This study aimed to divulge the factors associated with HRQOL in BC patients in Khuzestan province, Iran, using specific (EORTC QLQ-BR23) and general (EORTC QLQ-C30) instruments designed for BC. In this study, the patients’ total QoL score was 59.58. In comparison, the QoL score in BC patients in Ethiopia (
1), Malaysia (
24), Poland (
25), Spain (
17), Greece (
12), Chinese Taipei (
26), Morocco (
27), Brazil (
28), Morocco (
29), and worldwide (
23) were reported as 65.5, 69.12, 60.7, 63.1, 63.43, 66.4, 50.00, 77.77, 57.2, and 70.5, respectively. These variabilities may be due to different types of treatments, disease stages, the physical and mental conditions of patients, and differences in patients’ socioeconomic and clinical variables.
The results of this study showed that in the functional domain, sexual pleasure scored the lowest (10.27), and social functioning scored the highest (80.74). In a study conducted in Ethiopia (
1), the scores of the sexual pleasure, which attained the highest score, and social functioning domains were reported as 85.5 and 68.9, respectively. Caceres et al. (
17), in Spain, also showed that sexual pleasure (77.33) and social functioning (76.57) obtained high scores; sexual functioning had the highest score, and the future perspective domain attained the lowest score. In the present study, sexual functioning had a low score, and the future perspective domain obtained a relatively better score. Maridaki and colleagues (
12) in Greece showed that the social functioning score was 68.52. Also, Fouhi et al. (
27) in Morocco reported a social functioning score of 75.39. Binotto et al. (
28) in Brazil showed that the scores of the social functioning and sexual pleasure domains were 87.38 and 68.89, respectively. Gonzalez et al. (
23) showed that the global scores of social functioning and sexual pleasure were 76.3 and 45.7, respectively. Differences in sexual pleasure functional scores could be attributed to spiritual states, the mean age of the population under study, frustration, mental conflicts, the attitudes of the sexual partner, and cultural-social differences. Furthermore, the differences and similarities between the results of these studies, including ours, regarding social functioning might be caused by social support, social attitudes, and the individual’s awareness and knowledge of his/her current situation. In other functional dimensions, other variables that can cause this difference are socioeconomic characteristics, education level, age, and stage of disease.
The findings of this study showed that in the domain of symptoms, financial difficulties (60.37) and diarrhea (6.23) had the highest and lowest scores, respectively. Similarly, financial difficulties obtained a high score (51.6) in Tamam et al.’s study (
2), and the score of the diarrhea domain was reported as 45.3. In another study by Caceres et al. (
17), the scores for financial difficulties and diarrhea were 16.82 and 8.82, respectively, showing that consistent with our study, they reported a low score for the diarrhea domain. Similar to our study, Getu et al. (
1) also reported a high score for financial difficulties (50) and a low score for diarrhea (6.4). Fouhi et al. (
27) also declared a high score for financial difficulties (61.90), which was consistent with the results of the present study. Akezaki et al. (
30) observed a low score for diarrhea (7.3) dimension, and Binotto et al. (
28) also affirmed that diarrhea had the lowest score among other BC symptoms at the beginning of treatment (1.01) and three months afterward (9.09), which was consistent with the results of the present study. Ismaili et al. (
29) showed that financial difficulties (54.1) had the highest score in the domain of symptoms, which was consistent with the present study. According to Gonzalez et al. (
23), the global scores for financial difficulties and diarrhea were 37.2 and 21.6, respectively. Financial difficulties were the second most common complaint, and diarrhea also had the lowest score among other symptoms. The results of the present study and other studies show that financial difficulties have the highest score and greatly affect BC patients’ QoL, which can be solved by cost management and financial support for patients. Among other symptoms, demographic characteristics, lifestyle, nutrition, resilience, physical functioning, and cultural differences can also play a fundamental role; however, in most studies, diarrhea obtained the lowest score. Diarrhea can be caused by the side effects of medications or by the disease itself.
