Is Bicalutamide needed after Orchiectomy

[QuestionsAbtMyDad]

Hi, My 73 years old dad has been in remission since last summer. I would like some opinion on the current medication that his doctor has put him on.

- Bicalutamide (50 mg): He has been taking this daily since June 2022. His doctor has told him that he might have to take it for two more years. Is this normal given that my dad had Orchiectomy in June 2022 and his PSA levels returned to normal few months after surgery?

Is an anti-androgen drug needed even after the source of testosterone is removed?

For reference, here is my dad's Diagnosis and Treatment Timeline:

Mar 2020: Benign Prostatic Hyperlasia (BPH) diagnosed and surgery was done. But during covid proper follow-ups werent done.

Jan 2022: He developed severe back pain.

May 2022: Prostate Cancer diagnosed through MRI which was done because he had back pain. Gleason 8, Grade 4, PSA: 78. Initially we were told that the cancer had spread to to his vertebral bones and that caused the back pain as it was pinching a nerve

June 2022: Surgery done to remove cancerous tissue in the prostate. Two weeks later Orchiectomy was performed. We were told that no other specific treatment was needed for the bones.

Since then monthly PSA level is being tested and it has been continuously decreasing and is currently at around 2.

[Justfor_]

What do you mean by "cancerous tissue in the prostate". Was it a radical prostatectomy i.e. taking out the whole of the prostate or not?

[QuestionsAbtMyDad in reply to Justfor_]

The whole prostate wasn't removed. It wasn't a prostatectomy. Only the cancerous growth area was removed.

[Justfor_ in reply to QuestionsAbtMyDad]

Good, so your query will become clearer by counting his serum Testosterone. After orchiectomy the bulk of it must have gone away leading to castration. The residual (adrenal) T consumed by the remaining prostate forms the source of his PSA. A portion of the latter may originate from benin cells and the rest from cancerous ones. How much comes from which is hard to tell. The only way to tell is by tappering down the Bicalutamide dose. If his T is in castrate level and his PSA starts climbing up he should continue taking it, even try a second line lutamide. Additionally a free PSA count may provide additional information.

[QuestionsAbtMyDad in reply to Justfor_]

Thank you very much for this suggestion. I will have him discuss this option with his doctor.

[Tall_Allen]

For men who have initially been diagnosed with metastases, castration plus a second-generation hormonal (abiraterone, enzalutamide or apalutamide) has been proven to be superior to castration alone. or castration :

prostatecancer.news/2017/06...

The ENZAMET trial specifically proved that castration+enzalutamide was superior to castration plus a first generation hormonal (like Casodex).

nejm.org/doi/10.1056/NEJMoa...

[QuestionsAbtMyDad in reply to Tall_Allen]

Thank you very much for sharing this. I will read through the articles. Appreciate the response.

[Magnus1964]

What is his PSA reading?

[pakb]

In addition to the above- I'd be sure your dad is seeing a medical oncologist that specializes in prostate cancer. And don't be afraid to get 2nd opinions.

[bean1008]

I was told by my MO that if I had an orchidectomy that I would have to continue with abiraterone and would drop the Lupron shots.

[MrFireworks]

In my (layman's) understanding, the reason for the hormone therapy is to prevent growth of metastases. Once PCa cells are established outside of the prostate, taking out the prostate is to some extent irrelevant.