Comparison of YS to AC
Overall, 27% of YS scored at or above the clinical cutoff for depression compared to 17% for their age-matched group, a difference reported in past research.[4, 31, 32] Many studies have found that breast cancer survivors at diagnosis and treatment have high rates of depression and that as many as 25% of survivors suffer depression 5 years from treatment, a finding consistent with our results.
YS reported more menopausal symptoms than AC including more hot flashes. Many survivors reported use of tamoxifen or aromatase inhibitors, which block estrogen and thus increase the likelihood of problems with vaginal lubrication or even sexual desire. We compared YS currently taking an anti-estrogen with those not on this medication but did not find significant differences. An obvious problem of premature menopause for YS is infertility, a concern often mentioned. A total of 16% of our YS reported that breast cancer prevented them from having additional desired children. Although we controlled for menopausal status, these differences remained, requiring additional analyses that might suggest possible causes of sexual dysfunction. Because menopausal status can influence many QoL variables, we compared women who had had periods within the last 12 months with women who had not. All tests were completed using multiple comparisons and P < .01 was the criterion for significance. Several significant differences were found. Fear of recurrence was less in women who were postmenopausal (Table 3). Postmenopausal women had worse reported physical function, worse sleep, worse sexual functioning, better scores on finding meaning within life, more social support, and less social constraint, and they perceived a greater impact of events.
Compared to AC, YS reported less sexual interest, decreased arousal, decreased lubrication, lower frequency of orgasm, and less ability to relax, findings reported by other researchers. These areas of sexual dysfunction were also reported in a sample of 186 patients with breast cancer whose mean age was 38 years. YS but not OS reported that their sexual relationship had gotten worse since the breast cancer diagnosis.
Fatigue, often considered one of the most problematic symptoms after breast cancer treatment, was significantly higher for YS than AC, a finding reported in other research. One study reported chronic fatigue had an overall prevalence of 48%. Chronic fatigue is often strongly associated with depression, and our findings indicate that both depression and fatigue were more problematic for YS than AC. YS were also found to have worse self-reported cognitive function, which most researchers believe is related to chemotherapy.
Not all differences between YS and AC would be considered negative. YS reported more support and less social constraint compared to AC, although this result should be interpreted with the caveat that AC rated social constraint in relation to a self-identified stressor that was different from the anchor of cancer diagnosis. These self-selected stressors for AC varied widely, ranging from a child leaving for college to death of a loved one, perhaps rendering comparisons difficult. A diagnosis of breast cancer may have required more interaction as a couple—in fact, it is often referred to as a “we” illness—leading to the perception of greater social support and less constraint.
Young survivors compared to their controls reported more personal growth, including relating to others, personal strength, spiritual change, and new possibilities, findings supported by other studies. Breast cancer may have created a greater opportunity for positive life changes than did the stressors reported by AC.
Differences Between YS and OS
Our results also indicated that YS experienced greater anxiety and fear of recurrence than OS, a conclusion reached by other researchers[4, 41] and one that has also been linked with sexual dysfunction (Table 4), Consistent with the comparisons of YS to AC, YS compared to OS reported more depressive symptoms and fatigue, worse attention function and sexual functioning, as well as lower scores on spirituality, a finding reflected in other research. YS have often been reported to have worse sexual functioning compared to peers, but our findings also indicate that a breast cancer diagnosis and treatment probably impact sexual function to an even greater extent than in OS. Menopausal status has been reported as a causative factor for sexual dysfunction in YS. The fact that YS were more likely to have experienced an abrupt menopause could have made symptoms such as hot flashes and vaginal dryness a greater problem, thus partially accounting for the greater number of problems experienced by YS. Body image, which was worse in YS than OS, has been found to be a significant problem in YS.[43-45]
Eligibility for this study required that both YS and OS had received similar chemotherapy regimens to control for potential drug-induced differences in cognitive function. Because cognitive function decreases with age, we anticipated that YS would be more likely to report better cognitive function; yet despite age-related cognitive declines, YS reported more problems with attention function. Prior research has reported worse attention function in survivors than controls, but little is known about whether treatment-induced cognitive dysfunction is different as a result of age at diagnosis.[45, 46] One possible explanation involves age-related demands for cognitive function. YS are more likely to be employed full-time and engaged in activities requiring greater cognitive ability, thus creating a greater difference between perceived need and ability. Cognitive limitations have also been associated with the use of estrogen inhibitors. In our study, 40% of YS used these medications compared to 52% of OS, and therefore the medication was probably not related to the differences found in our sample.
