Post-traumatic growth among elderly women with breast cancer compared to breast cancer-free women

Abstract

Background. Although breast cancer (BC) may have negative psychological sequelae, it may also be experienced as an existential challenge, which can derive personal growth. Only one study has been conducted, however, on whether women with BC experience more post-traumatic growth (PTG) than BC-free women. We examined PTG in women with and without BC and whether the characteristics and treatment of BC were associated with PTG. Material and methods. We used data from the questionnaire administered in the Diet, Cancer and Health cohort and included 774 women with BC and 666 randomly sampled BC-free women aged 63–81 years. PTG was measured with the PTG inventory, for which the women identified their own traumatic or life-changing event. Linear regression was used to compare PTG in women with and without BC and to examine the association between BC characteristics and treatment and PTG. Results. Although women with BC experienced significantly more PTG in the domains ‘appreciation of life’ and ‘relating to others’ compared to BC-free women, no statistically significant difference in overall PTG was observed according to BC status, indicating that PTG is not limited to women with BC. Tumor size, number of positive lymph nodes, having undergone mastectomy and having received endocrine treatment were positively associated with overall PTG and/or specific PTG domains, implying that the severity of disease plays a role in the development of PTG. Conclusion. In order to avoid unnecessary pressure for personal growth, healthcare professionals should not expect that women with BC experience more PTG than BC-free women.

The focus on positive psychology [1] has raised interest in positive changes after adverse events, such as a cancer diagnosis. More than 80% of breast cancer (BC) survivors have been found to benefit psychologically from their BC experience [2]. One positive consequence of struggling with an extreme event such as a BC diagnosis is post-traumatic growth (PTG). In the coping with trauma, the individual may be confronted with injustice, missing control and meaninglessness. This may challenge and change the individual's core-assumptions about the world, possibly resulting in a re-evaluation of life and an experience of significant positive changes in life perspective, interpersonal relationships and self-perception. PTG is characterized as a positive change that goes beyond the appreciation before the crisis occurred [3]. PTG may be experienced after traumas such as BC, but could also be triggered by, e.g. the loss of a spouse or an accident. Knowledge on whether PTG is greater among BC survivors or may be related to stressful life events in general is insufficient.

In the only previous study in which PTG was compared in women with BC (n = 70) and without BC (n = 70), the scores for overall PTG and the domains ‘relating to others’, ‘spiritual change’ and ‘appreciation of life’ were higher among women with BC, indicating that BC survivors experience more positive changes than others [4]. In search of disentangling the most important processes at play for developing PTG among BC survivors and thus explanations of why coping with BC may trigger PTG, several disease- and treatment-related factors have been suggested because they may alter the severity of the trauma experienced; however, the results have been inconclusive, with negative [5], positive [6–8] and null findings [9–11].

Knowledge on PTG after BC and thus the development that may take place during the cancer trajectory is important for the planning of future rehabilitation programs [12] and in the education of healthcare professionals. Women with BC may be comforted by a potential positive psychological change after BC, but might also be unnecessarily pressured if healthcare professionals have high and unrealistic expectations of psychological growth. The aftermath of BC disease and treatment, may include negative physical as well as psychological sequelae [13,14], and a potentially unrealistic assumption that the BC may enrich life may risk adding further stress to the demanding experience of BC [15]. We used data on women in a large Danish prospective cohort in which PTG was measured by letting the women identify their own traumatic or life-changing event, to examine whether women with BC experience more PTG than BC-free women and whether the severity of the trauma, measured as disease and treatment characteristics, influences PTG in women with BC. We hypothesized that women with BC experienced significantly more PTG compared to BC-free women, and that disease- and severity-related factors were positively associated with PTG.

Material and methods

The Diet, Cancer and Health cohort

We used data from questionnaires completed for the Danish Diet, Cancer and Health cohort, which has been described in detail elsewhere [16]. Briefly, between 1993 and 1997, 57 053 persons aged 50–64 with no previous cancer diagnosis completed a baseline questionnaire (response rate: 35%) and were invited in 1999–2002 to complete a follow-up questionnaire.

