The treatment of cranial germ cell tumours

Germ cell tumours of the central nervous system (CNS) include many subtypes whose response to treatment varies, even though the symptoms and radiologi cal appearances are similar. Five-year survival rates are 96% for germinoma s, 100% for mature teratomas, 67% for immature teratomas and 69% for immatu re teratomas mixed with germinomas; for P-HCG secreting germinomas the rate is only 38%. Patients with choriocarcinoma, embryonal carcinoma, or yolk s ac tumour have the lowest survival rates; patients with germinoma or mature teratoma have longer survival rates. Although a wider resection is associated with a higher rate of survival for patients with non-germinomatous germ cell (NGGC) tumours, tb date an aggre ssive surgical approach has been advocated only for pineal region tumours, but not for hypothalamic/neurohypophyseal tumours. Beside the delayed injury induced by radiotherapy, the late injury induced by chemotherapy is becoming increasingly evident. Cisplatin is considered a n indispensable drug, but it may cause renal damage, ototoxicity, periphera l neuropathy and sterility, while etoposide is associated with an excess fr equency of second neoplasms. Taking into account all of the published literature, the following therapeu tic options are suggested: in pure germinoma tumours (GT) radiotherapy alon e will usually ensure adequate control of the disease, and the long-term se quelae may be limited by reducing the dose delivered, as was proposed for g erm cell testicular tumours, to 30 Gy to limited fields plus 25-30 Gy to th e spinal axis if there is disseminated disease. In cases of recurrence, whi ch should be uncommon, patients may be rescued with both radiotherapy and c hemotherapy. In NGGC tumours, the prognosis is more unfavourable and there is often diss emination to the spine at diagnosis; however; the tumour's high chemosensit ivity suggests neoadjuvant treatment chemotherapy with cisplatin and etopos ide for three cycles followed by consolidation radiotherapy with 40 Gy to t he limited fields plus 30 Gy to the spinal axis if disseminated. In our opinion, a higher dose of radiotherapy in cases in which chemotherap y does not achieve a radiological complete remission is not advisable, beca use very often the residual radiological abnormality does not represent bio logically active tumour but differentiated forms such as mature teratoma. The challenge for 2000 is to both cure these patients, and avoid the late a nd permanent sequelae of radiation and/or chemotherapy that may subsequentl y impair quality of life. (C) 2000 Harcourt Publishers Ltd.