A new study by the Mayo Clinic has found that colorectal cancer can be driven by an inherited gene mutation – with one in six colon cancer patients found to have this.
This suggests that colorectal cancer can be passed down through different generations, with some patients ‘predisposed’ to the disease.
The study, which is published in Clinical Gastroenterology and Hepatology, also discovered 60% of the gene-linked cases would ‘not have been detected’ if relying on the usual ‘standard guideline-based approach’.
During the project, patients were tested with a sequencing panel that included over 80 cancer-causing or predisposing genes – standard panels for colorectal cancer typically include 20 or fewer genes.
The Mayo Clinic’s research looked at gene variants that patients were born with and found that they can ‘set off a cycle of events’ that lead to cancer. Other factors that can lead to mutations may include smoking, cancer, and environmental reasons.
It’s hoped that finding hereditary cancer mutations in patients could lead to more family members pursuing earlier disease detection. In this study, all blood-related family of participants were offered free genetic testing – but just 16% took up the offer.
Dr Niloy Jewel Samadder, the study’s senior author, said: “We found that 15.5% of the 361 patients with colorectal cancer had an inherited mutation in a gene associated with the development of their cancer.
“We also found that over 1 in 10 of these patients had modifications in their medical or surgical therapy based on the genetic findings.
“Though the most common mutations were found in genes typically associated with colorectal cancer, we found that a substantial number of mutations were present in genes typically associated with breast and ovarian cancer,” he continued.
“This may lead to novel targeted therapies based on the cancer’s unique genetic basis. For example, where a breast cancer drug can be used in a patient with colon cancer.”
He added: “The power of genetics is that we can foresee the cancer that will develop in other family members. This can allow us to target cancer screening to those high-risk individuals and hopefully prevent cancer altogether in the next generation of the family.”
Find out more about the research – and the larger cohort INTERCEPT study it was part of – at mayoclinic.org.