Article

# Kjaer SK, Mellemkjaer L, Brinton LA, Johansen C, Gridley G, Olsen JHTubal sterilization and risk of ovarian, endometrial and cervical cancer. A Danish population-based follow-up study of more than 65 000 sterilized women. Int J Epidemiol 33: 596-602

Danish Cancer Society, Institute of Cancer Epidemiology, Copenhagen, Denmark.
(Impact Factor: 9.18). 06/2004; 33(3):596-602. DOI: 10.1093/ije/dyh046
Source: PubMed

ABSTRACT

On the basis of a population-based cohort, we assessed the cancer risk, focusing on gynaecological cancers and pre-malignant lesions, among women with a previous tubal sterilization.
Using the Danish Hospital Discharge Register we identified 65 232 women who had a tubal sterilization (1977-1993). The cohort was followed for cancer occurrence, and compared with the expected number based on the national cancer incidence rates.
The overall risk of ovarian cancer was decreased (standardized incidence ratio [SIR] = 0.82; 95% CI: 0.6, 1.0), and it was still decreased > or =10 years after the sterilization (SIR = 0.65; 95% CI: 0.4, 1.0). The rate of endometrial cancer was also decreased (SIR = 0.66; 95% CI: 0.5, 1.0), the risk continued being moderately reduced during follow-up, although it was not statistically significant.
In this nationwide, population-based study we find that women with tubal sterilization have a decreased risk of subsequent development of ovarian cancer. As the protective effect is not decreasing with years of follow-up, our data do not support that 'screening' bias can explain the protective effect, but indicate that the sterilization itself may convey a reduction in risk. The same pattern is found for endometrial cancer, the association being less strong.

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Available from: Christoffer Johansen, Dec 16, 2013
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• "In secondary analyses, we identified studies that reported the relative risk of ovarian cancer by characteristics of surgery, such as age at or years since procedure, as well as by histological subtype of ovarian cancer. We identified eight studies that reported stratum-specific estimates of ovarian cancer risk by years since tubal ligation (Additional file 1: Table S1) [14,19,25,26,28,29,48] and nine studies that reported stratum-specific estimates for age at tubal ligation (Additional file 1: Table S2) [13,14,19,25,27-29,48]. In addition, 13 studies specified effect estimates for invasive ovarian cancer [10,12,15,17-23,31,33] and 11 studies on tubal ligation reported estimates for at least one histological subtype of ovarian cancer (Additional file 1: Table S3) [9,10,15,16,19,22,24,26,29,49]. "
##### Article: Rice MS, Murphy MA, Tworoger SSTubal ligation, hysterectomy and ovarian cancer: a meta-analysis. J Ovarian Res 5(1): 13
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ABSTRACT: The purpose of this meta-analysis was to determine the strength of the association between gynecologic surgeries, tubal ligation and hysterectomy, and ovarian cancer. We searched the PubMed, Web of Science, and Embase databases for all English-language articles dated between 1969 through March 2011 using the keywords "ovarian cancer" and "tubal ligation" or "tubal sterilization" or "hysterectomy." We identified 30 studies on tubal ligation and 24 studies on hysterectomy that provided relative risks for ovarian cancer and a p-value or 95% confidence interval (CI) to include in the meta-analysis. Summary RRs and 95% CIs were calculated using a random-effects model. The summary RR for women with vs. without tubal ligation was 0.70 (95%CI: 0.64, 0.75). Similarly, the summary RR for women with vs. without hysterectomy was 0.74 (95%CI: 0.65, 0.84). Simple hysterectomy and hysterectomy with unilateral oophorectomy were associated with a similar decrease in risk (summery RR = 0.62, 95%CI: 0.49-0.79 and 0.60, 95%CI: 0.47-0.78, respectively). In secondary analyses, the association between tubal ligation and ovarian cancer risk was stronger for endometrioid tumors (summary RR = 0.45, 95%CI: 0.33, 0.61) compared to serous tumors. Observational epidemiologic evidence strongly supports that tubal ligation and hysterectomy are associated with a decrease in the risk of ovarian cancer, by approximately 26-30%. Additional research is needed to determine whether the association between tubal ligation and hysterectomy on ovarian cancer risk differs by individual, surgical, and tumor characteristics.
Journal of Ovarian Research 05/2012; 5(1):13. DOI:10.1186/1757-2215-5-13 · 2.43 Impact Factor
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• "Thus, simultaneous risk-reducing salpingectomies may become more widespread whenever a hysterectomy needs to be performed for benign indications and may be worth evaluating as isolated preventive procedures for women at a certain age group. It is well established that tubal ligation has a protective effect against the development of ovarian cancer [43] [44] [45]. Although the mechanisms remain unclear, with a tubal model of serous carcinogenesis, this protective risk may be explained in 3 ways: 1) For mid tubal ligation procedures, the mechanical barrier created by the ligation may prevent potentially mutagenic factors (inflammation, "
##### Article: Fallopian tube as main source for ovarian and pelvic (Non-endometrial) serous carcinomas. Int J Clin Exp Pathol

