P3.01-101 A Retrospective Study of Lung Cancer that has Progressed to Brain Metastasis Alone

There is no consensus whether systemic therapy is needed after local treatment of lung cancer that has progressed to brain metastasis alone. To clarify the effect of treatment differences on patient survival, we conducted a retrospective study of treatment outcomes in patients with lung cancer that progressed to brain metastasis alone. The study included patients diagnosed with lung cancer at our hospital between January 2011 and December 2016 and those with disease progression to brain metastasis alone by December 2017. We divided the patients according to the treatment administered and compared their characteristics and survival. This study included 26 patients. Among them, 7 patients were followed up after local treatment (FU) and 19 patients received systemic therapy after local treatment (ST). The patient characteristics were as follows: median age (years): FU, 71 and ST, 68; sex (male/female): FU, 5/2 and ST, 8/11; disease stage at diagnosis (I/II/III/IV/postoperative recurrence): FU, 3/0/3/1/0 and ST, 0/1/7/9/2; and histology (small cell lung cancer/non-small cell lung cancer): FU, 1/6 and ST, 6/13. There were no significant differences in survival between the two groups (median progression-free survival [PFS; months], FU vs. ST=9 vs. 5, P=0.581; median overall survival [months], FU vs. ST=26 vs. 13, P=0.656). Analysis of prognosis showed significant differences only in disease stage at diagnosis based on univariate Cox analysis of PFS (I–III vs. IV or postoperative recurrence; hazard ratio, 3.440; 95% confidence interval, 1.16-10.22; P=0.026). In patients with lung cancer that has progressed to brain metastasis alone, administration of systemic therapy may not be necessary until further disease progression after local treatment.