With social and industrial transformations, the pattern of disease infection has undergone changes in the present era, with chronic diseases being recognized as the most significant physical and mental health issues in societies. These problems are known as the primary sources of tension, imposing heavy economic costs on society, such as cancer. Cancer, as one of the major health concerns globally, poses a threat to human life, leading to numerous personal, family, and social damages in physical, mental, and social aspects (
1).
Despite the advancements achieved in the field of timely diagnosis, treatment, and supportive care, the number of cancer survivors has been growing. However, the physiological issues (such as fatigue, pain, nausea, and changes in appearance) and psycho-social complications (such as mental discomfort, relationship difficulties, financial stress, and changes in cognitive and sexual functioning) arising from cancer and its treatment can considerably compromise their quality of life (
2,
3). Evidence shows that gender can impact the psychological consequences of cancer, which may be attributed to biological differences, such as chromosomes and hormones, as well as social roles, behaviors, and identities in women and men. For instance, women tend to experience more anxiety, depression, and psychological distress, while men with cancer and male cancer survivors have reported fewer issues (
4). Hence, female cancer survivors, being a more vulnerable group, often face more psychological challenges, less adjustment, and lower quality of life compared to their male counterparts (
5).
According to the World Health Organization (WHO) definition (
6), quality of life refers to an individual’s understanding of their position in life, values, and priorities. Research results have demonstrated that cancer significantly affects the quality of life and its various aspects, such as individuals’ physical, social, emotional, and cognitive health, particularly those who have recovered from chemotherapy (
7). Cognitive functioning is defined as intellectual activities, such as thinking, reasoning, and learning (
8). Cancer pharmacological treatments can have acute and long-term effects on cognitive functioning (
9). Cognitive function failure refers to an individual’s inability to perform tasks they can normally do. In other words, cognitive function failure is a series of cognitive mistakes occurring while performing tasks that an individual usually completes successfully. Cognitive function failure was first introduced by Broadbent. He believes that cognitive function failure includes failures in attention, memory, and motor functioning (
10). Cognitive function failure can affect individuals’ daily functioning, quality of life, and work capacity, particularly in cancer survivors (
11). Cognitive functioning decreases in men with prostate cancer after starting androgen deprivation therapy (
12). Additionally, in women who have recovered from breast cancer, cognitive functioning has shown a considerable reduction before and after treatment, which is associated with factors such as aging, irregular sleep, receiving chemotherapy, neuropsychological symptoms, and reduced quality of life. Other factors such as age, dosage, shorter treatment course, simultaneously or immediately after chemotherapy, and higher volumes of radiotherapy radiation can also culminate in cognitive function failure. This impairment may give rise to long-term memory loss years after treatment completion. Therefore, it is necessary to monitor the cognitive functioning of patients undergoing treatment (chemotherapy and radiotherapy) (
11,
13,
14).
Recent studies have indicated that, along with cognitive functioning, patients’ health literacy plays a crucial role in determining their quality of life (
15). Patients with cancer and survivors face problems in maintaining and benefitting from health information due to the psychological helplessness they experience. Therefore, health literacy is of great importance in cancer care and urgent attention must be paid to this issue (
16-
18). Behavioral changes through enhanced health literacy can play a significant role in medical decision-making and help individuals make more informed health decisions.
The WHO declares health literacy as one of the substantial factors in determining individuals’ health and links it to health outcomes (
19). The Institute of Medicine defines health literacy as the ability of individuals to achieve, process, and perceive basic information and services needed to make appropriate health decisions (
20). Since knowledge in the field of health can play a crucial role in promoting individuals’ health and quality of life, the significance of health literacy has been paid more attention.
Research has demonstrated that individuals with low health literacy have limited access to health services and experience a lower quality of life (
16). On the contrary, those with high health literacy possess more health knowledge and engage in more favorable health behaviors (
21,
22). Thus, promoting health literacy can greatly enhance individuals’ quality of life (
15).
Some studies have suggested that the link between health literacy and quality of life may be influenced by various factors such as cultural characteristics, geographical location, self-efficacy, perceived social support, age, gender, education level, and health skills (
23-
26). However, previous research (
27) indicated that education level, gender, and even the presence of a chronic diseases are unreliable predictors of health literacy and do not correlate with the quality of life (
17,
27).
On the other hand, as other studies found, gender can play a predictor role in relation to health literacy and quality of life. Research has shown that women are more inclined than men to understand and complete medical forms, comprehend instructions on the medicine bottles, and understand their writing; in other words, women possess higher health literacy than men (
28). Studies have acknowledged that women perform better than men in health literacy-related tasks, which can be due to women’s greater familiarity with healthcare systems (
28,
29).
On the other hand, according to research (
30), women’s health literacy was not regarded as a predictor for quality of life, while women were able to actively participate in managing their health and healthcare. Furthermore, health literacy is also crucial for men. For instance, a recent study (
31) has demonstrated that men with prostate cancer with higher communication skills and knowledge to enjoy a better quality of life. Therefore, improved mental health is primarily correlated with men’s ability to actively interact with healthcare providers and better physical health is correlated with having adequate information to manage their own health. In other words, it is essential for men to have the capability to deal with health challenges and to communicate effectively with healthcare professionals (
31,
32).