Oligometastatic adrenocortical carcinoma: the role of image-guided thermal ablation

Advances in Image-Guided Ablation Therapies for Solid Tumors

Image-guided solid tumor ablation methods have significantly advanced in their capability to target primary and metastatic tumors. These techniques involve noninvasive or percutaneous insertion of applicators to induce thermal, electrochemical, or mechanical stress on malignant tissue to cause tissue destruction and apoptosis of the tumor margins. Ablation offers substantially lower risks compared to traditional methods. Benefits include shorter recovery periods, reduced bleeding, and greater preservation of organ parenchyma compared to surgical intervention. Due to the reduced morbidity and mortality, image-guided tumor ablation offers new opportunities for treatment in cancer patients who are not candidates for resection. Currently, image-guided ablation techniques are utilized for treating primary and metastatic tumors in various organs with both curative and palliative intent, including the liver, pancreas, kidneys, thyroid, parathyroid, prostate, lung, breast, bone, and soft tissue. The invention of new equipment and techniques is expanding the criteria of eligible patients for therapy, as now larger and more high-risk tumors near critical structures can be ablated. This article provides an overview of the different imaging modalities, noninvasive, and percutaneous ablation techniques available and discusses their applications and associated complications across various organs.

Clinical outcomes of image-guided therapies in patients with adrenocortical carcinoma: a tertiary referral center retrospective study

BACKGROUND

Image-guided therapies (IGTs) are commonly used in oncology, but their role in adrenocortical carcinoma (ACC) is not well defined.

MATERIALS AND METHODS

A retrospective review of patients with ACC treated with IGTs. We assessed response to therapy using RECIST v1.1, time to next line of systemic therapy, disease control rate (DCR), local tumor progression-free survival (LTPFS), and complications of IGTs (based on the Common Terminology Criteria for Adverse Events [CTCAE] version 5.0).

RESULTS

Our cohort included 26 patients (median age 56 years [range 38-76]; n = 18 female) who had 51 IGT sessions to treat 86 lesions. IGTs modalities included cryoablation (n = 49), microwave ablation (n = 21), combined microwave and bland trans-arterial embolization (n = 8), bland trans-arterial embolization alone (n = 3), radio-embolization (n = 3), and radiofrequency ablation (n = 2). DCR was 81.4% (70 out of 86), of which 66.3% of tumors showed complete response, 18.6% showed progressive disease, 8.1% showed partial response, and 7.0% showed stable disease. LTPFS rates were 73% and 63% at 1 and 2 years, respectively. Fourteen lesions underwent re-ablation for incomplete response on initial treatment. Sixteen patients (61.5%) received new systemic therapy following IGTs, with a median time to systemic therapy of 12.5 months (95% CI: 8.6 months upper limit not reached). There was 1 reported CTCAE grade 3 adverse event (biloma) following IGT.

CONCLUSIONS

IGT use in properly selected patients with ACC is safe and associated with prolonged disease control and delay in the need for systemic therapy.

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.

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.

Early Detection of Recurrence and Progress Using Serum Steroid Profiling by LC-MS/MS in Patients with Adrenocortical Carcinoma

Serum liquid chromatography-tandem mass spectrometry (LC-MS/MS) steroid profiling is used for the diagnosis of adrenocortical carcinoma (ACC). Guidelines recommend endocrine work-up in addition to radiological imaging for follow-up in ACC, but data on this topic are scarce. Patients were included in this retrospective study if pre-therapeutic hormone values, regular tumour evaluation by imaging, steroid measurements by LC-MS/MS, and details on therapies were available. The utility of steroid profiles in detecting recurrence or disease progression was assessed, whereby "endocrine progress" was defined by an elevation of at least 3 of 13 analysed hormones. Cohort A included 47 patients after R0 resection, of whom 15 experienced recurrence and 32 did not. In cohort B, 52 patients with advanced disease (including 7 patients of cohort A with recurrence) could be evaluated on 74 visits when progressive disease was documented. In 20 of 89 cases with documented disease progression, "endocrine progress" was detectable prior to radiological progress. In these cases, recurrence/progression was detected at a median of 32 days earlier by steroid measurement than by imaging, with 11-deoxycortisol and testosterone being the most sensitive markers. Notably, these patients had significantly larger tumour burden. In conclusion, steroid profiling by LC-MS/MS is of value in detecting recurrent/progressive disease in ACC.

