Breast cancer cells could spread to other parts of the body even before the primary tumor develops, reports a recent study.
The researchers from University of Regensburg in Germany and Icahn School of Medicine at Mount Sinai who worked independently in two different studies carried out series of experiments to discover that breast cancer cells with few molecular alteration disseminate to other organs of the body before the primary tumor is fully developed. The cells that spread to other organs remain dormant for a long time and cause metastases up on activation.
Spread Of Early Stage Cancer Cells
In the studies that dealt with breast cancer metastases, the scientists from University of Regensburg noted that to be able to result in dissemination and metastases, the cancer cells needn't be overtly evolved, extensively mutated or pathologically defined as invasive tumors. In contrast, the cells from early stage cancer that are generally considered incapable of disseminating could result in metastases.
Meanwhile, the team from Mount Sinai found that the movement of breast cancer cells from mammary glands to lungs and other organs involves a mechanism of switching on and off of an oncogene and a suppressor.
Mechanism Of Breast Cancer Metastases
Julio A. Aguirre-Ghiso, the senior investigators of the study noted that the current research has given an insight on the mechanism involved in breast cancer metastases that is caused as a result of dissemination of early stage cancer cells. The researcher added that the study also answers the long held question on how about 5 percent of breast cancer patients in the world suffer metastases without developing original tumor.
The discovery challenges the concept of metastases that is believed to have been understood by far, added Aguirre-Ghiso. Experts might have to adjust their understanding on the spread of cancer and mechanism of metastases, which could help in coming up with better treatment options.
Tumor Suppressor P38 And HER2 Oncogene
The treatments like chemotherapy and radiotherapy that are targeted at proliferative cancer cells don't kill or destroy the early stage cancer cells that remain dormant in other organs. The turning off of the tumor suppressor p38 and switching on of HER2 oncogene is found to cause the spread of early stage cancer cells through the branching of milk ducts in female breasts.
"The best explanation for this phenomenon is that early metastasis occurs before or as DCIS [ductal carcinoma in situ] develops. A key finding from this second paper is that in the mouse models, 80% of metastasis originated from the early spread cells and not from the large tumors," noted the researchers, in a press release.
The studies were published in the journal Nature on Dec.14.