A gerontologic perspective on cancer and aging

Authors


  • Supplement sponsored by the American Cancer Society's Behavioral Research Center and the National Cancer Institute's Office of Cancer Survivorship.

Abstract

Most people diagnosed with cancer are aged >65 years, and many diagnosed younger live to become older survivors. Geriatric oncology is becoming recognized as a specialty area within oncology. It focuses specifically on the functional impacts of the interplay of aging and cancer, including the role of comorbidities. Nevertheless, to the authors' knowledge, little attention has been given to cancer from a gerontologic and lifespan perspective, especially quality of life and psychologic impact. Research has shown that the amount and type of psychologic impact of cancer is highly variable and that part of that variation is related to age, in that older persons are often less affected in both negative and positive ways. Gerontologic concepts and empiric findings related to physical, psychologic, and social aging processes may serve as partial explanations for that age-related pattern. Important potential contributors include psychologic factors, such as changes in future time perspective and goals, as well as social ones, such as roles and previous experience. The result is a complex interplay of factors that vary across persons but are covaried with age. Empiric findings regarding 1-year to 8-year prostate cancer survivors illustrate the age differences and the differential impacts of age itself and comorbidity. The use of gerontologic concepts to explain the age-related impact of cancer will benefit both research and clinical practice by providing a means to target interventions more effectively by taking into account the psychologic and social changes that often accompany aging. Cancer 2008. © 2008 American Cancer Society.

The intimate link between cancer incidence and aging is well understood in the medical community. Most of the major tumors occur in greater proportion in men and women over the age of 65 years.1–6 Many individuals diagnosed and treated earlier in life eventually become older cancer survivors because of the increased likelihood of long-term survival for many cancers. As a result, greater than 60% of the 10.8 million cancer survivors in the U.S. today are over the age of 65 years.1, 3

Despite the finding that older men and women are disproportionately affected by cancer, to our knowledge remarkably little attention has been given to cancer in gerontology and geriatric communities, and even less to aging processes in oncology. Fortunately, we are beginning to see changes in both sides of the equation, as reflected by a special issue of the Journal of Clinical Oncology on geriatric oncology and a recent Institute of Medicine workshop on cancer in the elderly.7, 8 Nevertheless, most of that attention is directed toward geriatrics, particularly to explaining and exploring the interplay of functional deficits resulting from cancer therapies with functional decrements because of the aging process.8–14 Obviously, these facets of attention are critically important for clinical purposes; they are also highly relevant for input into planning for screening, treatment, and follow-up care at both macrolevels (eg, healthcare policy) and microlevels (how individuals make decisions and follow treatment regimens).

However, this is only a portion of the picture of the relation of cancer and aging. The most neglected side of past attempts at understanding the cancer and aging interface is what is encompassed by gerontology. The broad area of gerontology includes the macrolevel of how aging of the population impacts on and is impacted by the healthcare system and healthcare policies, as well as cultural and societal influences on the aging process.15 It also includes the microlevel of psychology of aging, from cognitive processes to personality changes, and the intermediate level of social psychology, such as social support and caregiving.16, 17

Each of these areas deserves much more attention than it has received, attention that will enrich oncology, geriatrics, and gerontology. As noted, most of the health-related quality of life focus in geriatric oncology, as in oncology generally, has been directed to functional effects, with much less attention paid to psychologic impacts and social relationships. These are areas in which gerontology has a rich tradition16, 18–20 and are also an integral part of psycho-oncology.8, 21, 22 Including gerontologic perspectives in investigations of treatment decisions, treatment effects, and survivorship can provide researchers and practitioners with a richer understanding of psychologic and social impacts of cancer on older individuals. Concurrently, gerontology can be enhanced by the infusion of knowledge from clinical oncology about the ways that cancer, as both an acute treatment issue and, increasingly, as a chronic management issue, changes the face of old age and the health needs of the growing older population.

