The article in CLP Magazine, authored by Moshe Szyf, PhD, discusses the potential of epigenetics, particularly DNA methylation, in advancing cancer detection. Early cancer detection is crucial for reducing morbidity and mortality, but current methods like imaging and antigen-antibody screens have limitations in sensitivity and specificity, especially in early stages. DNA, with its resilience and role in physiological and pathological functions, offers a promising avenue for cancer screening.
DNA mutations and alterations in DNA methylation are hallmarks of cancer. These changes occur early in cancer progression and are present in nearly all cancers. DNA from dying tumor cells leaks into the bloodstream, but distinguishing this tumor-derived DNA from other sources is challenging. Research is focused on detecting cancer-specific mutations and changes in DNA methylation to identify cancer-derived cell-free DNA.
Several approaches are being explored, including targeting genes known to be differentially methylated in cancer, like the SEPT9 gene for colorectal cancer. Genome-wide DNA methylation data and machine learning techniques are used to develop blood tests capable of detecting over 50 types of cancer. These tests show high specificity and varying sensitivity across cancer types and stages.
One of the main challenges is the variable background of non-cancer DNA. Identifying positions in DNA with categorical differences in methylation between cancer and normal tissue is crucial. This approach has been used in developing tests like HKG’s epiLiver for early liver cancer detection.