Is Pelvic Inflammatory Disease a Risk Factor for Ovarian Cancer?

Pelvic inflammatory disease (PID) has been proposed as a risk factor for ovarian cancer. However, the existing literature on the association between PID and ovarian cancer risk is inconclusive, and only few cohort studies have been conducted. Using nationwide Danish registries, we conducted a population-based cohort study including all women from the birth cohorts 1940 to 1970 in Denmark during 1978-2012 (n = 1,318,929) to investigate the association between PID and subsequent risk of epithelial ovarian cancer. Among women in the cohort, 81,281 women were diagnosed with PID and 5,356 women developed ovarian cancer during follow-up through 2012. Cox regression models were used to estimate HRs and 95% confidence intervals (CI) for the association between PID and ovarian cancer, both overall and according to histotype. For ovarian cancer overall, we observed no association with PID (HR, 1.05; 95% CI, 0.92-1.20). However, in histotype-specific analyses, we found a statistically significantly increased risk of serous ovarian cancer among women with PID (HR, 1.19; 1.00-1.41; P = 0.047). Conversely, PID was not convincingly associated with risk of any of the other histotypes of ovarian cancer. PID was associated with a modestly increased risk of serous ovarian cancer, but not other histotypes. Our results indicate that PID is not a strong risk factor for ovarian cancer. Whether PID is slightly associated with risk of serous ovarian cancer has to be confirmed in other studies. Cancer Epidemiol Biomarkers Prev; 26(1); 104-9. ©2016 AACR.

Rasmussen CB ，Jensen A ，Albieri V ，Andersen KK ，Kjaer SK ... -  《-》

Increased risk of borderline ovarian tumors in women with a history of pelvic inflammatory disease: A nationwide population-based cohort study.

Some studies suggest that pelvic inflammatory disease (PID) is a potential risk factor for ovarian cancer. However, only few studies have investigated the association between PID and risk of borderline ovarian tumors. We conducted a population-based cohort study to investigate the association between PID and risk of borderline ovarian tumors. Using various nationwide Danish registries we identified all women in Denmark during 1978-2012, who were born during 1940-1970 (n=1,318,925). Of these, 81,263 women were diagnosed with PID in the study period, and 2736 women had a borderline ovarian tumor (1290 serous and 1344 mucinous). Hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between PID and risk of borderline tumors were estimated using Cox regression models with adjustment for potential confounders. A history of PID was associated with an increased risk of borderline ovarian tumors (HR=1.39; 95% CI: 1.19-1.61). However, histotype-specific analyses revealed significant variation in risk as PID was only associated with an increased risk of serous borderline tumors (HR=1.85; 95% CI: 1.52-2.24), but not with mucinous borderline tumors (HR=1.06; 95% CI: 0.83-1.35). PID is associated with an increased risk of serous borderline tumors. Further research on the potential underlying biological mechanisms and on the identification of the subset of women with PID who are at increased risk of serous borderline tumors is warranted.

Rasmussen CB ，Jensen A ，Albieri V ，Andersen KK ，Kjaer SK ... -  《-》

Pelvic Inflammatory Disease and the Risk of Ovarian Cancer and Borderline Ovarian Tumors: A Pooled Analysis of 13 Case-Control Studies.

Inflammation has been implicated in ovarian carcinogenesis. However, studies investigating the association between pelvic inflammatory disease (PID) and ovarian cancer risk are few and inconsistent. We investigated the association between PID and the risk of epithelial ovarian cancer according to tumor behavior and histotype. We pooled data from 13 case-control studies, conducted between 1989 and 2009, from the Ovarian Cancer Association Consortium (OCAC), including 9,162 women with ovarian cancers, 2,354 women with borderline tumors, and 14,736 control participants. Study-specific odds ratios were estimated and subsequently combined into a pooled odds ratio using a random-effects model. A history of PID was associated with an increased risk of borderline tumors (pooled odds ratio (pOR) = 1.32, 95% confidence interval (CI): 1.10, 1.58). Women with at least 2 episodes of PID had a 2-fold increased risk of borderline tumors (pOR = 2.14, 95% CI: 1.08, 4.24). No association was observed between PID and ovarian cancer risk overall (pOR = 0.99, 95% CI: 0.83, 1.19); however, a statistically nonsignificantly increased risk of low-grade serous tumors (pOR = 1.48, 95% CI: 0.92, 2.38) was noted. In conclusion, PID was associated with an increased risk of borderline ovarian tumors, particularly among women who had had multiple episodes of PID. Although our results indicated a histotype-specific association with PID, the association of PID with ovarian cancer risk is still somewhat uncertain and requires further investigation.

