Category: Prostate Cancer

Day 5,635 – Unexpected Call

On By DanIn Hormone Therapy, Prostate Cancer, Recurrence, Treatment4 Comments

I’m not sure how I managed it, but I picked up a nasty head cold after yesterday’s meeting with the oncologist. Perhaps it was from being at the hospital two days in a row, or from me riding our commuter-packed light rail system to get to the hospital (stops right at the hospital) that did me in, but whatever bug I caught kicked in around 5 p.m. yesterday.

Around 7 p.m. tonight, I was nursing the head cold, watching the ballgame on television when my phone rang, and I was surprised to see it was a call from the VA.

It was the head of the urology department inquiring about continuing my pelvic floor therapy at a community provider. (You may recall that I started that back in December, and the original end date of the therapy was 2 April.) I told her that the therapist and I agreed that I had plateaued and didn’t see a need for me to continue.

Not one to miss an opportunity, I mentioned me meeting with the oncologists yesterday and asked her for her take on whether starting hormone therapy would be appropriate. I also mentioned the negative scan results. She was more of the mindset of waiting until there was evidence of spread, and she said, “I wouldn’t chase numbers,” when I mentioned my current PSA level.

She noted that I had the follow-up with the oncologists on 2 June and a follow-up with urology on 23 June, and said we can review things then.

Once again, the “experts” offer differing approaches, and it’s up to us, the patient, to pick and choose what’s best. After 15 years, it’s not a surprise, but it still is frustrating at times. MO Jr. did mention that it may be appropriate to convene the “Tumor Board” to get all the key players in the same room and review the case for the best course of action.

At this point, I’m inclined to get the PSA test at the end of May and, with that new information, try to push to get everyone in the same room for a discussion of next steps forward. Or at least have them convene the Tumor Board without me.

In the meantime, I’m just going to curl up in a ball and try to get the worst of this head cold behind me before the weekend.

Be well!

Header image: Anza-Borrego Desert, California

Month 185 – Scan Results & Oncologist Meeting

On By DanIn Hormone Therapy, imaging, Prostate Cancer, Recurrence, Treatment7 Comments

It’s been a busy two days hanging out at the doctor’s offices between the scan and the oncologist. Here’s a summary of each, my final thoughts, and a quick explainer about hormone therapy for the uninitiated at the end.

18F-FDG PET Scan

“No evidence of metabolically active malignancy or metastatic disease.”

Well, I hate to say it, but I’m not necessarily surprised by that result. I didn’t have high hopes of getting a definitive answer going into the scan given its lower sensitivity and lower specificity, but I thought it was definitely worth the effort.

As far as the procedure itself was concerned, it was slightly different than the 68Ga-PSMA-11 PET scan. I had to fast for at least 6 hours (no food, just water) before the injection of the 18F-FDG tracer. They also had to measure my blood glucose level to ensure it was under 200 mg/dL (it was). If it was over, the scan would have been canceled.

There was a one-hour waiting period for the tracer to distribute through my body, and the scan itself took 45 minutes. Seeing as I had to get up at 4:30 a.m. for my 7 a.m. appointment, that hour in the recliner was much needed.

Oncologist

I actually met with two medical oncologists this morning, the resident about to complete his training (MO Jr.) and the full-blown MO Sr. who focuses on prostate and breast cancer. It was a good, nearly hour-long discussion. In a nutshell:

  • It was disappointing that the imaging didn’t show anything and, even though it would be nice to know where the cancer is located, MO Sr. felt it was time to start systemic treatment.
  • MO Sr.’s triggers for starting hormone therapy were a PSA greater than 2.0 ng/mL (I’m at 2.52) and a PSA doubling time less than 9 months (I’m at 8.9 months).
  • MO Sr. said that, with my numbers, I’m at “higher risk” for this to get away from us and metastasize.
  • MO Jr. said that the window for curative options has closed and that treatment going forward would be “palliative.” (I already knew that curative options were out the window.)
  • Both agreed it’s time for them (Oncology) to take the lead on my case at this point, with Urology still available in a supporting role.
  • Both suggested dual therapy involving androgen deprivation therapy (ADT) using Eligard (leuprolide acetate) and and androgen receptor pathway inhibitor (ARPI) using Xtandi (enzalutamide) as the current standard of care. [See explanation below if you’re unfamiliar.]
  • MO Sr. also suggested intermittent therapy over continuous therapy, using a 9-month schedule to start.

