Epidemiology of brain lymphoma among people with or without acquired immunodeficiency syndrome. AIDS/Cancer Study Group.
BACKGROUND
In recent years, brain lymphoma incidence has dramatically increased, presumably because of elevated risk of brain lymphoma among persons with acquired immunodeficiency syndrome (AIDS).


OBJECTIVE
The objective of this study was to estimate independent incidence and survival rates of brain lymphoma among persons with or without AIDS and to understand the epidemiologic features of this cancer.


METHODS
We linked AIDS and cancer registry reports at nine state and local health departments and compared the demographics, histology, and survival of brain lymphoma cases among persons with or without AIDS. The data were limited to people under 70 years of age. We calculated the incidence of brain lymphoma among persons with AIDS and compared observed cases with those expected. The differences were statistically analyzed using the Poisson test. Epidemiologic features of brain lymphoma in persons with or without AIDS were compared using the chi-squared test, the Student's t test, and the chi-squared test for linear trend. The logrank test was used to compare survival rates estimated by the Kaplan-Meier technique. All P values were two-sided.


RESULTS
We matched 50,989 AIDS registry reports to 859,398 cancer registry reports (data from 1981 to 1990) and found 431 people with both AIDS and brain lymphoma. Among people with AIDS, those developing brain lymphoma versus those without brain lymphoma were more likely to be white (70% versus 59%; P < .001) and had homosexuality as their only human immunodeficiency virus risk factor (75% versus 64%; P < .001). Of the 431 patients, 223 developed brain lymphomas during 47,465 person-years of observation after diagnosis of AIDS. The absolute incidence rate of brain lymphoma among persons with AIDS was 4.7/1000 person-years (95% confidence interval = 4.1-5.3/1000 person-years), 3600-fold higher than the base-line rate in the general population. From 1980 through 1989, overall counts of brain lymphoma increased ninefold. Most of this increase was derived from persons with AIDS, but a substantial increase also occurred among persons without AIDS (0.04/100,000 in 1982 to 0.28/100,000 in 1989) (chi-squared test for trend; P < .05). The median survival was shortest for persons with AIDS and brain lymphoma (2 months), was intermediate for persons with brain lymphoma without AIDS (5-7 months), and was longest for persons with AIDS without brain lymphoma (14 months) (P < .05 for all comparisons).


CONCLUSIONS
This analysis distinguishes the separate epidemiologies of brain lymphoma incidence among persons with or without AIDS and shows brain lymphoma incidence among persons with AIDS to be several thousand-fold higher than that in the general population. The study documents the overwhelming effect of AIDS-associated brain lymphoma on the overall rate in the general population and demonstrates a significantly rising trend, although of a lesser magnitude, among persons without AIDS.


CONCLUSIONS
This study emphasizes a greater need to bring health care resources to this burgeoning epidemic.
Coté
T R
TR
Division of Cancer Etiology, National Cancer Institute, Bethesda, MD, USA.
Manns
A
A
Hardy
C R
CR
Yellin
F J
FJ
Hartge
P
P
D000328:Adult; D001932:Brain Neoplasms / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D006801:Humans; D015994:Incidence; D016483:Lymphoma, AIDS-Related / Q000453:epidemiology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012042:Registries; D012306:Risk; D015996:Survival Rate; D014481:United States / Q000453:epidemiology