Comorbidity in patients with cancer: Prevalence and severity measured by cumulative illness rating scale

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Abstract

Comorbidity is defined as the presence of one or more diseases in addition to an index disease. In elderly people, the number and severity of comorbidity increase with age. We report the comorbidity data of 536 patients treated as in-patients: 231 elderly cancer patients (ECP), 172 younger cancer patients (YCP) and 133 elderly patients admitted for non-cancer reasons (EMP). Comorbidity was assessed with the cumulative illness rating scale geriatric version (CIRS-G). Data on number of affected organ systems (levels 1–4), number of affected organ systems with severe disease (levels 3–4), and sum score of levels per patient are reported. The number of comorbidities increases with age. A 76% of ECP, 51% of YCP, and 79% of EMP have severe comorbidity. Palliative treatment approach is not associated with higher levels of comorbidity in ECP. Vascular disorders were the most common comorbidity. The difficulty to rate haematological comorbidity in cancer patients is reflected. This is the first report on detailed results of assessment of comorbidity measured by CIRS-G in cancer patients. In addition, we provide a comparison to an elderly group of patients admitted for non-cancer reasons.

Introduction

Cancer is the second most leading cause of death in Europe and northern America [1]. About 60% of all people diagnosed with cancer are 65 years and older. Due to demographic changes, the number of people with cancer will increase substantially within the next decades [2]. The incidence and prevalence of other chronic medical conditions increase with age. Thus it is the rule and not the exception for elderly patients with cancer to have not only the diagnosis of cancer, but a number of other medically relevant conditions in addition. But as Feinstein stated as early as 1970, despite the importance of comorbidity in clinical practice, it has not gained a considerable role in clinical trials, medical statistics and clinical practice [3], [4]. Some authors have reported on the importance of comorbidity for survival in cancer patients [5], [6], [7], [8], [9]. The effect depends upon the kind and stage of tumour [10]. Seo et al. report that patients with a history of cancer had an average of three comorbid conditions [11]. In patients with a history of cancer the presence of comorbidty rather than the history of cancer, correlates with impaired functional status [12]. Frasci et al. reported on the predictive value of comorbidity for early termination of chemotherapy [13]. Extermann gave an overview on assessment of comorbidity in cancer patients [14]. A systematic review by de Groot et al. identified 13 different methods to measure comorbidity [15]. They classified the Charlson-Index [16], the cumulative illness rating scale (CIRS) [17], [18] and the Kaplan-Index [19] as valid and reliable methods to measure comorbidity that can be used in clinical research. Clinical trials for elderly patients with cancer should include a systematic collection of data on comorbidity [20], [21]. Otherwise, no one knows whether the reported data are of importance for all elderly patients or whether the group of included patients is highly selected, as it is often the case in phase III clinical trials [22], [23], [24], [25].

The mentioned facts demonstrate the need of a more profound knowledge on comorbid conditions in cancer patients. But detailed reports on their kind, number, and severity in newly treated cancer patients are rare. In addition, reference data, which can be used for planning of clinical trials, are not available so far. We want to close this gap by our following analysis reporting the data from our geriatric oncology program on the prevalence of comorbidity in cancer patients. Comorbidity was measured by the CIRS-G-score in cancer patients and in a group of elderly non-cancer patients, who served as a control.

Section snippets

Methods

The analysis is part of a larger prospective trial on decision making in elderly cancer patients. The trial was approved by the ethical committee of the Friedrich Schiller University of Jena and supported by the German Cancer Aid (Grant: 70-2445-Hö-3). Written informed consent was obtained prior to inclusion into the trial.

Patients’ characteristics

About 536 patients were included: 403 cancer patients (231 ECP and 172 YCP), and 133 EMP. Patient characteristics including age, sex, kind of tumour, and treatment approach are summarised in Table 1. Cancer patients’ diagnoses are presented in Fig. 1. The diagnoses of EMP were: diabetes mellitus n = 60, cardiovascular disease n = 18, disease of the liver, gallbladder or pancreas n = 14, benign haematological disorders n = 12, disease of the GI-tract n = 10, others n = 19.

Number of affected organ systems

The number of organ systems

Discussion

Comorbidity is defined as any disease that coexists with but is not related to the index disease being studied. Many elderly patients have an increasing number of comorbid diseases [4]. Extermann et al. reported data on comorbidity in patients from their senior adult oncology program. Of their 203 elderly cancer patients with a median age of 75 years (range 63–91 years), 6% of patients had no comorbidity [29]. This figure is higher than in our data, were only 0.8 patients had no comorbidity.

Conclusion

The results reported in this paper are the first detailed presentation on CIRS-G data in cancer patients and the first direct comparison with a control group of elderly patients admitted to hospital for non-cancer reasons. The average number of organ systems affected by comorbidities levels 1–4 and the sum score of levels of comorbidities were significant different between ECP, YCP, and EMP. However, the average number of organ systems affected by levels 3–4 comorbidities was comparable between

Reviewers

Cohen H.J., Doctor, Medical Center, Duke University, Center for the Study of Aging and Human Development, 3003 Durham, NC 27710, United States.

Piette F., Professor, Hôpital Charles Foix, Gérontologie 7, Avenue de la République, Ivry sur Seine, Cedex 94206, France.

Chaibi P., Docter, Hôpital Charles-Foix, Service de Médecine Interne Gériatrique 7, Avenue de la République, Ivry 94200, France.

Ulrich Wedding is physician (general internal medicine) and is specialist in haematology, oncology, and palliative care. He serves as a consultant at the Department of Haematology and Medical Oncology at the University Hospital of the Friedrich Schiller University Jena in Germany. Currently, he is research fellow of the Robert-Bosch Foundation. His main interest in clinical research is geriatric oncology. He is active member of national and international working parties in the field of

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    Ulrich Wedding is physician (general internal medicine) and is specialist in haematology, oncology, and palliative care. He serves as a consultant at the Department of Haematology and Medical Oncology at the University Hospital of the Friedrich Schiller University Jena in Germany. Currently, he is research fellow of the Robert-Bosch Foundation. His main interest in clinical research is geriatric oncology. He is active member of national and international working parties in the field of geriatric oncology.

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