In 2010–2011, we conducted a second follow-up focusing on life after BC. We invited all 1252 women who had previously participated and in whom BC had been diagnosed after baseline (excluding women who had emigrated, died or did not wish to be contacted again) and a random sample of 1422 BC-free women matched to the women with BC in five-year age intervals. The second follow-up included a mailed questionnaire to be returned within two weeks. Reminders were sent by mail after four weeks and by phone after six weeks. For questionnaires with incomplete sections, the women were phoned and asked to answer the questions on the phone.

Post-traumatic growth inventory

PTG was measured using questions from the second follow-up. Women with and without BC were asked to identify a traumatic or life-changing experience: loss of a close person, chronic or acute disease, violent crime, physical or psychological abuse, accident or injury, catastrophe, loss of job, economic difficulties, change of career or residence, change in family responsibility, divorce, retirement, war, other. With this traumatic experience in mind, the women were asked to respond to the PTG inventory, a 21-item scale [17]. For each item, the respondents were asked to report the degree to which the change had occurred as a result of their crisis. The degree of change was measured in a Likert response format ranging from 0 to 5, 0 being “I did not experience this change as a result of my crisis” and 5 being “I experienced this change to a very great degree as a result of my crisis” [17]. The inventory included overall PTG (the summed score of all 21 items) and the summed scores for the five domains: ‘personal strength’ (four items), ‘appreciation of life’ (three items), ‘relating to others’ (seven items), ‘new possibilities’ (five items) and ‘spiritual change’ (two items). The PTG inventory has been found to have good internal consistency and acceptable test–retest reliability [17], although it has not been validated in Denmark. The PTG inventory was translated into Danish using a forward-backward procedure.

Measures of prognostic and treatment factors

We obtained data on disease- and treatment-related factors from the Danish Breast Cancer Cooperative Group, which contains information on approximately 95% of all Danish women under 75 years of age in whom BC has been diagnosed [18]. The information included time since operation (in months), tumor size (in mm), number of lymph nodes with metastases, type of surgery (mastectomy or lumpectomy), radiation therapy (did or did not receive), chemotherapy (did or did not receive), and endocrine treatment (did or did not receive).

Demographic characteristics

Information on the level of education (≤ 7 years, 8–10 years, > 10 years) was retrieved from the Diet, Cancer and Health baseline study. The age of the participants was obtained from the Central Population Register and was included as a continuous variable [19].

Study sample

In the second follow-up, 71% (n = 893) of women with BC and 60% (n = 852) of BC-free women returned the questionnaires. Multiple responses to PTG inventory items and the choice of traumatic experience were registered as missing. If no more than one item on a subscale was missing, the average of the other items in the subscale replaced the missing item value. This approach has shown good parameter estimates in multiple item scales [20]. We thus excluded 119 (13%) women with BC and 185 (22%) BC-free women for whom more than one item on one or more of the PTG inventory subscales was missing. One BC-free woman was excluded because information on education was missing. The final study sample consisted of 774 women with BC and 666 BC-free women. In the analyses concerning BC treatment and PTG, 90 women were additionally excluded because information on disease characteristics and treatment was missing, leaving 684 women with BC (Figure 1).

Figure 1. The light-grey boxes show the study population used in the analyses of PTG according to BC status. The dark-grey box shows the study population used in the analyses of BC characteristics and treatment and PTG.

Statistical analyses

The mean overall PTG score and domain scores were analyzed descriptively. Linear regression was used to examine PTG (both overall score and domain scores) according to BC status. Furthermore, linear regression was used to examine the association between age, education and overall PTG. Similar analyses were conducted for women with BC examining PTG (overall PTG score and domain scores) according to time since BC surgery, disease and treatment characteristics. To ensure that the requirements for linear regression were met, the dependent variables were checked for normal distribution. Furthermore, all continuous variables were checked for linearity using linear splines in a linear regression model [21].

