Radiation in rectal cancer: what are the options and if/when can it be avoided?

Treatment of rectal cancer has improved greatly over recent decades. This review looks at the pivotal trials in the development of the current standard of therapy as well as new directions for more individualized therapy for rectal cancer. Rates of local recurrence and overall survival (OS) for surgery alone have improved with the use of (neo)adjuvant 5-fluorouracil (5-FU)-based chemoradiation. New surgical techniques have improved outcomes, but preoperative radiotherapy still confers an additional benefit. Despite benefits in the metastatic setting, the addition of oxaliplatin to 5-FU and radiotherapy has not shown improved outcomes, although it increased toxicity. Preoperative therapy also allows for the identification of predictive and prognostic markers for response to treatment, which has great potential to individualize treatment. Currently, the search for validated biomarkers and the refinement of risk stratification are the focus of ongoing study. Tailored therapy may include modification of the pelvic radiotherapy field, nonoperative therapy, or avoidance of radiotherapy.