How should a completely resected high‑grade stage 2 adrenocortical carcinoma be treated?

Treatment of Completely Resected High-Grade Stage 2 Adrenocortical Carcinoma

For completely resected high-grade stage 2 ACC, you should initiate adjuvant mitotane therapy for at least 2 years, targeting plasma levels of 14-20 mg/L, with appropriate glucocorticoid supplementation. 1

Risk Stratification and Treatment Decision

Your patient with stage 2 ACC and high-grade features (Ki-67 >10%) falls into the high-risk category that mandates adjuvant therapy. The 2020 ESMO-EURACAN guidelines explicitly recommend adjuvant mitotane for patients with high risk of recurrence, which includes Ki-67 index >10%, even with complete (R0) resection 1. The 2012 ESMO guidelines similarly state that patients with Ki-67 >10% should be offered adjuvant mitotane 2.

The rationale is compelling: more than half of patients with completely resected ACC will experience recurrence, often with metastases, and the greatest frequency occurs within the first 2 years 2.

Mitotane Administration Protocol

Starting and Dose Escalation

• Start with 1.5 g/day and increase within 4-6 days to 6 g/day
• After 3 weeks, adjust based on tolerability and blood levels
• Maximum dose is 12 g/day, though most patients cannot tolerate >8 g/day
• Target plasma mitotane level: 14-20 mg/L (less antitumor activity <14 mg/L; increased toxicity >20 mg/L) 2
• Approximately 50% of patients achieve target levels within 3 months using this regimen 2

Duration of Therapy

• Minimum 2 years of adjuvant mitotane, as this is when recurrence risk is highest 1, 2
• Do not continue beyond 5 years due to low recurrence rates after this timeframe 1
• Balance treatment duration individually, considering the significant quality of life impact 2

Essential Supportive Management

Mandatory Glucocorticoid Replacement

Due to mitotane's adrenolytic activity, all patients require glucocorticoid supplementation:

• 50 mg hydrocortisone daily (divided as 20-20-10 mg) or 75 mg cortisone acetate
• Higher doses may be needed due to increased metabolic clearance from mitotane 2
• Monitor with careful clinical assessment

Mineralocorticoid Supplementation

• Add fludrocortisone based on blood pressure, serum potassium, and plasma renin activity
• Monitor renin every 3 months; if elevated with symptoms of mineralocorticoid deficiency, add fludrocortisone 2

Additional Hormone Monitoring

• TSH, fT3, fT4 every 3-4 months (thyroid hormone replacement often needed)
• Testosterone in males with hypogonadism symptoms
• Mitotane induces widespread hormonal derangements requiring endocrinologist involvement 2

Laboratory Monitoring Schedule

Mitotane Levels

• Every 2-3 weeks during first 3 months until plateau achieved
• After plateau, extend to every 6 weeks 2

Liver Function

• GOT, GPT, bilirubin, GGT initially every 4 weeks
• After 6 months, every 8 weeks
• Critical caveat: GGT is invariably elevated without clinical consequences
• If other liver enzymes rapidly increase >3-fold baseline, stop mitotane immediately due to liver failure risk 2

Lipid Profile

• Cholesterol (HDL, LDL), triglycerides every 3-4 months 2

Surveillance Imaging Protocol

After complete resection, perform:

• Radiological imaging every 3 months for 2 years
• Then every 3-6 months for at least another 3 years
• Include abdominal CT (or MRI), thoracic CT, and monitoring of initially elevated steroids 1, 2
• Continue follow-up for at least 10 years total 2

Role of Adjuvant Radiotherapy

Adjuvant radiotherapy is NOT recommended for your patient with completely resected (R0) stage 2 disease. RT should only be considered on an individualized basis for:

• R1 or RX (uncertain margin) resections
• Stage III disease
• RT reduces local recurrence but does not prevent distant metastases or impact overall survival 1
• The combination of mitotane plus RT carries increased toxicity 1

Evidence Strength and Nuances

The recommendation for adjuvant mitotane in high-risk stage 2 ACC is based on a landmark case-control study of 177 patients showing significantly improved disease-free survival and overall survival in patients receiving adjuvant mitotane compared to those who did not 2. Research data confirms mitotane therapy increases recurrence-free survival, with this effect significantly improved by adjuvant radiation (though the latter is not indicated in your R0 resection case) 3.

Important caveat: While the evidence supports adjuvant mitotane for high-risk features, it comes from retrospective data rather than randomized controlled trials. The ADIUVO trial was designed to provide prospective evidence but results remain pending 2.

The presence of high-grade features (Ki-67 >10%) in your patient is a validated negative prognostic factor that justifies aggressive adjuvant therapy 3, 4. Research confirms that tumor grade (HR 2.4 for death, 2.0 for recurrence) independently predicts worse outcomes 3.

Common Pitfalls to Avoid

1. Underestimating glucocorticoid needs: Mitotane dramatically increases glucocorticoid metabolism; standard replacement doses are insufficient
2. Stopping mitotane for isolated GGT elevation: GGT rises universally and is not concerning unless other liver enzymes are elevated
3. Inadequate monitoring frequency: Early intensive monitoring is essential to achieve therapeutic levels and detect toxicity
4. Premature discontinuation: Despite significant quality of life impact, maintain therapy for minimum 2 years given recurrence patterns