The remainder of this article consists of 2 parts: 1) a brief overview of methodologic and conceptual approaches and issues in aging research that may change the way we think about many of the current findings and issues concerning cancer and aging; and 2) a description of findings from a specific research project that has taken a gerontologic approach to examining issues of aging and cancer in older survivors of prostate cancer. In both sections the focus is on aspects of cancer and aging that are intimately tied to quality of life and well-being, of ‘optimal cancer survivorship,’ in parallel to emphases in gerontology on optimal health and aging.16, 18, 19

Pathways of Life Impact on Cancer Survivorship

The initial diagnosis of cancer is likely to cause distress and uncertainty.23 Within a short time after initial diagnosis, individuals begin to vary greatly from each other in patterns or trajectories of psychosocial adjustment, quality of life, and well-being.24–26 A proportion (15%–20%) of individuals remain in a sustained negative trajectory of loss and distress.26–28 Most individuals appear to regain a sense of normalcy and quality of life similar to what they had before cancer.24 Others eventually experience growth (ie, having a better ‘new normal’).29–34 It is also common for cancer survivors to report a mixture of positive and negative trajectories in different aspects of their lives.31, 35

Several aspects about the varied pathways become very clear. There is not a pathway of survivorship, but rather several distinct ones, with great variability across persons but also, importantly, great variability within persons. The variability within persons includes both changes of direction across time and variability at one time, perhaps feeling growth about one's social relationships but negative decline about one's sense of self-esteem. Also, pathways are not linear, responding both to intrapsychic work and to a wide range of forces impinging on the person, only some of which are related to having cancer. In addition, one person's negative (or positive) trajectory may be greater or lesser in intensity than another person's, although both report the same direction of impact. Research suggests that growth and loss, negative and positive aspects, may often be intertwined and interconnected. Some persons may be ‘highly impacted’ by experiencing a change in trajectory that has resulted in a generally more intense experience in both directions, in ways very different from persons who report either little impact or major impact but in only 1 direction.24, 31, 35

Of course, much of the variation has to do with the fact that different people have different prediagnosis psychosocial starting points. Not everyone is the same at the moment when cancer is diagnosed. Different people have different resources, both personal and social (and financial); they live in different communities with different norms, attitudes, and beliefs; they interact with different care providers—who themselves vary in attitudes toward cancer, its treatment, and survivorship—and they are more or less healthy and more or less resilient to the potential rigors of treatment or cancer progression. Moreover, they are diagnosed with varying levels of cancer, from site to stage, that interact in complex ways with all that the person has brought to that moment.

One question—and the one that is the focus of this conceptual article—is whether age is associated with how people react and adjust to finding out they have cancer. If so, how, in what direction, and why is age related to health outcomes of cancer survivors?

Age, Aging, and the Survivorship Experience

Age affects screening, treatment options, and overall experience of cancer.14, 36, 37 Despite calls for attention to age differences, from the late 1980s to several more recent attempts,2, 7, 38–42 little attention has been given to this. If one uses prevailing wisdom, the emphasis would be on the adverse impacts of aging that we reviewed above, and the expectation that older individuals have more comorbidities and thus will report more problematic quality of life. Indeed, there is some evidence of long-term negative effects for older survivors.25–28, 43

Yet there appears to be more to the picture. When researchers have focused specifically on age differences in quality of life and overall psychologic impact, they consistently find that younger cancer survivors experience trajectories of greater impacts, both negative and positive, and are more likely to make health behavior changes than survivors who are older at diagnosis.24, 25, 38 The younger survivors do so despite fewer comorbidities and higher general physical functioning and health. These ‘age differences’ may be very important elements of subsequent quality of life for individuals dealing with cancer. In fact, any shift toward younger, healthier individuals because of early detection of disease may actually result in more negative psychologic and behavioral impact and continuing stress than has previously been found.

An examination of gerontologic and lifespan developmental perspectives may aid us in understanding the mechanisms by which age is associated with survivorship health outcomes. Understanding the processes through which age impacts well-being is important because age per se is not an explanatory factor, but only a proxy for underlying intraindividual and interindividual mechanisms. We see at least 3 distinct factors of importance: 1) physiologic aging; 2) psychologic aging and lifespan development; and 3) life course, social aging (Table 1).

