Randomized Trial of Standard Dose Versus High Dose of Radiotherapy in Rectal Preservation With Chemo-radiotherapy to Patients With Early Low and Mid Rectal Cancer: The Watchful Waiting 3 Trial (WW3)
In recent years, an increasing number of retrospective and prospective observational studies have indicated that a subset of rectal cancer patients may avoid surgery if they can achieve a complete response to chemoradiotherapy. Prospective trials, including the previous Danish Watchful Waiting trials (NCT00952926, NCT02438839) in early rectal cancer have demonstrated high levels of organ preservation with dose-escalation, but it is unclear whether this was primarily due to tumor stage or dose level. The aim of the present study is to investigate if a higher dose of radiotherapy is superior compared to a standard dose in patients with early rectal cancer undergoing chemoradiotherapy with curative intent.
• Histopathologically verified adenocarcinoma of the rectum
• MDT conference finds patient a candidate for rectal resection
• Clinical tumor category cT1-3
• MRI findings
‣ Maximal cross-sectional size of 4.5 cm (axial plane relative to the rectum)
⁃ Lowest edge of tumor located at or below the peritoneal reflection on MRI
• Performance status 0-2
• Age ≥ 18 years
• Eligible for radiotherapy and capecitabine according to investigator, including
‣ Adequate function of bone marrow (neutrophils ≥ 1.5 x 10\^9/l and thrombocytes ≥ 100 x 10\^9/l)
⁃ Adequate function of liver (ALAT \< 2.5 x upper limit of normal, bilirubin \< 2.5 x upper limit of normal)
⁃ Adequate kidney function (Serum creatinine \< 1.5 x upper limit of normal or measured GFR \> 30 ml/min)
• Fertile women must present a negative pregnancy test and use secure contraceptives during and three months after treatment
• Written and orally informed consent