Cancer is one of the major health challenges of the present century. 1 The detrimental effects of this disease impact all physical, emotional, spiritual, social, and economic dimensions of people's lives, something which has attracted the attention of experts. 23 Meanwhile, women diagnosed with breast cancer experience high levels of psychological disorders ranging from depression, anxiety, maladjustment to the disease, and decreased selfconfidence to different emotional disturbances and fears of recurrence and mortality. 4 It has been predicted that the worldwide incidence of female breast cancer will reach approximately 3.2 million new cases per year by 2050. 5 Cancer is often a chronic and sometimes lifethreatening illness that requires intense treatments with potential side effects and the possibility of disease recurrence. 6 One effective approach to reduce healthcare costs, prevent symptom recurrence, and increase the lifespan of these individuals is to promote health-enhancing behaviors. 7 Health-promoting behaviors encompass actions that empower individuals to take control of their health and contribute to their well-being and that of society. 8 These behaviors hold particular significance due to their potential to enhance the quality of life and reduce the burden of healthcare in the community, ultimately leading to a healthy lifestyle. 9, 10 Park et al. 11 demonstrated that factors influencing healthpromoting behaviors in patients with cancer vary depending on the stage of the disease. In the acute phase, self-efficacy and social support are influential factors. In the advanced stage, social support and fear of recurrence play significant roles in healthpromoting behaviors. In the chronic stage, social support and age are significant variables with an impact on health-enhancing behaviors.

Social support is one of the determining factors in community health, which highlights the social aspect of human beings. 12 Social support refers to the love, respect, consolation, assistance, and resources provided by others to an individual, which lead to increased coping abilities, enhanced satisfaction, and efficacy in life. 1314 Studies have shown that a positive perception of social support has a significant effect on the quality of life, mental health, physical health, and self-confidence. 1516 Lower levels of social support are associated with higher mortality rates due to chronic illnesses, including cancer and cardiovascular diseases. 1718 Sources of social support can come from family, friends, relatives, social organizations, or even resources available at an individual's workplace or educational institution. 19 Mohaghegh et al. 20 demonstrated that perceived social support would affect health-promoting behaviors in patients with cancer with the most and least effective aspects stemming from family and friends' support, respectively.

The increasing trend in chronic diseases and the significance of improving the quality of life for these patients, alongside prolonging their lifespan, have highlighted the need for educational interventions more than ever before. 21 Health literacy is a relatively new concept that has gained more recognition in recent years in educational interventions. 22 In fact, health literacy refers to an individual's capacity to obtain, interpret, and comprehend basic health information and services. 23 It includes knowledge, motivation, and the ability of an individual to access, perceive, evaluate, and utilize health information to make conscious decisions about maintaining or improving their quality of life. 24 The theory of self-efficacy has a long history in the evaluation and intervention of various health domains, e.g., cancer. In general, higher self-efficacy is positively associated with quality of life, cancer adaptation, positive mood, and seeking treatment. 25 Self-efficacy refers to an individual's confidence in their ability to manage the requirements and healthrelated outcomes of chronic diseases. 2627 Individuals with low self-efficacy hold pessimistic thoughts about their capabilities; hence, they tend to avoid situations that they perceive as beyond their capabilities. By contrast, individuals with high selfefficacy regard challenging tasks as opportunities to develop mastery over them. 28 Research has confirmed the effective role of self-efficacy in health-promoting behaviors. 2930 Additionally, high levels of selfefficacy alleviate cancer-related symptoms, improve the mental image of patients with cancer, and enhance their communications with healthcare staff. 3132 The level of participation of women with breast cancer in early detection and screening programs depends on several factors, including the level of social support. Meanwhile, there are few studies that focus on the mutual effect of social support and health-promoting behaviors in women with breast cancer and its role in preventing or improving their diseases. Accordingly, the present study aimed to investigate the mediating role of cancer self-efficacy in the association between health literacy and social support with healthpromoting behaviors in women with breast cancer.

