April 29, 2011
Stress Affects Cancer Survival?
(Ivanhoe Newswire) -- Research shows chronic, prolonged stress suppresses our immunity and makes us vulnerable to illness and disease. What's more, in cancer patients this stress can have an effect on a tumor's ability to grow and spread. Now, researchers at Fox Chase Cancer Center have discovered that poor psychosocial functioning is connected with greater vascular endothelial growth factor (VEGF) expression.
"There is research showing that high VEGF expression in other cancers, such as ovarian, is associated with psychosocial factors," Carolyn Fang, Ph.D., Co-Leader of the Cancer Prevention and Control Program at Fox Chase, was quoted as saying. "This information coupled with what we already know about VEGF promoting tumor aggressiveness and poorer prognosis in head and neck cancer patients, certainly gave us a reason to look at this biomarker."
VEGF not only performs a crucial function in angiogenesis, but it is also synchronized by stress hormones and key cytokines -- small cell-signaling protein molecules that are secreted by the glial cells of the nervous system and by numerous cells of the immune system and are a category of signaling molecules used extensively in intercellular communication.
In the present study, Fang and colleagues observed 37 recently diagnosed, pre-surgical head and neck cancer patients to determine if psychosocial functioning, such as perceived stress and depressive factors, was connected with VEGF. The patients were primarily male (70.3 percent) and just about 57 years old, with chief tumor sites of the oral cavity (65.9 percent), larynx (19.9 percent), and oropharynx (13.5 percent). More than 40 percent of them were classified as having early-stage disease.
Each of the patients were given a psychosocial feedback form to finish prior to the treatment, which ultimately required them to respond to questions regarding social support, depression, and perceived stress. Additionally, VEGF expression in tumor tissue acquired throughout surgery was assessed via immunohistochemistry -- the process of detecting antigens (e.g., proteins) in cells of a tissue section by exploiting the principle of antibodies binding specifically to antigens in biological tissues.
"Our analysis indicated that higher levels of perceived stress and depressive symptoms were associated with greater VEGF expression in the tumor tissue of these patients," says Fang. Greater VEGF expression was, in turn, connected with shorter disease-free survival amongst patients.
The links relating psychosocial functioning and VEGF were strong amid early-stage patients; however, they were less evident among late-stage patients.
"It's possible that in early stage disease, psychosocial stress makes patients more susceptible to cancer-related death, while in patients with advanced disease, other factors become more important in determining outcome," Miriam N. Lango, M.D., Medical Director of Speech Pathology Service and Attending Surgeon in Head and Neck Oncology at Fox Chase, was quoted as saying. "In patients with advanced cancers, psychosocial interventions may have less of an impact since these cancers are inherently more aggressive."
In the near-term, Fang along with her colleagues anticipate the expansion of the study to further observe a larger sample of patients in addition to incorporating more signaling pathways that are related to cancer, such as EGFR, which researchers involved in Fox Chase's Keystone Program in Head and Neck Cancer are currently investigating.
"The next step is to conduct a longitudinal study that would allow us to examine patient psychosocial functioning in conjunction with biomarkers of disease aggressiveness and survival from pre-treatment through post-treatment and beyond, which would give us a more complete picture of how these factors may contribute to patient outcomes," Carolyn concludes.
SOURCE: 32nd Annual Meeting & Scientific Sessions of the Society of Behavioral Medicine on Thursday, April 28, 2011