If she had her way, I believe MO Sr. would have had me start the therapy in the next week or so. I tapped on the brakes on that idea. I told her that Urology wanted another PSA test done in early June, and I thought it would be good to get that done before starting anything. Also, I’m traveling in May and I simply wanted to postpone anything until after I return. Six weeks won’t make that much of a difference.

We agreed, in concept, to the following:

  • No more scans to try to located the cancer for now.
  • Get pre-therapy lab work done the week after Memorial Day to establish baseline testosterone and PSA levels (among others) ahead of therapy.
  • Get a Dexa bone density scan to get a baseline prior to starting treatment (extended ADT can weaken bone density).
  • Meet on 2 June to review the results and make the final decision as to whether to start treatment.

Final Thoughts

It’s only been a few hours since the meeting, and I’m still trying to absorb it all and process it. Of course, after 15+ years of dealing with this, I knew we would eventually get to this point. Am I ready or willing to take the advice of the National Cancer Institute doctors in the video I shared recently to just monitor and delay treatment? I don’t know. It’s something that I’ll have to contemplate over the next six weeks or so.

I will say that I was pretty impressed with the Oncology Department as a whole. You’re assigned a care coordinator and given their direct phone number for all questions or concerns, and both doctors were good at listening and engaging in a real conversation. It seemed like they were a bit more empathetic over all, and that’s a good thing.

Certainly a lot to take in in the days and weeks ahead. I’m open to thoughts and feedback.

Be well!

—Dan

Hormone Therapy Explained

For those who aren’t really familiar with how prostate cancer works and what role hormone therapy plays, here’s a grossly over-simplified explainer.

Prostate cancer feeds off of testosterone and, as long as there’s a supply of testosterone, the cancer will continue to grow.

There are two ways to deprive the cancer of testosterone. The first is to stop or slow the production of testosterone. The second is to block the cancer cells from receiving the testosterone. The current standard of care is to use both methods simultaneously.

Let’s say the cancer cells are in the bottom of your favorite travel mug, thirsty for testosterone. If you put the mug under running water from your tap, the cells get the water (testosterone) they need and the cancer grows. But if you turn the tap off, the water (testosterone) stops flowing, and the cells in the bottom of the mug can’t grow. This is called androgen deprivation therapy (ADT).

The other way to stop the cancer cells in the bottom of the mug from getting water (testosterone), is to simply put the lid on and block the water from entering the mug. This is called androgen receptor pathway inhibitors (ARPI).

If you do both simultaneously, you can really slow the growth of the cancer. But we also know that some taps have slow leaks that drip water and, if the lid is slightly open, water (testosterone) and still make it to the cancer cells inside the mug.

There are two ways of turning the tap off. One, an orchiectomy, is a radical, surgical and permanent removal of the testes. But the adrenal glands also produce a small amount of testosterone, too, so the flow isn’t completely stopped.

The other is to use an ADT drug to have the brain tell the testes to stop producing testosterone. The drug is given via an injection in typically one, three, or six month doses, and it has significant side effects: hot flashes, mood swings, fatigue, loss of libido, loss of muscle strength, and loss of bone density, to name a few.

The way to put a lid on the mug is through an ARPI drug that’s usually taken in pill form daily. In my case, MO Sr. was recommending Xtandi (enzalutamide) as the ARPI. It has its own host of side effects: muscle and joint pain, fatigue, falls and bone fractures, headaches, high blood pressure and others.

