IMRT only without radical prostatectomy

Born Jul 1961 in Hawaii of Japanese descent. No PSA screening. Made appointment with PCP because of problems urinating. After abnormal DRE, she ordered PSA test and referred me to urologist. PCa was diagnosed Feb 2014 (PSA 56, Gleason 4+4 in 4/4 left cores PNI, 3+3 in 3/4 right cores, stage T2c with negative bone and CT scans). Started neoadjuvant ADT Mar 2014 (bicalutamide 50mg + leuprorelin 30mg at four month intervals), IMRT (80Gy in 40 fractions including seminal vesicles and lymph nodes May 2014 - Jul 2014) with continued hormone suppression for one year (last injection Nov 2014) reduced PSA (63ng/ml Mar 2014, 0.15 May 2014, <0.01 every two months until 0.02 Aug 2015) and total T (2.5ng/ml Mar 2014, 0.10 May 2014, similar every two months until 0.62 Aug 2015). Then another one year on ADT (first injection Aug 2015) reduced PSA to <0.01ng/ml and total T to 0.20ng/ml). Last injection for this second round of androgen deprivation therapy is next month.

Other: tamulosin 0.4mg for urinary retention, oxybutynin 5mg for urge incontinence after IMRT, CPAP to treat obstructive sleep apnea, bupropion XL 450mg for depression (possible side effect of the ADT?), BMI 47, cholesterol 210, triglycerides 169, fasting glucose 112, hypertension (amlodipine 5mg + losartan 100mg + hydrochlorothiazide 12.5mg).

My urologist at Kaiser and the second opinion at Johns Hopkins both recommended IMRT alone since the probability was low that prostate cancer was confined to my prostate (I also calculated probabilities with pretreatment Kattan and Partin nomograms) and the significant toxicity associated with prostatectomy followed by external beam radiation. I know there is disagreement, but the majority opinion appeared to advise avoiding such toxicity if there was a high probability of positive surgical margins. Of greater relevance to how I handle stress and my reaction to local anesthesia than PCa treatment, I did not suffer any adverse reaction after transrectal ultrasound-guided needle biopsy (TRUS) but I passed out after fiducial markers were placed in my prostate by the radiation oncologist. I assume this was orthostatic hypotension caused by anxiety since I had a similar incident during blood donation 30 years ago. I was evaluated in the emergency room and released after a few hours.

Questions after reading clinical literature:

1. Why is radiotherapy described as "definitive" or "with curative intent" when the treatment is unlikely to eliminate the cancerous cells or to cure disease?

2. When high risk patients are likely to have micrometastasis and extracapsular extension already, why is their prostate cancer described as "locally confined"?

3. What are the differences between "locally confined" and "locally advanced" since both appear to be applicable (perhaps an incorrect assumption) for high risk patients staged at N0 M0?

4. Is there consensus on when to begin salvage treatment with respect to increased PSA values from nadir and PSA velocity over several tests?

Although I know good, clinical studies of high risk patients treated with escalated dose IMRT have not yet been done, my admittedly selfish interests are in cases like mine: effectiveness of intermittent ADT, prognosis after biochemical or clinical relapse, what to do after progression to hormone resistance and metastasis, and disease specific survival.

2 Replies

oldestnewest
  • Gary,

    You have asked some very interesting questions which I will take a stab at answering.  I might not correct, but here goes:

    1. Why is radiotherapy described as "definitive" or "with curative intent" when the treatment is unlikely to eliminate the cancerous cells or to cure disease?

        I believe that radiotherapy is described as being curative in two different disease states.  The first is when the cancer is 100% contained within the gland.  At this stage the radiation is used as primary treatment and is used for curative effect.  The second is post surgery failure, also with a curative intention. If the cancer reoccurs as demonstrated by PSA only (aka biochemical recurrence) the hope is that at this very early stage of recurrence (locally advanced) that radiation to the surrounding tissue could damage any left over cancer cells that might have escaped to the surrounding tissue or to any prostate gland tissue that might have been left behind.

     

    2. When high risk patients are likely to have micrometastasis and extracapsular extension already, why is their prostate cancer described as "locally confined"?

          I have never heard that term, but my guess of this terminology is that it is the same as locally advanced where the escaped cells have not yet moved beyond the immediate tissue from the prostate bed, thus they are still local to the prostate bed.  The hope is that by treating the local area with radiation post surgery the cancer can be stopped.  In reality, we don't yet have an effective way to be sure that the cancer is in fact still confined to this local area.  Our scanning technology is just not yet up to that task.

    3. What are the differences between "locally confined" and "locally advanced" since both appear to be applicable (perhaps an incorrect assumption) for high risk patients staged at N0 M0?

             Localized prostate cancer (I am not sure if this is the same as your term locally confined) means that the cancer is confined within the prostate. Locally advanced prostate cancer means that most of the cancer is confined within the prostate, but some has started to escape to the immediate surrounding tissues such as the capsule or seminal vesicles. In metastatic disease, the prostate cancer is growing outside the prostate and its immediate environs, often to lymph nodes but possibly to more distant organs. (from PCF)

    4. Is there consensus on when to begin salvage treatment with respect to increased PSA values from nadir and PSA velocity over several tests?

        Yes, the earlier the better, but always prior to reaching a PSA of 1.0.  The problem is to balance the possible side effects of radiation, if it isn't really needed against the possible curative potential of an earlier treatment course.  Even with a very low PSA there is no guarantee of effective treatment.

    Joel

  • Good luck with your treatments. I hope you get the help you need.

You may also like...