In total we identified 37 studies examining psychosocial factors and breast cancer survival; 31 descriptive analytical studies and 6 studies with psychological intervention. In Tables and we summarize the 31 studies regarding psychosocial/psychological factors and survival or recurrence among patients with breast cancer [
4-
34]. In Tables and we summarize the six studies regarding the impact of psychosocial intervention on survival of breast cancer patients [
35-
40]. In Table we summarize the association of psychosocial factors with survival/recurrence. A total number of 61,611 female patients with breast cancer were examined regarding psychosocial factors and survival (52,857 of them in retrospective studies). Of the total 31 identified descriptive analytical studies, 15 were conducted in the US [
5-
8,
10,
11,
15,
16,
22,
24,
26,
27,
31,
32,
34], 2 in Canada [
9,
29], 1 in Israel [
18], 2 in Australia [
23,
30], 1 in Japan [
19] and the rest of them in Europe (6 in the UK, [
4,
12-
14,
21,
25] 1 in Switzerland and Germany [
17], 1 in Denmark [
28], 1 in Belgium [
20] and 1 in Finland [
33]). Two studies examined the same cohort of women to assess the impact of psychosocial factors on survival [
26] and the effect of cancer specific beliefs on survival [
27]. Out of the 31 studies that did not employ psychological intervention, 12 examined patients with all stages of breast cancer [
6,
7,
9,
12,
15,
19,
22,
26-
28,
32,
34]. Five and two studies examined patients with metastatic/recurrent cancer [
5,
8,
11,
23,
24] and invasive stage I or II to III cancer [
20,
31], respectively, whereas twelve studies examined patients with early stage cancer [
4,
10,
13,
14,
16-
18,
21,
25,
29,
30,
33] characterized either as operable, stage I and II in the TNM classification (that is, the staging system based on tumour size, lymph node involvement, and the presence of metastasis), or localized regional and non-metastatic. Fourteen studies focused on patients' reactions to having cancer and their feelings whereas nine focused on social factors (that is, marital status, social ties, religion) that can offer significant support to breast cancer patients, and seven studies focused on both. One study examines the effect of beliefs about cancer curability.
| Table 1Characteristics of studies examining psychosocial factors associated with breast cancer survival |
| Table 2Methods and outcomes of studies examining the association of psychosocial factors and breast cancer survival |
| Table 3Characteristics of studies examining the effect of psychological intervention on breast cancer survival |
| Table 4Methods and outcomes of studies examining the effect of psychological intervention on breast cancer survival |
| Table 5Association of the examined psychosocial factors with survival/recurrence |
Out of the 31 studies, 25 (80.6%) revealed that various psychological factors are significantly associated with survival/recurrence. Increased survival is associated with role functioning (one study [
29]), fighting spirit (one study [
30]), joy (one study [
11]), depression (one study [
5]), perceived social support (two studies [
15,
26]), social support (four studies [
5,
15,
31,
34]), minimization (two studies [
23,
33]), adjustment (one study [
18]), denial (one study [
29]), anger (one study [
5]), guilt (one study [
5]), extroversion (one study [
9]), expressive activities (one study [
9]), participation in religious/nonreligious groups (one study [
6]), psychiatric symptoms (one study [
5]), hobbies (one study [
19]), female child (one study [
19]), and marriage (three studies [
6,
19,
32]). Decreased survival is associated with stressful events (one study [
29]), anxiety/stress (one study [
7]), hopelessness (one study [
7]), higher perceived emotional support (one study [
33]), depression (five studies [
11,
21,
24,
28,
33]), repressive defensiveness (three studies [
7,
24,
33]), positive constructive daydreaming (one study [
7]), denial/avoidance (one study [
33]). Cognitive functioning (one study [
29]), stressful events (one study [
12]), anxiety (one study [
20]), hopelessness (three studies [
4,
10,
21]), fatalism (one study [
4]) and anger/hostility (one study [
9]) were associated with higher recurrence rates. Fighting spirit (one study [
4]), stressful events (two studies [
13,
25]), denial (one study [
4]) and expressive activities (one study [
9]) significantly reduced recurrence rates.
As seen in Table , for most of the separate psychosocial factors examined with regard to breast cancer survival and/or recurrence there was only one study supporting the association (either a positive or a negative impact on survival/recurrence). For several psychosocial factors (specifically, depression, social support, marriage, perceived support, stressful events, denial/avoidance, minimizing, repressive defensiveness, anger/hostility and hopelessness/helplessness) more than one study reporting a statistically significant association with breast cancer survival. For five of these eight psychosocial factors (stressful events, depression, perceived social support, anger/hostility, denial/avoidance) there are contradictory results (showing both negative and positive effects) on survival/recurrence. For example, while five studies show that depression is associated with decreased survival, there is one study where depression seems to increase survival. Perceived social support, social support, minimization and marriage were associated with prolonged survival in more than one study. Similarly, repressive defensiveness and depression are associated with decreased survival in more than one study. As far as recurrence is concerned, only stressful events appeared to reduce recurrence rates while hopelessness appeared to increase recurrence rates in more than one study.
In the 6 studies that used psychological intervention, a total of 389 female patients with breast cancer were examined (34 of them in a retrospective study). Psychological intervention varied from study to study, including group therapy, behavioral/cognitive therapy, peer support/family therapy, counseling, mental imagery, meditation, and psychology classes. Three of these studies were conducted in the US [
35,
36,
39], two in Canada [
37,
40] and one in Australia [
38]. Four studies examined patients with metastatic breast cancer, one patients with early breast cancer and one patients with breast cancer of any stage. Two studies showed that there is a survival benefit for those patients that received psychological intevention [
35,
39], while in four studies there was no influence on survival [
36-
38,
40].