Arturo Loaiza-Bonilla, MD, medical oncologist, specializing in gastrointestinal malignancies, assistant professor of Clinical Medicine at the University of Pennsylvania, discusses a clinical trial focused on the differences between left- and right-sided tumors of colorectal cancer (CRC).

The most recent data that have been presented regarding the sidedness of CRC has been investigated, explains Loaiza-Bonilla. Patients with right-sided CRC, regardless of the chemotherapy they receive, are going to have different survival outcomes compared with patients with left-sided tumors.

When looking at that data it is important to look for specific mutations, genomic alterations, or any molecular underpinning that may explain the reason as to why these patients have less effective outcomes, says Loaiza-Bonilla.

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Dr. Loaiza-Bonilla on Trial of Left- and Right-Sided Colorectal Cancer

Arturo Loaiza-Bonilla, MD, medical oncologist, specialized in gastrointestinal malignancies, assistant professor of Clinical Medicine at the University of Pennsylvania, discusses findings of patients with right- versus left-sided tumors of colorectal cancer (CRC).

Among the 250 samples from the University of Pennsylvania, there were 2 common genomic alterations that were statistically significant. The first was 

, which tends to have a worse prognosis compared with 

Most of the phase II and III clinical trials had not included next-generation sequencing as part of the biomarker test, due to more costly technologies and uncertainty as to which biomarkers are appropriate to test, explains Loaiza-Bonilla.

Dr. Loaiza-Bonilla on Right- Versus Left-Sided Colorectal Cancer

Arturo Loaiza-Bonilla, MD, medical oncologist, the University of Pennsylvania, discusses a study investigating differences in mutation rates between right- and left-sided colorectal cancer (CRC).  

The most recent data presented regarding sidedness of CRC has been the subject of much investigation, Loaiza-Bonilla explains. It is now known that patients with right-sided tumors have worse outcomes than patients with left-sided tumors, regardless of what type of chemotherapy they receive. This knowledge spurred researchers to question if anything besides sidedness contributes to this outcome.

To address this question, researchers at the University of Pennsylvania looked at more than 250 samples of targetable genes in patients with colorectal cancer and stratified the samples between right-sided tumors and left-sided tumors. They looked for specific mutations or genomic alterations that could explain why patients with right-sided tumors have worse outcomes.

Amongst the different genomic alterations, researchers found that 

mutations were the most common and statistically significant among the samples. Loaiza-Bonilla notes that BRAF mutations tend to have a worse prognosis than BRAF wild type tumors. This discovery is hypothesis generating, as it may explain, to some degree, why CRC patients with right-sided tumors may have different outcomes when treated with chemotherapy.

Arturo Loaiza-Bonilla, MD, medical oncologist, the University of Pennsylvania, discusses a study investigating differences in mutation rates between right- and left-sided colorectal cancer.

Arturo Loaiza-Bonilla, MD

Articles

Dr. Loaiza-Bonilla on Trial of Left- and Right-Sided Colorectal Cancer

Dr. Loaiza-Bonilla on Right- Versus Left-Sided Colorectal Cancer

Dr. Loaiza-Bonilla on Differences in Mutation Rates Between Right- and Left-Sided CRC