Gastrointestinal Cancer

Lynch syndrome (also known as hereditary nonpolyposis colorectal cancer or HNPCC) is an autosomal dominant hereditary cancer syndrome associated with germline mutations in the mismatch repair genes, MLH1, MSH2, MSH6, and PMS2. Deletions within the 3' end of the EPCAM gene, which lead to inactivation of the MSH2 promotor, have also been associated with Lynch syndrome.

This “Specialty Testing” webinar will describe the utility of microsatellite instability testing in colorectal cancer care and discuss the limitation of various assays used to diagnose microsatellite instability.

Fewer than half the people found to have colorectal cancer are diagnosed at an early stage, when treatment is most effective. New therapies can reduce tumor size and prolong life, but they can also be costly and not work as intended. The results and interpretations from our laboratories provide clinically actionable results to guide treatment selection, ensuring every patient receives the medication most appropriate for care. In addition to guiding treatment, our testing also assesses risk for developing hereditary cancer syndrome.

Targeted cancer therapies are defined as antibody or small molecule drugs that block the growth and spread of cancer by interfering with specific cell molecules involved in tumor growth and progression. Multiple targeted therapies have been approved by the US Food and Drug Administration (FDA) for treatment of specific cancers. Molecular genetic profiling is often needed to identify targets amenable to targeted therapies and to minimize treatment costs and therapy-associated risks.

Rondell P. Graham, M.B.B.S., gives an overview of this test available through Mayo Clinic Laboratories. He discusses when this testing should be ordered, how this testing improves upon previous testing approaches, what clinical action can be taken due to the results of this testing.

This week’s Research Roundup highlights the detection of gastric cancer with novel methylated DNA markers: discovery, tissue validation, and pilot testing in plasma.

This week’s Research Roundup highlights the role of deficient DNA mismatch repair status in patients with stage III colon cancer treated with FOLFOX adjuvant chemotherapy.

This week’s Research Roundup highlights Mayo Clinic researchers who conducted a study to characterize the clinical, pathologic, and survival implications of non-V600 BRAF mutations in metastatic colorectal cancer.

Insights gained from algorithms should be shared with clinicians as a way to improve patient care, increase efficiency, and reduce costs.

An algorithm is a step-by-step procedure to guide clinicians and laboratorians in appropriate laboratory test ordering.