Table 1. Age-related Pathways to Impact of Prostate Cancer
Types of agingProcessesDirection of impact on older persons
PhysiologicPrimary and secondary aging changesMore
Comorbidity-related impairmentMore
Comorbidity experienceLess (?)
Lifespan developmental/ psychologicPersonality shifts (eg,developmental tasks, future time perspective, goalselection, gerotransendence)Less
Life course/life eventsPrevious life event experienceLess
Age at diagnosis: on time vs off timeLess
Role competitionLess

Physiologic aging

The physiologic and biologic aspects of aging have received the greatest attention for understanding cancer in a geriatric sense. Some aspects of normal aging affect nearly everyone: recovery time is longer, reserve capacity and functional resilience are often lower, and there are adverse effects on cognitive processing speed and depth of processing.9, 14, 44, 45 Other effects are secondary in nature; that is, many diseases, not just cancer, become more prevalent with age, and so there is a distinct and clear increase in comorbidity, and especially multiple comorbidities, among older populations.46, 47 Evidence suggests that the coexistence of comorbidities can exacerbate the effects of cancer on older adults.6, 11, 13, 14, 46, 48, 49 Solely considering the physiologic aspects of aging would lead to the assumption that cancer is likely to have greater impact for older patients and longer-term survivors.

Psychologic, lifespan developmental aging

When aging is viewed from an individual-oriented, identity-focused psychologic perspective, incorporating both psychologic gerontology and lifespan developmental concepts,16, 50 a more complex picture emerges. This picture is one in which being older at diagnosis presents a mixed array of likely effects on quality of life and psychologic trajectories. Aging often leads to changes in personality and focus, shifting perspectives on the ways that people view the world.18–20, 50 As people age, they face different developmental tasks and orientations to life, opening up new opportunities and closing off others. A set of related conceptual models that are particularly influential in current gerontology focus on the notion that as people get older, they 1) develop a shorter time perspective for their goals and, concurrently, 2) become more selective in their goals and activities, as they rebalance their energies toward emotional regulation and maintenance rather than active ‘penetration’ of their world, and, 3) become better at ‘damping’ emotional highs and lows.51–55 As a result, they emphasize comfort and conservation rather than expansion and active control and maximization of experiences, are less likely to use active coping strategies or be concerned with control, and may be less likely to make major health behavior changes. In a related vein, Erikson's theory of the life cycle,56 and related concepts of gerotranscendence or wisdom in later life,57, 58 emphasize that middle age is likely to be a time for being focused on generativity, or expanding one's self to leave behind a legacy on future generations. It is an active, outward looking time of life. Moving into later life, people turn more toward integrality and wisdom, a more internally focused, less overtly active approach.

These developmental shifts from midlife activity and a long future time perspective to a shorter time perspective; from active, expansive goals toward ones of emotional regulation; toward decreasing need for control; and toward more passive coping all would lead to a moderated or muted effect of having cancer. This may be a partial basis for the reduced reactivity to cancer diagnosis, treatment, and survivorship at later ages. Although this may be positive in terms of reducing the likelihood of becoming trapped into a long-term sense of distress, it also mitigates the likelihood of making major changes in a positive direction in one's life or experiencing a sense of growth. Most models of psychologic growth emphasize the necessity of experiencing the event as traumatic and as shattering previous world views in order for growth to occur.32, 34, 59, 60 To the degree that younger persons experience their cancer diagnosis in this way, they are more likely to form the foundation for growth and positive impacts. Older persons who do not ‘code’ their cancer experience as traumatic may not be likely to have the opportunity to experience a sense of growth.24, 54, 55, 61 The corresponding lower likelihood of health behavior change is important because health-promoting behaviors play an important role in attenuating some of the longer-term medical late effects of cancer treatment in an older population, who are now living decades after their diagnosis.

Life course placement and social aging

Another gerontology-related perspective that may aid in understanding the impact of cancer on older persons is a less personal or individual one. Interconnected with individual lives, and associated with age, are roles and experiences. Life course theory62, 63 concerns one's ‘placement’ in society and in the life cycle. Persons of different ages are likely to have had different life event histories (eg, older persons having had more significant previous life events), and also they currently fill different roles (eg, work vs retirement, caregiving of children or parents). Because of the age-linked nature of the life course, people diagnosed early (in their 30s, 40s, and 50s for most cancers) are likely to be at very different ‘places’ in their lives than are older survivors.63, 64 More involvement in life course-related roles associated with middle age, including work, caring for preadult children, and caregiving for elderly parents, may increase the impact of cancer, because of competition for attention among these roles.65–67 This competition among roles may make it more difficult for younger persons to deal with and come to terms with their cancer. Alternatively, having had more experience with previous negative life events, including downturns in health, may enable older individuals to minimize the impact of cancer,68 and in that way previous life experience and current roles may serve as a resource for older individuals. Indeed, in open-ended responses in previous research by this team many older men reported having prostate cancer was “no big deal,” because of either previous experiences or current comorbidities.69 At the same time, because of the demographic realities, cancer is a much more expectable, on-time event later in life than earlier. This aspect of the life course, too, will make it more likely that older persons will feel less impact from their diagnosis.

