Endocrine Abstracts

Background: The recent ESE-ENSAT guidelines on adrenocortical carcinoma (ACC) indicated new treatment options for patients with “high risk for recurrence” as one of the major research topics for the field. However, since almost no data were available on the use of cytotoxic drugs in an adjuvant setting, no clear recommendation could be given. Here we report our experience with adjuvant platin-based therapy since 2002 at the University of Würzburg and MD Anderson.

Methods: 22 presumably high risk patients (12 female, 10 male, median age 38.5 years) after radical resection (R0 n = 16, RX n = 4, R1 n = 2), ENSAT stage (II n = 9, III n = 10, IV n = 3) and with median Ki67 of 30%, who were treated with adjuvant platin-based chemotherapy (initiated < 3 months after primary surgery) were matched to patients without adjuvant chemotherapy (using the following criteria: ENSAT stage, resection status, Ki-67, other adjuvant therapies, age and cortisol excess). 19 patients in both group have been treated with concomitant mitotane, none with adjuvant radiotherapy. Primary endpoint was recurrence-free survival (RFS), secondary overall-survival (OS).

Results: Twelve of 22 patients with adjuvant platin-based therapy experienced recurrence, whereas this was the case in 20/22 matched controls. Patients with adjuvant chemotherapy had a significant longer median RFS than matched controls (639 vs 336 days; multivariate adjusted HR: 0.33 (95% CI 0.14-0.79; P = 0.012). At last follow-up, 4 patients in the chemotherapy group and 12 patients in the control group have been died leading to a trend toward improved overall survival (HR 0.39; 0.09-1.55; P = 0.173). Neither the highest mitotane blood level in the first three months (12.2 mg/l vs 9.6 mg/l; P = 0,37) nor the highest mitotane blood level until progress or end of therapy (17.8 mg/l vs 16.3 mg/l; P = 0,67) were significantly different between the two groups.

Conclusions: Our retrospective cohort study provides first evidence that adjuvant platin-based chemotherapy may lead to a prolonged recurrence-free and overall survival. The retrospective nature and the size of the study are major limitations. A prospective study (like the just started ADIUVO-2 study) is needed to prove the value of adjuvant platin-based therapy.