Trichomoniasis infection ups prostate cancer, benign prostate hyperplasia risk

Men with Trichomoniasis vaginalis infections appear to be at an elevated risk of prostate cancer (PCa) and benign prostate hyperplasia (BPH), according to a recent study.

From 2000 to 2015, a total of 62,544 patients with BPH, PCa, and bladder cancer (BC) were enrolled from the National Health Insurance Program of Taiwan; in parallel, a cohort of 187,632 healthy controls was also included. The proportion of trichomoniasis was significantly higher in patients than controls (0.02 percent vs 0.01 percent; p<0.001). [Sci Rep 2022;12:15358]

Multivariable logistic regression analysis confirmed that trichomoniasis was significantly associated with BPH, PCa, or BC, increasing the odds of such diagnoses by nearly threefold (adjusted odds ratio [OR], 2.999, 95 percent confidence interval [CI], 1.426–5.301; p=0.002). Depression likewise strongly aggravated the likelihood of such conditions (adjusted OR, 3.124, 95 percent CI, 1.808–4.838; p<0.001).

Other notable correlates of BPH, PCa, and BC included season of disease diagnosis, health insurance coverage, level of care, and urbanization of residence.

Of note, stratified analysis showed that T. vaginalis infection significantly increased the risk of BPH (adjusted OR, 2.685, 95 percent CI, 1.233–4.286; p=0.013) and PCa (adjusted OR, 5.801, 95 percent CI, 1.296 to 26.035; p=0.016), but not BC (adjusted OR, 4.012, 95 percent CI, 0.524–31.145; p=0.151).

“The mechanism of T. vaginalis inducing BPH and PCa still remains unclear,” the researchers said, adding that several studies have posited different possible pathways.

For instance, the infection could induce the production of proinflammatory cytokines, leading to a cycle of cell damage and repair under chronic inflammatory conditions. This could lead to BPH and eventually malignant transformation. [Differentiation 2011;82:200-2; Parasite Immunol 2016;38:678-687]

There is currently not enough evidence to establish a definitive link between BC and trichomoniasis, the researchers added. “However, our study shows no significant association between T. vaginalis infection and BC probably because of limited sample.”

Most vulnerable to trichomoniasis

The researchers also conducted stratified analyses to identify characteristics that further worsened BPH, PCa, or BC risk overall.

They found that participants aged >65 years with trichomoniasis saw a much higher likelihood of these diagnoses (adjusted OR, 3.685, 95 percent CI, 1.705–8.015), as did participants with depression (adjusted OR, 3.104, 95 percent CI, 1.706–5.972).

“We added depression as one of the comorbidities in our study due to another previous nationwide population-based cohort study in Taiwan which showed that patients with trichomoniasis had higher risks for developing an individual psychiatric disorder, including depression, anxiety, bipolar disorder, schizophrenia, and substance abuse,” the researchers explained.

“Our study results demonstrate that except for depression, no comorbidities had a significant association with BPH, PCa, or BC,” they added. [Parasit Vectors 2019;12:88]

The presence of depression and trichomoniasis exerted what the researchers called a “joint effect” on the risk of BPH, PCa, and BC, leading to a more than 7.6-times increase in the likelihood of these diagnoses as compared with controls.

“Due to the lack of awareness of this pathogen, clinicians should not only treat patients who are already diagnosed but should also pay more attention to groups with higher trichomoniasis exposure risk,” the researchers said.