The management of postoperative disease recurrence in patients with adrenocortical carcinoma: a retrospective study in 106 patients

OBJECTIVE

The management of adrenocortical carcinoma (ACC) recurrences remains controversial, and we present herein our experience with postoperative ACC recurrences.

DESIGN AND METHODS

Retrospective analysis in a single reference center of 106 patients with ACC recurrence.

RESULTS

The median follow-up was 45 months, the median recurrence-free survival (RFS) 12 months (IQR 6-23), and the median overall survival (OS) 45 months (IQR 29-75). ACC recurrences occurred as a unique lesion (group A) in 35.8%, multiple lesions in a single organ (group B) in 20.8%, and affecting multiple organs (group C) in 43.4% of patients. Baseline characteristics of patients stratified by the type of recurrence did not differ between them, except RFS, which was significantly longer in group A. Locoregional treatments were used in 100% of patients of group A, 68.2% in group B, and 26.1% in group C. After treatment of recurrence, 60.4% of patients became free of disease attaining a second RFS of 15 months (IQR 6-64). Margin status RX and R1, percent increase in Ki67, and recurrence in multiple organs were associated with an increased risk of mortality, while adjuvant mitotane treatment and longer time to first recurrence were associated with reduced risk. Recurrence in multiple organs and systemic treatment of recurrence had a negative impact on survival from the treatment of recurrence.

CONCLUSIONS

This study shows that patients with ACC have a better prognosis when the disease recurs as a single lesion and supports the use of locoregional treatments to treat disease recurrence.

A Case of Adrenocortical Carcinoma With a Favorable Tumor Control by Radiofrequency Ablation for Liver Metastasis

A 57-year-old woman was diagnosed with adrenocortical carcinoma. Following the adrenalectomy, she underwent adjuvant radiation and mitotane therapy; however, liver metastases were observed. Repeated radiofrequency ablation (RFA) was performed for liver metastases. In addition, a multidisciplinary approach combining systemic chemotherapy, radiotherapy, and surgery was used for lung and distant lymph node metastases that arose during the course of treatment. Notably, 49 months have passed since the adrenalectomy and 36 months since the recurrence of the liver metastases, and the patient remains on multidisciplinary therapy. Thus, RFA for liver metastasis of adrenocortical carcinoma may be an effective component of a multidisciplinary treatment.

Bridging the Scientific Gaps to Identify Effective Treatments in Adrenocortical Cancer

Adrenocortical cancer (ACC) typically presents in advanced stages of disease and has a dismal prognosis. One of the foremost reasons for this is the lack of available systemic therapies, with mitotane remaining the backbone of treatment since its discovery in the 1960s, despite underwhelming efficacy. Surgery remains the only potentially curative option, but about half of patients will recur post-operatively, often with metastatic disease. Other local treatment options have been attempted but are only used practically on a case-by-case basis. Over the past few decades there have been significant advances in understanding the molecular background of ACC, but this has not yet translated to better treatment options. Attempts at novel treatment strategies have not provided significant clinical benefit. This paper reviews our current treatment options and molecular understanding of ACC and the reasons why a successful treatment has remained elusive. Additionally, we discuss the knowledge gaps that need to be overcome to bring us closer to successful treatment and ways to bridge them.

