Colorectal cancer (CRC) disproportionately affects patients aged 70 years and older. Surgery is the main treatment modality for CRC, but is associated with increased risk of postoperative morbidity, disability and loss of health related quality of life (HRQL).Frailty is an age related state of functional decline and considered to be an important risk factor for adverse outcome in geriatric oncology.Risk models for adverse outcome may be used for treatment decisions in the elderly, but are often not designed to predict patient related outcome measures and do not include frailty characteristics.

Multicentre, prospective, observational cohort study with a follow up time of one year. After initial diagnosis of CRC subjects will be screened for frailty using validated questionnaires, physical tests and non-invasive measurements. Frailty characteristics and HRQL are determined by Geriatric 8 (G8), Hospital Anxiety and Depression Scale(HADS), Euroqol- 5 dimensional (EQ-5D), Lawton Instrumental Activity of Daily Living scale(IADL), Mini Nutrition Assessment (MNA), 6 Item Cognitive Impairment Test (6-CIT), Identification of Seniors At Risk - Hospitalized Patients(ISAR-HP) and the EORTC-QLQ-C30/CR29 (HRQL in CRC patients). Physical tests include the Timed to Get Up (TUG) test and the hand grip strength test. Furthermore, the non-invasive measurements consist of a sarcopenia analysis using an existing CT/MRI scan and measurement of Advanced Glycation Endproducts (AGE reader).

Additional patients characteristics including medication use, medical history, tumor characteristics, neoadjuvant therapy and laboratory results of preoperative routine blood sampling will be collected. At three, six and twelve months after diagnosis, EORTC QLQ-C30/EORTC QLQ-CR29 and EQ-5D questionnaires are used to determine HRQL and disability free survival.

Inclusion Criteria:

• Age ≥ 70 years
• Histologically proven non-metastatic colorectal cancer
• Signed informed consent

Exclusion Criteria:

• - Emergency surgical procedures
• Insufficient understanding of the Dutch language

aged ≥ 70 years with a new diagnosis of non-metastatic CRC