1. ¹Division of Internal Medicine, Cancer Institute Hospital, Japanese Foundation For Cancer Research, Ariake 3-10-6, Koto-ku, Tokyo 135-8550, Japan
2. ²Department of Chest Surgery, Cancer Institute Hospital, Japanese Foundation For Cancer Research, Tokyo, Japan
3. ³Department of Pathology, Cancer Institute, Japanese Foundation For Cancer Research, Tokyo, Japan
4. ⁴Pharmacology Division, National Cancer Center Research Institute, Tokyo, Japan

Correspondence: Dr M Nishio, E-mail: mnishio@jfcr.or.jp

Received 13 December 2004; Revised 21 March 2005; Accepted 21 March 2005; Published online 3 May 2005.

Abstract

Gefitinib, an inhibitor of the epidermal growth factor receptor (EGFR, HER1/ErbB1) tyrosine kinase, has been shown to have clinical activity against non-small-cell lung cancers (NSCLCs), especially in women nonsmokers with adenocarcinomas. The aim of the present study was to clarify the relationship between androgen levels and gefitinib treatment in patients with advanced NSCLCs. Sera from 67 cases (36 men and 31 women) were obtained pretreatment and during treatment with gefitinib monotherapy (days 14–18) for examination of testosterone, dehydroepiandrosterone sulphate (DHEA), and dehydroepiandrosterone sulphate (DHEAS) levels. Testosterone and DHEA during treatment were significantly lower than the pretreatment values in both women and men, and the DHEAS levels during treatment were also significantly lowered in women. Gefitinib treatment significantly suppressed androgen levels, especially in women who had no smoking history. In addition, hormone levels in women responding to gefitinib were significantly lower during the treatment than in women who did not respond. Gefitinib-associated decrease in serum androgen levels may play a role in its clinical efficacy.