Brain metastases in adenocarcinoma of the lung: frequency, risk groups, and prognosis

A consecutive group of 259 patients with inoperable adenocarcinoma of the lung (ACL) were observed to define risk groups for and frequency of brain metastases together with prognosis. All patients received chemotherapy in a three-armed randomized trial. Brain metastases were diagnosed in 25 patients before protocol entry and in 37 during treatment. Brain autopsy was performed in 87 patients and was positive in 38 (44%). Eleven of these (29%) were not diagnosed clinically. Patients younger than 60 years had a somewhat higher overall frequency of brain metastases than older patients. Patients with initial performance status above 60% and patients responding to chemotherapy had higher risk for developing brain metastasis during treatment than other patients, probably because of the increasing cumulated risk for this complication with prolonged survival. Median survival after onset of brain metastases was 73 days and survival was significantly shorter for these patients than for patients without this complication at days 0, 90, 180, and 365 after protocol entry. Thus, brain metastases is a frequent complication in ACL and the frequency increases with prolonged survival. Survival after development of brain metastases is short and it is questionable whether the inclusion of this subgroup of ACL patients into experimental cytostatic treatments is justified.