Try out PMC Labs and tell us what you think. Learn More. To investigate that whether an association between marital status and the female breast cancer risk exists. The Newcastle-Ottawa Scale was used to rate the methodological quality of included studies. Study data were pooled using random-effects meta-analyses to compare the breast cancer risk between unmarried, widowed, divorced or lifelong single women and married women. Forty-nine publications were included in the meta-analysis. Compared with married women, unmarried and lifelong single women had an elevated risk of breast cancer, and the pooled ORs of case-control studies were 1.
In the subgroup analyses under these two comparisons, hospital-based estimates and multivariate-adjusted estimates demonstrated a strong association, while population-based estimates and age-adjusted estimates produced nonificant .
Most people think of women as breast cancer patients, but about one in every 1, cases diagnosed is found in a man.
The pooled OR of cohort studies examining the effect of being a lifelong single woman was 1. Marital status may correlate with the risk of developing female breast cancer. However, suboptimal selection of controls, insufficient exploration of confounding effects, inadequate ascertainment of marital status, and possible publication bias may have limited the quality of the available evidence. Overall, conclusions that marital status is an independent risk factor for breast cancer could not be drawn, and further prospective rigorous cohort studies are warranted.
Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer death among women worldwide [ 1 ]. Approximately Feasible changes in risk behaviors, such afair alcohol consumption, physical activity and obesity, can contribute to an important reduction in mammary carcinoma risk [ 34 ].
Under these circumstances, further progress for be achieved by identifying new, modifiable lifestyle-related risk factors. One factor that may be associated with breast cancer is marital status. Married individuals typically enjoy a higher socioeconomic status than unmarried individuals, which may translate into better access to healthcare [ 5 ].
Marriage could also promote healthier lifestyle behaviors, such as regular screenings, healthy diet, and exercise, all of which may be mediating factors preventing breast cancer [ 6 ]. The woman is different for the unmarried people. For instance, being widowed or divorced often leaves individuals with a period of intense suffering and induces a series of unhealthy coping approaches that can for the development of breast cancer [ 7 ].
Additionally, looking single women tend to have no experience with childbirth or breastfeeding, while parity, age at first full-term birth and the duration of breastfeeding have been proven to have a substantial influence on the incidence of breast cancer [ 8 — 10 ]. Some local studies have detected Brest rates of breast cancer in unmarried people than married people [ 1112 ], while some studies argue that marital status has no influence on this malignant disease [ 1314 ].
Despite the disparity inno systematic research has been carried out.
Thus, we conducted this systematic review and meta-analysis of observational studies to obtain valid knowledge regarding the associations between marital status and the risk of breast cancer in women. The search duration was from the inception of the databases to July We confined our search to papers published in English. The reference lists of all eligible articles were also checked to identify additional studies. The search strategy is shown in S3 Table. When two articles reported data from the same study, to avoid duplication, we only used the analysis with the higher methodological quality.
The full texts of all potentially relevant articles were investigated.
Disagreements were resolved by discussion between the two reviewers and, if necessary, a third reviewer For. The data were independently extracted from the included trials by two reviewers MLL and NZ and entered into a structured characteristics table. The extracted data included the following: the name of the first author, publication year, study de, features of the study population, strategies used to confirm breast cancer, assessment of marital status, research findings and other required information.
We resolved any differences in opinion through consultation with a third person MH. We rated the methodological quality of the included studies using an adapted version of the Newcastle-Ottawa Scale NOS [ 17 ]. The NOS consists of eight items focusing on the following three domains: selection of study groups, ascertainment of exposure and Brest, and comparability of groups. The ratings are based on a star system with a maximum rating of nine.
We provided a narrative synthesis afair the findings from the included studies and pooled the if the studies adopted the same methods to categorize marital status. Married women were used as the reference category. In all analyses, we woman inverse-variance weighted random-effects models with the DerSimonian-Laird estimator to for the high expected heterogeneity across studies resulting from differences in the samples, measures, and des.
Subgroup analyses by control type population-based studies versus hospital-based studies and by adjustment level multivariate-adjusted estimates versus age-adjusted estimates were performed to determine the association between marital status and the risk of breast cancer. The odds ratios ORs were used to measure the effect. If a study did not use married people as the reference group, we inverted the ORs based on the method proposed by Greenland and Longnecker [ 18 ] with Microsoft Excel software developed by Hamling et al [ 19 ].
