To investigate a potential toxicity benefit of preoperative radiation therapy with protons compared to conventional photon beam radiation therapy in patients with locally advanced rectal cancer.
Biopsy-proven, newly diagnosed primary rectal adenocarcinoma, i.e. with the lowest part of the tumour less than 16 cm from the anal verge detected using a rigid rectoscope.
Clinical stage (c) T4b, i.e. infiltration of an adjacent organ or structure like the prostate, urinary bladder, uterus, sacrum, pelvic floor or side-wall (according to TNM version 8).
cT4a, i.e. peritoneal involvement.
Extramural vascular invasion (EMVI+).
Extensive growth into cranial part of the sacrum (above S3) or the lumbosacral nerve roots indicating that surgery will never be possible even if substantial tumour down-sizing is seen.
Presence of metastatic disease or recurrent rectal tumour. Familial Adenomatosis Polyposis coli (FAP), Hereditary Non-Polyposis Colorectal Cancer (HNPCC), active Crohn's disease or active ulcerative Colitis.
Concomitant malignancies, except for adequately treated basocellular carcinoma of the skin or in situ carcinoma of the cervix uteri. Subjects with prior malignancies must be disease-free for at least 5 years.
Known DPD deficiency.
Alexander Valdman
Lead sponsor
Karolinska University Hospital
Sponsor institution