The population of this descriptive-correlation study included all women diagnosed with breast cancer in Ahvaz, Khuzestan Province (Iran) in 2021. The inclusion criteria for participation in the study were as follows: having passed at least the middle school level, being 18 years of age or older, and being diagnosed with breast cancer. However, the exclusion criteria included having acute psychiatric disorders, using psychotropic medications, and not responding to all questions in the questionnaire. Based on the number of research variables 33 , the purposive sampling technique was employed to select 300 women as the research sample to test the proposed model and analyze the research hypotheses. After incomplete questionnaires and outlier data were removed, a total of 282 questionnaires were analyzed.

Chemotherapy centers at hospitals in Ahvaz and the chemotherapy clinics of specialized oncologists and surgeons were visited for sampling, and a total of 300 patients with breast cancer were selected through purposive sampling. To adhere to ethical principles in this study, the distribution and completion of all questionnaires were conducted by the researcher. Initially, the researcher approached the authorities with an introductory letter to seek the cooperation of participants. After obtaining their consent, the researcher provided a detailed explanation of the research objectives to each participant and scheduled the administration of questionnaires.

Developed by Walker et al. 34, the HPLP-II includes six dimensions with 52 items rated on a 4-point Likert scale (Always, Often, Sometimes, and Never). Positive performance on this scale is scored as 4, 3, 2, and 1, respectively. The total score of health-promoting behaviors ranges between 52 and 208. The original version of the health-promoting lifestyle inventory has been found to have good reliability with a Cronbach's alpha ranging from 0.79 to 0.87 for the six dimensions and 0.94 for the overall questionnaire. 34

This questionnaire was designed and normalized by Montazeri et al. 35 , considering the cultural and social characteristics in Iran. The questionnaire includes 33 items in five domains: reading (4 items), access (6 items), understanding and comprehension (7 items), appraisal (4 items), and decision-making and behavior (12 items). The scoring of this questionnaire is based on a 5-point Likert scale, where 5 represents "completely easy," 4 represents "easy," 3 represents "not easy," 2 represents "difficult," and 1 represents "completely difficult." Montazeri et al. 35 reported an alpha Cronbach coefficient of 0.89 for the questionnaire.

To measure social support, the researchers used the MOS Social Support Survey developed by Sherbourne and Stewart. 36 This test assesses the levels of social support received by the respondents and consists of 19 statements and 5 subscales. The subscales are as follows: tangible support, which measures material and behavioral help; emotional support, which evaluates positive emotions, empathy, and encouragement to express feelings; informational support, which measures guidance, information, or feedback provided; affectionate support, which assesses love and affection; and positive social interaction, which evaluates the presence of individuals to engage in recreational activities. Musavinasab et al. 36 reported an alpha Cronbach coefficient of 0.85 for the questionnaire.

This questionnaire is a multidimensional scale consisting of 33 items with seven subscales. The subscales include continuation of activities and maintaining independence, coping with treatment side effects, acceptance of cancer/maintaining a positive attitude, seeking and acquiring medical information, emotion regulation, seeking support, and stress management. The total score of the Cancer Behavior Inventory is obtained by adding up the scores of all 33 items with minimum and maximum scores of 33 and 297, respectively. 37 Karamoozian et al. 38 reported an alpha Cronbach coefficient of 0.75 for the questionnaire.

Data analysis was done using descriptive statistics (mean and standard deviation). Skewness and kurtosis were used to determine the normality of the data. The Variance Inflation Factor (VIF) was used to check multicollinearity. The association between the research variables was examined using Pearson's correlation coefficient and structural equations modeling (SEM) in SPSS v27.0 and AMOS v25.0 software. The Bootstrap method was also employed to test the significance of mediation associations. Incremental Fit Index (IFI), Tucker-Lewis Index (TLI), Comparative Fit Index (CFI), Normative Fit Index (NFI), and Root Mean Square Error of Approximation (RMSEA) were used to evaluate model fit. The significance level of the research was considered to be α=0.05.

