The patient cohorts comprised 278 cases vs. 556 controls from the Polish study, and 160 cases vs. 159 controls from the PLCO study. Serum samples were collected at the time of ovarian cancer diagnosis in the Polish cohort, and before diagnosis in the PLCO cohort.
Dr. Trabert presented odds ratios for a Pgp3 antibody titer cut point indicative of past chlamydia infection, and a “more stringent” higher cut point indicative of current or chronic infection. She and her colleagues found statistically significant associations for each cut point in both studies.
In the Polish cohort, the lower Pgp3 cut point was associated with a 63% increased risk of ovarian cancer (odds ratio, 1.63). The higher cut point was associated with a doubling of risk (OR, 2.0).
In the PLCO cohort, the lower cut point was associated with a 43% increased risk (OR, 1.43). The higher cut point more than doubled the risk of ovarian cancer (OR, 2.25).