Informing therapeutic lymphadenectomy: Location of regional metastatic lymph nodes in adrenocortical carcinoma

Adrenocortical carcinoma: a practical guide for clinicians

Adrenocortical carcinoma is a rare endocrine malignancy. The management of patients with adrenocortical carcinoma is challenging for several reasons, including its heterogeneous but frequently aggressive biological behaviour; tumour-related hormonal excess (eg, Cushing's syndrome or virilisation); the overall paucity of evidence regarding diagnostic investigation and treatment; the approval of only one drug (mitotane); and the scarcity of centres with sufficient experience. In this Review, we present 25 questions on the most important aspects of the clinical management of adult patients with adrenocortical carcinoma that we have frequently asked ourselves over the past 25 years. We offer our personal answers and perspectives, drawing upon published evidence as well as more than 60 years of collective clinical experience and insights from our management of more than 1700 patients across two centres in Germany and Italy.

Which lymphadenectomy for adrenocortical carcinoma?

BACKGROUND

Lymph node dissection improves adrenocortical carcinoma staging, but remains anatomically poorly defined. This ambiguity stems from limited knowledge of the adrenals lymphatic network. This work aims to define lymph node dissection for adrenocortical carcinoma through a systematic review and anatomical study.

METHOD

First, an anatomical study was conducted on fresh cadavers by injecting blue dye into each adrenal gland before dissection. Concurrently, a systematic review of anatomical and clinical studies was performed, focusing on adrenals lymphatic network, lymph node dissection, and location of invaded lymph nodes in surgical series.

RESULTS

Twelve adrenals from 6 cadavers were resected en bloc with a median of 3 lymph nodes (1.5-6) removed. Screening of 6,506 studies revealed (1) 18 anatomical studies on cadavers detailing a 3-stage compartmentalized adrenals lymphatic network with distinct right/left lymph nodes relays; (2) 4 clinical studies highlighting discrepancies in lymph node involvement in adrenocortical carcinoma patients compared with anatomical description of adrenals lymphatic network, notably: lower implication of celiac lymph node, preponderance of ipsilateral renal hilum lymph nodes, potential contralateral involvement; (3) 21 series of adrenocortical carcinoma surgery demonstrating the heterogeneity of lymph node dissection practice (22% ± 4% lymph node dissection rate), with an average of 2.7 ± 0.6 lymph nodes removed, already fewer than in our cadaveric study.

CONCLUSION

Synthesis of anatomical and clinical studies suggest the following lymph node dissection protocol during adrenocortical carcinoma resection: capsular, renal hilum, para-cava, and inter-aortic-cava lymph nodes (right adrenocortical carcinoma); and capsular, renal hilum, para-aortic, and inter-aortic-cava lymph nodes (left adrenocortical carcinoma).

ENDOCRINE TUMOURS: Our experience with the management of patients with non-metastatic adrenocortical carcinoma

Adrenocortical carcinoma (ACC) accounts for a minority of all malignant tumors in adults. Surgery remains the most important therapeutic option for non-metastatic ACC. Whether a subset of patients with small ACC may benefit from minimally invasive surgery remains a debated issue, but we believe that surgeon's expertise is more important than surgical technique to determine outcome. However, even a state-of-the-art surgery cannot prevent disease recurrence that is determined mainly by specific tumor characteristics. We consider that the concomitant presence of the following features characterizes a cohort of patients at low risk of recurrence, (i) R0 resection (microscopically free margin), (ii) localized disease (stage I-II ACC), and (iii) low-grade tumor (ki-67 <10%). After the ADIUVO study, we do not recommend adjuvant mitotane as a routine measure for such patients, who can be managed with active surveillance thus sparing a toxic treatment. Patients at average risk of recurrence should be treated with adjuvant mitotane. For patients at very high risk of recurrence, defined as the presence of at least one of the following: Ki67 >30%, large venous tumor thrombus, R1 resection or stage IV ACC, we increasingly recommend to combine mitotane with four cycles of platinum-based chemotherapy. However, patients at moderate-to-high risk of recurrence should be ideally enrolled in the ongoing ADIUVO2 trial. We do not use adjuvant radiotherapy of the tumor bed frequently at our institutions, and we select patients with incomplete resection, either microscopically or macroscopically, for this treatment. In the long-term, prospective multicenter trials are required to improve patient care.