The mean and standard deviation of the participants' age were 42.06 and 6.4, respectively. The minimum and maximum ages of the participants were 29 and 68 years, respectively. Table 1 reports the means, standard deviations, minimum, maximum, kurtosis, and skewness of the research variables, and Table 2 demonstrates the correlation matrix of the research variables. Evaluating statistical assumptions, including skewness and kurtosis indicated the normal distribution of all the research variables ( Table 2). According to the results, the VIF for all variables was less than 10. Therefore, the assumption of multicollinearity was met. According to Table 2, there were significant correlations between all research variables (P<0.001). Path analysis was employed to test the simultaneous hypotheses in this study. Table 3 presents the tested model fitness based on goodness-of-fit indices. According to the resulting values, the proposed model did not show a good fit. The proposed model is shown in Figure 1. Moreover, Table 3 presents the fitness of the modified tested model based on goodness-of-fit indices. According to the resulting values, the modified model had a good fit and was accepted as the final model. Figure 2 illustrates the standard coefficients of the paths in the final modified model. Table 4 depicts the structural model, paths, and their standard coefficients in the proposed and modified models. Based on the standard parameter coefficients and their corresponding significance level in Table 4, one of the direct paths in the model was not significant (Health literacy → Healthpromoting behaviors) and should be removed from the model for further evaluation of the modified model fitness. The results showed that there was a significant association between perceived social support with health-promoting behaviors (β=0.17, P=0.004) and cancer self-efficacy (β=0.37, P=0.001).

There was a significant association between health literacy and cancer self-efficacy in women (β=0.31, P=0.004). Moreover, there was a significant association between cancer self-efficacy and healthpromoting behaviors in women with breast cancer (β=0.44, P=0.001). There existed a mediating variable in this study, and bootstrap testing was used to determine the significance of the mediating associations. For this purpose, the overall effects of the predictor variables on the criterion variable in the absence of the mediator were determined through a simple mediation model test of the association between each predictor variable and the criterion variable without the mediator. The results showed that all predictor variables had significant associations with the criteria variable in the absence of the mediator, which is reported along with the mediation analysis in Table 5.

The present study aimed to investigate the mediating role of cancer self-efficacy in the association between health literacy and social support with health-promoting behaviors in women with breast cancer. According to the research findings, there was a significant direct association between perceived social support and health-promoting behaviors in women with breast cancer. Consistent with our findings, Mohaghegh et al. 20 reported that a higher perception of social support had a direct association with engagement in health-related activities, e.g., proper nutrition, exercise, relaxation, safety, and health promotion. These results indicate the positive effects of social support on the adoption of a healthy lifestyle. Social support, in the context of this study, refers to the provision of both material and emotional support by close relatives to someone experiencing stressful or challenging circumstances. 13 In women with breast cancer, interpersonal relationships may be compromised. This might lead to a loss of support resources, which has been linked to the symptoms of depression and disease recurrence. 14 Therefore, continuous and effective support from family members, friends, and other individuals, and sharing sympathy with them can affect the treatment and utilization of healthcare services. Patients with higher levels of perceived social support tend to adopt better strategies for promoting their health and well-being in their daily lives.

The non-significant association between health literacy and health-promoting behaviors can be explained such that since these variables have been tested in the framework of this model. This direct association might be non-significant due to the appropriate selection of mediators in the assumed model. These mediators may fully mediate the association through indirect pathways and make the direct association statistically non-significant. However, this non-significant result does not mean it lacks clinical significance. After the mediating variables were removed from the model, as demonstrated by the simple correlation coefficients in the study, the association was found to be significant. This finding is consistent with the research results of previous research. 35 This finding can be explained by the fact that health literacy leads to the adoption of preventive behaviors to maintain health. Women with higher health literacy levels are more likely to be health-conscious and take better care of their wellbeing. They are better informed about health risks and can improve their health behaviors accordingly, and aim for a healthier lifestyle. 22 Thus, the significance of education in the field of health and hygiene is evident in today's world. The likelihood of developing various diseases is higher in individuals with lower health literacy than in those with higher health literacy and better education. Health literacy plays a key role in determining one's selfmanagement indicators, including compliance with medication and dietary regimens as well as exercise. Women with breast cancer who have higher health literacy levels are more likely to engage in preventive behaviors and take proactive measures to maintain their health. 23 Another finding of the research indicated a significant direct association between perceived social support and cancer self-efficacy in women with breast cancer. This aligns with research by Hamed Bieyabanie et al. 30 In fact, the challenges faced by women with breast cancer include coping with severe symptoms such as pain and fatigue and the ability to manage their lives independently. Therefore, patients with cancer have a strong need for supportive individuals around them who can provide encouragement. If support is provided in a way that the patients with cancer perceive and understand it as constant and compassionate, it can help them better cope with the stress and anxiety before undergoing chemotherapy and radiation therapy. 30 Additionally, social support, especially from family and healthcare facilities, can foster the patients' confidence in their ability to manage and control the disease. Patients who receive emotional and practical support from their surroundings will adhere more to treatment plans. 13 In fact, social support helps with accepting the illness, reduces concerns about self-care behaviors, and enhances self-efficacy in disease management. 27 This will lead to an improvement in the patient's belief in the effectiveness of treatment and better disease management.

