The correlation between marital status and health has been demonstrated [14]. Manzoli et al. examined the association of marital status and survival in old cancer patients [15]. Huynh-Le et al. evaluated the impact of marital status on receipt of brachytherapy and survival outcomes in cancer patients diagnosed at late stage [16]. Siddiqui et al. investigated the relationship between marital status and clinical outcomes in patients with lung cancer [17]. According to these studies, being married or having good relationship with partners is associated with early diagnosis of cancer, and can act as a protective factor for cancer survival [18]. In the present study, we conducted a meta-analysis to examine the impact of marital status on stage of diagnosis and cancer survival in female patients with breast and gynecologic cancers. Our meta-analysis of 107 datasets from 55 studies, including 1195773 female cancer patients, confirms that unmarried women are more likely to be diagnosed at late stage and have poorer survival rates than the married. Pooled OR and HR showed that, compared to the married, unmarried female cancer patients had a 28% increased risk to be diagnosed at late stage and a 20% higher risk of death.
Marriage offers protective benefits on the diagnosis and prognosis of female patients with women’s cancer in several ways. The first is the effect on behavior. Living with a spouse or a partner has a positive effect on lifestyle and health behaviors in women. One explanation is that sexually active women present early symptoms for some cancers, such as cervical cancer [19], since postcoital bleeding is a typical symptom. Moreover, close partners may notice early symptoms [20] and encourage their wives to seek medical care instantly once symptoms develop. Another possible explanation is that spouses may promote timely health screenings [21]. Studies have shown that married women are more likely to receive surveillance mammography [22, 23] and participant in cervical cancer screening [24–26]. In addition, marriage may reduce risk-taking behavior and exert social control on behavior, such as diet and exercise [27, 28].
Secondly, economic and social support may lead to timely diagnosis and favorable prognosis [29, 30]. Compared with the unmarried, married women may receive financial assistance from spouses and other family members, therefore having an increased opportunity to seek and receive effective medical treatments [31]. Moreover, marriage may offer a protective benefit through family assistance and care, as well as larger social support networks [32]. Consequently, marriage is positively associated with physical and mental health. In addition, married cancer patients perceive more social support through extended family network and enjoy overall better health. Furthermore, family members can share the emotional burden; therefore, patients display less depression, fatigue and anxiety [33]. In contrast, unmarried women lack social and economic support, thus suffer from psychological distress and physical symptoms.
Since breast cancer is the most frequent cancer and the second leading cause of cancer death in women, breast cancer-related studies accounted for the largest number of studies included in the subgroup analysis. Compared to married women with breast cancer, the unmarried had a 25% higher risk to be diagnosed at late stage and a 19% increased risk of death. Studies suggest that married women have a higher rate of breast cancer screening than the unmarried [34], and the married breast cancer survivors are more optimistic than the unmarried, especially within 5 years since diagnosis [35]. In cervical cancer patients, marriage is positively associated with early diagnosis and better survival. This can be explained by better health behaviors, more comprehensive health insurance coverage and greater socio-economic support in married women with cervical cancer [36]. However, it should be noticed that, from the only one eligible study, the married ovarian cancer patients have a higher risk of being diagnosed at late stage than the unmarried, although the evidence level of this conclusion was not improved.
Results of the subgroup analysis showed that single, divorced and widowed female cancer patients are associated with late stage at diagnosis and worse prognosis. Unmarried female cancer patients (especially the single individuals) showed a distinct tendency to receive no surgery compared with those of married status, partly resulting in their survival disadvantages [37]. Potential explanations could be that, divorce or death of a spouse can cause not only severe disruption of the patient's social support network, but also great emotional stress such as anxiety and depression [38, 21]. Moreover, women of divorced and widowed status have lost the spousal effect which may promote cancer screening and the seeking of medical attention and treatment. In addition, they are less likely to receive surgical treatments and chemotherapy.
Marriage and marital status are closely related to cultural background and social status. Therefore, we conducted subgroup analyses for provenances: patients from America, Europe, Asia and Africa. Marriage showed a protective effect in patients from America and Europe, whereas its influence was not significant in patients from Asia and Africa. In addition, marriage plays a significant protective role in women with high social support, whereas its influence was not statistically significant under low social support. However, due to the limited number of studies, any conclusions regarding the potential impact of cultural background and social status shall be avoided until further evidence is available.
The present meta-analysis study has some limitations that should be addressed. The first methodological limitation of this meta-analysis is the quality of included studies. All the included studies were observational studies (cross-sectional studies and cohort studies). 80% of the studies had a sample size of over 500 patients. To assess the methodological quality of included studies, two authors independently evaluated each study using an adapted form of the NOS scale, with consensus reached following discussion of any differences. Nevertheless, data of some studies could not be further extracted, resulting in relatively few eligible studies included in the subgroup analysis for some clinical outcomes. For example, when evaluating the impact of marital status on the CSM of women with vulvar cancer and on the survival of women with high social support, only 1 or 2 studies were included, which was unable to improve the evidence level. The second methodological limitation is heterogeneity. Like most meta-analyses, among the included studies in our analysis, there was a high heterogeneity in study design, sample size, characteristic of patients, etc. This heterogeneity persisted even in subgroup analyses conducted for cancer type, unmarried status, social characteristic of patients, and number of adjustment factors. Nonetheless, the investigation of heterogeneity could be essential for identifying high-risk individuals.
Additionally, several limitations to this study must be considered in interpreting the results. First, diverse cultural backgrounds may lead to different concepts and institutions of marriage, as well as difference in the age at first marriage, the age at first birth, breastfeeding, etc. Therefore, we carried out subgroup analyses stratified by different provenances of female cancer patients. Second, marriage is a double-edged sword for health. Studies [39, 40] have shown that high marital quality is associated with better physical and mental health, while low marital quality may increase the risk of stress, depression and worse health outcomes.
In this study, we focused on the relationship between marital status (being married or unmarried) and the clinical outcomes of female cancer patients. However, the potential effect of marital quality is difficult to delineate. Finally, although some factors are known to affect the survival of cancer patients (e.g. genetics, treatments, medical resource utilization, etc.), this is not against our investigation into the impact of marriage on cancer survival. From the perspective of public health and population health intervention, this topic is of utmost importance to pay specific attention to high-risk populations and develop screening strategies. Furthermore, most of the included studies in this meta-analysis had adjusted for known factors when constructing the influencing factor analysis models.