Hindawi Publishing Corporation Infectious Diseases in Obstetrics and Gynecology Volume 2008, Article ID 219672, 5 pages doi:10.1155/2008/219672 Research Article Chlamydia trachomatis Serology in Women with and without Ovarian Cancer Roberta B. Ness,1 Caixia Shen,2 Debra Bass,3 Carlynn Jackson,3 Kristen Moysich,4 Robert Edwards,5 and Robert C. Brunham2 1 School of Public Health, University of Texas, Houston, TX 77030, USA 2 UBC Centre for Disease Control, Vancouver, BC, Canada V5Z 4R4 3 Graduate School of Public Health and Pittsburgh Cancer Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA 4 Department of Epidemiology, School of Public Health and Health Professions, University at Buﬀalo, Buﬀalo, NY 14214, USA 5 Magee-Women’s Hospital, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA Correspondence should be addressed to Roberta B. Ness, roberta.b.ness@uth.tmc.edu Received 10 January 2008; Revised 7 August 2008; Accepted 20 October 2008 Recommended by Jeanne Marrazzo Pelvic inﬂammation has been implicated in the genesis of ovarian cancer. We conducted serologic measurements of Chlamydia trachomatis antibodies as a surrogate marker of chlamydial pelvic inﬂammatory disease. Women with ovarian cancer (n = 521) and population-based controls (n = 766) were tested. IgG antibodies to serovar D of chlamydia elementary bodies (EBs) were detected using an ELISA assay. The odds of having ovarian cancer among women with the highest titers (≥0.40 OD units) were 0.6 (95% CI 0.4–0.9). These data do not support our earlier ﬁnding of elevated titers for antibodies to C. trachomatis among women with ovarian cancer. Copyright © 2008 Roberta B. Ness et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 1. INTRODUCTION Ovarian cancer is an often fatal disease with an uncertain etiology. We suggested that pelvic inﬂammation may play a role in the development of ovarian cancer [1]. PID has been linked to ovarian cancer risk in some [2, 3] but not all [4] studies. However, PID is poorly recalled in retrospective studies. One quarter to three quarters of proven cases of PID are caused by Neisseria gonorrhoeae or Chlamydia trachomatis ascending into the upper genital tract to inﬂame the endometrium, tubes, and ovarian epithelium [5]. Of the two pathogens, C. trachomatis is the most common in American women [6]. Chlamydia serology is a relatively speciﬁc marker of past chlamydial PID, particularly of more severe infections [7]. Its sensitivity is not complete; of women with chlamydial PID, about 60% will have antibodies to C. trachomatis [8] and among women with tubal factor infertility, a similar proportion will have IgG titers to chlamydia [9]. We previously reported pilot results from a population- based case-control study (117 cases and 170 controls) of ovarian cancer showing that ovarian cancer was signiﬁcantly associated with high IgG antibody titers to chlamydia [10]. The purpose of the present study was to attempt to replicate this ﬁnding in a larger population-based case-control study of ovarian cancer. 2. MATERIALS AND METHODS Subjects for this serologic analysis were part of a population- based case-control study conducted in a contiguous region comprising Western Pennsylvania, Eastern Ohio, and South- western New York State. Cases were residents of this geographic region with histologically conﬁrmed, primary, epithelial ovarian, fallopian tube, or peritoneal cancer diagnosed between February 2003 and July 2006. Both invasive and borderline tumors were included. Women were referred from hospital tumor registries, clinical practices, or pathology databases and contacted with the permission of