Colorectal cancer (CRC) is the third most common type of cancer diagnosed in the United States. Approximately 147,950 cases will be diagnosed in 2020, with a rising incidence being found among younger adults. This is one group of cancer that can be prevented with a screening colonoscopy. Early stages are typically cured with surgery. In advanced stages, treatment differs between rectal and colon cancers. By working with multidisciplinary treatment teams, advanced stages can be controlled, and in some cases even cured. In addition to standard of care chemotherapy, patients’ systemic treatment options can include targeted therapy and immunotherapy.
Systemic Therapy
Personalized systemic therapy for advanced stages has developed in the recent years, leading to tumor-agnostic FDA-approvals of treatments such as pembrolizumab for tumors with microsatellite instability-high (MSI-H) or mismatch repair deficiency (dMMR) in 2017, and lactrectinib and entrectinib for neurotrophic tyrosine receptor kinase (NTRK) gene fusion tumors in 2018 and 2019.
Targeted Therapy
Using targeted therapy against tumor genetic mutations that may be driving the tumor growth is a key option for systemic therapy to treat advanced CRC. This treatment targets the specific genes, proteins or tissues contributing to the tumor growth. Bevacizumab and ramucirumab targeted vascular-endothelial-growth-factor-receptor (VEGFR), cetuximab and panitumumab targeted epidermal-growth-factor-receptor (EGFR), and vemurafenib targeted BRAF mutation, are used in combination with systemic therapy to treat advanced CRC.
Immunotherapy
The immune system helps the body fight infections and other diseases. Immunotherapy fights cancer cells. By stimulating or boosting the natural defenses of your immune system, it works harder and smarter to find and attack cancer cells. We also can develop substances in the lab that act like immune system components and use them to help restore or improve how your immune system works to find and attack cancer cells.
Pembrolizumab is an immune checkpoint inhibitor, a type of immunotherapy that works to treat CRC by releasing the patient’s own natural immune system to fight cancer cells. Five to 10% of CRC patients who have MSI-H can receive immunotherapy. Researchers are working on combining immunotherapy with other therapy to treat the percentage of CRC patients without MSI-H. Vaccines to keep CRC from coming back are also being developed.
The overall survival rate for patients with CRC has increased due to improved treatment options and delivery of care. At UT Health East Texas, each patient with CRC will have a personalized plan of care formulated for them, utilizing a multidisciplinary team approach and innovative treatment options.
Information provided by Alexandria Phan, MD, FACP, at UT Health North Campus Tyler MD Anderson Cancer Center – Hematology, Oncology and Radiation Oncology. For more information, visit UTHealthEastTexas.com or call 903-596-DOCS.