As BC incidence and PTG have been found to be associated with age [6,9,10,22,23] and level of education [9,24], these factors were included as potential confounders in the analyses; thus, the results were adjusted for age and education. Time since operation is associated with disease and treatment characteristics and has also been found to affect PTG [2]. As time since operation may therefore be a mediator, the analyses of BC characteristics and treatment and PTG were adjusted for this factor.

Analyses comparing respondents to non- respondents were conducted separately among women with and without BC with t-tests for continuous variables (age, time since operation, tumor size, number of lymph nodes with metastases) and χ²-tests for categorical variables (education, type of surgery, radiation therapy, chemotherapy and endocrine treatment). SAS 9.2 was used for the statistical analyses.

Results

The mean age of women with and without BC was 70 years (range, 63–81). The mean overall PTG was 36.0 for women with BC and 34.2 for BC-free women. The mean time since operation was 6.9 years (range, 0.5–15.5 years) (Table I). A total of 221 (29%) women with BC and 113 (17%) BC-free women chose ‘chronic or acute disease’ as their traumatic or life-changing experience, whereas 196 women with BC (25%) chose ‘loss of a close person’ instead. A response to this item was missing for 214 (28%) women with BC and 163 (24%) BC-free women (Figure 2).

Table I. Descriptive characteristics of women with breast cancer (BC) and BC-free women in the Diet, Cancer and Health cohort, Denmark.

	Women with BC n = 774	BC-free women n = 666
Age at second follow-up (years)	Mean: 70, range: 63–80	Mean: 70, range: 64–81
Education (years) ≤ 7 8–10 > 10	203 (26%) 407 (52%) 164 (21%)	159 (24%) 347 (52%) 160 (24%)
Mean Overall PTG ± SD	36.0 ± 26	34.2 ± 26
Mean PTG domains ± SD Appreciation of life New possibilities Personal strength Spiritual change Relating to others	7.0 ± 4.8 7.0 ± 6.8 7.5 ± 5.9 1.7 ± 2.5 12.7 ± 9.7	6.2 ± 4.7 7.4 ± 6.9 7.2 ± 6.0 1.6 ± 2.6 11.7 ± 9.8
Time since operation (years)	n = 684 Mean: 6.9, range: 0.5–15.5
Tumor size (mm) 0–9 10–19 20–29 30–39 40–49 ≥ 50	123 (18%) 322 (47%) 159 (23%) 47 (7%) 20 (3%) 13 (2%)
Number of positive lymph nodes 0 1–3 ≥ 4	406 (59%) 199 (29%) 79 (12%)
Grade of malignancy 0 (carcinoma in situ) I II III Not registered Missing	3 (0.5%) 228 (38%) 259 (43%) 97 (16%) 11 (2%) 86
Histology Ductal Lobular Other Unclassified	549 (80%) 82 (11%) 46 (7%) 7 (1%)
Radiation therapy Received treatment Did not receive treatment	501 (73%) 183 (27%)
Chemotherapy Received treatment Did not receive treatment	95 (14%) 589 (86%)
Endocrine treatment Received treatment Did not receive treatment	369 (54%) 315 (46%)
Type of surgery Mastectomy Lumpectomy Lumpectomy followed by mastectomy	307 (45%) 368 (54%) 9 (1%)

Figure 2. Choice of traumatic experience reported by the women with BC (n = 774) and BC-free women (n = 666) in the Diet, Cancer and Health cohort, Denmark. The categories on the x axis correspond to the categories of traumatic experience available in the questionnaire.

