Tumor samples stored since the 1950s may help explain rising colorectal cancer in young people

Researchers will sequence tumor samples preserved at St. Mark's since the 1950s to compare historical and modern DNA signatures and investigate reasons for rising colorectal cancer among younger adults.

Researchers are preparing to analyze tumor samples that have been kept at St. Mark's National Bowel Hospital since the 1950s. Colorectal cancer rates have risen, especially among adults under 55, and scientists hope comparing older and modern tumors will reveal changes over time. The preserved specimens will be sent to the Institute of Cancer Research for genome sequencing and detailed molecular analysis. Medical advisers have reported common warning signs that clinicians monitor, including persistent changes in bowel habits, rectal bleeding, and unexplained weight loss. Key details: - St. Mark's has collected and stored tumor specimens in a basement archive since the 1950s. - The samples are fixed in paraffin wax and are due to be analyzed using genome sequencing at the Institute of Cancer Research. - Researchers plan to compare historical and contemporary tumors to identify DNA mutation patterns that could point to specific causes. - One leading hypothesis is damage linked to colibactin, a toxin produced by certain E. coli strains; the number of diagnoses among people under 55 has been reported to have nearly doubled in the last decade, according to the American Cancer Society. Summary: The genomic analysis of decades-old tumor samples aims to determine whether particular DNA signatures have become more common over time, which would narrow the list of possible causes for the rise in colorectal cancer among younger adults. Results from the sequencing will inform further research directions; the timing and outcomes of that follow-up work are undetermined at this time.