Neoadjuvant chemoradiotherapy combined with immunotherapy: a promising strategy for MSS/pMMR locally advanced rectal cancer.

Research prospects of neoadjuvant immunotherapy based on different microsatellite status in locally advanced rectal cancer patients are a key area of current research. Neoadjuvant chemoradiotherapy followed by total mesorectal excision is the first-line treatment for locally advanced rectal cancer (LARC). In recent years, extensive clinical studies have demonstrated the significant importance of immunotherapy in improving survival rates for LARC patients with microsatellite instability (MSI), while also highlighting the potential benefits for those with microsatellite stability (MSS). Microsatellite status is one of the key markers for the classification of LARC subtypes and is also the decisive basis for the formulation of immunotherapy strategies. Although the important therapeutic value of immunotherapy in LARC patients with MSI has been strongly confirmed, LARC patients with MSS do not appear to benefit from immune monotherapy. The current article seeks to synthesize the progress of immunotherapy for LARC based on MSS. By highlighting these comparative insights, we aim to advance our understanding of how immunotherapy may address the unique needs of LARC patients with MSS profile characteristics. Furthermore, this research paves the way for future studies that can guide clinical decision-making in treating LARC patients with MSS.