In the adjusted analyses, no significant difference in overall PTG was observed between BC and BC-free women. Women with BC experienced significantly more PTG than BC-free women in the domains ‘appreciation of life’ (β = 0.80; 95% CI 0.31–1.29 per year) and ‘relating to others’ (β = 1.03; 95% CI 0.03–2.04 per year). Age was negatively associated with overall PTG (β = 2 0.50; 95% CI − 0.82 to − 0.18 per year) (Table II).

Table II. Regression-derived coefficients (β) and 95% confidence intervals (CIs) of overall and domain-specific post-traumatic growth (PTG) by breast cancer (BC) diagnosis status among 1440 women in the Diet, Cancer and Health cohort study.

	Unadjusted		Adjusted^2
	β	95% CI	β	95% CI
BC^1 Overall PTG Appreciation of life New possibilities Personal strength Spiritual change Relating to others	1.83 0.81* −0.39 0.26 0.11 1.03*	−0.88; 4.54 0.31; 1.30 −1.09; 0.32 −0.36; 0.88 −0.16; 0.38 0.02; 2.04	^4 1.86 0.80* −0.36 0.27 0.12 1.03*	−0.85; 4.57 0.31; 1.29 −1.06; 0.34 −0.35; 0.88 −0.15; 0.38 0.03; 2.04
Age (years)^2 Overall PTG	−0.51*	−0.82; −0.19	−0.50*^5	−0.82; −0.18
Education3 Overall PTG	−3.05	−6.98; 0.87	−2.53^6	−6.46; 1.40

*, statistically significant; ¹Reference group, BC-free women; ²β-value applies to increasing age; ³Education stratified according to number of years: ≤ 7, 8–10, > 10. β-value applies to a higher level of education; ⁴Adjusted for education and age at second follow-up; ⁵Adjusted for education; ⁶Adjusted for age at second follow-up.

Among women with BC, time since operation was positively associated with overall PTG (β = 0.04; 95% CI 0.002–0.08 per month) (Table III). Tumor size was positively associated with overall PTG (β = 0.22; 95% CI 0.05–0.40 per mm) and with the domains ‘appreciation of life’ (β = 0.05; 95% CI 0.01–0.08 per mm), ‘personal strength’ (β = 0.02; 95% CI 0.006–0.09 per mm) and ‘relating to others’ (β = 0.09; 95% CI 0.03–0.16 per mm). The number of positive lymph nodes was positively associated with overall PTG (β = 0.60; 95% CI 0.02–1.18 per positive lymph node) and with the domains ‘spiritual change’ (β = 0.08; 95% CI 0.02–0.13 per positive lymph node) and ‘relating to others’ (β = 0.22; 95% CI 0.0006–0.43 per mm). Having undergone mastectomy versus lumpectomy was positively associated with overall PTG (β = 4.59; 95% CI 0.54–8.6) and with the domains ‘personal strength’ (β = 1.33; 95% CI 0.41–2.26) and ‘relating to others’ (β = 1.78; 95% CI 0.27–3.30). Endocrine treatment was positively associated with the domain ‘appreciation of life’ (β = 0.83; 95% CI 0.09–1.58 per mm).

Table III. Regression-derived coefficients (β) and 95% confidence intervals (CIs) for overall and domain-specific post-traumatic growth (PTG) by age, education, characteristics and treatment of disease, N = 684 women with breast cancer.

