A study, carried out by researchers at Weill Cornell Medical College and published in the Annals of Oncology, found that copper depletion treatment has the ability to successfully prevent organs from receiving migrating cancer tumor cells - putting a stop to the spread of tumors.
The average survival time is 9 months for patients suffering from metastatic triple-negative breast cancer. However, the study found that patients who were at high risk of cancer recurrence and received copper depletion therapy - in the form of the drug tetrathiomolybdate (TM) - experienced an overall increase in survival time as well as a decreased risk of relapse.
The clinical trial began in 2007 and included 60 patients, of whom more fifty percent suffered from triple-negative breast cancer. However, the research from this report only looked at the first 40 patients involved in the study.
Only two of 11 participants who had a history of advanced triple-negative breast cancer relapsed within 10 months of being treated with TM. In addition, four of the participants experienced long-term benefits, living cancer free for between three and five and a half years.
According to the senior investigator of the study and director of the Breast Cancer Research Program, Dr. Linda Vahdat:
"These study findings are very promising and potentially a very exciting advance in our efforts to help women who are at the highest risk of recurrence.
The anti-copper compound appears to be keeping tumors that want to spread in a dormant state. We believe one of the important ways it works is by affecting the tumor microenvironment, specifically the bone marrow-derived cells that are critical for metastasis progression."
The progression-free survival rate among 29 patients with other forms of high-risk for relapse - such as stage 4 or stage 4 breast cancer - was also surprisingly good (at 85 percent to date).
However, Dr. Vahdat notes that the benefits of TM treatment can't be fully appraised until it's compared with other forms of therapy.
Copper depletion preventing cancer from spreadingRecent breakthroughs in the science of metastasis have improved our understanding of exactly how and why the human body uses copper - and the role it plays in the spread of cancers.
Researchers from Weill Cornell identified the important role bone marrow cells - in particular VEGFR1+ hematopoietic progenitor cells (HPCs) - play in metastasis. Studies show that they are responsible for preparing special sites in organs that accept and nurture migrating cancer cells, as well as inviting Endothelial progenitor cells (EPCs) which feed the cancerous cells.
Immediately before cancer relapse, the levels of EPCs and HPCs significantly increase. This indicates that targeting EPCs with copper depletion is viable. Copper is one of the key components of enzymes that control tumor microenvironment, as well as appearing to have a role in how cancer cells migrate.
Depleting copper decreases proliferation of EPCs.
Dr. Vahdat concludes:
"Breast tumors want to move to specific organs, and these EPCs and HPCs cells leave a 'popcorn trail' for cancer cells to follow, as well as provide the building blocks for blood vessels to greet them as they arrive.
There are a lot of cancer experts at Weill Cornell working very hard to understand this precise mechanism, define the clinical benefit in this ongoing copper depletion drug clinical trial, and determine its future study. Keeping cancer dormant is what we all want for our patients -- especially triple-negative breast cancer patients at highest risk of recurrence."
Written by Joseph Nordqvist