Top down treatment: Why we prioritize treating brain mets over the chest/body disease in metastatic lung cancer
This morning, I saw a lady who was just diagnosed with lung cancer after developing problems with speaking that led her to the ER. There, she was found to have several brain metastases, then a lung mass that was biopsied and proven to be a new lung cancer. In talking with her and her family about how to proceed, I outlined a plan of starting with treating the brain lesions with radiation, then following with chemotherapy (she doesn’t have a driver mutation like EGFR or ALK). Why do we prioritize treating the brain metastases?
The simple answer is that they are a more pressing problem that set the pace if not treated quickly. Encased by a hard skull, the brain has limited real estate and is intolerant of being squeezed by metastases growing faster than the brain around it. If not treated quickly, problems like balance problems, vision changes, seizures, and eventually death can occur. While there is a lot more room in the chest or abdomen, making a delay in the start of treatment by a few weeks unlikely to make much of a difference, brain metastases need to be treated within days to a week or so.
You might ask, “why not treat brain and body at the same time, with both brain radiation and chemo (or targeted oral therapy) together?”. Yes, that’s a possibility, but that involves combining the side effects of concurrent therapies when there isn’t a clear value in doing so. Certainly, if a patient has just one or a few brain lesions and can get focal radiation like Gamma Knife/Cyber Knife in a single session, that can be done with concurrent chemotherapy and likely no additive side effects. Some patients may be motivated enough and/or hardy enough to do whole brain radiation and chemo at the same time, but there isn’t a clear advantage to that overlap. Instead, it’s most important to tackle the most imminent threat first, and that’s the brain metastases. The cancer in the rest of the body is important, too, but it usually be safely deferred until the higher priority brain mets are treated.
http://expertblog.lungevity.org/2013/11 ... ver-heart/
