692P - Role of adjunctive surgery after platinum-based chemotherapy in management patients with adrenocortical carcinoma: Observation study

Background

The most effective first-line regimen for adrenocortical cancer (ACC) is a combination of EDP chemotherapy (ChT) with mitotane (M), with one-year disease control rate of 21%. Some retrospective analysis showed that cytoreduction after ChT improves progression-free survival (PFS) and overall survival (OS) in patients (pts) with primary unresectable or metastatic (m) disease. We analyzed the impact of adjunctive surgery on outcomes for pts with mACC in our center.

Methods

The retrospective analysis included pts ≥18 y.o. with histologically confirmed mACC; ECOG 0-2 with disease control after platinum-based ChT ± M at least 6 months at the N.N. N.N. Blokhin from 1995 to January 2023 (N=50).

Results

Surgical treatment after 6-8 ChT cycles was performed in 13 pts (27.6%), of which 5 (38.5%) achieved an objective response. The median time from completion of ChT to surgery was 3.4 months. (2.13-6.3 months). R0-resection was performed in 8 cases, R2-resection – in 5. The surgical treatment and control groups were comparable in terms of ki67 level (>10% vs ≤10%), ECOG status, age, rate of reaching the therapeutic concentration of mitotane in the blood, and the number of metastatic sites. In the control group lung metastases were more common (p=0.04) but peritoneal metastases were less common (p=0.05). The median PFS was 34.1 months (11.02-57.2, p=0.01) in surgery group versus 11.1 (9.4-12.8) in the control. There was a trend towards improvement in OS, the median of which was not reached in the surgical group (95% CI, NR-NR) and was 34.2 months. (20.2-48.2) in control.

Conclusions

In our study, residual tumor resection was performed in 13 pts (27.6%), which is significantly less than in the Italian retrospective study - 50%. Surgical treatment in our study was performed only in pts with a potentially feasible R0 resection. R2 resection was performed only in pts with a complete response in lung/liver lesions and residual adrenal tumor or peritoneal lesions. The study limitation is the retrospective design and significant differences in some pts characteristics. However, this PFS benefit allows us to recommend all pts with disease control after 6-8 ChT cycles be considered as candidates for resection of the residual tumor.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Y.A. Zhulikov.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.