May 25, 2013 | by Nicole White
In an effort to predict, treat and cure disease, scientists are exploring the smaller ecosystems that exist within the body. The tumor microenvironment – the site and surroundings where tumor cells grow – can hold important clues to help predict which cancer patients are at highest risk of their cancer spreading. Even the pretumor microenvironment could hold clues, a new study suggests.
City of Hope scientists scoured the lymph nodes of lung cancer patients for signs of a “pro-metastatic environment,” and found some potential predictors that a patient will have a narrower chance of survival. The study, published online May 24 by the peer-reviewed, open-access journal PLoS One, analyzed lymph nodes of 67 patients whose lung cancer had not yet spread. Researchers found two distinct populations among the patients in the study – and significant differences in their survival rates.
“We looked at benign lymph nodes to see if a pattern was evident before a tumor was detectable, to see if there was a primed environment for metastases,” said Karen Reckamp, M.D., M.S. , associate professor in the Department of Medical Oncology & Therapeutics Research and co-chair of the Lung Cancer and Thoracic Oncology Program. Reckamp served as a co-senior author on the study. “It’s an interesting step toward understanding the tumor microenvironment.”
Patients in the study had stage I to III nonsmall cell lung cancer, which tends to be related to smoking. Those patients whose lymph nodes had both myeloid cell clusters (groups of blood-forming cells) combined with elevated levels of STAT3 (a protein that is highly activated in cancer cells) had significantly poorer survival rates than those without those factors.
The study also found that the presence of myeloid cell clusters alone were predictors of survival in patients with a history of smoking. Detecting these cells in lymph nodes could potentially serve as a novel method of informing therapy choices, if further validation studies pan out, Reckamp said.
Hua Yu, Ph.D. , professor in City of Hope's Department of Cancer Immunotherapeutics & Tumor Immunology, was co-senior author on the study and Wang Zhang, Ph.D., was first author.