Fortunately, prostate cancer has a significantly low mortality rate relative to other common cancers such as lung cancer. Therefore, it is important to distinguish the difference between what is call disease specific survival and biochemical freedom from recurrence.
Disease specific survival calculates the chances of actually dieing from prostate cancer. Only a small percentage of patients go on to die from widespread prostate cancer as a result of treatment failure. The range for most patients is generally about 2-7% at 10 years.
The PSA blood test is both a sensitive and specific marker that has been used to define failure. The biochemical PSA test, repeated at each follow-up visit should nadir to some level, meaning is should fall and then remain stable. If the PSA begins to rise on successive tests, then we call that a biochemical failure. Biochemical failure can be calculated using the nomogram tools and on average is about 15-20% for both IMRT or seed implants at 7 years. New Data appears to indicate that not all patients with a biochemical failure will go on to develop widespread metastasis. This is good news for some patients who may be observed. For others, salvage therapies such as hormone treatment may be indicated to prevent clinical recurrence.
It is important to understand that patients can experience a biochemical failure after radical prostatectomy, even when the surgical margins are clear. Use of the nomogram algorithm will help outline the risk of failure, but in general, there is overlap between the 3 main modalities: Brachytherapy, IMRT and surgery.
