First, we were analysed the differences between the two intervention groups in the different variables depending on each type of group therapy. Secondly, the evolution of the different dependent variables in the three measuring moments was studied, independently of the therapy group. Finally, we analysed the evolution of these variables in the three measurement moments considering the two intervention groups.

Also we considered the differences between the intervention groups in the several variables depending on the type of therapy group.

From the statistical analysis, no statistically significant differences were found in the means of the eight dependent variables analysed (see Table 1): depression [F (2, 99)=0.00; p=.989], anxiety [F (2, 99)=0.74; p=.389], social/familiar well-being [F (2, 99)= 1.00; p =.318], emotional well-being [F (2, 99)=0.39; p=.531], QoL [F (2, 99)=0.62; p=.628], functional well-being [F (2, 99)=0.08; p=.777], physic well-being [F (2, 99)= 0.12; p=.726] and other worries [F (2, 99)= 0.51; p=.474].

A statistically significant evolution was observed in five of the eight variables (see Table 2). In emotional well-being there was a significant increase in the means between the different moments of measurement with a large effect size [F (1.67, 99) = 18.84; p = .000; partial η2 = 0.161], showing differences between moment I and II, and moment I and III. Regarding the group of variables with a medium effect size, we found anxiety, depression and QoL. In anxiety, statistically significant differences were observed in the different measurement moments [F (1.82, 99) = 9.06; p = .000; partial η2 = 0.085], observing a greater difference between moments I and II, and I and III. The means of the variable anxiety had been decreasing throughout the intervention. Another variable with a medium effect size is the QoL, in which statistically significant differences were observed in terms of the different measurement moments [F (2, 99) = 13.80; p = .000; partial η2 = 0.123]; his score improved significantly between the moment I and II, there was almost no difference between moments II and III. And, finally, in depression significant differences were observed [F (2, 99) = 6.31; p = .002; partial η2= 0.061], whose means throughout the intervention had decreased, being significant the differences between I and II, and I and III. Among the variables that present a small effect size was functional well-being [F (2, 99) = 3.32; p = .038; partial η2 = 0.033]; the mean of this variable had increased between I and II, but decreases in III.

No statistically significant differences were found between the different measurement moments in physical well-being [F (1.88, 99) = 0.875; p = .140; partial η2 = 0.009], social/family well-being [F (2, 99) = 1.83; p = .162; partial η2 = 0.018] and other worries [F (2, 99) = 2.40; p = .093; partial η2 = 0.024].

Finally, the interaction between the time evolution in the three measurement moments and the two therapy groups (Self-esteem and SS group, and CBT group) in the different variables is presented. The only variable in which statistically significant differences were found with a small effect size (partial η2 = 0.042) was in emotional well-being [F (1.67, 99) = 4.27; p = .021]. See Table 3. The evolution of this variable was that patients who received intervention based on cognitive-behavioral therapy tended to increase their emotional well-being. This difference between the two intervention groups was observed throughout the intervention process and at the three-month follow-up. Patients who belonged to the intervention group focused on self-esteem and social skills also showed an increase in emotional well-being, although this improvement was not statistically significant.

Concerning the other variables, there were no statistically significant differences between the different measurement moments and the two intervention groups: anxiety [F (1.82, 99) = 1.23; p = .290; partial η2 = 0.012], depression [F (2, 99) = 651; p = .523; partial η2 = .007], QoL [F (2, 99) = 0.22; p = .796; partial η2 = 0.002], physical well-being [F (1.88, 99) = 0.21; p = .793; partial η2 = 0.002], functional well-being [F (2, 99) = 0.18; p = .829; partial η2 = 0.002], social/family well-being [F (2, 99) = 1.65; p = .194;partial η2 = 0.017] and other worries [F (2, 99) = 0.258; p = .773; partial η2 = 0.003].

This study aimed to analyse the effectiveness of group therapy intervention in the emotional state and QL of women with localized breast cancer at the end of the adjuvant medical treatments (chemotherapy / radiotherapy), as well as knowing if this effectiveness is the same in two types of psychological intervention group and if it is maintained both at the end of the intervention and in the follow-up after three months.