	Unadjusted		Adjusted
	β	95% CI	β	95% CI
Time since^1 operation (months) Overall PTG	0.04*	0.001; 0.08	0.04*^6	0.002; 0.08
Tumor size (mm)^2 Overall PTG Appreciation of life New possibilities Personal strength Spiritual change Relating to others	0.19* 0.04* 0.03 0.04* 0.001 0.08*	0.02; 0.36 0.007; 0.07 −0.02; 0.07 0.001; 0.08 −0.01; 0.02 0.02; 0.15	^7 0.22* 0.05* 0.04 0.05* 0.003 0.09*	0.05; 0.40 0.01; 0.08 −0.008; 0.08 0.006; 0.09 −0.01; 0.02 0.03; 0.16
Number of positive lymph nodes^3 Overall PTG Appreciation of life New possibilities Personal strength Spiritual change Relating to others	0.53 0.08 0.08 0.10 0.07* 0.20	−0.05; 1.11 −0.03; 0.19 −0.07; 0.23 −0.03; 0.24 0.01; 0.13 −0.02; 0.42	^7 0.60* 0.10 0.10 0.11 0. 08* 0.22*	0.02; 1.18 −0.01; 0.20 −0.05; 0.25 −0.02; 0.25 0.02; 0.13 0.0006; 0.43
Type of surgery^4 Overall PTG Appreciation of life New possibilities Personal strength Spiritual change Relating to others	4.77* 0.58 0.98 1.27* 0.13 1.81*	0.82; 8.71 −0.15; 1.31 −0.05; 2.00 0.37; 2.18 −0.25; 0.51 0.34; 3.28	^7 4.59* 0.60 0.78 1.33* 0.08 1.78*	0.54; 8.64 −0.14; 1.35 −0.28; 1.83 0.41; 2.26 −0.31; 0.48 0.27; 3.30*
Radiation therapy^5 Overall PTG Appreciation of life New possibilities Personal strength Spiritual change Relating to others	0.95 0.34 0.04 0.04 0.20 0.32	−3.47; 5.37 −0.48; 1.16 −1.10; 1.19 −0.97; 1.06 −0.22; 0.62 −1.33; 1.97	^7 0.58 0.16 0.13 −0.12 0.20 0.22	−3.93; 5.10 −0.67; 0.99 −1.05; 1.31 −1.16; 0.92 −0.23; 0.63 −1.47; 1.91
Chemotherapy^5 Overall PTG Appreciation of life New possibilities Personal strength Spiritual change Relating to others	2.76 0.77 0.42 0.86 −0.18 0.89	−2.90; 8.41 −0.27; 1.81 −1.05; 1.89 −0.44; 2.15 −0.72; 0.36 −1.22; 3.00	^7 2.36 0.65 0.44 0.73 −0.19 0.71	−3.29; 8.00 −0.38; 1.69 −1.03; 1.91 −0.56; 2.03 −0.73; 0.36 −0.40; 2.83
Endocrine treatment^5 Overall PTG Appreciation of life New possibilities Personal strength Spiritual change Relating to others	2.22 0.57 0.38 0.23 0.11 0.93	−1.70; 6.15 −0.15; 1.30 −0.64; 1.40 −0.67; 1.13 −0.26; 0.49 −0.53; 2.39	^7 3.80 0.83* 0.85 0.44 0.22 1.43	−0.29; 7.83 0.09; 1.58 −0.21; 1.90 −0.49; 1.38 −0.17; 0.61 −0.09; 2.95

*, statistically significant; ¹β-value applies to increasing time since operation; ²β-value applies to increasing tumor size; ³β-value applies to increasing number of positive lymph nodes (lymph nodes with metastases); ⁴Reference group, women who underwent lumpectomy; ⁵Reference group, women with BC who received no treatment (radiation, chemo- or endocrine treatment); ⁶Adjusted for age at second follow-up and education; ⁷Adjusted for age at second follow-up, education and time since operation.

Age was negatively associated with respondent status among women with and without BC (β = − 0.01 per year in both groups, and p = 0.02 and < 0.0001, respectively). BC-free respondents had a significantly higher level of education than non-respondents (p < 0.0001). No statistically significant difference was found between respondents and non-respondents with BC with regard to education or any disease- or treatment-related factors (data not shown).

Discussion

We found no significant difference in overall PTG between women with and without BC, although women with BC experienced significantly more growth in the domains ‘appreciation of life’ and ‘relating to others’ than BC-free women. Increasing tumor size, number of positive lymph nodes, having undergone mastectomy and receiving endocrine treatment were positively associated with PTG, for either overall PTG or PTG domains.