YS reported significantly more anxiety and sleep difficulty than OS. Prior research has reported anxiety at or within a year of diagnosis but frequently reported a decrease in anxiety over time. Our sample included YS who were 3 to 8 years from diagnosis but still reporting more anxiety than OS. Anxiety may be related to fear of recurrence, which was also significantly greater in YS than OS. YS reported a mean fear of recurrence score of 39.2, almost three-fourths of a standard deviation from the mean of 22.76 for OS.
Although YS fared better than AC on dimensions such as social support, social constraint, impact of events, posttraumatic growth, and overall QoL, they were significantly worse than OS on these constructs. Similar results were reported by Stava and Lopez, who found that, although a cancer diagnosis in general resulted in more social support, YS perceived less intimate or partner support than a cohort of OS. Finally, younger survivors reported less religiosity and greater social constraint than OS. In conclusion, we found that YS fared worse than AC on depression, fatigue, attention function, sexual function, and spirituality. More importantly, YS reported more difficulty than OS on the variables of body image, anxiety, sleep, marital satisfaction, and fear of recurrence. Symptoms persisted even though our sample was 3 to 8 years from diagnosis.
Postmenopausal women experienced less fear of recurrence, but significantly lower scores on physical functioning, sleep, and sexual functioning. We can only speculate on why fear of recurrence was lower in women without periods. Perhaps having periods were reminders of being a woman, which triggered fear of breast cancer. Worse scores on physical function including sleep and sexual functioning are commonly reported for both women who have experienced breast cancer and those who have not. Women who had gone through menopause reported more social support and less social constraint, but also reported less ability to find meaning in life.
Our findings suggest a major differential impact of breast cancer for survivors diagnosed at age 45 years or younger compared to survivors diagnosed from 55 to 70 years of age. Although the clinical relevance of any single construct may differ, it is apparent when considering mean differences and standard errors (Table 2) that differences between groups were not marginal. Research is needed to understand the mechanisms underlying the differential impact of breast cancer diagnosis and treatment for YS and OS. It is also important to note that, overall, YS fared worse on many outcomes. These findings show that a diagnosis of breast cancer results in lifelong symptoms for many survivors, as well as that YS may be especially vulnerable to effects of diagnosis and treatment. Proactive symptom assessment and treatment for YS at the time of treatment must be a priority. The breast cancer survivor population will continue to increase as early diagnosis and better treatment make long-term survivorship a reality. This, along with the increase in life span, will impose significant burdens on both the survivors and our health care system. In addition, it must be recognized that problems associated with breast cancer diagnosis and treatment may be compounded by the aging process, an important issue for our aging population.
Although these data provided a unique opportunity to explore QoL in breast cancer survivors several years after diagnosis and treatment, the study has several limitations. First, the data are cross-sectional, limiting the ability to determine how one set of factors may have led to others. Secondly, on some measures such as the PTGI or the Impact of Events Scale, AC were asked to identify a stressor in order to complete the measure. We cannot know if the stressor of breast cancer was equivalent to those selected by AC. A prospective analysis might have provided more insight into the relationships among variables. Furthermore, the sample included women who had previously been involved in ECOG trials and therefore might not have been representative of the general population of survivors diagnosed at 45 or younger. However, data generated from this and other studies support the need to develop interventions that will help alleviate long-term problems resulting from the cancer diagnosis and its treatment.