Using Trelstar alone after using zytiga

[Shanti1]

Hi All,

My husband had a PSA of 5 after RP with mets to pelvic and abdominal lymph nodes, 2 small mets to the left lung and 1 in the sacrum, detected via C11 Acetate scan. Gleason 9. After a year on ADT/zytiga/prednisone/xgeva and a PSA of <0.006 my husband stopped the above meds due to QOL issues. A year later, PSA is just starting to show on an ultra-sensitive test: 0.029 in June, 2019, 0.053 in July, 0.051 in Aug.

Axumin PET negative for activity Aug, 2019.

Our MO has indicated that PSA of 1 is when he would like my husband to start on ADT again, but this time he will only give trelstar because he states my husband is no longer considered metastatic...... Of course, we know that the PSA is being produced by mets, but since they are not visible on scan, our MO is anticipating giving trelstar alone if the next scan at PSA 1 is negative or shows very little activity. He believes we will get more mileage out of ADT this way. I would like to hear others thoughts on this approach. Also wondering if insurance would pay for zytiga if mets are no longer visible when we restart ADT.

Thank you!

[NPfisherman]

Hi Shanti1.

The Axumin scan will not detect anything most likely at PSA of .051....The 18F DCFPyl PET CT would be a better choice for a scan IMHO. You could wait for a rise to the 0.5 level and the 18F or GA 68 scan could pick it up...I had an Axumin scan at close to 3 and found my met lesion. At the level, it is in the range of 88% accuracy...

I think he should be back on Zytiga/Prednisone and see if his PSA will start down again or switch to Zytiga/Dexamethasone if it slows it down, but keeps going up. Adding indomethacin may be helpful with the switch....

This disease is hard on QOL....Enjoy each day....

Good luck...

Don Pescado

[Shanti1 in reply to NPfisherman]

Hi Don, Thank you for sharing your view, I am also in favor of more than lupron for ADT, hubby is not sure since he had a rough go of it on Zytiga. We know there are quite a few options out there including estrogen patches etc. We didn't expect to see anything on the axumin but our MO wanted to rule out progression with a low PSA producing cancer, we questioned the value of the scan but in the end decided to take it. I haven't looked for clinical studies offering the 18FDCFPyl PET CT, but we would consider it if he qualifies for a trial. Even though 18FDCFPyl PET CT appears more sensitive than Ga65-PSMA, we have been considering early intervention with Lu-177, in which case we would do the Ga65-PSMA as the next scan once the PSA is up into a range where the mets might be detected .I appreciate your responding.

Warmly, Shanti

[Tall_Allen]

Once metastatic, always metastatic. Metastatic means there are cancer cells in the body that are in a different place from the original tumor. Shrinking the larger tumors doesn't change the fact. It doesn't matter if you can see them or not (you can only see mets larger than 4 mm by any means, and it is useless to look for them with PSA is below 0.2. The insurance company will consider him metastatic (M1). Patients are not restaged after metastases.

Now, what kind of salvage ADT he wants to use and when he wants to start using it is really a matter of personal choice. Some may prefer continuous multimodal hormone therapy, some may prefer intermittent Casodex.

[Shanti1 in reply to Tall_Allen]

Thanks for the response TA

[Shanti1 in reply to Tall_Allen]

I have been thinking about the STAMPEDE results showing zytiga benefit for M1 with both high and low volume mets. Since my husband was originally staged as M1 high volume, does it make sense to deviate from from the zytiga just because he had such a great response that his PSA was <0.006 for 2 years (the second of which was off all meds)?

My husband may opt not to go back on zytiga for QOL reasons, but I wonder if it isn't the best option from a treatment standpoint.

[Tall_Allen in reply to Shanti1]

STAMPEDE was among newly diagnosed men. Your husband is in a different situation. For men recurrent after prostatectomy there was no advantage. (although it was a small sample, and a limited time frame.)

[Shanti1 in reply to Tall_Allen]

ok, I see the difference, but his PCa diagnosis, prostatectomy, and discovery of mets were in such quick succession, I'm sure he had undetected mets from diagnosis. They only did a bone scan and missed the lung and lymph mets and didn't pick up the sacral spot. So on paper, he wasn't M1 until we got the C11 acetate scan 3 months after the prostatectomy.

[Tall_Allen in reply to Shanti1]

A bone scan is usually done with a CT. The CT would pick up the larger soft tissue mets. STAMPEDE was based on bone scan/CT detection.

[Shanti1 in reply to Tall_Allen]

You are right TA, a CT was done as well, don't remember the wording, but basically that 2 lymph nodes were suspicious due to their size. They didn't image high enough to include the area where the lung mets were found. I don't know if they would have shown or not on the CT they were 3cm and 1.5cm. So yes, by STAMPEDE standards he was not metastatic preprostatectomy. Thank you.

[Tall_Allen in reply to Shanti1]

Anything over 1.2 cm is suspicious for metastasis. It's often a full body bone scan and full body CT. I guess visceral mets at the time of Dx are so rare they didn't bother.

[Shanti1 in reply to Tall_Allen]

I just checked it was an abdominal and pelvic CT, and a bone scan. CT did not include the upper chest where the mets were.