The strengths of the present study include the availability of data from a large nationwide, population-based prospective cohort. The statistical power of our study is a strength compared to most previous studies, which have been small (n < 200) [4,5,9–11]. We also had access to nearly complete record-linkage information on essential prognostic clinical parameters, as they were retrieved from the Danish Breast Cancer Cooperative Group, which is a register of high quality [25] and thus results in a low risk for misclassification. Furthermore, we had information on potential confounders.

We used the approach of asking women with and without BC to respond to the PTG inventory in light of a self-selected traumatic life-changing experience. This approach was necessary in order to compare PTG in the two groups and also allowed the women with BC to indicate that they had experienced something more traumatic than their BC. However, this method does not allow conclusions regarding the PTG specifically related to BC. Instead, we address the PTG related to a self-selected trauma among women with BC compared to BC-free women.

Previous studies on PTG and BC included women in a wide age range or of younger age (mean, 49–63 years; range, 22–86 years) [2,4,7,9,22]. As in previous studies [6,9,10,22], we found that age was negatively associated with PTG, and generalization are mainly appropriate to women of the same age group. Differences in age across studies might explain our finding that the mean overall PTG among women with BC was 36.0 (SD = 26), which is lower than the values of 55.7–64.1 found previously [2,4,7,9,22]. Still, the women in our study were 63–81 years old (mean age of women with BC, 70 years) at the second follow-up, and as the incidence of BC is high in this age group [26] knowledge of PTG among older women with BC is of relevance.

One limitation of our study derives from the fact that the treatment recommended for BC is based on a joint assessment of the pathoanatomical characteristics of the disease. Thus, it is not possible to separate the effect of treatment and the effect of severity of disease in analyses of the effects of disease characteristics and treatment on PTG. The effect of disease characteristics and treatment should therefore not be interpreted as isolated factors.

The missing observations on PTG inventory were addressed by using imputations based on substitution of the mean. When imputing missing data, there is a risk of introducing information-bias if the missing data are not missing at random, or if the items representing a given domain of growth are not equally reliable measures of the domain in question, however, the risk of introducing bias is also present when excluding large amounts of data. The imputation of missing data may introduce a downward bias with regard to the standard deviation, thereby distorting the estimated variance [27]; however, comparisons of the standard deviations did not indicate a downward bias (data not shown).

Participants of lower social class have been shown to be underrepresented in the Diet, Cancer and Health cohort at baseline [16], limiting the generalizability of our findings. Also, a comparison of respondents and non-respondents in the second follow-up showed that age was negatively associated with being a respondent among women with and without BC. Age was negatively associated with PTG in the present and previous studies [6,9,10,22]. The difference between respondents and non-respondents might have affected the levels of PTG found in the present study, possibly resulting in higher levels of PTG than would have been found if non-respondents had been included. The results should therefore be generalized with caution.

We observed no significant difference in overall PTG among women with and without BC, suggesting that women with BC do not experience higher levels of PTG compared to other women. According to Tedeschi and Calhoun [3], PTG may be achieved if the trauma is severe enough that it challenges the individual's assumptions about self, the world and the future. Confrontation and coping with trauma may also change thought patterns, including a focus on the present and a re-evaluation of life, allowing a perception of personal growth. BC as a trauma may differ from acute traumas (e.g. a car accident) where the stressor is not a traumatic experience, which lies in the past. Instead, BC may constitute an ongoing threat due to fear of how the disease progresses or fear of cancer recurrence. This may cause other domains of PTG to be prominent among women with BC compared to women who have experienced acute traumas. Several interpretations may explain why women with BC do not experience significantly more PTG compared to BC-free women. First, BC may not be considered the most serious trauma in life. The five-year survival rate after BC in Denmark is 81% [26], which could mean that BC is not experienced as life-threatening by all women. Second, BC may not overshadow other possible traumas. In this study, fewer than one third of the women with BC indicated ‘chronic or acute disease’ as their most traumatic event, while one quarter experienced the loss of a close person as a greater trauma. Additionally, the high number of multiple responses to the request to indicate a traumatic event (22% among women with BC and 19% among BC-free women) suggest that many women had experienced more than one traumatic experience (Figure 2). Supporting this interpretation, the women in this study had reached an age where they had lived long lives and they may have seen BC as just one of several challenges which have impacted their lives gradually. Also, some traumatic events experienced by the BC-free women may correspond in severity to the trauma of BC. These considerations may help explain the absence of a difference in PTG according to BC status.