Rasmussen CB ，Kjaer SK ，Albieri V ，Bandera EV ，Doherty JA ，Høgdall E ，Webb PM ，Jordan SJ ，Rossing MA ，Wicklund KG ，Goodman MT ，Modugno F ，Moysich KB ，Ness RB ，Edwards RP ，Schildkraut JM ，Berchuck A ，Olson SH ，Kiemeney LA ，Massuger LF ，Narod SA ，Phelan CM ，Anton-Culver H ，Ziogas A ，Wu AH ，Pearce CL ，Risch HA ，Jensen A ，, on behalf of the Ovarian Cancer Association Consortium ... -  《-》

Risk of ovarian cancer in women with pelvic inflammatory disease: a population-based study.

Ovarian cancer is commonly fatal and incidence has persistently risen in Taiwan over the past 20 years. Prevention strategies, however, are limited. Pelvic inflammatory disease (PID) has been suggested to increase the risk of developing ovarian cancer, but the results of studies have been inconsistent. Therefore, we investigated whether PID increases the risk of developing ovarian cancer in a large, nationwide cohort. From the Longitudinal Health Insurance Database 2005 (LHID2005) in Taiwan, we obtained data for women aged 13-65 years for whom a diagnosis of PID, confirmed by multiple episodes, had been recorded between Jan 1, 2004, and Dec 31, 2005. We also obtained data for two controls per patient, matched for age and the year of first entry into the LHID2005. All patients were followed up from the date of entry in the LHID2005 until they developed ovarian cancer or to the end of 2006, whichever was earlier. We used Cox's regression models to assess the risk of developing ovarian cancer, with adjustment for age, comorbid disorders, and socioeconomic characteristics. We identified 67,936 women with PID and 135,872 controls. Among these 90 had developed ovarian cancer during the 3-year follow-up period (42 patients with PID and 48 controls, incidence 2·78 and 1·44 per 10,000 person-years, respectively). The adjusted hazard ratio for ovarian cancer in patients with PID was 1·92 (95% CI 1·27-2·92) compared with controls, which rose to 2·46 (1·48-4·09) in women who had had at least five episodes of PID. The adjusted hazard ratio was slightly higher for women aged 35 years or younger with PID than in older women with PID (2·23, 1·02-4·79 vs 1·82, 1·10-3·04). We found an association between PID and ovarian cancer. PID might, therefore, be a useful marker for ovarian cancer, and early treatment could help to improve prognosis. Whether pelvic inflammation itself accelerates the growth of ovarian cancers or affects cancer-cell differentiation in ways that adversely alter prognosis needs to be investigated. None.

Lin HW ，Tu YY ，Lin SY ，Su WJ ，Lin WL ，Lin WZ ，Wu SC ，Lai YL ... -  《-》

Association of pelvic inflammatory disease (PID) with ovarian cancer: a nationwide population-based retrospective cohort study from Taiwan.

Pelvic inflammatory disease (PID) is an important health issue for women. Infection and inflammation play an important role in carcinogenesis and PID has been reported to be associated with ovarian cancer in some small scale studies. We sought to determine whether PID is associated with an elevated risk of ovarian cancer in Asian women. Using data from Taiwan's National Health Insurance Research Database (NHIRD), our retrospective cohort study included women diagnosed with PID (cases) between the years of 2000 till 2012. Each case was matched with two women without PID (controls) by age and the year of first entry into the database. Both study cohorts were followed-up until the first event of ovarian cancer, withdrawal from the NHI program, death, or the end of the study period (December 31, 2012). Cox proportional hazards regression models were used to estimate crude and adjusted hazard ratios (HRs and aHRs) with their corresponding 95% confidence intervals (95% CIs) for the association of PID and ovarian cancer risk, with and without adjusting for potential confounders. During an approximate 10 years of follow-up, cases were significantly more likely than controls to develop ovarian cancer (incidence rates of 0.27 and 0.16 per 1,000 person-years, respectively; P < 0.001). Women with a history of PID had a 1.49-fold elevated risk for ovarian cancer (aHR, 1.49; 95% CI, 1.21-1.84; P < 0.001). Our study evidence supports the contention that PID increases the risk of developing ovarian cancer among Taiwanese women. Gynecologists should undertake careful assessments and closely follow patients with PID, who are at long-term risk of developing ovarian cancer. Our findings need further verification in other international cohorts.

Chang CY ，Lin KY ，Huang CC ，Lin WC ... -  《BMC Womens Health》