Link between STI and advanced prostate cancer debunked

December 6, 2023

Most studies investigating the potential association of trichomoniasis involved only White populations.

A University of Hawaiʻi Cancer Center study challenges existing research notions about the potential link between trichomoniasis, a sexually transmitted infection caused by a parasite called Trichomonas vaginalis, and advanced prostate cancer. The study was recently published in the journal Cancers.

From left to right: Dr. Loic Le Marchand, Dr. Brenda Hernandez, Michelle Nagata, and Anne Tome
From left to right: Dr. Loic Le Marchand, Dr. Brenda Hernandez, Michelle Nagata, and Anne Tome

Prostate cancer, a common concern both in the United States and globally, holds the title of the most frequently diagnosed cancer in men in Hawaiʻi. However, the exact reasons behind its occurrence remain murky. Prior research has presented conflicting ideas about the role of T. vaginalis in the development of prostate cancer, with most studies focusing on predominantly White populations.

Researchers from the University of Hawaiʻi Cancer Center led by Brenda Hernandez, PhD, MPH, conducted a case-control study nested within the Multiethnic Cohort Study (MEC) to explore the link between having a T. vaginalis seropositive status and an increased risk of advanced prostate cancer in a diverse population.

"Over 800 Hawaiʻi men are newly diagnosed with prostate cancer each year. Identifying how to lower risk factors is critical to informing future prevention strategies," said Hernandez.

Diversifying study populations

The study, encompassing Japanese-American, White, African-American, Native Hawaiian, and Latino populations in Hawaiʻi and California, aims to broaden the research scope beyond predominantly White populations, given the known variations by race and geographic location.

The researchers analyzed blood samples from MEC participants diagnosed with advanced prostate cancer and those without prostate cancer, ultimately finding no statistically significant association between T. vaginalis infection and advanced prostate cancer.

Even when focusing on advanced prostate cancer cases with tumors spread outside the prostate, the association remained non-significant, challenging previous findings of a potential infectious link.

Known risk factors for prostate cancer are limited and include older age, race, and family history, which has been previously shown in the MEC and other studies. The research team will explore other potential roles of infection-related inflammation in the development of cancers, including prostate cancer.