Health promotion behavior is one of the important factors in mental and physical consequences of cancer patients. The chronic and threatening nature of cancer causes mental crisis and disappointment in patients. Mental health promotion and hope enhancement are significant factors for decreasing stress caused by cancer and passing treatment days. The results of this research indicate that, using precede model leads to the enhancement of average score of precede pattern constructs, the promotion of mental health, the increase of hope and the improvement of health promotion behaviors.
Obtained results indicated that, 6 months after educational intervention, the average score of knowledge in experimental group had significant enhancement, while there seemed no changes in control group. Holding educational sessions, presenting educational contents in group discussions and asking and answering questions and giving educational booklet caused the enhancement of knowledge of experimental group. Results of Khashfi et al. , McCree-hale et al. , Didarlou et al.  and Khani Jeihooni et al. [57, 58] revealed that, educational intervention caused the enhancement of knowledge of studied subjects.
Results of this research showed that, before educational intervention, the average score of experimental and control groups attitude was very low, however, 6 months after intervention, significant enhancement was observed in experimental group, while control group had no changes. In precede pattern, the predisposing factors such as knowledge and attitude are very important for changing behavior . In present research, the increase of knowledge and positive attitude caused the facilitation of health promotion behaviors, enhancement of hope and mental health of cancer patients. Also,, presenting educational contents through practical shows, asking and answering questions and providing a Whatsapp group for exchanging information and experiences caused the enhancement of attitude in experimental group. The results of other studies are in a good agreement with the results of present research [54, 60, 61 and 62].
Results of this research indicated significant enhancement in average score of self-efficacy 6 months after intervention in experimental group, while control group had no changes. When cancer patients have high control on their disease, they have rational behaviors for promoting their health. Self-efficacy indirectly influences the attitude through perceived barriers and stability for continuing a special activity . In study of Khani Jeihooni et al. , educational intervention based on precede model caused the enhancement of average score of self-efficacy 6 months after intervention in experimental group, while control group had no changes. In another study performed by Khani Jeihooni et al. , for promoting the prevention behaviors from skin cancer, he used precede pattern and figured out that, 4 months after the intervention, the average score of self-efficacy of experimental group increased. In study of Zare et al. , educational intervention caused the enhancement of average score of self-efficacy in men for doing prostate cancer screening. In studies of Khiyali et al. , Malmir et al.  and Yates et al. , educational intervention caused the enhancement of average score of self-efficacy in studied subjects. Najafi et al.  investigated the factors related to prevention behaviors from skin cancer in high school students and revealed that, there is a significant and positive relationship between prevention behaviors, attitude, self-efficacy, social supports and enabling factors.
In current study, before educational intervention, the average score of perceived social supports was very low, however, 6 months after the intervention, a significant enhancement was observed in experimental group. By increasing social supports, health promotion behaviors of patients improve. Holding educational sessions, creating helper and friends groups, continuous contact with patients and following their activities caused the increase of average score of perceived social supports in experimental group. Mathews et al.  investigated efficient factors for searching medical information in cancer patients including knowledge, social supports, religious beliefs, insurance, anxiety, fear and etc. In study of Satia et al. , doctors’ recommendations and family supports were effective factors for having positive behavior in prostate cancer patients. Dugglebg et al.  investigated the efficiency of mental and social supports in the enhancement of life quality in cancer patients. He also studied the effect of Live with Hope Program (LWHP) on the enhancement of hope and life quality of cancer patients. In his research, experimental group whom received LWHP had higher score in hope enhancement. In study of Taghdisi et al. , by using BASNEF model, there seemed no significant differences in average score of social supports (subjective norms) and enabling factors in both of the experimental and control groups after educational intervention. In studies of Khani Jeihooni [75, 76], Kashfi et al.  and Hazavehei et al. , educational intervention caused the enhancement of average score of subjective norms (social supports) of experimental group.
Matin et al.  studied the effective factors on life quality of addicted men by using precede pattern. He revealed that, the studied variables determine 17% variance in life quality and the social support plays an important role in life quality of people. Chambers et al.  investigated 140 cancer patients in Australia and showed the reduction of stress and disappointment and the improvement of life quality and correct judgment about disease.
