The primary goal of the patient-led follow-up from home, is the improvement of quality of life and the reduction of stress in patients, while obtaining a more complete picture of their health status.

A series of assessments are performed in the home setting:

• Blood withdrawal for CEA determination
• Quality of life questionnaires to assess both mental and physical symptoms
• Vital parameters using a Smart Sensor

Primary Objective: To further develop and evaluate a personalised patient-centred surveillance programme including a feedback platform for patients after curative treatment for CRC in terms of health-related quality of life (HRQoL) and significantly decrease the number of in-hospital appointments, by relocating the follow-up care to the home-setting. The goal is for this surveillance program to be non-inferior to standard of care follow-up at 36 months, in terms of quality of life. The quality of life in patients will be assessed with the EQ 5D-5L questionnaire and compared to median EQ-5D-5L scores for patients receiving standard of care follow-up. In current literature, the median HRQoL VAS score for patients after surgery for CRC is 62.05 points (1).

The second goal of the program is to relocate part of the in-hospital follow-up care to the home-setting. In standard of care follow-up, at 36 months patients would have had 10 in-hospital appointments. The effect of the PROMISE study on the number of in-hospital appointments, will be assessed at 36 months postoperatively.

The PROMISE study is a multi-centre prospective regional implementation study of a personalised patient-centred surveillance program including a feedback platform for patients after curative treatment for CRC.

All patients who underwent surgery with curative intent for non-metastatic CRC with scheduled postoperative surveillance are potentially eligible.

Follow-up in this study is performed according to the acting Dutch national guidelines. Current guidelines advocate CEA level measurements to be performed every 3-6 months for first 2 years after surgery and every 6-12 months for years 3 to 5. Medical imaging (thoracic and abdominal CT) should be performed 1 year postoperatively. Changes to the Dutch national guidelines during the course of the study will be implemented accordingly into the follow-up.

Within this study surveillance will for the greater part be performed at home:

• Serum CEA level monitoring is performed using the automatic capillary blood withdrawal device (TAP-II) - every 6 months during the first two years and every 12 months thereafter
• Vital parameters will be measured with a LifeSignals Multi-parameter Remote Monitoring System - every 3 months during the first two years and every 6 months thereafter
• QoL is measured with the use of questionnaires - every 3 months during the first two years and every 6 months thereafter
• One scheduled in hospital evaluation with medical imaging (according to national guidelines) performed 1 year after surgical treatment

inclusion criteria

• Age ≥ 21 years
• Histologically confirmed colorectal adenocarcinoma without distant metastasis and treated with curative intent surgical resection less than 6 months ago
• Scheduled or currently undergoing postoperative surveillance according to national guidelines
• Written informed consent by the patient
• Access to a smartphone

Exclusion criteria

• Patients with a severely complicated postoperative course, needing in hospital follow- up longer than 6 months postoperatively
• Patients enrolled in other studies that require strict adherence to any specific follow-up practice with regular imaging - yearly or more frequent - of the abdomen and/or thorax
• Patients with comorbidity or other malignancy that requires imaging of the abdomen and/or thorax every year or more frequent
• Patients with active implantable devices - e.g. pacemaker or implantable defibrillator
• Inability to complete the questionnaires due to illiteracy and/or insufficient proficiency of the Dutch language

IPD can be shared, but exclusively upon reasonable request with the affiliated researchers