Peripheral neuropathy induced by combination chemotherapy of docetaxel and cisplatin PHE Hilkens1, LC Pronk2, J Verweij2, CJ Vecht1, WLJ van Putten3 and MJ van den Bent1Departments of 2Medical Oncology and 3Biostatistics, Dr Daniel den Hoed Cancer Center and University Hospital, Rotterdam, The Netherlands Summary 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.Keywords: neuropathy; docetaxel; cisplatin; neurotoxicity; peripheral nerves; chemotherapy Docetaxel (Taxotere) is a new semisynthetic taxoid that has demonstrated substantial clinical activity against a wide variety of solid tumours (Pazdur et al, 1993;Aamdal et al, 1994;Fossella et al, 1994;Francis et al, 1994a;Francis et al, 1994b;Smyth et al, 1994;Chevallier et al, 1995). Docetaxel inhibits tubulin depolymerization and promotes microtubule assembly, resulting in dysfunctional microtubules (Pazdur et al, 1993).In view of their partly non-overlapping side-effects and their activities in a wide range of tumour types, developing combination chemotherapy regimens, including both taxoids and platins, is of major interest (Rowinsky et al, 1991;Rowinsky et al, 1993;Chaudhry et al, 1994). An important dose-dependent side-effect of cisplatin is the development of peripheral neuropathy, mainly affecting thick-fibre-mediated sensory qualities (Thompson et al, 1984;Roelofs et al, 1984;Gerritsen van der Hoop et al, 1990a;Vecht et al, 1991; Hilkens et al, 1994). Neuropathy has also been reported as a dose-dependent side-effect of treatment with paclitaxel (Taxol) (Lipton et al, 1989;Gerven et al, 1994). As expected, trials on combination chemotherapy of cisplatin and paclitaxel found a high incidence of peripheral neuropathy (Rowinsky et al, 1991;Rowinsky et al, 1993;Chaudhry et al, 1994).Peripheral neurotoxicity has been reported as a frequent, but usually mild side-effect of docetaxel in several phase I and phase II studie...