Central nervous system metastasis (mCNS) accounts for most brain and spinal cord tumors. While recent advances have developed new, effective methods to treat primary cancers, the incidence of mCNS continues to rise. As managing these metastatic tumors remains complicated, any improvement to detection techniques could greatly benefit patient care and survivorship.
Patients with inflammatory breast cancer (IBC), a rare subset of breast cancer associated with swelling caused by cancer cells blocking lymph vessels, exhibit a high risk of developing mCNS. However, the rarity of this type of breast cancer has limited the number of participants in many studies investigating the links between IBC and mCNS.
To identify mCNS risk factors in IBC patients, a team of researchers conducted a study and published their findings in the journal Cancer. The data generated in the study emerged from a retrospective review of over 500 patients diagnosed with stage III or IV breast cancer who exhibited symptoms of IBC. The researchers obtained a sizable number of participants as they included patients diagnosed over 22 years (1997 to 2019).
The retrospective study included 372 patients with stage III and 159 patients with stage IV breast cancer. Overall, 124 patients developed mCNS. In those diagnosed at stage III, 5%, 9%, and 18% incidence of IBC occurred within one, two, and five years, respectively. Stage IV patients exhibited accelerated incidence of mCNS at all follow-up times: 17%, 30%, and 42% and one, two, and five years. Sadly, most patients survived less than a year following mCNS.
The researchers used multivariate statistical techniques to identify risk factors predisposing IBC patients to mCNS. Those whose first metastasis occurred in a visceral organ, like the liver or lung, or diagnosed with a triple-negative breast cancer subtype experienced an elevated risk of developing mCNS. Further, patients diagnosed at a younger age also exhibited a higher risk of mCNS than older patients.
The authors suggest that their findings underestimate mCNS incidence because many brain metastases go undetected without the onset of neurological symptoms. Based on this report, additional studies investigating how early detection of mCNS relates to outcomes in IBC patients are warranted. An editorial accompanying the publication of this study raises the provocative question of whether implementing routine screening for brain metastasis could improve survival in IBC patients.
Sources: Neurooncol Adv, Cancer (Uemura), Cancer (Warren), Cancer (Dhakal)