Quality of Life Among Long-Term Cancer Survivors

Ferrell and Hassey Dow summarize research on the domains of qualityof life (QOL) most important to the adaptation of survivors, and offerinsights about possible interventions to support and promote this adaptation.In addition, they note that the field is poised to make great progressin understanding the concerns and needs of survivors, due, in part, tothe establishment of the Office of Cancer Survivorship, an institutionalhome at the National Cancer Institute (NCI) that will coordinate and promoteresearch on this critical topic.

In response to their article, I raise the question: How can researchon cancer survivorship best be advanced? To assist in answering this question,I will draw on findings from the Quality of Life Literature Database (QOLLIT),a database of abstracted articles on QOL in cancer patients developed byresearchers from the NCI, the EMMES Corporation, and Johns Hopkins University.The database currently includes approximately 900 abstracted articles publishedfrom 1990 to 1995; 106 of these focus on cancer survivors. While the databaseis not exhaustive, it provides, to the best of our knowledge, an unbiasedsample of the literature.

As those who follow the cancer QOL literature will attest, the fieldhas made steady progress in defining and measuring global life quality,as well as disease- and treatment-specific QOL. Although questions lingerabout whether instruments developed for patients can be generalized tosurvivors, there is an active cadre of researchers attending to this andrelated methodologic issues. However, other issues have gained less attention;some of these will be addressed here.

Who Is in Greatest Need of Being Studied?

A prominent feature of this literature is that there is no commonlyaccepted definition of survivorship, in terms of both time since diagnosisand active treatment status. Given this, we have relied on the intent anddefinition of the study authors in designating an article as one that concernssurvivors. Abstracted in QOLLIT is the population under investigation.To be designated as an investigated population, an article has to pertainexclusively to the population or provide separate analyses for it. Usingthis definition, when the QOL of specific groups, as opposed to survivorsin general, was reported in the 106 articles, it was most likely to befor female (27.4%), male (24.5%), or pediatric (22.6%) survivors. Virtuallyunstudied were the elderly (more than 60 years; 4.7%) or minorities (1.0%);and although the database does not track the socioeconomic (SES) characteristicsof those studied, low SES populations have also been largely ignored.

An urgent need, and one noted by Ferrell and Hassey Dow, is to turnour attention to vulnerable, hard-to-reach populations: Do they have thesame QOL concerns and outcomes as other identifiable groups? We need todevelop creative, effective ways of identifying, contacting, and followingmembers of vulnerable populations. It is not enough to do this under theguise of special initiatives, it must become a routine aspect of researchaimed at looking for differences among sociodemographic subgroups.

How Do QOL Domains Relate to Each Other?

There is a growing consensus in the QOL literature about the life domainsthat are most important to study. Table 1lists the domain frequencies for the 106 survivorship studies; over halfof the studies included measures of psychological/emotional functioning,social functioning, physical symptoms, and physical functioning. Relatingthis to the domains noted by Ferrell and

Hassey Dow, we see an undercoverage of patient-specific economic outcomes(12.3%) and spiritual outcomes (10.4%).

It is heartening that researchers are construing QOL to be multidimensional.However, largely absent from the literature are studies investigating howthe domains relate to each other statistically; this critique is largelytrue of the field in general, with some exceptions.[1,2] It is now timeto push the field forward from descriptive models that serve as usefulheuristics in selecting domains to explanatory models that demonstratecausal relationships among domains.

It is important to know how individual domains relate to each otherand to global quality of life. For example, can deficits in some domains(eg, the often-noted fatigue in survivors) be offset by high levels offunctioning in other areas (eg, spirituality)? It is likely that "dominant"domains will vary by subgroups of survivors; for example, return to workmay be the driving force at one life stage and ability to maintain familyrelationships at another. Factors limiting our ability to model these domainsin the past have been the field's overwhelming reliance on cross-sectionaldesigns (80.4% of the abstracedstudies) and relatively small samples sizes(median, 64).

Explaining Differences in QOL

Researchers in psychosocial oncology have a long-standing interest instudying how internal (eg, coping strategies) and external (eg, socialsupport) resources explain variations in how individuals adapt to the cancerdiagnosis and treatment.[3] This tradition is reflected in a sizable proportionof QOL studies. Although this is an important avenue for research, otherfactors that may explain variations in QOL have been studied less often.

Perhaps the most obvious omission in studies of survivorship, as notedby Ferrell and Hassey Dow, is any attempt to link the severity of subsequenthealth problems and physical morbidity with other outcomes. Also understudiedis the role of health behaviors after cancer treatment in explaining variationsin QOL. For example, a recent study[4] of QOL in laryngeal cancer survivorsfound that nearly 60% continued to drink alcohol every day. It is not hardto imagine that continuing such a health behavior could cause a cascadingof other events (eg, social isolation, inability to maintain social roles)that would affect QOL.

Positive Outcomes

Although there is evidence in the psychosocial oncology literature thatmany survivors report positive aspects to their cancer experience[5] andthat these positive aspects can offset the effects of negative outcomes,[6,7]in general attention has not been paid to this phenomenon in the QOL literature.Most suggested QOL domains focus on negative outcomes, and researchersimplicitly assume that the absence of negative outcomes is positive--aposition not accepted in the broader field of psychological adaptationto chronic illness.

The QOL literature could profit from some attempt to conceptualize therole of positive experiences, such as renewed spirituality, increased closenessto family members, and newfound joy in living, in explaining variationsin adaptation among long-term survivors. This is particularly importantgiven the renewed scientific interest in the role of spirituality and religiousbeliefs and behaviors in recovery from illnesses.

Cancer QOL researchers do have the opportunity to make great stridesin understanding survivorship issues: There is a large extant literaturefrom which to gain insights about areas that are as yet unstudied or poorlystudied; there are exciting developments in related fields; and there isan institutional base from which to gain direction. We need, however, toadvance the field to a higher level, not to repeat the studies of the past.

References:

1 Brenner M, Curbow B, Legro M. The proximal-distal continuum of multiplehealth outcome measures: The case of cataract surgery. Med Care 33(suppl):AS236-244,1995.

2. Lewis F, Hammond M, Woods N: The family's functioning with newlydiagnosed breast cancer in the mother: The development of an explanatorymodel. J Behav Med 16:351-370, 1993.

3. Curbow B, Somerfield M (eds): Psychosocial Resource Variables inCancer Studies: Conceptual and Measurement Issues, pp 1-9. New York, HaworthMedical Press, 1995.

4. de Boer M, Pruyn J, van den Boorne B, et al: Rehabilitation outcomesof long-term survivors treated for head and neck cancer. Head Neck 17:503-515,1995.

5. Curbow B, Legro M, Baker F, et al: Loss and recovery themes in survivorsof bone marrow transplantation. J Psychosoc Oncol 10:1-20, 1993.

6. Curbow B, Somerfield M, Baker F, et al: Personal changes, dispositionaloptimism and psychological adjustment to bone marrow transplantation. JBehav Med 16:423-443, 1993.

7. Fromm K, Andrykowski M, Hunt J: Positive and negative psychosocialsequelae of bone marrow transplantation: Implications for quality of lifeassessment. J Behav Med 19:221-240, 1996.