Also important from a life course perspective, but even less understood, is that at any given time persons who differ by age also differ by birth cohort.62, 63, 70 Although age and cohort are often intimately interwoven, they are distinguishable from each other. Each cohort bears certain characteristics that make it unique, and thus age is expressed differently from cohort to cohort. The current already well-worn phrases such as “60 is the new 40” make it very clear that cohort matters in the sense of physiologic aging. Cohorts differ in such areas as timing and number of children, timing of retirement, and specific historical experiences. Indeed, the experience of cancer is a very different one for baby boomers than for their parents—treatments are different, success rates and longevity are greatly increased, and so on. Everyone dealing with cancer now is experiencing a diagnosis and disease that is literally different from what their parents and grandparents experienced. Also, period of time is intertwined with cohort, such that persons brought up earlier when cancer was seen as a death sentence and not talked about openly may not respond to the changed environment in the same way as younger cohorts. Although it is not clear how cohort may affect the cancer experience, cohort effects are inextricably linked to ‘age,’ that is, chronologic age. It is certainly not a leap to think about the degree to which cohort may influence aspects of the age-related impact effects, altering time perspective, life course experiences, and the trajectory and parameters of physiological processes of aging.

Interplay of factors

The notion that because of life course placement as well as psychologic ‘place,’ older persons may be less likely to interpret a cancer diagnosis as a truly life-altering event illustrates several important aspects of using a full range of gerontologic and lifespan developmental/life course perspectives to understand the experience of cancer at different ages. The 3 factors are not independent, but interactive. Thus, some aspects of quality of life or well-being may show negative impacts from being older and other impacts that are positive, even within a person. An example may be something as ‘obviously negative’ as comorbidity. Clearly, comorbidity increases the problematic nature of cancer and its treatments. Concurrently, though, comorbidity, if it is not severely impairing, may in part serve a ‘protective’ function in relation to the impact of cancer. Individuals with comorbidities may have previous experience dealing with health management conditions that they consider more critical than early stage cancer.

Second, these factors are differentially distributed from person to person, and so some will show primarily or entirely negative or entirely positive impacts because of these age-related factors. In part this is because of the diversity among people, but in part it results from the important point that these factors are ‘age-related,’ but are not age itself nor entirely encapsulated by chronological age.70

Third, the factors may be differentially distributed from group to group, such as ethnicity, race, class, sexual orientation, thus resulting in different impacts of ‘age’ in different groups. These aspects are virtually unstudied in cancer research.

Finally, the interlinking of these factors is clearly seen in the very nature of the age-related results, that older persons are less likely to be affected in either positive or negative ways. It appears that distress and growth, even for the long term, may be the reality of the experience of cancer survivorship for a sizable portion of persons. ‘Pure’ trajectories of only negative impact or only positive impact may be less common than those of intermingled positive and negative impacts that make the experience more intensified for those survivors.24, 31, 35

A Brief, Illustrative Example

Objective

A recent study of prostate cancer survivors provides a partial illustration of the merging of aging/gerontologic interests with cancer survivorship.24, 69, 71, 72

Methods

Using a metropolitan tumor registry, we collected self-report data from 509 men (mean age of 69.7 years at time of study; age range, 47–88 years) who had been diagnosed with prostate cancer between 1 and 8 years prior. Nearly all men were diagnosed with early stages of disease and had had surgery or radiation as primary therapy. Approximately 20% had experienced some level of disease recurrence, with a small number having had initial or secondary hormonal therapy. In addition to age itself, we collected information regarding comorbidities (measured as a sum of comorbid conditions), to tap into physiologic aging, and psychologic factors, such as control (Midlife Development Inventory [MIDI] Mastery and Constraints) and optimism (Life Orientation Test-Revised [LOT-R]). We also included measures of both positive and negative impacts, including depression (Center for Epidemiologic Studies Depression Scale [CES-D]), positive and negative emotional state (Positive and Negative Affect Schedule [PANAS]), Impact of Events Scale [IES], benefit finding, well-being, and adaptive lifestyle changes.

