Plasma antibodies against Trichomonas vaginalis and subsequent risk of prostate cancer.
BACKGROUND
Although several previous case-control studies have investigated associations between sexually transmitted infections (STI) and prostate cancer, most have focused on gonorrhea and syphilis, two well-recognized, symptomatic STIs. Another STI of interest for prostate carcinogenesis is trichomonosis, a less well recognized and frequently asymptomatic STI with known prostate involvement. We investigated this infection in relation to incident prostate cancer in a nested case-control study within the Health Professionals Follow-up Study.


METHODS
Prostate cancer cases were men diagnosed with prostate cancer between the date of blood draw (1993-1995) and 2000 (n = 691). Controls were men who had had at least one prostate-specific antigen test and who were free of prostate cancer and alive at the time of case diagnosis. One control was individually matched to each case by age (n = 691). Serologic evidence of a history of trichomonosis was assessed by a recombinant Trichomonas vaginalis alpha-actinin IgG ELISA.


RESULTS
Thirteen percent of cases and 9% of controls were seropositive for trichomonosis (adjusted odds ratio, 1.43; 95% confidence interval, 1.00-2.03). This association persisted after additional adjustment for such factors as a history of other STIs, and was strongest among men who used aspirin infrequently over the course of their lives (odds ratio, 2.05; 95% confidence interval, 1.05-4.02, P(interaction) = 0.11).


CONCLUSIONS
Serologic evidence of a history of trichomonosis was positively associated with incident prostate cancer in this large, nested case-control study of male health professionals. As this study is the first, to our knowledge, to investigate associations between T. vaginalis serology and prostate cancer, additional studies are necessary before conclusions can be made.
Sutcliffe
Siobhan
S
Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Room E6138, 615 North Wolfe Street, Baltimore, MD 21205, USA.
Giovannucci
Edward
E
Alderete
John F
JF
Chang
Te-Hung
TH
Gaydos
Charlotte A
CA
Zenilman
Jonathan M
JM
De Marzo
Angelo M
AM
Willett
Walter C
WC
Platz
Elizabeth A
EA
D000328:Adult; D000368:Aged; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000453:epidemiology / Q000469:parasitology*; D012749:Sexually Transmitted Diseases / Q000453:epidemiology / Q000469:parasitology*; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires; D014245:Trichomonas Infections / Q000150:complications* / Q000453:epidemiology; D014246:Trichomonas vaginalis
D000913:Antibodies, Protozoan; D007074:Immunoglobulin G