The results of this study showed that there was a significant difference in the mean QoL score between different categories of education level (P = 0.01), residence (P = 0.02), supplemental insurance (P = 0.02), employment status (P = 0.02), and duration of the illness (P = 0.02), but no significant difference was found regarding the variables of age, marital status, type of insurance, illness expenses, family history, and type of therapeutic interventions (P > 0.05). Socha and Sobiech (
25) in Poland found no significant difference in the QoL of BC patients regarding the variables of age and therapeutic interventions, which was consistent with the results of the present study. However, unlike the present study, Socha and Sobiech found no significant association between QoL and the variables of education level, residence, and employment status. Getu et al. (
1) in Ethiopia showed that QoL had a significant link with residence but not with age and marital status, which was consistent with the results of our study. A study by Park et al. (
31) showed that there was a significant difference in QoL regarding the type of therapeutic interventions, which was not consistent with the results of the present study. However, like our study, Park et al. declared no significant association between QoL and age. Akezaki et al. (
30) witnessed a significant correlation between the QoL of BC patients and the duration of the illness, which was consistent with the results of the present study. Konieczny et al. (
6) also showed that there was no significant difference in QoL with regard to the variables of age and marital status, which was consistent with the results of the present study. Our observations and those of other studies suggest that socio-demographic, economic, and clinical factors are of paramount importance in determining the QoL of BC patients. Therefore, to improve and enhance the QoL of these patients, appropriate interventions and programs should be executed considering the role and weight of these factors.
The results of multiple linear regression particularly showed that emotional functioning (P < 0.001), breast symptoms (P < 0.001), and appetite loss (P = 0.03), all together, could predict 23% (R2 = 0.23) of changes in the QoL of BC patients. Gayatri et al. (
32) in Indonesia showed that emotional functioning and appetite loss were predictors of QoL, which was consistent with the results of the present study. Socha and Sobiech (
25) in Poland showed that the variables of marital status, physical activity, depression, obesity, chronic comorbidities, living conditions, and pregnancy were the predictors of QoL. Crouch et al. (
33) in the United States declared that age, education, number of comorbidities, and mental status were the predictors of QoL in BC patients. Chow et al. (
34) in Singapore showed that age, education level, and type of treatment could predict QoL. Akezaki et al. (
30) also showed that the type of therapeutic intervention and arm symptoms were the most important predictors of QoL in BC patients. Mohlin et al. (
35) demonstrated that physical functioning, physical condition, pain, general health, social functioning, emotional role, mental health, and well-being were the most important predictors of QoL in women with BC. Comparing the results of this study with those of other studies, one can argue that socio-demographic, economic, and clinical factors can reliably predict QoL in BC patients. Also, based on the results of our study, like other studies, functional, symptomatic, and psychological dimensions were the most prominent predictors. Therefore, the QoL of these patients can be improved by implementing appropriate interventions to address functional dimensions, symptoms, and psychological performance. Identification and analysis of relevant predictors of QoL help physicians and healthcare providers recognize patients who are at risk of low QoL. Thus, restoring the balance between these factors through suitable interventions can improve the patient’s QoL (
28,
36).
This study had some limitations and strengths. This study was conducted with a cross-sectional design, and it was not possible to measure changes in QoL during different stages of the disease due to difficulties in access to patients secondary to their physical and mental conditions. This study was conducted on a relatively small population. Data were collected through self-reporting instruments, and yet another limitation of this study included the cultural and ethnic differences between the participants. On the other hand, one of the strengths of this study was the use of general and specific BC questionnaires, sampling from all BC treatment centers in Khuzestan, and analyzing a variety of demographic-social and clinical variables.
5.1. Conclusions
Quality of life is an important patient-related outcome that provides insights into disease burden and is useful for patient empowerment, interpretation of clinical results, and decision-making about the treatment (
32). The QoL of BC patients can be improved and maintained by implementing appropriate strategies such as avoiding social restrictions and increasing social support (
14), offering comprehensive oncology services or palliative care (
32), regular monitoring to identify women at risk of poor HRQOL (
37), implementing appropriate national policies (
8), providing sufficient social and psychological support (
38), holding self-care training programs (
39), delivering spiritual and acceptance-based therapies (
40), managing and relieving stress (
18), managing treatment duration (
41), improving resilience (
35) and giving financial support (
29). Finally, the present study identified several factors to be associated with HRQOL in women with BC. Our results can be used to develop and implement policies to improve the QoL of women with BC. Healthcare systems can improve the QoL of BC patients using targeted interventions to address QoL-related factors, especially socio-demographic, economic, clinical, and functional factors, as well as the symptoms of the disease.