A group of Canadian researchers have decoded the genetic structure of metastatic lobular breast cancer. This major breakthough could lead to further advancement in the fight against the disease by assisting scientists in the development of new breast cancer treatments and therapies. In all, the analysis uncovered 32 separate mutations of a tumor, with at least 5 of them never having been associated with cancer before. Their report can be found in the journal Nature.

According to the researchers, their mapping method may be a tool that can be used prior to the beginning of treatment of certain types of cancer, as well as to monitor patient progress. In a statement, lead researcher Dr. Samuel Aparicio, head of the breast cancer research program at the British Columbia Cancer Agency, “This is a watershed event in our ability to understand the causes of breast cancer and to develop personalized medicines for our patients. The number of doors that can now be opened to future research is considerable.”

The breast tumor examined by the research team came from patient with estrogen-positive cancer.

This type of cancer accounts for about 15 percent of all breast tumors. By comparing samples from the patient’s original biopsy to a tumor that spread (metastasized) 9 years later, the researchers were able to identify a total of 32 mutations including 19 that were not present in the original tumor. The researchers also tracked mutations in the woman’s healthy cells for purposes of comparison.

Study co-author, Dr. Marco Marra of the cancer agency’s Genome Sciences Center stated, “This study demonstrates the remarkable capacity of next-generation DNA sequencing technology.” He went on to explain, “The project that decoded the first human genome in 2001 took years and an enormous amount of funding. We were able to sequence the breast cancer genome in weeks and at a fraction of the cost.” Aparicio predicts that gene sequencing will cost increasingly less and eventually take only “a matter of days,” which will allow doctors to customize future treatments to each individual patient.

According to the research report, “the ability to analyze both the original and the metastatic cancer cells has given us unprecedented information about how breast cancer develops and progresses.” Aparicio noted that one key finding was “not only that the primary cancer evolved a lot, but the primary tumor was a mosaic of different mutations which then increased over time.” He said that the new knowledge will lead to advancements in cancer testing and treatment, as it shows that cells within a tumor are not all the same, and each type of cell could respond differently to treatment.

In the statement, the agency pointed out that a normal cell divides as lifelong process, and its DNA genetic code gets copied to each new cell. However, when mutations cause the new cells to begin growing out of control, cancer can occur.

Breast cancer is the most common form of cancer, and the leading cause of cancer death among all women. The disease will be diagnosed in 1.2 million women worldwide this year alone, and will claim 400,000 lives.

By: Drucilla Dyess