CGA is a validated holistic approach to evaluate the elderly population. It is a multidisciplinary, multidimensional, and intensive evaluation of a patient who is at significant risk for subsequent functional decline (Reuben et al. 1999). CGA measures aspects such as functional status, comorbid medical conditions, nutritional status, physiological state, social support, and geriatric syndromes involving multidisciplinary interpretation as well as transdisciplinary implementation. Such comprehensive approach reveals information missed by routine history and physical alone (Hurria et al. 2006). Evidence for the value of integrating geriatric evaluation principles into oncology is increasingly being documented in the literature (Extermann et al. 2005).

Evaluation for oncologic treatment consideration routinely includes cancer pathology, staging of the disease, basic functional assessment, functional assessment of several organs, and consideration of comorbid illness. In older cancer patients, this may not be sufficient to predict potentially adverse outcomes such as toxicity, morbidity, disability, and mortality and to properly support clinical decisions. Objectives of performing geriatric assessment in cancer patients are to provide an approximate estimation of life expectancy, help the oncologist understand the potential impact of the patient’s cancer during his or her remaining life, identify cancer patients for whom one could expect the greatest benefit from treatment, identify medical and social problems that may decrease the tolerance of cancer treatment and/or be amenable to intervention, formulate appropriate treatment and management strategies, and assist in monitoring clinical and functional outcomes going forward (Hurria and Balducci 2009). A prospective observational cohort study looking at CGA as a predictor of complications in elderly patients after elective surgery for colorectal cancer showed that CGA was able to identify frail patients who have significantly increased risk of severe complications after elective surgery (Kristjansson et al. 2010).

The ultimate goal of CGA is to provide the patient with a holistic view of what to expect in going through cancer treatment and have the patient participate in shared decision-making process of selecting the best treatment option in accordance with the patient’s wishes. A recent review on geriatric assessment in the oncology setting showed that it is feasible, and some domains were significantly associated with adverse outcomes. However, they found limited evidence that geriatric assessment impacted treatment decision-making (Puts et al. 2012).

Existing oncology performance status measures (such as Karnofsky performance status [KPS] (Yates et al. 1980) or Eastern Cooperative Oncology Group performance status (Oken et al. 1982)) are applied to adult patients with cancer regardless of age to estimate functional status, assess eligibility for clinical trials, and predict treatment toxicity and survival. However, these tools were validated in younger patients and do not address the heterogeneity in the aging process. There is a need to develop a predictive model that incorporates geriatric and oncologic correlates of vulnerability to chemotherapy toxicity in older adults. The Cancer and Aging Research Group (CARG) study using a pre-chemotherapy geriatric assessment was able to identify risk factors for chemotherapy toxicity in older adults and develop a risk stratification schema. A predictive model for grade 3–5 toxicity was developed. It consisted of geriatric assessment variables, laboratory test values, and patient, tumor, and treatment characteristics. This model had a greater ability to discriminate risk of chemotherapy toxicity than the KPS (Hurria et al. 2011).

The Chemotherapy Risk Assessment Scale for High-Age Patients (CRASH) score is another predictive instrument of chemotoxicity in older adults. Through the assessment of 24 parameters, this study was able to stratify patients into four categories for risk of chemotherapy-related toxicity. The study confirmed that hematological and non-hematological toxicities are associated with different predictors, which may prove important for clinical application and for designing future trials (Extermann et al. 2012).

The determination of surgical risk for the elderly patient is complex. For these patients, traditional organ system-oriented preoperative assessment has been shown to be lacking in predicting adverse postoperative outcomes. The assessment should encompass multiple domains including underlying functional status, physiologic changes of normal aging, changes related to comorbidities, and the surgical procedure itself. There have been several studies showing that geriatric assessment incorporated into preoperative assessment provides a more accurate picture of what to expect in terms of perioperative morbidity and mortality. In 1991, the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) was developed, and since then it has been used in assessing the risk of colorectal surgery (Copeland et al. 1991). By using a validated frailty scoring system which encompasses weight loss, exhaustion, physical activity, walk time, and grip strength, Makary et al. were able to show that frailty independently predicted postoperative complications, length of stay, and discharge to a skilled or assisted living facility in older surgical patients (Makary et al. 2010). Robinson et al. showed that preoperative impaired cognition, low albumin level, history of falls, low hematocrit level, any functional dependency, and a high burden of comorbidities were closely related to 6 months’ mortality and postdischarge institutionalization in patients undergoing major thoracic and abdominal operations (Robinson et al. 2009). In the Preoperative Assessment of Cancer in the Elderly (PACE) study, functional dependency, fatigue, and abnormal performance status were associated with a 50 % increase in the relative risk of postoperative complications (Audisio et al. 2008). In patients >65 years of age, lower Mini-mental State Examination score and older age were significantly associated with the development of post-cystectomy delirium, and those who developed delirium were more likely to face readmission and reoperation (Large et al. 2013). In patients undergoing pancreaticoduodenectomy, older age and worse scores in geriatric assessment predicted major complications, longer hospital stays, and surgical ICU admissions (Dale et al. 2014).

A validated and brief preoperative evaluation tool that recognizes the unique physiologic vulnerabilities of the geriatric population and accurately predicts outcomes is greatly needed. The Memorial Sloan Kettering Cancer Center (MSKCC) Geriatric Service has incorporated selected elements of the geriatric assessment into its daily clinical practice (Annals of Surgery, accepted for publication). Preoperative assessments are performed by a team that includes a nurse, pharmacist, and geriatrician. Patients are referred to a nutritionist, physical therapist, social worker, and other medical disciplines if needed. The patients have the chance to discuss age-specific concerns and potential geriatric syndromes which may complicate postoperative outcomes.