October 18, 2012
Depression, telomere length double-team bladder cancer patients
BY Katrina Burton
According to data from the National Cancer Institute's SEER database, less than 50% of patients with stage three bladder cancer will survive five years past their diagnosis.
Recent data presented at the11th Annual AACR International Conference on Frontiers in Cancer Prevention Research revealed shortened telomeres - a biomarker linked to aging - and depression significantly reduced bladder cancer patients' survival.
Telomeres are found on the tips of chromosomes and protect the chromosomes from damage, like the plastic tip on the end of a shoelace. They shorten as cells divide, eventually causing lethal genomic damage to the cell. When damaged cells survive, they can promote cancer development.
The data collected from 464 patients enrolled in MD Anderson's ongoing epidemiology bladder cancer study, showed a significant increase in mortality for patients who had high levels of depressive symptoms as well as short telomeres.
On the other hand, patients with low levels of depression - as indicated by the Center for Epidemiologic Studies Depression Scale (CES-D) - and long telomeres lived longer. The study found a six-fold increase in survival for these bladder cancer patients - 31.3 months vs. 199.8 months. Those with short telomeres and high levels of depression had a three-fold risk of mortality.
"We anticipated a strong association with combined shortened telomere length and high levels of depressive symptoms," said lead investigator Meng Chen, Ph.D., instructor of MD Anderson's Department of Epidemiology. "Patients who aren't treated for depression tend to exhibit anxiety and stress that increases the shortening of the telomere process." Naturally, most cancer patients are faced with a multitude of factors that can lead to high levels of depression. Treatment decisions and financial worries can be contributing factors. "This is the first study to examine psychological data in bladder cancer outcomes," said Chen.
The lifestyle factor Although bladder cancer is three times more likely to develop in men than in women, research has shown that some lifestyle factors contribute to the development of bladder cancer and may also play a role in increasing mortality risk.
Other research has directly linked smoking-cessation, exercise and a healthy diet to improved chances of preventing and surviving various cancers.
For this study, Chen and a team of MD Anderson epidemiologists, general oncologist and behavioral scientists also analyzed clinical and mental health data to compare the mortality rates of the four different groups.
Research has also linked lifestyle changes, mainly exercise, with lowering stress and reducing symptoms of depression.
"With this newly identified area of risk, it is important for clinicians to consider stress management and physiological factors when developing interventions and risk prediction models," said Chen.