The Evolving Landscape of Neoadjuvant Radiation Therapy for Locally Advanced Rectal Cancer.

Purpose of Review: Neoadjuvant long-course chemoradiation (LCRT) and short-course radiotherapy (SCRT) are evidence-based treatment options for locally advanced rectal cancer. Both paradigms improve local control but have not shown to impact distant metastases or overall survival. Herein, we compare these two radiation approaches and review their role in the multidisciplinary management for locally advanced rectal cancer. Recent Findings: There are no significant differences in disease outcomes between LCRT and SCRT. Delaying surgery after either radiation regimens is safe and leads to tumor downstaging without compromising oncologic outcomes. Attempts to incorporate chemotherapy to intensify neoadjuvant radiation regimens are under active investigation. Summary: LCRT and SCRT are proven neoadjuvant regimens that improve local control. Supporters of LCRT emphasize the higher likelihood for tumor downstaging and sphincter preservation, while those favoring SCRT highlight lower acute toxicities, decreased costs, and patient convenience. Delaying surgery after either LCRT or SCRT is safe and provides pathologic downstaging. The optimal timing of surgery has yet to be determined. There is growing interest in total neoadjuvant therapy which incorporates chemotherapy with neoadjuvant radiation. [ABSTRACT FROM AUTHOR]