Cordova et al. [4] found that women with BC experienced more PTG than BC-free women. The difference from our results may be due to a difference in use of the PTG inventory. Cordova et al. asked women with BC to think of their BC-disease and asked BC-free women to rate changes in their lives since the cancer diagnosis of their age-matched counterpart. In the present study, women were asked to identify their own traumatic event. If the BC-free women in the study of Cordova et al. had not experienced any traumatic event in the given timeframe, this could result in a higher level of PTG among women with BC compared to the BC-free women. Another explanation could be the difference in age in the two studies: our study, mean age of 70 years (range, 63–81); Cordova et al., mean age of 54.7 years (range, 27–87). The higher mean age in our study may imply that the BC-free women had accumulated more traumatic events, thus diluting any differences between the two groups.

Consistent with the findings of Cordova et al., we observed that women with BC experienced significantly more growth in the domains ‘appreciation of life’ and ‘relating to others’ than BC-free women. The growth experienced by women with BC may therefore be characterized by an appreciation of life as a privilege and a change in priorities, which could lead to a new understanding of what is important. Also, the growth may involve closer relationships with family and friends.

Contrary to our study, Cordova et al. found that women with BC experienced significantly more PTG in the domain ‘spiritual change’ than BC-free women. Cultural values and behavior have been shown to affect PTG [10], and previous findings suggest that the domain ‘spiritual change’ plays a different role in western Europe compared to the USA [28]. Denmark is a secular country, and women may therefore be less likely to seek help from the church after a BC diagnosis compared to women in the USA.

We observed a positive association between tumor size, nodal status and PTG. Furthermore, women with BC who underwent mastectomy experienced significantly more growth compared to women who underwent lumpectomy. Contrary to Cordova et al., we found that endocrine treatment was significantly associated with PTG on ‘appreciation of life’ [9]. Consistent with Mystakidou et al. [10] but in contrast to other studies [5,7], we observed no statistically significant association between radiation and chemotherapy therapy and PTG. The standard duration of endocrine treatment in Denmark is five years, which is considerably longer than standard postoperative treatment with radiation therapy and chemotherapy [29]. The long duration of endocrine treatment may maintain the role of women as BC patients, possibly contributing to an increased experience of severity of disease, thereby leading to increased PTG.

In support of the hypothesis of Cordova et al. and the study of Sears et al. [2], time since operation was positively associated with PTG, suggesting that time may allow increased cognitive, affective and interpersonal processing, thereby facilitating PTG [4]. Other studies, however, found no significant association between time since diagnosis and PTG [6,7,9–11].

Overall, our results suggest that severity of disease plays a role for the PTG experienced and that women with severe disease or undergoing the most comprehensive treatment may experience the highest degree of PTG, which is consistent with the theory of PTG where a more seismic trauma is able to catalyze more PTG [3].

Conclusion

Healthcare professionals should not assume that elderly women experience more PTG after a diagnosis of BC than women without BC. As women with BC who do not experience PTG may be pressured unnecessarily by expectations of psychological benefit, healthcare professionals should be cautious in ascribing the struggle with BC disease and treatment a unique opportunity to promote PTG.

Acknowledgements

We wish to thank Sygekassernes Helsefond and The Nordic Cancer Union for financial support of the project.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.