Development and Validation of The Post-RT LARS Prediction Model (PORTLARS)

Development and Validation of a Nomogram to Predict Severe Bowel Dysfunction After Rectal Cancer Resection and Neoadjuvant Radiotherapy: A Multicenter, Observational Clinical Study

Bowel dysfunction is common after a restorative rectal cancer resection. Neoadjuvant radiotherapy is an influential factor that impairs bowel function and quality of life. However, almost half patients who have received primary surgery with preoperative radiotherapy are able to restore a good or moderate bowel function in the long term. This multicenter observational study aims to identify the risk factors of severe bowel dysfunction after rectal cancer resection and neoadjuvant radiotherapy, in accordance with the LARS score, and to build a model that predicts long-term major LARS in the early stage of follow-up. Development and validation cohorts are enrolled from tertiary hospitals in China.

Inclusion Criteria:

• Curative low anterior resection for nonmetastatic rectal cancer
• Preoperative radiotherapy

Exclusion Criteria:

• Death
• Metastasis or recurrence
• Postoperative radiotherapy
• Cognitive disorder
• Intestinal stoma
• Rectal cancer resection for <12 months
• Stoma reversal for <6 months