Adenocarcinoma was linked to significantly longer survival outcomes than other histologies in a certain subgroup of patients with brain metastatic non–small cell lung cancer, according to recent study results.
The study was conducted in response to recent data suggesting that differential response and outcomes to chemotherapy are associated with different histologies of NSCLC. The effect of histologic subtypes on survival stratified by the graded prognostic assessment was evaluated in a cohort of 780 NSCLC patients with brain metastases.
Findings were culled from an institutional review board-approved database and included patients treated between 1982 and 2004. Several graded prognostic assessment (GPA) variables were factored into the analysis, including age, Karnofsky performance score, number of brain metastases and presence of extracranial disease.
The researchers calculated median survival time and used a log rank test to determine statistical differences.
Results indicated that 464 patients with adenocarcinoma had median survival time of 6.2 months, compared with a survival time of 4.1 months among 98 patients with large cell disease and 4.2 months among 108 patients with squamous cell disease (P=.0549).
No significant differences in median survival time were observed by histology for GPA values of 3.5 to 4. However, differences in median survival time were reported for GPA values of 3 (P=.04), 1.5 to 2.5 (P=.01), and 0 to 1 (P=.02).
When all patients with brain metastases from NSCLC were evaluated, median survival times by GPA score were 12.6 months for 3.5 to 4; 10.2 months for 3; 5.8 months for 1.5 to 2.5; and 2.7 months for 0 to 1.0.
“Adenocarcinoma showed a statistically significant higher [median survival time] than other histologies of NSCLC for patients with GPA 0–3.0,” the researchers wrote. “Using histology as a prognostic factor for [brain metastases] from NSCLC warrants further investigation.”