cisplatin. The cumulative paclitaxel and cisplatin doses ranged from 175 to 1225 mg/m2 and 100-700 mg/m2, respectively. Neurological examinations as well as motor nerve conduction studies of the peroneal nerve were performed and summarised by means of a peripheral neuropathy score. Neurotoxicity with onset usually after the second treatment cycle occurred in 13 patients. 12 patients complained about sensory symptoms, 13 patients had impaired vibration sense and 8 patients developed additional muscle weakness, predominantly of the legs. Dysfunction of peroneal motor nerve conduction occurred in 13 patients. Reduction of amplitudes as well as slowing of conduction velocities were seen in 13 patients and prolonged distal latencies in 10 patients. The peripheral neuropathy score was elevated in 13 patients. Neurological symptoms, impairment of both vibration sense and tendon reflexes, and the peripheral neuropathy score increased with the cumulative doses of paclitaxel/cisplatin. Serial analysis among selected patients also revealed an increase in neurotoxicity with increasing cumulative drug doses. These data indicate the development of neurotoxicity in most patients treated with paclitaxel/cisplatin and also suggest that early signs of neurotoxicity can be detected by clinical examination with emphasis on symptoms as well as vibration sense and can be well documented by electrophysiological investigations.

Clinical characteristics of severe peripheral neuropathy induced by docetaxel (Taxotere)

BACKGROUND

Docetaxel, a semi-synthetic taxane may cause a usually mild sensory neuropathy. We describe the clinical characteristics of five patients who developed a more severe neuropathy following treatment with docetaxel.

PATIENTS AND METHODS

All patients were treated in phase II studies with 100 mg/m2 docetaxel in three weekly cycles, without steroid administration.

RESULTS

The clinical picture in these patients was dominated by a sensory neuropathy, but in one case severe weakness was present. Another patient developed Lhermitte's sign. Signs and symptoms are usually reversible after discontinuation of docetaxel administration, but in three patients symptoms worsened for some time after the end of treatment before improvement occurred.

CONCLUSION

Severe docetaxel neuropathy may especially occur following treatment with cumulative dosage over 600 mg/m2; in patients treated with this dosage a moderate or severe neuropathy may not be rare.

Peripheral neuropathy induced by combination chemotherapy of docetaxel and cisplatin

Docetaxel, a new semisynthetic taxoid that has demonstrated promising activity as an antineoplastic agent, was administered in combination with cisplatin to 63 patients in a dose-escalating study. As both drugs were known to be potentially neurotoxic, peripheral neurotoxicity was prospectively assessed in detail. Neuropathy was evaluated by clinical sum-score for signs and symptoms and by measurement of the vibration perception threshold (VPT). The severity of neuropathy was graded according to the National Cancer Institute's 'Common Toxicity Criteria'. The docetaxel-cisplatin combination chemotherapy induced a predominantly sensory neuropathy in 29 (53%) out of 55 evaluable patients. At cumulative doses of both cisplatin and docetaxel above 200 mg m(-2), 26 (74%) out of 35 patients developed a neuropathy which was mild in 15, moderate in ten and severe in one patient. Significant correlations were present between both the cumulative dose of docetaxel and cisplatin and the post-treatment sum-score of neuropathy (P < 0.01) as well as the post-treatment VPT (P < 0.01). The neurotoxic effects of this combination were more severe than either cisplatin or docetaxel as single agent at similar doses.

Australasian multicentre phase II study of paclitaxel (Taxol) in relapsed ovarian cancer

BACKGROUND

Until recently there has been no effective therapy for patients with relapsed ovarian carcinoma following standard platinum based chemotherapy. Paclitaxel has recently been approved for clinical use in this malignancy.

AIMS

To evaluate the objective response rate and toxicity of paclitaxel in patients with relapsed ovarian cancer.

