Figure 2

Landmark analysis. Kaplan–Meier survival curve for comparison of the group which experienced acute exacerbation (AE group) with one which did not experience acute exacerbation (no AE group) during the first-line chemotherapy with landmark points of (a) 30, (b) 60, (c) 90, and (d) 120 days, respectively, after the date of administration of the first-line regimen.