In a breakthrough finding, recent research concluded that nearly 20 percent of all cases of the most severe form of breast cancer may originate from the small group of normal tissue cells carrying an epimutation of a specific gene. The study was conducted by investigators at the University of Bergen, in association with the US Women’s Health Initiative.
Cancer is one of the major health threats faced by the world today. According to a study published in BMJ Oncology journal last September, more than a million people below the age of 50 years die of cancer every year.
Early Gene Change Associated with Breast Cancer – Study Reveals
The most alarming part is that there will be a 21% spike in this number by 2030. If we take into account the total number of cancer cases and related deaths, breast cancer tops the list with 13.7 and 3.5 occurrences per 100,000 of the population across the world, respectively.
Scientists have been deeply examining both genes and the environment, in an attempt to determine what sets the stage for cancer.
As part of the study conducted at the University of Bergen, “epimutations” were also researched. It is based on changes in how human genes are turned on or off rather than changes to the actual genes.
Latest Discovery And Research On Breast Cancer
In the new study, the researchers also found a link between certain epimutations in a gene known as BRCA1 and an elevated risk of the most severe form of breast cancer termed triple-negative breast cancer (TNBC).
According to Per Eystein Lønning, professor at Section of Oncology, University of Bergen, a higher risk was found despite the fact that epimutations affected a very minor part of normal cells in the affected persons.
The new study is already featured in the journal Genome Medicine by the Bergen Group. It will also be presented at the international SABCS to be held on December 6, in collaboration with other Norwegian researchers. To explain, SABCS stands for The San Antonio Breast Cancer Symposium, an annual event cosponsored by UT Health San Antonio’s Mays Cancer Center and the AACR.
As part of the study, the BRCA1 methylation status in breast cancer tissue was analyzed and it was matched with white blood cells collected from 408 patients. Out of these, 411 were primary breast cancers. The most interesting part was that concordant tumor and mosaic white blood cell BRCA1 epimutations were found in 10 out of 66 patients with triple-negative breast cancer.
Thus, it may be concluded that 20% of the total cases of TNBC may arise from the small group of normal tissue cells carrying BRCA1 epimutations. The other important finding was that epimutations in the white blood cells and tumor tissue from the same person display the same profile, thus pointing to a common cell origin, possibly happening in the very early stages of pregnancy.
The research also points to the information that these epimutations might occur twice as commonly in girls when compared to boys and might happen early during pregnancy.
Though the the exact causes of these BRCA1 epimutations are yet to be fully known, prenatal BRCA1 epimutations may originate through gender-related mechanisms in utero, without any dependence on Mendelian inheritance.
The latest discovery is also opening further avenues for research. The Bergen Breast Cancer Group is currently working on the exact mechanism of early life epimutations. Furthermore, their other study, in collaboration with WHI investigators is checking out whether epimutations in other genes might be linked to other types of cancer.
While commenting on this matter, Lønning said that understanding this could potentially be a game-changer in how they approach and prevent cancer in the future.
Though there are different types of breast cancer, the most common among them are Invasive ductal carcinoma and Invasive lobular carcinoma. In the case of Invasive ductal carcinoma, the cancer cells start from the ducts.
Later they grow outside the ducts and spread into other parts of the breast tissue. When it comes to Invasive lobular carcinoma, cancer cells start with the lobules and then spread into the breast tissues that are nearby. The other types of breast cancer that are less common include Paget’s disease, medullary, mucinous, and inflammatory breast cancer which is lesser known.