METHODS

Paclitaxel was given on an outpatient basis as a three hour infusion every 21 days for a maximum of ten cycles to 72 patients with advanced ovarian cancer previously treated with at least one platinum containing regimen. The starting dose was either 175 mg/m2 (patients with one or two prior chemotherapy regimens) or 135 mg/m2 (three previous regimens). Premedication was given because of the documented risk of hypersensitivity reactions to paclitaxel.

RESULTS

The overall response rate was 22% (95% confidence interval [CI] 13% to 34%) in the 72 patients enrolled in the study: four patients had a complete response. Three patients (4%) ceased treatment due to hypersensitivity reactions. Other significant (WHO grade 3 or 4) toxicities included neutropenia (51%), myalgia (14%), neurological (3%), alopecia (93%) and nausea and vomiting (3%). The estimated median survival of all patients was 9.8 months (95% CI: 9.1-13.0 months) with 44% alive at one year (standard error [SE] 7%).

CONCLUSIONS

This study confirms that paclitaxel given as a three hour infusion has significant activity and acceptable toxicity in advanced ovarian carcinoma previously treated with platinum regimens.

Peripheral neurotoxicity of taxol in patients previously treated with cisplatin

BACKGROUND

Taxol is a new anticancer drug that acts as a tubulin polymeration enhancer. Its major toxicities are myelosuppression, hypersensitivity, and mucositis, but it also induces peripheral nerve damage. The use of taxol has recently been proposed for platinum-resistant cancers, but in these cases there is a possibility of cumulative toxicity in the peripheral nervous system.

METHODS

Twenty-two patients affected by a relapse of cisplatin-treated ovarian cancer were examined clinically and neurophysiologically to determine the evolution of taxol-induced peripheral somatic and autonomic neurotoxicity and the possible cumulative effect of a combination of taxol and cisplatin. Each patient was examined before, during, and after taxol treatment (using a dose of 135 or 175 mg/m2 in 3 hours every 3 weeks).

RESULTS

No patients were excluded from the study because of unacceptable toxicities of any kind. The serial examinations demonstrated that taxol induced onset of (or worsening of preexisting) neuropathic symptoms and signs in almost all the patients. The features were those of a distal, symmetrical, sensory polyneuropathy due to an axonopathy. Motor nerves and the autonomic nervous system were unaffected. Taxol neurotoxicity appeared early in the course of the treatment (i.e., after three courses) and was not severely disabling. In most cases after the early onset of peripheral neuropathy, stabilization of this side effect occurred.

CONCLUSIONS

Considering the low doses of taxol used in this study, the sensory nerve damage was unexpectedly severe. It appears that a cumulative, but not dose-limiting, neurotoxic effect occurs using taxol in patients previously treated with cisplatin.

Neurotoxicity is not enhanced by increased dose intensities of cisplatin administration

It is uncertain whether intensive dosing schedules of cisplatin, intended to attain a higher anti-tumour efficacy, alter the severity of cisplatin-induced neuropathy. We assessed the development of neuropathy in three groups of patients treated with cisplatin in different dosing schedules. The severity of neuropathy was determined by measurement of the vibration perception threshold (VPT) before treatment and during follow-up for 2-12 months after the last cycle. 66 patients were treated with an intensive weekly regimen of doses varying from 70 to 85 mg/m2 in 1 day (trial A), 21 patients with a 3-weekly combination chemotherapy containing cisplatin 75 mg/m2 in 1 day (trial B) and 20 patients with a 3-weekly regimen containing cisplatin 20 mg/m2 for 5 consecutive days (trial C). The mean dose intensity achieved was 59 mg/m2/week in trial A, 21 mg/m2/week in trial B and 33 mg/m2/week in trial C. The maximum post-treatment VPT correlated significantly with pretreatment VPT (P < 0.001) and with the cumulative dose of cisplatin (P < 0.001). Following correction for these two variables, the maximum posttreatment VPT did not show a statistically significant association with dose intensity. These results suggest that neuropathy is not related to dose intensity of cisplatin. This implies that treatment with more intensive dosing schedules, employing equal cumulative doses of cisplatin, does not result in a concomitant increase in neurotoxicity within a cumulative dose range of 280-675 mg/m2.