A nested case-control study of non-Hodgkin lymphoma and serum organochlorine residues.
BACKGROUND
The steady worldwide increase in the incidence of non-Hodgkin lymphoma during the past few decades remains mostly unexplained. Several studies suggest that there may be an association between the agricultural use of the organochlorine 1,1,1-trichloro-2,2'bis(p-chlorophenyl)ethane (DDT) and increased risk of non-Hodgkin lymphoma. We have investigated the association between risk of non-Hodgkin lymphoma and body burden of selected organochlorines in the general population in a nested case-control study.


METHODS
We measured prediagnostic serum concentrations of DDT, its metabolites, and other organochlorines, including polychlorinated biphenyls (PCBs), in 74 cases of non-Hodgkin lymphoma and 147 matched controls identified from a prospective cohort of 25,802 adults, established in 1974 in Washington County, Maryland, USA. We report results for total lipid-corrected serum concentrations of DDT and total PCBs.


RESULTS
There was a strong dose-response relation between quartiles of total lipid-corrected serum PCB concentrations and risk of non-Hodgkin lymphoma overall (odds ratios by quartile: 1.0; 1.3 [95% CI 0.5-3.3]; 2.8 [1.1-7.6]); and 4.5 [1.7-12.0]; p for trend = 0.0008) and separately in men and in women. There was also evidence suggesting that seropositivity for the Epstein-Barr virus early antigen potentiated the effects of serum PCBs. By contrast, total lipid-corrected serum concentrations of DDT were not associated with risk of non-Hodgkin lymphoma.


CONCLUSIONS
These results should be regarded as hypothesis-generating. Before causal inferences can be made about exposure to PCBs and increased risk of non-Hodgkin lymphoma, our findings require replication and the biological plausibility of the association needs further investigation.
Rothman
N
N
Division of Cancer Edidemiology and Genetics (EPN 418), National Cancer Institute, Bethesda, MD 20892, USA.
Cantor
K P
KP
Blair
A
A
Bush
D
D
Brock
J W
JW
Helzlsouer
K
K
Zahm
S H
SH
Needham
L L
LL
Pearson
G R
GR
Hoover
R N
RN
Comstock
G W
GW
Strickland
P T
PT
D000328:Adult; D001822:Body Burden; D016022:Case-Control Studies; D003634:DDT / Q000009:adverse effects / Q000097:blood; D005260:Female; D006566:Herpesviridae Infections / Q000150:complications; D004854:Herpesvirus 4, Human / Q000302:isolation & purification; D006801:Humans; D015994:Incidence; D007306:Insecticides / Q000009:adverse effects / Q000097:blood*; D008228:Lymphoma, Non-Hodgkin / Q000097:blood* / Q000453:epidemiology / Q000209:etiology; D008297:Male; D008396:Maryland / Q000453:epidemiology; D008875:Middle Aged; D012042:Registries; D014412:Tumor Virus Infections / Q000150:complications
D007306:Insecticides; D003634:DDT