Tumor Volume and Prostate Cancer
by William J. Catalona, MD
Even when the pathology report after a radical prostatectomy states that it looks like all of the cancer was confined to the prostate gland, some percentage of men have a recurrence of the cancer at a later date.
In these instances, although it looks as if the cancer is organ-confined; in fact, some cancer cells have spilled out but they can't be measured or detected at the time of surgery.
Being able to predict whether the cancer might recur at a later date, in instances when it looks as if the cancer was confined to the prostate gland, is a goal of follow-up treatment and practices.
One factor to help in making the predictions regarding non-recurrence or recurrence is the tumor volume, which is measured as the percentage of the prostate involved by the tumor.
My research group completed a study on my 3,000 plus radical prostatectomy patients to see if tumor volume can predict the frequency of recurrence of the cancer in those patients whose pathology reports showed the cancer to be confined to the organ.
We found that the tumor volume estimate is an independent predictor of possible cancer progression (recurrence) after a radical prostatectomy (RP) in patients with organ-confined prostate cancer.
An independent predictor means that we can look at that tumor volume and make a prediction without considering any other factors or conditions.
"Predicting whether cancer might recur is a goal of follow-up practices."
In our studies, we found the following:
The 5-year progression-free survival rates were as follows
The 10-year progression-free survival rates were as follows:
Clearly, tumor volume is a predicator of non-recurrence or recurrence of prostate cancer after the prostate is removed.
At the present, this tumor volume information does not make a practical difference in post RP treatment except to ensure that men are vigilant about coming back for their follow-up visits.
Some men want to forget that they had cancer and are afraid of getting follow-up PSA tests.
However, if there is a recurrence, salvage radiotherapy can sometimes cure the cancer if one does not wait until the PSA has risen to a high level.
Accordingly, I tell my patients the good news is that their tumor appears to be completely contained within the prostate gland; however, I add that it was a large-volume tumor and we know from past experience that they have a higher risk for recurrence.