A diagnosis of brain cancer is a terrible thing to hear. A patient is likely to become depressed, especially if diagnosed with a high-grade tumor. Depression is not only bad for the patient's peace of mind; however, a new study shows that clinical depression before surgical removal of the tumor can significantly decrease the survival rate of the patient after the operation.
Several investigators at the medical school, including neurosurgeons Matthew McGirt, Henry Brem and Alfredo Quinones-Hinojosa, recently published the results of a longitudinal study following over 1,000 patients diagnosed with astrocytoma, which is a cancer of specific brain cells called astrocytes.
A patient's prognosis for surviving brain cancer used to be based solely on the patient's age, the severity of the tumor and the functional capabilities of the patient. These novel results propose that preoperative depression may also be a survival indicator.
"There's a lot of data that shows mood disorders are important in outcomes across the board. This has to do with caregiver interactions, self-care, motivation for rehabilitation and taking ownership of one's health. There's no question that depression, in part, affects this. This manifests with an increased stress burden associated with the disease process, with both surgical and nonsurgical treatments. This association with depression has never been looked at it in brain tumors," McGirt said.
Between the years 1995 and 2006, over 1,000 patients participated in this study. Five percent of the subjects were diagnosed with clinical depression before the time of their surgery. Importantly, these patients received their diagnosis of depression before their brain tumors were found.
The main finding of this study was that the preoperatively depressed patients had a 40 percent increased risk of mortality post-surgery than the non-depressed patients. Additionally, this increased risk occurred regardless of treatment option, age, severity of tumor or the functionality of the patient prior to surgery.
Previous studies had examined the role of depression after surgery without preoperative diagnoses and had also seen an increased mortality rate in depressed patients. One major factor is that post-surgical depression affects a patient's quality of life, which in itself may influence the prognosis. Quality of life is an important consideration because the predicted lifespan of a patient diagnosed with a high-grade astrocytoma is about 15 months.
Another important finding from this study is that the greatest discrepancy between the mortality rate of depressed and nondepressed patients occurred after 12 months, which suggests that depression may effect the long-term recovery of the patient.
The results of this study show a clear association, which does not mean that there is a causal relationship between preoperative depression and survival rate. The authors assert that there are a lot of unknowns in the relationship between tumors and depression. For instance, a tumor might affect neural circuits involved in mood thereby leading to depression. Additionally, the authors postulated further mechanisms of association between tumors and depression, such as through the immune system. One disease state could make the patient more susceptible to the other.
Finally, the authors were unable to follow the psychopharmacological treatment of each patient's depression. They proposed that further research is needed to understand the difference between medicated and unmedicated depression patients in terms of post-surgical recovery.
"This is not a perfect study. But it does show a statistically significant decrease in survival in a depressed patient when taking into account known factors with survival. There are shortcomings associated with a retrospective study. How will this study change patient care? It raises awareness of the issue and leads to the design of a level one study that can more definitively prove a relationship," McGirt said.
