The role of metastasectomy in ACCs is still debatable, but sometimes suggestive in a selected subset of patients. Usually, metastasectomy is often undergone when all metastatic tumors are potentially completely resectable under the control of the primary site and patients have an adequate performance status and a good cardiopulmonary function. Of interest, low tumor burden or less than 6 metastatic tumors and favorable disease-free interval of more than 3 years were sometimes suggested to be selection criteria for pulmonary metastasectomy of ACC.7
The lack of systemic therapeutic alternatives is also suggested one of important selection criteria. In the current case, she had disease-free interval of 3 years, potentially resectable 2 metastatic nodules, and good performance status and residual liver function as well as cardiopulmonary function.
Some argue that as tumor growth of metastatic tumors of ACCs is slow, watchful waiting can be more appropriate, especially when there are no or few symptoms. However, although metastatic tumors grow optimistically slowly, they have relentless and progressive disease course, and long-term outcomes are dismal. Whereas, the response rates for cytotoxic chemotherapy are extremely variable and inconsistent, and response duration was generally short.10
In addition, disease stabilization is more often seen after cytotoxic chemotherapy than objective response but it should be interpreted very cautiously because the ACC, as mentioned above, usually grow slowly. Therefore, systemic cytotoxic chemotherapy should be reserved for those who have symptomatic and rapidly progressive disease. If recurrent or metastatic tumors are totally resectable with conserving organ functions, metastasectomy could be considered as one of the treatment options, such as cytotoxic chemotherapy or watchful waiting.
In conclusion, metastasectomy in patients with ACCs can be resorted to in a very highly selected subset of patients, who have potentially completely resectable metastatic tumors under the control of primary tumors and adequate performance and organ functions.