How breast cancer differs for men
For studies that provided estimates of the relative risk based on different multivariate models, we prioritized the from the model with the largest of covariates. Heterogeneity was tested using the Cochran Q statistic and quantified with the I-squared I 2 statistic, which describes the variation in the effect size attributable to the heterogeneity across studies.
The confidence intervals for I 2 were also calculated using the formula proposed by Higgins [ 20 ]. The potential sources of heterogeneity were explored if high heterogeneity was detected using a random-effects-weighted meta-regression based on the following variables: 1 adjustment level: multivariate-adjusted estimates versus age-adjusted estimates; 2 control type: population-based studies versus hospital-based studies; 3 geographic region: Asian versus non-Asian populations; and 4 publication year continuous.
Review Afair V. We identified articles using the search strategies. After removing the duplicates and reviewing the titles and abstracts, we retrieved full-text articles. Of these articles, 49 studies [ for — 1421 — 65 ] fulfilled the inclusion criteria and were included in the meta-analysis Fig 1. Table 1 describes the key woman characteristics. We included two cohort studies [ 1113 ] and 47 case-control studies [ 121421 — 65 ]. The looking studies included in our analyses involved 1, women, including 59, breast cancer cases.
The studies were published between and and included participants from Europe, the United States, Australia, Africa and Asia. Overall, 19 Brest [ 1421252933373840 — 434648515256576063 ] only provided age-adjusted estimates, while 30 studies [ 11 — 1322 — 2426 — 2830 — 3234 — 3639444547495053 — 55585961626465 ] controlled for multiple confounding factors, such as demographic characteristics, reproductive factors, behavior and lifestyle factors and several local variables full details are displayed in S4 Table.
Married people ed for between In our review, the diagnosis of breast cancer was considered definitive if confirmed by pathological records. Guided by this criterion, all studies were deemed qualified and rated one star, except for three studies [ 404954 ].
For the local regarding the ascertainment of exposure, studies using a looking record or structured questionnaire with details regarding the timing of potential changes in marital status were rated one star. Almost all studies failed to meet this standard, except for three studies that used regularly updated marriage registry records [ 1114for ]. All afair looking for age, but only 12 studies [ 132227323436394547555865 ] were considered to have adequate comparability between the cases and controls.
Regarding the second selection item, both studies obtained the non exposed cohort from the same source as the exposed cohort. In addition, both studies demonstrated that the outcome of interest was afair present at the start of the study. Concerning follow-up, one study [ 11 ] followed up for less than 10 years with a dropout rate of 5. Among the case-control studies, 19 studies [ 12212427303233353741434446485455626465 ] woman rated one star for the item of representativeness of the cases since they selected consecutive eligible cases in a defined area over a defined period.
However, selection bias was still possible as only 12 studies recruited controls from the same community as the cases, while the remaining studies either local a hospital-based de [ 22 — 24272830 — 32353942 — 45474850525355 — 5759606365 ] or provided no description of the source [ 252629 Brest, 373846515860 ]. Eight studies [ 1429303640414446 ] did not receive a star in the domain of control definition since these studies did not clearly demonstrate that the controls had no history of breast cancer.
Overall, for des failed to demonstrate a satisfying woman in the domain of ascertainment of exposure and Brest of participants.
The case-control studies also scored poorly on the item related to the representativeness of the cases and selection of controls. The full details of the methodological assessment are shown in S5 Table.
Table 2 displays a summary of the effect estimates of the association between marital status and risk of breast cancer. Since the method used to categorize marital status varied across studies, we performed meta-analyses using the following comparisons:.
No eligible cohort study was included in this comparison. According to another subgroup analysis, the studies that adjusted for multiple variables resulted in an OR of 1.
The analysis of the 13 case-control studies [ 12142135374043 — 4552616465 ] yielded a similar combined OR of 0. Subgroup analyses did not identify any statistically ificant association between Brest widowed and the breast cancer risk. The population-based studies produced an OR of 0. The women with maximal adjustment produced an OR of 1. One cohort study [ 11 ] investigated afair association between divorced status and the breast cancer risk and provided an RR of 1. The hospital-based subgroup analysis produced an OR of 1.
The multivariate-adjusted subgroup analysis resulted in an OR of 1. Two cohort studies [ 1113 ] investigated the association between lifelong single status and the breast cancer risk and looking an OR of 1. The hospital-based studies local a combined OR of 1. The multivariate-adjusted estimates increased the overall OR to 1. Our study summarized all accessible published evidence and demonstrated that unmarried women, especially lifelong single women, had a higher risk of developing breast cancer than for women.