The good news is that this combined treatment option can keep the cancer at bay for years (as long as you stay on it for years). However, at some point, the cancer can become resistant to the drugs, and you may have to move to stronger treatment options like chemotherapy.

Again, this is an oversimplification for those new to the topic.

Header image: Anza-Borrego Desert, California

Video: “Playing the Long Game” – Does your Recurrent/Advanced Prostate Cancer Need Treating? NCI Seminar

On By DanIn Hormone Therapy, Prostate Cancer, Recurrence, TreatmentLeave a comment

One of the best things about keeping this blog going over the years is learning new information from you, the readers.

Recently, a reader left a link to this video in the comments of one of my recent posts. It highlights the work that two doctors from the National Cancer Institute (NCI) have been doing when it comes to assessing whether and/or when to treat patients with recurrent/advanced prostate cancer.

The video is about an hour long (I changed the playback speed to 1.25x to get through it a little faster) and was very timely for my current situation.

One of the interesting parts was the discussion on how to define metastatic prostate cancer. It’s still pretty squishy if you ask me.

It will be interesting to see what the oncologist says tomorrow.

Be well!

Header image: Anza-Borrego Desert, California

Day 5,629 – FDG Scan Scheduled

On By DanIn imaging, Prostate Cancer2 Comments

Nuclear Medicine called this morning to schedule the FDG scan and I was surprised that they were able to get me in on this Monday, 13 April. With luck, the results will be recorded in my record before my appointment with the oncologist on Tuesday, 14 April.

I’ll hold off my monthly update on Sunday until after I have the information from both.

Be well!

Header image: Anza-Borrego Desert, California

Day 5,623 – FDG 18 PET Scan

On By DanIn imaging, Prostate Cancer, Recurrence2 Comments

Well, that was a surprise at 3 p.m. on Good Friday afternoon.

A resident from the urology department called to let me know that she had reviewed my email with the original urologist and, after consulting with the nuclear medicine department, they came to the conclusion that I made a strong case for me getting an alternate scan.

Unfortunately, the VA doesn’t offer the Axumin scans, but they do offer Fludeoxyglucose F18 (FDG) PET scans which are also reliant on PSMA for the ligand to attach itself to.

She said that the F18 ligand interacts differently than the 68-gallium does, so it’s possible that it will attach to the PSMA molecules on the cancer cells. (In a prostate cancer forum, one patient was in a similar situation. The 68-gallium scans didn’t work for him, but a Pylarify PSMA PET scan did.)

I know from earlier reading that F18 FDG scans aren’t as sensitive and may not work best in a recurrent cancer situation, but they definitely won’t pick anything up if we don’t do them. She offered to put the order in to do one, and I said yes.

I’ll give nuclear medicine a few days next week to receive and process the order before calling them to schedule the scan.

I thanked the doctor at the end of the call and she, in turn, thanked me for advocating for myself.

I’ll post more when the date is scheduled, and I’ll be putting my list of questions together for the medical oncologist appointment on 14 April.

Be well!

A little reading: Is There Utility for FDG PET in Prostate Cancer?

Header image: Anza-Borrego Desert, California

Day 5,621 – Oncology Appointment Set

On By DanIn imaging, Prostate CancerLeave a comment

The scheduler called this afternoon and we set up an appointment with the medical oncologist (MO) on Tuesday, 14 April 2026.

Hopefully, I can enlist the MO as an ally in trying to get an alternate scan to see if we can find out what’s happening with the cancer.

I did write to the urologist on Monday to let him know that I came away from the phone call with a different understanding of what’s next compared to what he wrote in his summary notes. (My emails are included in my medical chart, and I wanted to be on the record that we had a disconnect in communications.)

I did my best to keep my emotion out of what I wrote, and tried to present it as me wanting him to further explain his viewpoint. I wrote, in part:

I agree with you that PSMA PET scans have become the gold standard for most patients. But we also know from multiple studies that 5% – 10% of patients don’t express PSMA and the scans won’t work for them.

