March 29, 2011

The numbers can drive you crazy

The PSA (Prostate Specific Antigen), the primary marker used to diagnose, track and manage a patient with prostate cancer is at best a confusing indicator. There are men dealing with advanced PCa that have low PSA and high levels of pain. There are men like me that have high PSA and little to no pain. Then there are cases everywhere and in between.

Another idiosyncrasy regarding the PSA test is the differences in labs. Since I started this journey I have always been advised to stick to one lab, due to the variances in the processing between labs.  My current state is a perfect example. In January I began traveling to Atlanta as part of a clinical trial for a promising drug called Abiraterone. To date I have had three PSA tests in Atlanta and each time I have had a PSA five days later as part of my routine, monthly Oncologist visit in Kansas City.  The differences in the tests are reflected in the table below:

Date:     KC                         Atlanta:
1/27      349                         200
2/24      356                         250
3/24      403                         293

As you can see, not only does the overall number vary greatly, the percentage of change is completely different. As a patient this can drive you crazy, believe me! Mary is particularly frustrated with the lack of explanation and frankly, concern with respect to the variance in test results between the locations. However, we have repeatedly questioned it and been reassured by both doctors that it is standard practice to have a variance, sometimes even significant variance between labs. At this point in time, we don't have much choice but to accept it. Looking only at Atlanta the encouraging aspect is the trend line is slowing. January to February my PSA increased by 25% month over month. February to March my PSA increased 17%.  Looking at my KC PSA scores the January to February, the increase was only 2%. February to March my PSA went up 13%.

What does all this mean? Where does it lead? No where really. Since entering the clinical trial back in January we agreed that aside from a crazy increase (perhaps doubling) in either my PSA or excessive symptoms (pain), we would give it six months as recommended by Dr. A. With the trend slowing and pain mostly non-existent we stay the course for at least another month and God willing much, much longer. Patience is a virtue.  We are just anxious to see the PSA decrease to signal to us that we are finally successfully managing the cancer.


LeftTenant said...

You are my hero, David. Man, you've been through a lot with our old sidekick "C".

Serenity now, day at a time. God hasn't even created tomorrow, so who am I to worry?

Thank you for sharing your journey and inner conversation.

Anonymous said...

David , It is my understanding that it can take 3 months to work.
Those different labs look very frustrating as it seems something is wrong there they are so far off.
What is your testosterone doing on abby?
I am glad you are asymptomatic.
Know that you are always in my Prayers .
Thanks for sharing your Journey and thoughts. Your attitude is amazing.
Dan J

Anonymous said...

Thank you for posting your comments on the trial. I am considering this drug as my next treatment step. Your comments are extremely helpful! My thoughts and prayers are with you!

Merle said...

Wow David who'd think there would be such variability in the numbers. It makes the analysis much more difficult. I'm glad your pain levels are reduced. Mine are headed up and I've doubled my Oxycotin and still addign Oxycodone on top to knock the pain down. I'm taking a treatment break for a few weeks to give my body a chance to rest. Good luck to you on the trial.