This selection from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Colon Cancer focuses on systemic therapy options for the treatment of metastatic colorectal cancer (mCRC), because important updates have recently been made to this section. These updates include recommendations for first-line use of checkpoint inhibitors for mCRC, that is deficient mismatch repair/microsatellite instability-high, recommendations related to the use of biosimilars, and expanded recommendations for biomarker testing. The systemic therapy recommendations now include targeted therapy options for patients with mCRC that is HER2-amplified, or BRAF V600E mutation–positive. Treatment and management of nonmetastatic or resectable/ablatable metastatic disease are discussed in the complete version of the NCCN Guidelines for Colon Cancer available at NCCN.org. Additional topics covered in the complete version include risk assessment, staging, pathology, posttreatment surveillance, and survivorship.

The NCCN Guidelines for Rectal Cancer provide recommendations for the diagnosis, evaluation, treatment, and follow-up of patients with rectal cancer. These NCCN Guidelines Insights summarize the panel discussion behind recent important updates to the guidelines. These updates include clarifying the definition of rectum and differentiating the rectum from the sigmoid colon; the total neoadjuvant therapy approach for localized rectal cancer; and biomarker-targeted therapy for metastatic colorectal cancer, with a focus on new treatment options for patients with BRAF V600E– or HER2 amplification–positive disease.

This selection from the NCCN Guidelines for Rectal Cancer focuses on management of malignant polyps and resectable nonmetastatic rectal cancer because important updates have been made to these guidelines. These recent updates include redrawing the algorithms for stage II and III disease to reflect new data supporting the increasingly prominent role of total neoadjuvant therapy, expanded recommendations for short-course radiation therapy techniques, and new recommendations for a “watch-and-wait” nonoperative management technique for patients with cancer that shows a complete response to neoadjuvant therapy. The complete version of the NCCN Guidelines for Rectal Cancer, available online at NCCN.org, covers additional topics including risk assessment, pathology and staging, management of metastatic disease, posttreatment surveillance, treatment of recurrent disease, and survivorship.

High-volume surgeons had lower perioperative mortality rates for elective surgery, and were more likely to use restorative rectal procedures.

A novel approach for the preparation of a biotinylated dendrimer-based MRI agent 5 is described, in which a unique disulfide bond in the core of the Gd(III)-1B4M-DTPA chelated G2 PAMAM dendrimer was reduced and then attached to a maleimide-functionalized biotin. The new MRI agent 5 features a well-defined dendron structure and a unique biotin functionality. Immobilization of up to four copies of biotinylated dendrimer 5 to fluorescently labeled avidin yields a supramolecular avidin-biotin-dendrimer-Gd(III) complex. Validation of the complex in mice bearing ovarian cancer tumors demonstrates that the avidin-biotin-dendrimer targeting system efficiently targets and delivers sufficient amounts of chelated Gd(III) and fluorophores (e.g., Rhodamine green) to ovarian tumors to produce visible changes in the tumors by both MRI and optical imaging, respectively. Thus, the avidin-biotin-dendrimer complex may be used as a tumor-targeted probe for dual-modality magnetic resonance and fluorescence imaging.