Breast cancer was divided into ten types instead of three
The new classification of breast cancer includes 10 subtypes of the disease
According to scientists, this classification will make a breakthrough in the diagnosis and treatment of this disease. Details are set out in the journal Nature (The genomic and transcriptomic architecture of 2,000 breast tumours reveals novel subgroups).
Currently, oncologists distinguish 4 subtypes of breast cancer depending on its response to hormone therapy (ER-type) or trastuzumab /herceptin therapy (HER2-type) – the reaction can be negative (–) or positive (+). The most common subtype is ER+ / HER2– (70 percent of all cases breast cancer). 7.5 percent each accounted for ER+ /HER2+ and ER– /HER2+. The remaining 15 percent is the so–called "thrice negative" subtype (ER and NONR2-negative, as well as negative when exposed to progesterone receptors) – the most severe and aggressive form of cancer that is poorly treatable. It was 70 percent of the cases included in the first subtype of breast cancer that interested the researchers. Among this huge number of patients, there are those who will respond better to therapy, and those who will respond worse, and those whose chances of survival are higher or lower. Hence the need to develop an additional classification.
The basis for the new classification was the largest genetic study of breast tissue affected by cancer. Researchers from the UK and Canada analyzed 2,000 samples of affected tissue taken from women diagnosed with breast cancer 5-10 years ago. They assessed gene expression and the presence of genetic mutations in each sample and compared them with the long-term survival of patients. As a result, scientists were able to identify 10 subtypes of the disease. At the same time, 7 out of 10 new subtypes guarantee the survival of 80 percent of patients for 15 years. The survival rate for the remaining 3 subtypes is less than 40 percent.
During the study, scientists also discovered new genes associated with the development of breast cancer. Some of them, such as kinases and phosphatases, may become a new target for the development of modern drugs for the treatment of cancer. "We managed to look at the problem of breast cancer with new eyes," says one of the authors, Carlos Caldas from the Department of Oncology at the University of Cambridge (Cambridge University), Great Britain. "Now we know that each of the 10 subtypes of cancer has its own unique genetic "fingerprints" that will help to correctly diagnose and treat the disease, as well as give the correct prognosis."
Portal "Eternal youth" http://vechnayamolodost.ru19.04.2012