Efficacy and safety of radiation therapy in advanced adrenocortical carcinoma

The Value of Local Therapies in Advanced Adrenocortical Carcinoma

International guidelines recommend local therapies (LTs) such as local thermal ablation (LTA; radiofrequency, microwave, cryoablation), transarterial (chemo)embolisation (TA(C)E), and transarterial radioembolisation (TARE) as therapeutic options for advanced adrenocortical carcinoma (ACC). However, the evidence for these recommendations is scarce. We retrospectively analysed patients receiving LTs for advanced ACC. Time to progression of the treated lesion (tTTP) was the primary endpoint. The secondary endpoints were best objective response, overall progression-free survival, overall survival, adverse events, and the establishment of predictive factors by multivariate Cox analyses. A total of 132 tumoural lesions in 66 patients were treated with LTA (n = 84), TA(C)E (n = 40), and TARE (n = 8). Complete response was achieved in 27 lesions (20.5%; all of them achieved by LTA), partial response in 27 (20.5%), and stable disease in 38 (28.8%). For the LTA group, the median tTTP was not reached, whereas it was reached 8.3 months after TA(C)E and 8.2 months after TARE (p < 0.001). The median time interval from primary diagnosis to LT was >47 months. Fewer than four prior therapies and mitotane plasma levels of >14 mg/L positively influenced the tTTP. In summary, this is one of the largest studies on LTs in advanced ACC, and it demonstrates a very high local disease control rate. Thus, it clearly supports the guideline recommendations for LTs in these patients.

Efficacy and safety of adjuvant radiation therapy in localized adrenocortical carcinoma

Context

Adrenocortical carcinoma (ACC) is rare and have high rates of recurrence and mortality. The role of adjuvant radiation therapy (RT) in localized ACC was controversial.

Methods

We conducted a retrospective study in our center between 2015 and 2021 to evaluate the efficacy and safety of adjuvant RT in localized ACC. Overall survival (OS) and disease-free survival (DFS) were estimated using the Kaplan-Meier method. Cox proportional hazards regression models were used to estimate the independent risk factors. Adverse events associated with RT were documented according to the toxicity criteria of the radiation therapy oncology group (RTOG) and the common terminology criteria for adverse events (CTCAE v5.0).

Results

Of 105 patients with localized ACC, 46 (43.8%) received adjuvant RT after surgery. The median radiation dose was 45.0Gy (range:30.0-50.4) and median follow up time was 36.5 (IQR: 19.7-51.8) months. In comparison to the no adjuvant RT group, patients with adjuvant RT had better 3-year OS (87.9% vs 79.5%, P=0.039), especially for patients with ENSAT I/II stage (P=0.004). Adjuvant RT also improved the median DFS time from 16.5months (95%CI, 12.0-20.9) to 34.6months (95%CI, 16.1-53.0). Toxicity of RT was generally mild and moderate with six grade 3 events.

Conclusions

Postoperative adjuvant RT significantly improved OS and DFS compared with the use of surgery alone in resected ACC patients. Although this retrospective study on RT in localized ACC indicates that RT is effective in ACC, its findings need to be prospectively confirmed.

High-Dose Rate Brachytherapy Combined with PD-1 Blockade as a Treatment for Metastatic Adrenocortical Carcinoma - A Single Center Case Series

The response rate of advanced adrenocortical carcinoma (ACC) to standard chemotherapy with mitotane and etoposide/doxorubicin/cisplatin (EDP-M) is unsatisfactory, and benefit is frequently short lived. Immune checkpoint inhibitors (CPI) have been examined in patient's refractory to EDP-M, but objective response rates are only approximately 15%. High-dose rate brachytherapy (HDR-BT) is a catheter-based internal radiotherapy and expected to favorably combine with immunotherapies. Here we describe three cases of patients with advanced ACC who were treated with HDR-BT and the CPI pembrolizumab. None of the tumors were positive for established response markers to CPI. All patients were female, had progressed on EDP-M and received external beam radiation therapy for metastatic ACC. Pembrolizumab was initiated 7 or 23 months after brachytherapy in two cases and prior to brachytherapy in one case. Best response of lesions treated with brachytherapy was complete (n=2) or partial response (n=1) that was ongoing at last follow up after 23, 45 and 4 months, respectively. Considering all sites of tumor, response was complete and partial remission in the two patients with brachytherapy prior to pembrolizumab. The third patient developed progressive disease with severe Cushing's syndrome and died due to COVID-19. Immune-related adverse events of colitis (grade 3), gastroduodenitis (grade 3), pneumonitis (grade 2) and thyroiditis (grade 1) occurred in the two patients with systemic response. HDR-BT controlled metastases locally. Sequential combination with CPI therapy may enhance an abscopal antitumoral effect in non-irradiated metastases in ACC. Systematic studies are required to confirm this preliminary experience and to understand underlying mechanisms.

Current Evidence on Local Therapies in Advanced Adrenocortical Carcinoma

International guidelines emphasise the role of local therapies (LT) for the treatment of advanced adrenocortical carcinoma (ACC). However, large studies are lacking in this field. Therefore, we performed a review of the literature to synthesise current evidence and develop clinical guidance. PubMed database was searched for systematic literature. We identified 119 potentially relevant articles, of which 21 could be included in our final analysis. All were retrospective and reported on 374 patients treated with LT for advanced ACC (12 studies on radiotherapy, 3 on transarterial chemoembolisation and radioembolisation, 4 on image-guided thermal ablation [radiofrequency, microwave ablation, and cryoablation, and two studies reporting treatment with several different LT]). Radiotherapy was frequently performed with palliative intention. However, in most patients, disease control and with higher dosage also partial responses could be achieved. Data for other LT were more limited, but also point towards local disease control in a significant percentage of patients. Very few studies tried to identify factors that are predictive on response. Patients with a disease-free interval after primary surgery of more than 9 months and lesions<5 cm might benefit most. Underreporting of toxicities may be prevalent, but LT appear to be relatively safe overall. Available evidence on LT for ACC is limited. LT appears to be safe and effective in cases with limited disease and should be considered depending on local expertise in a multidisciplinary team discussion.