In relation to the results obtained, it can be affirmed that both intervention groups are associated with significant benefits, improving the QL and mood of women with breast cancer. This improvement in the reduction of anxiety and depression levels throughout the follow-up is significant, being somewhat greater in anxiety than in depression. As we indicated in our first hypothesis, we can conclude that both anxiety and depression have been reduced after finishing the group treatment. This confirms the results obtained in other studies with group therapy with women with localized breast cancer (Bellver, 2007; Taylor et al., 2003).

The proposed hypothesis describes that it is expected to find an improvement in the levels of depression, anxiety and QL in the intervention group based on CBT than in the self-esteem and SS group. Regarding the comparison between the two intervention groups, the results indicate that no significant differences have been found in the symptoms of anxiety and depression and in QL, so it can be inferred that both the intervention in self-esteem and SS and the intervention. Based on CBT are equally effective for the reduction of anxiety and depression and for the increase of the QL in patients surviving breast cancer. One of the reasons for this improvement in the QL in the intervention group based on self-esteem and SS is because it is closely related to self-esteem (Sehati et al., 2018). In fact, this type of intervention has also proved very useful in other types of cancer (Barrera et al., 2017). However, there does seem to be significant differences between the two intervention groups in emotional well-being throughout the follow-up. Patients who received treatment based on CBT tend to increase their emotional well-being with respect to the self-esteem group and SS. This difference between the two intervention groups is observed throughout the group intervention process and at the three-month follow-up. Therefore, we can partially confirm the second hypothesis, since there is an improvement in the emotional well-being dimension, but not in the rest of the variables. It is considered that CBT is the most effective technique in localized breast cancer, both in group interventions and in individual interventions (Boutin, 2007; Jassim, Whitford, Hickey, & Carter, 2015).

This benefit is maintained after three months in the variables anxiety, depression, QL and emotional and functional well-being. In relation to the symptoms of anxiety and depression, a greater difference can be observed between the beginning of the therapy and the three months of follow-up. The benefit provided by the two types of group intervention for these symptoms is maintained after three months at the end of therapy. Other studies have obtained benefits that tend to be prolonged in the medium term once the intervention is finished (McGregor et al., 2009). In terms of emotional and functional well-being, it also improves the group intervention process. After three months of follow-up, it is observed that the improvement in this variable is maintained. This is relevant since it indicates that the learning of the CBT and self-esteem and SS are maintained over time and that they continue to be put into practice in the daily life of the patients. However, in the rest of the areas of the QL group psychological therapy does not seem to have influenced significantly, confirming the third hypothesis rose where maintenance of the positive results of the therapy was expected after three months of follow-up, regardless of the group of intervention.

Psychotherapy groups have the advantage of being more beneficial if they are discussed in terms of cost-effectiveness than individual therapy, since it involves serving a larger number of patients. This generates a network of support with the group of equals (Spiegel, 1994).

The limitations of the study are that there is no control group with which to compare both types of group therapy used in this study; having a control group can pose ethical problems because you can not benefit from group therapy. However, a control group would be necessary to carry out a purely experimental study, in addition to forming the intervention groups with adequate randomization. Another limitation is that there is only a follow-up after three months of the group intervention, with what we believe is necessary in future studies to follow up in the long term.

Different studies have delved into the benefits that other less conventional or novel therapies can bring. It has been shown that hypnosis-based psychotherapy and CBT is beneficial, as it teaches patients in treatment and survivors to reduce fatigue, cancer-related pain and control sleep disturbances (Gregoire et al., 2017; Mendoza et al., 2016; Téllez et al., 2017). On the other hand, mindfulness based on stress reduction has been found to be effective in promoting QL for both patients (Haller et al., 2017; Johns et al., 2015; Sarenmalm, Martensson, Andersson, Karlsson, & Bergh, 2017; Lengacher et al., 2016; Park et al., 2018; Rosen, Paniagua, Kazanis, Jones, & Potter, 2018) and survivors (Gonzalez-Hernandez et al., 2018; Lengacher et al., 2016). Psychodynamic psychotherapy has resulted in a short-term improvement in patients’ depressive symptoms (Beutel et al., 2014). Finally, interventions based on physical activity promote an improvement of health in cancer survivors (Maxwell-Smith et al., 2018).