Breast cancer is the most frequent type of cancer in women. Even though mammography is an excellent screening tool, it may still not be enough for early detection of breast cancer. Could there be any other form of early identification?
Scientists discovered that dissemination of cancerous cells starts at the very early stages. This means that they can be found in the blood. Taking advantage of this event, these cells’ DNA can be a tool for identifying breast cancer even a year prior to the manifestations that could be detected by the mammogram!
A story about methylated DNA
At first, they took samples of cancerous tissue and White Blood Cells (WBC) in order to extract DNA. Then, using Reduced Representation Bisulfite Sequencing (a method that cuts DNA into specific segments, then sequences it) together with PCR and methyltransferases (in order to maintain the methylation sequences) they found tumor-specific methylation patterns (18 to be exact). And one of them is the region called EFC#93. Methylated DNA has now entered the discourse. But what even is a methylation pattern?
Our DNA has some regions called CpG islands – regions formed of cytosine followed by a guanine that repeats every few bases. A methyl radical can be attached to these C-G repeats, forming methylation patterns. EFC#93 contains 5 C-Gs. Some of these patterns are specific to cancer cells (the more methylated ones) and some are WBC specific (the less methylated). This is important, because in the bloodstream, the most cell-free DNA comes from WBC, and it is necessary to have a clear distinction between them.
The scientists then compared these results to DNA extracted from the serum of cancer patients and discovered a correlation between the presence of EFC#93 methylation pattern and the disease prognosis. If present, the prognosis is unfortunately worse. Furthermore if Circulating Tumor Cells (CTCs) are also present, the chances of survival become less and less favorable. But it is not just bad news! EFC#93 presence in seemingly healthy people could indicate a very early diagnosis of breast cancer, thus enabling earlier diagnosis and treatment.
If you found this article interesting and want to take part in shaping the future, stay tuned and stay curious with us! Read the full text here. See ya’ later!
About the author…
Hi, my name’s Teodor, a second year medical student. I am a science enthusiast, amateur speedcuber, and hardcore metalhead.