Cancer Treatment Today

“Chemoradiation” refers to the carefully orchestrated simultaneous administration of chemotherapy and radiation treatments. Chemoradiation is an important tool in the treatment of rectal cancer. The term “neoadjuvant” refers to the concept of administering chemotherapy and/or radiation therapy prior to surgery. The purpose of neoadjuvant chemoradiation therapy is twofold: to shrink a tumor to facilitate subsequent surgical removal and to improve a patient’s chance for cure. Alternatively, patients with rectal cancer of a size and location that permit resection first should subsequently have adjuvant chemoradiation therapy to improve their chance for a cure.

A typical chemoradiation regimen might consist of daily (Monday through Friday) radiation treatments concurrent with daily (Monday through Friday) continuous infusion 5-fluorouracil (5-FU). This chemoradiation is typically given over a period of five to six weeks. Chemotherapy is given with radiation therapy in order to sensitize tumor cells to radiation, and because the combination has been shown to be more effective than the use of either modality alone. Continuous infusion rather than bolus (a daily 5-10 minute infusion) chemotherapy is preferred as it has resulted in improved survival rates in one study. This regimen may be given pre- or postoperatively for locally advanced tumors (T3/T4 or N1/N2) where it has been shown to reduce the chance of tumor recurrence and improve the chance for cure.

Single-agent neoadjuvant capecitabine combined with radiation therapy demonstrated similar outcomes as previously established standards of care for patients with stage II or stage III rectal cancer, according to findings from the four-arm phase III NSABP R-04 trial presented at a press conference prior to the 2014 Gastrointestinal Cancers Symposium held January 16-18.The single-agent oral chemotherapy capecitabine was compared to 5-fluorouracil (5-FU), 5-FU plus oxaliplatin, and capecitabine plus oxaliplatin. Overall, a significant difference between treatments arms was not observed for local-regional control (LRC), disease-free survival (DFS), and overall survival (OS). Moreover, when oxaliplatin was added to either regimen, it did not provide additional clinical benefit but increased overall treatment toxicity, including diarrhea and fatigue. Infusional 5-FU and capecitabine had similar side effects.

NCCN recommends capecitabine for more advanced cancers with radiation.

Allegra CJ, Yothers G, O’Connell MJ, et al. Neoadjuvant therapy for rectal cancer: Mature results from NSABP protocol R-04. Presented at: The 2014 GI Cancers Symposium; January 16-18, 2013; San Francisco, CA. Abstract 390.

Sarah E. Hoffe, MD; Ravi Shridhar, MD, PhD; Matthew C. Biagioli, MD, Radiation Therapy for Rectal Cancer: Current Status and Future Directions
Cancer Control. 2010;17(1):25-34.

R. Glynne-Jones and M. Harrison,  Locally Advanced Rectal Cancer: What Is the Evidence for Induction Chemoradiation?
Oncologist, November 1, 2007; 12(11): 1309 – 1318.