Efficacy and safety of radiation therapy in advanced adrenocortical carcinoma.

BACKGROUND

International guidelines emphasise the role of radiotherapy (RT) for the management of advanced adrenocortical carcinoma (ACC). However, the evidence for this recommendation is very low.

METHODS

We retrospectively analysed all patients who received RT for advanced ACC in five European centres since 2000.

PRIMARY ENDPOINT: time to progression of the treated lesion (tTTP). Secondary endpoints: best objective response, progression-free survival (PFS), overall survival (OS), adverse events, and the establishment of predictive factors by Cox analyses.

RESULTS

In total, 132 tumoural lesions of 80 patients were treated with conventional RT (cRT) of 50-60 Gy (n = 20) or 20-49 Gy (n = 69), stereotactic body RT of 35-50 Gy (SBRT) (n = 36), or brachytherapy of 12-25 Gy (BT) (n = 7). Best objective lesional response was complete (n = 6), partial (n = 52), stable disease (n = 60), progressive disease (n = 14). Median tTTP was 7.6 months (1.0-148.6). In comparison to cRT20-49Gy, tTTP was significantly longer for cRT50-60Gy (multivariate adjusted HR 0.10; 95% CI 0.03-0.33; p < 0.001) and SBRT (HR 0.31; 95% CI 0.12-0.80; p = 0.016), but not for BT (HR 0.66; 95% CI 0.22-1.99; p = 0.46). Toxicity was generally mild and moderate with three grade 3 events. No convincing predictive factors could be established.

CONCLUSIONS

This largest published study on RT in advanced ACC provides clear evidence that RT is effective in ACC.