International journal of clinical and experimental pathology 01/2012; 5(3):182-6. DOI:10.4172/2161-0681.1000e107 · 1.89 Impact Factor
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• "References from relevant articles were searched for additional relevant studies. A total of 32 casecontrol (Mori et al., 1984, 1988; Harlow et al., 1988; Hartge et al., 1988; Whittemore et al., 1988, 1992a, b; Booth et al., 1989; Shu et al., 1989; Irwin et al., 1991; Chen et al., 1992; Risch et al., 1994; Rosenberg et al., 1994; Cramer and Xu, 1995; Purdie et al., 1995; Risch et al., 1996; Rosenblatt and Thomas, 1996; Cornelison et al., 1997; Green et al., 1997; Modugno et al., 2001, 2004; Narod et al., 2001; Ness et al., 2001; Tung et al., 2003; McGuire et al., 2004; Mills et al., 2004; Pike et al., 2004; McLaughlin et al., 2007; Jordan et al., 2008; Moorman et al., 2008; Nagle et al., 2008), 5 prospective cohort (Hankinson et al., 1993; Miracle-McMahill et al., 1997; Tworoger et al., 2007; Antoniou et al., 2009; Dorjgochoo et al., 2009) and 3 historical cohort (Koch et al., 1984; Kreiger et al., 1997; Kjaer et al., 2004) studies were identified and included in the overview (Tables 1–3). The studies available were categorized into three groups for the main meta-analysis (Tables 1–3). "
##### Article: Tubal ligation and the risk of ovarian cancer: Review and meta-analysis
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ABSTRACT: The reduction of ovarian cancer (OC) risk in women with a history of tubal ligation (TL) has been reported repeatedly, mostly on small populations. We have aimed to provide a critical overview of the studies available to date and to conduct a meta-analysis. There were 40 relevant studies identified. The studies were divided into two groups for strict and extended meta-analysis, respectively. Subgroup analysis was performed for age, time dependency since TL, histological types of OC and BReast CAncer (BRCA) mutation. Meta-analysis of 13 strictly selected studies showed a reduced risk of epithelial OC by 34%. The protective effect of TL was confirmed even in a subgroup of women 10-14 years after the procedure. The risk reduction was confirmed for the endometrioid (RR = 0.40) and serous (RR = 0.73) cancers but not for mucinous. The review of relevant articles, as well as the meta-analysis of selected studies, yields consistent data on a significant reduction of OC risk in women who had undergone TL. The results of this meta-analysis should provide an impulse for further research on the etiology of ovarian epithelial cancers, focusing particularly on the importance of retrograde transport of endometrial cells.
Human Reproduction Update 12/2010; 17(1):55-67. DOI:10.1093/humupd/dmq030 · 10.17 Impact Factor