Introduction: Cancer is one of the most common diseases that has affected many people around the world. Regarded to the need for intervention to improve the characteristics of women with breast cancer and little research on the effectiveness of Cognitive Behavior, present research aimed to determine the effectiveness of Cognitive Behavior emotional regulation and subjective well-being in women with breast cancer.
Methods: This study was a semi-experimental with pretest, posttest and follow-up design with control group. The research population was women with breast cancer referred to Shohadaye Tajrish Hospital of Tehran city in 2019-2020 year. 30 people were selected by available sampling method and via simple randomly method replaced to into three equal groups (each group 15 people). The experimental group trained 10 sessions of 60 minutes by Cognitive Behavior method and the control group was placed on a waiting list for training. Data were collected with using, emotional regulation and subjective well-being questionnaires and analyzed by Chi-square, independent t and analysis of variance with repeated measures in SPSS version 19 software.
Results:  The findings showed that the groups in the pretest stage did not significant difference in terms of emotional regulation and subjective well-being (P>0.05), but in the post-test and follow-up stages was a significant difference in terms of all two variables (P<0.001). In addition Cognitive Behavior led to improved emotional regulation and subjective well-being in women with breast cancer (P<0.001).
Conclusion: Using cognitive-behavioral therapy can improve emotional regulation and mental well-being of women with breast cancer.