[Development of treatments for head and neck squamous cell carcinomas]

Histopathologically, about 90% of head and neck carcinomas are squamous cell carcinomas. In this paper, the changes and the recent developments in treatment modalities for squamous cell carcinomas in the head and neck are reviewed. The curative treatments for head and neck carcinomas are radiation and/or surgical resection. The development of diagnostic techniques and the introduction of these curative treatments have contributed to an improvement in the long-term outcome. In terms of surgical procedures, reconstructive surgeries such as free cutaneous and/or muscle flap procedures have been developed and led to extended radical resection, while with curative radiotherapy, the increase in total dose and improvements in radiation field have been made possible. However, there has been a limit regarding significant improvements in prognosis with these curative therapies alone, excluding laryngeal cancer, because of the difficulty of early detection. Since the 1980 s, multi-drug chemotherapy including cisplatin (CDDP) has been administered in advanced cases. First, this chemotherapy was applied as neo-adjuvant chemotherapy (NAC) for previously untreated cases followed by curative surgery or radiotherapy. As a result, chemotherapy including CDDP and 5-fluorouracil has been shown to be the most efficacious with a high complete response (CR) rate. Furthermore, cases with CR have shown better outcomes than those without CR. Curative treatment modalities including impact chemotherapy have been invented and trials have begun with the aim of organ preservation. These include NAC followed by curative radiotherapy, curative radiotherapy with chemotherapy with almost the same anti-tumor effect as NAC and potential a radiation sensitizer (concomitant chemoradiotherapy), and NAC followed by concomitant chemoradiotherapy. These treatment modalities, including impact chemotherapy, are recommendable for the preservation of functions, e. g., swallowing and/or articulation, without worsening the prognosis. Furthermore, maintenance chemotherapy subsequent to curative treatment is advisable for advanced head and neck carcinomas. Besides the future development of the above-mentioned treatment modalities, new treatment modalities taking QOL into consideration for the elder are necessary, and improvements in poor prognoses of cases with complications and those with double cancer which are common in patients with head and neck squamous cell carcinomas is indispensable.