Identifying an accurate pre-screening tool in geriatric oncology

Abstract

The use of comprehensive geriatric assessment (CGA) in cancer patients older than 70 is recommended. Three pre-screening instruments have been proposed: the abbreviated comprehensive geriatric assessment (aCGA), the Vulnerable Elders Survey (VES-13), and the Groningen frailty index (GFI). The objective of the study was to identify the most efficient pre-screening tool that accurately determines individuals who may benefit from the entire CGA. A total of 113 elderly cancer patients were assessed by means of the aCGA, VES-13, GFI and the full CGA. The sensitivity, specificity of the three instruments was calculated, using the results from the entire CGA as the gold standard for the GFI and the VES-13. The aCGA was assessed whether each sub-component reliably predicts impairment on each sub-component of the full CGA.

The majority of the participants were defined as being at risk of vulnerability: 68.14% had two or more impairments of the CGA or were cognitively impaired. The physical and disability questions are useful, but all other screening instruments miss too many cases.

Introduction

There is a remarkable increase in the number of older patients with cancer. Persons over the age of 70 are the fastest growing proportion of the population. In addition, the most important risk factor for cancer is age [1]. Often, tumor diagnosis is made at a later stage compared with younger individuals, resulting from a restriction in screening programs and often an underestimation of symptoms [2]. Senior adults have been underrepresented in clinical trials, leading to a limited existence of evidence-based guidelines for treatment. Elderly patients are often treated with less intense and possibly suboptimal standard regimens, under the assumption that therapy is less effective and has more toxicity [3]. Furthermore, in senior adults, case complexity (related to possible existing co-morbidities and impaired functional status) and care complexity (related to the presence of multiple health care providers) are added up [4].

Senior citizens represent a inhomogeneous group. Within a decade of age, there is a substantial variety in life expectancy, capacity to live independently, and burden of co-morbidities. Thus, treatment choices should not be ascertained by calendar age per se. Just as when staging the tumor, its size and spread, clinicians need to determine the functional age of the patient and anticipate the functional response to treatment [5].

The International Society of Geriatric Oncology (SIOG) recommends the use of comprehensive geriatric assessment (CGA) in cancer patients older than 70 [6]. The CGA is a multidisciplinary evaluation of an older individual's functional status, cognition, psychological status, social support, nutritional status, co-morbidity, and review of the medications being taken [5], [7]. Several instruments have been developed to assess the different components. Common measures of functional status, which investigate the necessary abilities enabling independence in everyday life, are activities of daily living (ADL) and instrumental activities of daily living (IADL). The mini-mental state examination (MMSE) investigates orientation, short-term memory, recall, and language and praxis function. A score less than 24 points suggests ‘probable cognitive impairment’ [8]. Emotional status is assessed by means of the geriatric depression scale (GDS), a validated screening tool for depression. The GDS-15 measures emotional factors present in depression and does not rely on somatic symptoms that confound the diagnosis of depression [9].

In more than 50% of patients older than 65 years, the CGA detects unexpected difficulties, which may lead to premature discontinuity of the cancer treatment [5]. Therefore, CGA may serve the decision-making process by identifying patients who are fit for treatment [5].

Unfortunately, the CGA is time-consuming. Exhaustion of both the patient and his physician frequently lead to the abandonment of the CGA [10]. A two-step approach is a pragmatic alternative, using a less time- and manpower-consuming pre-screening tool [11]. Pre-screening is a process in which a brief assessment is conducted to determine whether further screening is indicated. It is a short evaluation that is not intended to be diagnostic, and does not replace, but rather optimizes screening by selecting those senior patients who may benefit from an intensive survey [12]. Several pre-screening instruments have been proposed.

The abbreviated comprehensive geriatric assessment (aCGA) combines the items of the CGA that are most predictive of the total rating score of each scale [13]. The aCGA is developed to determine whether patients should undergo the ADL, IADL, GDS and MMSE based on cut-off point scores [12]. A cut-off point of two out of the selected four GDS items indicates insisting on the use of the full GDS. In the event of any detected impairment, the full ADL or IADL should be administered. Concerning the MMSE, a score of six or lower out of a maximum score of eight indicates cognitive screening with the complete MMSE [12]. The aCGA is not a complete pre-screening instrument with clear cut-offs such as the two described below, but was designed to conduct the CGA more efficiently.

The Vulnerable Elders Survey (VES-13) is a 13-item screening tool that asks elderly people to report their age, physical status, functional capacity, and their self-estimated health. In a US sample, a score of ≥3 identified 32% of individuals as being vulnerable [14]. These vulnerable elderly had a four times greater risk of functional deterioration or death over 2 years than those with a score less than three [14], [15]. The clear cut-off point makes the VES-13 a practical instrument; nevertheless, patients may overestimate their own physical competences.

The Groningen frailty index (GFI) is a simple tool that screens for diminished abilities and resources in physical, cognitive, social and psychological functioning. A score of four or more indicates a higher risk for frailty [16]. Thus, like the VES-13, a distinct cut-off point is an advantage of the GFI.

In order to identify the most efficient pre-screening tool that accurately determines individuals who may benefit from the entire CGA, we conducted a study among elderly Flemish and Dutch cancer patients. The objective was to compare the results of three selected pre-screenings tools, currently insufficiently validated, using the results from the entire CGA as the gold standard.