What are the indications and efficacy of mitotane? What factors affect the effectiveness of treatment?

Mitotane (Mitotane) is an anti-tumor drug used to treat adrenocortical carcinoma (ACC) in patients with unresectable, metastatic or recurrent ACC. As an adrenocortical cytotoxic drug, mitotane can selectively destroy adrenocortical cells and inhibit the synthesis of corticosteroids, thereby reducing tumor growth and hormone secretion. For patients with functional adrenocortical cancer, mitotane can also effectively reduce the level of excessive secretion of corticosteroids and relieve related symptoms such as Cushing's syndrome.

The therapeutic effects of mitotane vary between individuals. Studies have shown that when the blood concentration reaches 14–20 µg/mL, the drug has stronger anti-tumor activity and the patient's survival may be prolonged. However, because individuals metabolize mitotane at different rates, some patients may take longer to reach effective plasma concentrations. In addition, mitotane is often used as part of postoperative adjuvant therapy or combination chemotherapy to improve the therapeutic effect, but its efficacy when used alone is relatively limited.

The therapeutic effect is affected by many factors, including the patient's tumor stage, histological type, whether it is accompanied by abnormal hormone secretion, and drug tolerance. Patients with earlier tumor stages, better liver function, and the ability to maintain stable blood concentrations usually benefit more from mitotane treatment. For cases that progress rapidly or are insensitive to drugs, the effect of mitotane may be limited, and comprehensive treatment needs to be combined with other means such as radiotherapy, chemotherapy, or targeted therapy.

Although mitotane is effective in inhibiting the growth of adrenocortical cancer, it has many side effects, including gastrointestinal discomfort, neurological symptoms (eg, dizziness, confusion), and suppression of adrenal function. Therefore, patients need to regularly monitor blood concentration, electrolyte levels and adrenal gland function during the use of mitotane, and supplement glucocorticoids when necessary to reduce endocrine imbalance caused by the drug. Doctors also need to adjust the dosage according to the patient's tolerance to minimize side effects while controlling the disease.