I briefly mentioned the potential value of surgery for a solitary brain metastasis, where it is commonly used, in another post. Today I'll talk more specifically about where the role for surgery has been specifically tested for brain metastases in lung cancer. Aside from possibly removing the only lesion (in certain cases, where it can be associated with long-term survival, as I described in my post on solitary brain metastases), neurosurgery is used to offer rapid relief of symptoms resulting from the mass effect of a large tumor, to improve local control of brain metastases, and/or to clarify the tissue diagnosis when there is some question about the underlying diagnosis of a brain lesion. Improvements in anesthesia and neurosurgery have made this intervention safer and more feasible for patients over time.

One way to assess the value of surgery in the treatment of brain metastases is by comparing the results of WBRT vs. a combination of neurosurgery and SRS, and three randomized trials have done that (abstracts here and here and here). The first was an influential trial by Patchell and colleagues (abstract here), of 48 patients with a single brain metastasis who underwent surgery followed within two weeks by WBRT (36 Gy over 12 fractions) or WBRT alone. This study, although small, did show very clear and statistically significant improvements in likelihood of recurrence of brain metastases (20% vs. 52%) and median overal survival (40 vs. 15 wks). These results were corroborated by another trial (abstract here) of 63 patients with a single brain lesion who received WBRT alone or preceded by surgery, showing a significant improvement in survival (10 vs. 6 months). These trials both also showed that patients undergoing a combination of surgery and WBRT remained functionally independent for longer. The third and largest trial (abstract here), with 84 patients who also had a single brain lesion, actually did not demonstrate a significant improvement in survival or functional status, but this trial had patients with a greater burden of distant disease than the other trials. The results of these three studies are shown here:

(click to enlarge)

The differences among these trials reminds us that the value of surgery for brain metastases is still questionable, and it is a most compelling consideration for patients with a single metastasis, good performance status, and controlled disease outside of the brain. There is really remarkably little experience to guide us on the value of surgery for more than a solitary brain metastasis, but it is generally felt to be far less appealing than in the more commonly advocated setting of treating a single brain metastasis.