In this study, before the educational intervention, the average score of enabling factors of subjects was low. However, 6 months after intervention, experimental group had significant enhancement. Providing educational booklet for cancer patients, availability of doctors, providing Whatsapp group, following subjects’ activities after educational sessions, holding an educational session for one of the family members and presenting motivational contents caused the increase of patients’ ability to perform health promotion behaviors and the enhancement of hope and mental health. Castellanos et al.  investigated the effect of diet on post-migrant Hispanic men by using precede-proceed model and grounded theory. He indicated that, educational interventions should be based on enabling, predisposing and improving factors. Cannick et al.  carried out a study about the prevention and early diagnosis of oral cancer by using precede-proceed model for educating dentistry students. In his study, the educational intervention caused the enhancement of enabling factors and other constructs of this model. The results of other similar studies are in a good agreement with the results of this investigation [54, 57, 81 and 82].
According to the importance of hope in cancer patients, for retaining and promoting hope of experimental group, educational intervention was performed by presenting motivational contents, ways of being happy and positive structures. In this research, participants were active in different discussions and presented their opinions and were responsible for solving their problems. Herth et al.  studied the enhancement of hope in primary stages of cancer and observed significant differences between hope and life quality in experimental and control groups and after educational intervention, the average score of hope in experimental group enhanced, while control group had no changes. In study of Taghdisi et al. , educational intervention caused the enhancement of hope in cancer patients and their families. Movahedi et al.  investigated the effect of hope treatment education on life expectancy and general health of cancer patients. His results revealed that, hope treatment caused the promotion of life expectancy and general health of experimental group. The role of psychological intervention in managing stress and other mental symptoms of cancer patients is significant because, after psychological interventions, the level of stress and disappointment of cancer patients reduced significantly and the interpersonal relationship of patients improved . The studies of Taylor and Brown  and Mehmet and Synder  indicated that, hope treatment was effective on the improvement of general health of cancer patients. In study of Kamian et al.  on 100 women suffering from breast cancer, it was revealed that, educational intervention caused the enhancement of average score of hope and mental health of experimental group. Also, there was a significant relationship between mental health and hope. Felder et al.  investigated hope and adaptation of patients with cancer and indicated a significant and positive relationship between hope and adaptation skills. He also observed that, patients with higher level of hope have more adaptation skills. Rusteen et al.  showed that, after treatment sessions and 3 months after follow-up session, hope and life quality of patients enhanced significantly.
Results of this study showed that, 6 months after educational intervention, the average score of mental health of experimental group was significantly higher than control group. The educational intervention for promoting mental health included religious-based meaning treatment about the aim and meaning of suffer, life, death, pray and its effect on health. Mental health causes the improvement of life expectancy and social performance of patients. The religious beliefs enhance patients’ resistance and it is effective on the reduction of pain, disappointment and anxiety. Hamid et al.  showed that, the religious-based treatment caused the enhancement of hope and life quality of women suffering from breast cancer. Nelson et al.  indicated that, high level of mental health with low level of some variables related to the mental disorders (such as disappointment, frustration and suicide) are related to each other. The results of Tatsumural et al.  revealed that, mental supports and religious sources are very important for compatibility of cancer patients with disease during treatment process. Hopko et al.  investigated the efficiency of cognitive behavioral therapy on disappointment, life quality, physical and entertaining activities, interpersonal problems and sleeping problems of patients and revealed that, after cognitive behavioral therapy, the mentioned problems reduced and life quality of patients enhanced. Results of Moghimian and Salmani  showed that, there is a direct and significant relationship between mental health and hope in cancer patients and health officials should be aware of the mental needs of patients and perform appropriate educational interventions.
Obtained results of present research showed that, 6 months after intervention, the average score of health promotion behaviors of experimental group was significantly higher than control group, while before the educational intervention, there was no significant differences between two groups and the level of health promotion behaviors was low. In this research, 6 aspects of health promotion behaviors including nutrition, physical activity, mental growth, health responsibility, stress management and interpersonal relationships were emphasized. The results of Basharpoor et al.  indicated that, understanding about cancer and its complications plays an important role in cancer patients’ interest for performing health promotion behaviors. In study of Taghdisi et al. , educational intervention caused health promotion of cancer patients. The results of this study are in a good agreement with the results of other similar researches [5, 9, 10, 20, 27, 28, 31, 35, 36, 92, 93 and 94].