Author Interviews, Colon Cancer, Genetic Research, Journal Clinical Oncology, MD Anderson / 18.08.2016
Molecular Subtyping of Rectal Cancers Can Guide Prognosis, Treatment and Future Screening
MedicalResearch.com Interview with:
Y. Nancy You, MD, MHSc
Associate Professor
Section of Colorectal Surgery
Department of Surgical Oncology
Medical Director
Familial High-risk Gastrointestinal Cancer Clinic
University of Texas MD Anderson Cancer Center
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Despite the progress in the treatment of many cancers, colorectal cancer (CRC) remains the third most common and lethal cancer in the US. Over 130,000 people are expected to be diagnosed and over 50,000 patients will die from CRC this year. In the recent years, the most exciting development has been our understanding of the molecular complexity of CRC.
Currently, four major molecular subtypes of colorectal cancer are recognized. Our study focuses on the Consensus Molecular Subtype 1, which accounts for up to 15% of CRCs, and is characterized by a deficiency in DNA mismatch repair (dMMR), a high level of mutations (i.e. hypermutated), by instability in parts of the genome called microsatellites, and by strong immune activation. Prior to our study, patients with rectal cancer that belong to this molecular subtype have represented an unknown, in terms of their prognosis, and how the tumors respond to current treatments. More importantly, this molecular subtype harbor a genetic condition that can be transmitted within the family called “Lynch Syndrome”. So we designed our study to fill these gaps in our understanding that exist in this subtype of CRCs and to highlight key clinical care issues related to the caring for patients with a genetic syndrome.
The main findings are that rectal cancers belonging to this molecular subtype have favorable prognosis, respond well to standard chemoradiation, and are linked to Lynch Syndrome and should be treated at centers with expertise in hereditary cancer syndromes. (more…)