By studying the cannabilistic tendency of cancer cells, my research team has made some progress in finding out why.

The chances of recurrence and disease outcome vary with cancer subtype. About one-third of patients diagnosed with triple negative breast cancer, the most aggressive subtype, may experience a recurrence in another part of the body. This is called distant recurrence.

It has been difficult, if not impossible, to predict if and when the same cancer will recur and to stop it. Recurrent disease may arise from just a single cancer cell that survived the initial treatment and became dormant. The dormancy allowed it to hide somewhere in the body, not growing or causing harm for an unpredictable amount of time.

Determining what puts these dormant cells to sleep and what provokes them to wake up and begin multiplying uncontrollably could lead to important new treatments to prevent a demoralizing secondary cancer diagnosis.

Recently, my research team and I uncovered several clues that might explain what triggers these breast cancer cells to go dormant and then reawaken. We showed that cell cannibalism is linked to dormancy.

How do bone stem cells affect breast cancer?

Breast cancer can recur in the breast or in other organs, such as the lungs and bone. Where breast cancer decides to grow depends largely on the microenvironment. This refers to the cells that surround it, including immune cells, cells comprising blood vessels, fibroblasts and the select proteins they produce, among other factors.

Over a century ago, a surgeon named Stephen Paget famously compared the organ-specific prevalence of cancer metastasis to seeds and soil. Because breast cancer often relapses in bones, in this metaphor, which still holds forth today, the bone marrow provides a favorable microenvironment (the soil) for dormant breast cancer cells (the seeds) to thrive.

Just as seeds need soil to provide an environment for growth, cancer cells need an environment to grow. From http://www.shutterstock.com

Thus, a substantial amount of recent work has involved trying to determine the role in cancer dormancy of a special type of cell, called mesenchymal stem cells (MSCs). These are found in bone marrow.

MSCs in bone marrow are highly versatile. They are able to form bone, cartilage and fibrous tissue, as well as cells that support the immune system and formation of blood. They are also known to travel to sites of tissue injury and inflammation, where they aid in healing.

Breast cancer cells readily interact with MSCs if they meet in the bone marrow. They also readily interact if the breast cancer cells recruit them to the site of the primary tumor.

My research team and I recently focused on potential outcomes of these cellular interactions. We found an odd thing happens, which may provide insight into how these breast cancer cells hide for a long time.

In the laboratory setting, we produced breast tumor models containing MSCs. We also re-created the hostile conditions that naturally challenge developing tumors in patients, such as localized nutrient deficits caused by rapid growth of cancer cells and overcrowding.

See more here:
How 'Cannibalism' By Breast Cancer Cells Promotes Dormancy: A Possible Clue Into Cancer Recurrence - IFLScience