The aim of this study was to describe the incidence, clinical and histological characteristics, treatment and long-term follow-up of bilateral germ-cell tumours (BGCT) of the testis in order to determine in what respects they differ significantly from unilateral germcell tumours. In all, 31 patients with BGCT had metachronous tumours and 14 had synchronous tumours. Among the metachronous tumours, 61% occurred more than 5 years after the first tumour. The overall incidence of BGCT in patients with testicular germ-cell tumours (TGCT) was 1.9%. The incidence was 3.2% in patients presenting with a seminoma and 1.4 % in patients presenting with a nonseminomatous germ-cell tumour (NSGCT). Patients under 30 years of age at the time of the initial diagnosis had a higher incidence of bilateral tumours compared with older men. The outcome of BGCT was excellent. A high association was found between BGCT, sterility and suspected genetic risk factors for TGCT. These results argue against a systematic contralateral biopsy at diagnosis of first TGCT in all patients, but emphasise the importance of patient education and of the need to better identify patients at risk for a second TGCT. Therapeutic indications for synchronous BGCT, including conservative treatment, need to be better defined. Testicular germ-cell tumour (TGCT) is a rare disease with an estimated incidence of five out of 100 000. An increase of more than 50% has been demonstrated in all Western countries during the last decades (Grenlee et al, 2001). Several risk factors for developing a TGCT have been identified, uppermost among which is a previous TGCT (Osterlind et al, 1991). The incidence of bilateral testicular germ-cell tumour (BGCT) ranges between 1 and 5% in previously published large series (Bokemeyer et al, 1993;Dieckmann et al, 1993Dieckmann et al, , 1999Dieckmann et al, , 2002Heidenreich et al, 1995Heidenreich et al, , 1997Heidenreich et al, , 2000Gerl et al, 1997;Tekin et al, 2000;Geczi et al, 2001;Ondrus et al, 2001;Che et al, 2002;Ohyama et al, 2002). The charts of 2383 consecutive patients treated at the Institut Gustave Roussy over a 22-year period were analysed to estimate the incidence of BGCT, to identify potential risk factors and to evaluate the long-term survival of patients with BGCT.
PATIENTS AND METHODSBetween 1979 and 2002, 2383 patients with TGCT were treated in the Adult Cancer Department at the Institut Gustave Roussy (IGR). The list of patients was obtained from a computerised database. Among these 2383 patients, 45 had a BGCT. The medical records of these 45 patients were reviewed to collect the following information: previous personal and family medical history, clinical characteristics at presentation, histopathology, treatment, interval between the development of the two tumours and follow-up.All available pathology slides were reviewed. Most patients had their orchidectomy at other institutions. Haematoxylin-and eosinstained slides of both testicular tumours were available for 36 patients, and slides of only one tumour were avai...