Loco-Regional Therapies in Oligometastatic Adrenocortical Carcinoma

Objective: The recommended first-line treatment for low-tumor-burden ACC (stage IVa ACC) not amenable to radical resection is mitotane in association with loco-regional treatments (LRs). The aim of this study was to determine the patient population that would benefit the most from LR. Materials and methods: This retrospective monocentric expert center chart review study was performed from 2008 to 2021 and included stage IVa patients (≤2 tumoral organs) treated with LR (either radiotherapy, surgery, or interventional radiology). The primary endpoint was disease control (DC). Correlations between DC, time to systemic chemotherapy (TTC), overall survival (OS), and tumor characteristics were analyzed using Kaplan−Meier survival analysis and Cox’s proportional hazards regression model for multivariate analysis. Results: Thirty-four women (57%) and 26 men with a median age of 48.1 years (IQR: 38.3−59.8) were included. One hundred and nine LRs were performed, with a median of 2 (IQR: 1−3) per patient. DC was achieved in 40 out of 60 patients (66.7%). Patients with DC had a significantly longer TTC (HR: 0.27, p < 0.001) and OS (HR: 0.22, p < 0.001). Patients with less than or equal to 5 metastases (HR: 6.15 (95% CI: 1.88−20.0), p = 0.002) or a maximum metastasis diameter below 3 cm had higher rates of DC (HR: 3.78 (95% CI: 1.09−13.14), p = 0.035). Conclusion: stage IVa ACC patients with ≤5 metastases or a maximum metastasis diameter below 3 cm had favorable responses to LR. We propose the name oligometastatic ACC for this subgroup of patients.

Combination of Mitotane and Locoregional Treatments in Low-volume Metastatic Adrenocortical Carcinoma

CONTEXT

European and French guidelines for ENSAT stage IV low tumor burden or indolent adrenocortical carcinoma (ACC) recommend a combination of mitotane and locoregional treatments (LRT) as first-line treatment. Nevertheless, the benefit of LRT in combination with mitotane has never been evaluated in this selected group of patients.

OBJECTIVE

This work aimed to evaluate the therapeutic strategy of LRT combined with mitotane in patients with low tumor burden stage IVA ACC.

METHODS

A retrospective chart review was performed from 2003 to 2018 of patients with stage IV ACC with 2 or fewer tumoral organs who received mitotane in our center. The primary end point was the delay between mitotane initiation and first systemic chemotherapy. Secondary end points were progression-free survival (PFS) and overall survival (OS) from mitotane initiation. Adjusted analyses were performed on the main prognostic factors.

RESULTS

Out of 79 included patients, 48 (61%) patients were female and the median age at stage IVA diagnosis was 49.8 years (interquartile range [IQR], 38.8-60.0 years). Metastatic sites were mainly lungs (76%) and liver (48%). Fifty-eight (73%) patients received LRT including adrenal bed radiotherapy (14 patients, 18%), surgery (37 patients, 47%), and/or interventional radiology (35 patients, 44%). Median time between mitotane initiation and first chemotherapy administration was 9 months (IQR, 4-18 months). Median PFS1 (first tumor-progression) was 6.0 months (95% CI, 4.5-8.6). Median OS was 46 months (95% CI, 41-68). PFS1, PFS2, and OS were statistically longer in the mitotane plus LRT group compared to the mitotane-only group (hazard ratio [HR] = 0.39; 95% CI, 0.22-0.68; HR = 0.35; 95% CI, 0.20-0.63; and HR = 0.27; 95% CI, 0.14-0.50, respectively). Ten (13%) patients achieved complete response (CR), all from the mitotane plus LRT group.

CONCLUSION

Our results endorse European and French guidelines for stage IV ACC with 2 or fewer tumor organs and favor the combination of mitotane and LRT as first-line treatment. For the first time, a significant number of CRs were observed. Prospective studies are expected to confirm these findings.

Thermal ablation in adrenal disorders: a discussion of the technology, the clinical evidence and the future

PURPOSE OF REVIEW

To summarise the emerging role of thermal ablation as a therapeutic modality in the management of functioning adrenal tumours and metastases to the adrenal gland.

RECENT FINDINGS

Observational evidence has demonstrated the benefit of thermal ablation in (i) resolving adrenal endocrinopathy arising from benign adenomas, (ii) treating solitary metastases to the adrenal and (iii) controlling metastatic adrenocortical carcinoma and phaeochromocytoma/paraganglioma.

SUMMARY

Microwave thermal ablation offers a promising, minimally invasive therapeutic modality for the management of functioning adrenocortical adenomas and adrenal metastases. Appropriate technological design, treatment planning and choice of imaging modality are necessary to overcome technical challenges associated with this emerging therapeutic approach.