A blue-ribbon team of national experts on brain cancer said that professional pessimism and out-of-date myths rather than current science may compromise the care of patients with cancer that has metastasized to the brain.
Assumptions underlying key clinical trials in the past are now out-of-date, and some physicians have lumped together brain metastases without regard to the primary site of the cancer. This has resulted in less-thanoptimal care for individual patients. Furthermore, insurers may question care that deviates from these entrenched misconceptions, the authors concluded.
“It’s time to abandon this unjustifiable nihilism and think carefully about individualized care,” said lead author Douglas S. Kondziolka, MD, director of the gamma knife program in the department of neurosurgery at New York University, in New York, New York. The authors identified five leading misconceptions that may lead to poor care.
• All tumor cell types act the same way once they metastasize to the brain. This oversimplification assumes that histologically diverse cancers respond the same way to chemotherapy and are equally sensitive (or insensitive) to radiation. It assumes that patients are at the same risk for subsequent brain cancer relapses, development of additional metastatic lesions, and have similar survival rates. This type of thinking overlooks important biological differences in brain metastases resulting from very different types of cancer, such as those originating in the lung, breast, or skin.
• The number of brain metastases is the best guide for disease management. Strict adherence to the number of metastases can limit treatment options inappropriately. Physicians should look at the total tumor burden, including the size and scope of metastases, rather than just the number of metastases.
• All cancers in the brain reflect the presence of micrometastases. Aggressively monitoring for and treating individual brain metastases can improve disease control and patient survival.
• Whole brain irradiation is unjustified because it causes disabling cognitive dysfunction if a patient lives long enough. The risks and benefits of whole brain irradiation should be evaluated for each patient. New studies examining the cognitive impact of whole brain irradiation on thinking and learning are underway.
• Most brain metastases cause obvious symptoms and therefore regular screening for brain metastases is unnecessary and does not affect survival. Advances in screening allow detection of metastases earlier, before symptoms occur. This allows earlier treatment, which can affect quality of life and survival.
Molecular and genetic subtyping will continue to reveal why brain metastases from specific primary tumors develop in some patients, but not in others. These answers should in turn influence how best to manage brain metastases in patients.
“We are in an era of personalized medicine,” Kondziolka said, “and we need to begin thinking that way. It is time for fresh thinking and new, critical analyses.”