What is your approach to asymptomatic patients with progressing lung metastatic adenoid cystic carcinoma originally arising from the trachea?  

In my practice, it depends on the disease burden and the rate of progression. If it's very slow, and the disease burden is modest, which is not uncommon, then often the risk of potential side effects can outweigh the potential benefit, given the lack of good data on systemic treatment, especially on...