The older cancer survivor: consequences of cancer and ageing.

Abstract

The increasing number of older cancer patients will become an important challenge for healthcare services, as older cancer patients often present with complex combinations of both cancer- and ageing-related problems. Older cancer patients represent the largest and fastest growing group of cancer patients, and despite overall agreement that –in addition to prolongation of survival– the main goal of treating older cancer patients is “quality of survival”, questions regarding the quality of survival of older cancer patients after initial treatment remain largely unanswered and unexplored. The aim of this thesis was to gain a deeper insight into the impact of a diagnosis and treatment of cancer, ageing, and the interaction between both, on subsequent well-being of older cancer patients. Well-being was operationalized as comorbidity (an indicator of physical well-being), loneliness (an indicator of social well-being), depression, cognitive impairment, and fatigue (indicators of mental well-being). Subsequently, we explored ways to facilitate the identification of older cancer patients at risk for negative outcomes, focusing on functional decline, decline in quality of life, and the emergence of depression. The majority of our research questions were addressed with data of the KLIMOP-study, an observational cohort study that includes Belgian and Dutch older cancer patients (≥70 years) with a new diagnosis of breast, prostate, lung or gastrointestinal cancer and two control groups: younger cancer patients (50 – 69 years) with a new diagnosis of breast, prostate, lung or gastrointestinal cancer were included to act as a control for ageing; older patients (≥70 years) without a previous diagnosis of cancer were included as a control for a diagnosis and treatment of cancer. The study on comorbidity was addressed with data from the Registration Network Family Practices of Maastricht University. This is a primary care database including a population of approximately 135,000 people. We also conducted a systematic literature review and meta-analysis on the topic of loneliness. We found that the frequency of comorbidity in older cancer patients was high, but it appeared to be predominantly associated with high age, and the absolute increase in disease occurrence due to cancer was small. For loneliness we found that it is an important and common concern in cancer patients. We showed that at time of diagnosis, older cancer patients were less lonely compared to their peers without cancer, but over the course of one year, levels of loneliness –in particular emotional loneliness– significantly increased in cancer patients, young and old. Risk factors for loneliness were changes in fatigue, cognitive functioning, or having no partner. For other psychosocial problems we showed that within a one-year timeframe from cancer diagnosis, older as well as younger cancer patients experienced an increase in the frequency of depression, slight worsening of cognitive functioning, and relatively stable levels of fatigue, albeit more than half of the cancer patients reported fatigue. Multivariate analyses showed that the main risk factors for psychosocial problems were presence of the problem at baseline and functional impairment. For the second objective of this thesis –to identify older cancer patients at risk for negative outcomes– we showed that in older persons with a relatively good prognosis, geriatric screening tools are of limited use in identifying those who are at risk for decline in functional status or quality of life after one year. Furthermore, we explored the added value of using fatigue severity as a cue to further investigate the presence of depression. We showed that fatigue severity cannot replace proper clinical assessment of depression, but it offers a useful trigger for increased alertness and additional testing for depression in older cancer patients. In conclusion, the overall message of this thesis is rather optimistic: older cancer patients are doing better than expected. The amount of problems older cancer patients face is not disproportionate compared to the problems faced by younger cancer patients or older people without cancer. However, this is only true for the population described in this study: mainly female patients with breast or colorectal cancer with a good prognosis. Nonetheless these optimistic results, a diagnosis and treatment of cancer has a serious impact on a person’s life, and at an individual level there are persons who face enormous challenges. This was true for all three groups; older cancer patients, younger cancer patients and older persons without cancer. With those people who are vulnerable in mind, we believe that attention is needed especially for the social and mental aspects of functioning.status: publishe