Results

On average, men reported being generally hopeful and positive, with low levels of depression.24, 69 Correlational analyses indicated that increasing age was moderately correlated with comorbidity, lower physical health, and a sense of constraint (and less sense of control). Comorbidity, conversely, was correlated in problematic ways with several outcomes, increasing negative outcomes and decreasing positive ones.

Results from regression analysis, adjusted for confounders, showed independent effects of age. In each case, younger men were higher on both negative and positive outcomes and on likelihood of making adaptive changes. Results are consonant with the notion that older persons are less likely to feel as significantly and deeply impacted as younger ones. Also of note is that in open-ended questions regarding how prostate cancer has changed their lives, younger men, especially those aged younger than 60 years, were much more likely to report positive changes than older men, but had approximately the same likelihood of reporting negative changes (Table 2).69

Table 2. Open-ended Reports of Changes by Age
 <60 years60–69 years≥70 years
No change15%48%59%
Positive change72%42%30%
Negative change13%10%11%

Likewise, in a brief face-to-face interview adjunct to this study, older men expressed considerably less impact of their prostate cancer than younger men.73

Discussion

Thus, although chronologic age is correlated with comorbidity, they have very different relations to many outcomes. Age is not highly important in determining quality of life in absolute terms, but younger men do exhibit a distinct pattern of more impact and likelihood of making adaptive behavioral changes. Conversely, comorbidity was found to be a significant independent predictor of a range of negative consequences—higher negative impact and depression scores, along with lower positive impact, well-being, and perceived benefit scores; it has a more generalized negative impact.

Age by itself appears to be ‘protective’ (that is, older men report less negative impact); conversely, it also appears to close off opportunities for growth, benefit-finding, and a shift to a healthier lifestyle. Comorbidity is neither protective nor allowing for opportunity for growth. New methodologic and analytical approaches to comorbidity are necessary if we are to examine the nuances of comorbidity on quality of life-related outcomes. The results of the current study demonstrated that separating 1 kind of aging—physiologic aging—from another—psychologic aging—and both of these from chronologic age provides a unique insight into understanding how cancer affects people of different ages and ‘places’ in life.

Future Directions

Many avenues of research and clinical application are opened up when psychosocial aspects of cancer research are merged with psychologic and social gerontologic research and conceptualization. Certainly, much more remains to be known about the degree to which age-related psychologic changes in goals, orientations, and perspective alter the context for the cancer experience. Likewise, placement of individuals in time and space and constraints afforded by their social contexts are, in turn, the frame for both physiologic and psychologic aging and cancer survivorship. On the other side, nearly all conceptualization related to the psychologic and social aspects of aging has been developed without attention to the frequency and disproportionate burden of cancer among older persons and concurrent need to understand how this burden is incorporated into people's lives as they age. Gaining an understanding of the cancer experience and pathways will open up psycho-oncology researchers to new avenues to pursue.

Most important, perhaps, a better understanding of the psychologic and social aspects of aging and cancer will complement the burgeoning literature concerning more geriatric aspects of cancer and aging. These developments will have direct and immediate impact on both clinicians and cancer survivors by providing information regarding differential impacts because of lifespan development and life course circumstances. They can focus attention on age-related aspects rather than concentrating on chronologic age itself, and can sensitize oncologic healthcare providers to the factors in individuals lives that may increase or decrease the likelihood of either positive or negative impacts of cancer. Indeed, the finding that the intensified experience of younger persons includes both positive and negative impacts may provide an avenue to lead those experiencing negative impacts to be able to see how those negative aspects may be accompanied by positive ones. The marriage of the gerontologic and oncologic perspectives may enhance the lives of many people, younger and older, as they deal with a cancer diagnosis and as they move into longer-term survivorship.

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