Objective: To determine whether the clinical course of patients with testicular teratoma differentiated (TD) and those with testicular teratoma undifferentiated justify a different follow-up protocol.
Patients and methods: Between 1979 and 1989, 16 adult patients with testicular TD were treated at the Royal Marsden Hospital. These represented 2.7% of the 592 testicular teratoma patients seen during this period. With the exception of a propensity to involve the right testis (76%), there were no differences in clinical presentation between TD and non-TD histological subtypes.
Results: The mean follow-up was 55 months (range 7-137). Seven of the 16 patients had Stage I disease and were entered into surveillance programmes; one relapsed at 7 months. Ten men were treated with cisplatin or carboplatin-based chemotherapy for metastases, of whom three had had prior chemotherapy at other hospitals and were referred after relapse. In the seven previously-untreated chemotherapy group two patients failed. In the concurrent era, 375 patients with other subtypes of metastatic testicular non-seminoma were treated with chemotherapy and 47 (12.5%) failed (Progress Free Survival chi square (chi 2) = 2.73, P = 0.01). Although no difference in progression-free survival was demonstrated between TD and non-TD patients, the former had a worse overall survival probability (chi 2 = 9.02, P = 0.003); this may be an artefact due to the small number of events.
Conclusion: Despite the apparently more benign histology, it is recommended that the management of adult TD should not deviate from the general principles established for other histological subtypes of testicular teratoma.