Personalized Care Pathways for Bowel Symptoms in Rectal Cancer patients_development of E-diary

Towards Personalized Care Pathways for Bowel Symptoms in Rectal Cancer Patients Through Precision Medicine

Colorectal cancer is the 2nd and 3rd most common cancer in respectively women and men, of which about 40% is located in the rectum. The gold standard treatment for rectal cancer (RC) is a low anterior resection, combined with chemoradiotherapy. However, this treatment will negatively impact different aspects of bowel function and the patients' quality of life. These bowel symptoms often remain prevalent, even at 12 months after RC treatment. Most assessment tools are however not capable of capturing the full range or therapeutic-related evolution of these bowel symptoms. Consequently, the aim is to develop a validated bowel diary for diagnosing and evaluation of all bowel symptoms.

In recent years, organ-preserving strategies such as Watch and Wait have become more widely implemented. Although these patients avoid surgical morbidity, emerging evidence shows that neoadjuvant radiotherapy alone can also cause substantial and persistent bowel dysfunction. Therefore, the study population was expanded to include patients managed with a Watch and Wait strategy in addition to those undergoing TME/PME.

Colorectal cancer is the 2nd and 3rd most common cancer in women and men, respectively and represents approximately 13% of all new cancer diagnoses, with 40% of cases specifically situated in the rectum. The gold standard treatment for rectal cancer (RC) is a low anterior resection, combined with chemoradiotherapy. However, given the improved oncological results, functional outcomes, such as bowel symptoms, become more and more important. Approximately 60-90% of RC patients are affected with a wide range of new onset bowel symptoms (incontinence for flatus or feces (solid, liquid), frequent bowel movements, urgency, clustering of defecation and evacuation problems) immediately after rectal treatment. The combination of these specific bowel symptoms and their impact on quality of life (QoL) has been summarized in an international consensus definition and is referred to as the Low Anterior Resection Syndrome (LARS).

Major LARS has an important impact on QoL and has major health economic consequences. This is attributable to its high prevalence after RC treatment, the chronic nature of symptoms and the limited evidence of available therapeutic options. This context leads to repetitive medical consultations, additional technical examinations which are often not very useful and need for prolonged medical treatment (multiple drug regimens), with often limited therapeutic gain. Furthermore, there is a lack of a comprehensive scoring system to identify the different aspects of LARS, leading to inadequate diagnostics and follow-up of symptoms. Based on these considerations, there is a clear need for a comprehensive scoring system for identification of the different aspects of LARS and monitoring of therapeutic treatment.

In recent years, organ-preserving strategies such as Watch and Wait have gained importance in the management of rectal cancer. Although these patients avoid surgical morbidity, growing evidence shows that neoadjuvant radiotherapy alone can also induce substantial and persistent bowel dysfunction, likely due to radiation scatter affecting adjacent pelvic structures. As Watch and Wait is increasingly implemented in clinical practice, it is essential that this patient group is included in the development of a comprehensive scoring system to accurately capture the full spectrum and evolution of bowel symptoms across all treatment pathways.

Inclusion Criteria:

• Voluntary written informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedures.
• At least 18 years of age at the time of signing the Informed Consent Form (ICF).
• Proficient in reading, comprehending, and conversing in Dutch .
• Patients after rectal surgery for rectal cancer or under Watch and Wait protocol (also referred to as active surveillance).

Exclusion Criteria:

• The participant has undergone a different type of surgery, including a Hartmann procedure, abdominoperineal excision, transanal endoscopic microsurgery, or sigmoid resection.
• Experienced fecal incontinence prior to undergoing surgery.
• Are affected by neurological disorders affecting bowel function.
• Already underwent previous pelvic radiation or rectal surgery for non-cancer reasons.