Cisplatin and radiotherapy in the treatment of locally advanced head and neck cancer--a review of their cooperation.

A review of the published literature has been undertaken to ascertain the trends in treatment schedules of unresectable head and neck cancer (HNC) using cisplatin in conjunction with radiotherapy. In addition, four trials were reviewed where cisplatin was examined as a single agent without radiotherapy, demonstrating that cisplatin alone has a palliative effect only, and for a curative intent should be used in combination with radiation. Of the numerous clinical trials published on such combined chemo-radiotherapy, 16 were selected for analysis fulfilling the following criteria: cisplatin used as the sole chemotherapeutic agent in combination with radiation for patients with unresectable squamous cell carcinomas of the head and neck, with no previous treatment for the same malignancy. Daily low-dose cisplatin performed in 6 out of the 16 trials demonstrated increased tumour control with less toxicity as compared to weekly high-dose drug delivery. The increased tumour control with a daily low-dose schedule reflects the observation that cisplatin dissociates from the DNA in 24 h. Other cisplatin properties (e.g. radiosensitizing) also have the potential to influence chemo-radiotherapy treatment outcomes. There is significant scope to further optimize the treatment schedule for the unresectable HNC through detailed study of the pharmacokinetics and radiobiology of combined chemo-radiotherapy.