The treatment of adrenocortical carcinoma with o,p'-DDD: prognostic implications of serum level monitoring.

Thirty-four patients with adrenocortical carcinoma were treated with o,p'-DDD. Twenty-eight patients presented with metastases at entry, and spillage of tumour cells occurred at surgery in 6 other patients. Eight patients had objective tumour regression, of whom 7 had serum levels over 14 micrograms/ml. The 3 patients with a lasting remission had levels of greater than 15, greater than 25, greater than 25 micrograms/ml respectively during prolonged periods. Increased survival times were found in the group of 14 patients with o,p'-DDD serum levels higher than 14 micrograms/ml when compared with patients not treated after discovery of metastases. In the patients with levels less than or equal to 10 micrograms/ml no therapeutic effect was seen. Levels of over 20 micrograms/ml are associated with symptoms of reversible neuromuscular toxicity. Monitoring of serum levels during treatment is mandatory. It is suggested that serum levels of about 25 micrograms/ml during longer periods may be curative.