Short‐Course Versus Standard Chemoradiation in T3 Rectal Cancer

Presentation of the Case A 68‐year‐old woman with no past medical history presents with rectal bleeding. Colonoscopy reveals a mass in the midrectum at approximately 8 cm. Biopsy shows adenocarcinoma. On physical exam, the tip of the mass is barely palpable. A magnetic resonance imaging (MRI) scan of the pelvis demonstrates a tumor with invasion through the muscularis in the midrectum ( Fig. 1). There is at least 2 cm between the tip of the mass and the mesorectum. A single 8‐mm lymph node is seen in the perirectal space. A medical oncologist, surgical oncologist, and radiation oncologist see the patient and they recommend that the patient receive 6 weeks of infusional 5‐fluorouracil (5‐FU) and external beam radiation to a dose of 50.4 Gy. After chemoradiation, the oncologists expect the patient to undergo a low anterior resection and, upon recovery, 4 months of 5‐FU–based adjuvant chemotherapy. The oncology fellow asks the attending physicians whether short‐course radiation therapy is appropriate for this patient. 1An adenocarcinoma of the rectum showing invasion through the muscularis propria for a cT3 stage on a T2‐weighted magnetic resonance imaging scan. The arrow shows the penetration of the tumor through the thick black line of the muscularis propria.