Moreover, there was a significant association between health literacy and cancer self-efficacy in women with breast cancer. This finding is in accordance with the research results of previous studies. 39 Therefore, as people's health literacy increases, their self-efficacy in performing self-care behaviors also increases. In fact, women with breast cancer who have higher health literacy exhibit greater self-efficacy in disease management. Having a high level of health knowledge and literacy can instill more confidence in individuals regarding their ability to use disease control programs. 40 Women with higher health literacy have a better understanding of their health status, something which leads to more effective disease management.

The mediating role of cancer self-efficacy in the association between perceived social support and health literacy with health-promoting behaviors was found to be significant in women with breast cancer. In other words, in addition to the direct effect of perceived social support on health-promoting behaviors, it was also effective through self-efficacy. In fact, women who report higher levels of selfefficacy have greater access to social support. Perceived social support, especially family support, influences an individual's belief in their capabilities and their self-efficacy. Furthermore, self-efficacy also had a direct association with adherence to prescribed treatment regimens or exercise programs provided by the healthcare team, and this had a positive effect on health-promoting behaviors. Furthermore, self-efficacy increases self-confidence in patients who, despite suffering from the disease, can perform the assigned self-care tasks. Therefore, these patients exhibit higher perseverance and lower despair. Thus, even if perceived social support is low, they can still improve health-promoting behaviors through their self-efficacy. As individuals' health knowledge and literacy increase, they come to believe that they can significantly control the symptoms of the disease to a great extent and manage their condition with higher self-confidence. In fact, health literacy-related skills are key factors in improving self-care in patients. The mechanism of this effect is such that these skills increase patients' selfconfidence and self-efficacy, enabling them to obtain health information from various sources and believe in their ability to manage the disease in addition to ultimately leading to the adoption of self-care behaviors.

This study faced some limitations. Since this research was conducted on women with breast cancer in Ahvaz, Khuzestan Province, the results cannot be conclusively generalized to other individuals, groups, and patient populations. Special caution is needed in this regard. The study was of the cross-sectional type, and the research variables were measured at a single point in time. Hence, it is possible that the relationships may have different patterns over time.

In this study, we evaluated the mediating role of cancer self-efficacy in the association between health literacy and social support with health-promoting behaviors in women with breast cancer. The findings of this research showed the effective role of cancer self-efficacy in the outcome of social support and health literacy to increase health-promoting behaviors in women with breast cancer. According to the findings, it is recommended to use the research results to increase the awareness of patients about cancer. Moreover, healthcare providers and counselors are advised to consider the roles of the research variables in assisting patients and to pay more attention to refining the treatment process. Therapists and counselors are also recommended to use a variety of methods for improving patients' self-efficacy and social support.

The study was approved by the Ethical Committee of Islamic Azad University-Ahvaz Branch (code: IR.IAU.AHVAZ.REC.1400.087).

This research did not receive any grant from funding agencies in the public, commercial, or nonprofit sectors.

There are no conflicts of interest regarding the publication of the current research.