Relative survival of adult patients with Burkitt lymphoma in The Netherlands, 1989 to 2018. Relative survival rates (RSRs) are presented for the following age categories: (A) 18 to 39, (B) 40 to 59, (C) 60 to 75, and (D) >75 years. The table presents the projected 1- and 5-year RSRs with 95% confidence intervals according to age at diagnosis and calendar period of diagnosis. The asterisk indicates the P value for likelihood ratio test assessing linear trends from the calendar period 1989 to 2002 to the calendar period 2009 to 2018. RSRs for patients aged >75 years were truncated at 5 years, because comparatively few were alive 5 years after diagnosis.