I believe the fact that I’ve had four 68-Ga-PSMA-11 PET scans that haven’t located my cancer is strong, objective evidence that I may be in that small group of patients for whom the scans don’t work (barring any other possible test/proof that shows I don’t express PSMA). The last two scans should have had an 80% – 90% chance of detection at my respective PSA levels.

Please help me understand more definitively why you believe PSMA PET scans work for me, and what further evidence you would need to convince you that I may be in that group for whom the scans don’t work.

Finally, you stated that there was “limited likelihood that Axumin would provide additional clinically actionable information.” How would we know that unless we try? Axumin scans have an 80% chance of detecting something at PSA levels over 2.0 ng/mL.

We banked on PSMA PET scans to provide that clinically actionable information, yet time after time, they haven’t.

I’ll let you be the judge as to whether I kept the emotion out of my email. Again, the email to him went out Monday afternoon, so I wouldn’t expect a response for a few more days (if he’s even inclined to respond). I’m not sure if it was coincidence or if he pushed Oncology to call me because I did note at the end of my email that I hadn’t heard from them yet.

We’ll have to see how this plays out. More to come.

Be well.

Header image: Anza-Borrego Desert, California

Day 5,616 – Ugh.

On By DanIn imaging, Prostate Cancer, Treatment1 Comment

As soon as I hung up the phone with the doctor yesterday, I started memorializing our conversation in Google Keep while waiting for my turn in the barber’s chair, and that was the outline I used for last night’s post about the conversation.

As I said last night, I had planned on documenting the conversation in an email to the doctor this morning. I drafted what I thought was an accurate, reasoned response but, before I was going to send it, I wanted to see if I could get his take on the conversation in my patient notes. I logged onto the patient portal and found his notes from the conversation.

Apparently, the doctor and I have had a massive disconnect.

He mentioned our discussion about Axumin scans, saying, “that this is not recommended at this time given prior negative PSMA PET imaging and the limited likelihood that Axumin would provide additional clinically actionable information.”

He also referenced our discussion about Pylarify scans, saying, “he recently underwent PSMA PET and that repeat advanced imaging would not be expected to change immediate management. Will review timing/appropriateness of repeat PSMA-based imaging if PSA continues to rise.”

He closed his comments with a recommendation to see Hematology/Oncology.

It was like a sucker punch to the gut—I had a genuine physical reaction to reading his notes.

This tells me two things.

First, he is not convinced that there is such a thing as a PSMA-negative patient for whom PSMA PET scans won’t work. That view is reinforced by his comments yesterday that he was confident my cancer expresses PSMA. In his mind, the 68Ga-PSMA-11 PET scan is definitive in its findings.

Second, it tells me that he isn’t pursuing any alternate imaging at all. Just let my PSA continue to increase and try again with another PSMA PET scan.

Needless to say, I discarded my draft e-mail to him, stepped away for most of the day, and have just been trying to process how to proceed. Of course, I’ll re-write my email to him politely highlighting the disconnect between our versions of the conversation.

I wish I could understand his reluctance to believe that I may be PSMA-negative. A quick search last night gave me a handful of papers from reputable organizations on the topic:

The clinical characteristics of patients with primary non‐prostate‐specific membrane antigen‐expressing prostate cancer on preoperative positron emission tomography/computed tomograph

Finding Metastatic Prostate Cancer that Doesn’t Make PSMA

The Blind Spot of Prostate-Specific Membrane Antigen Positron Emission Tomography Staging? Intraductal Carcinoma of the Prostate Is Overrepresented in Patients With No Uptake Pattern on Prostate-Specific Membrane Antigen Positron Emission Tomography and High-Grade Prostate Cancer

The oncological characteristics of non-prostate-specific membrane antigen (PSMA)-expressing primary prostate cancer on preoperative PSMA positron emission tomography/computed tomography

Normal Variants, Pitfalls, and Artifacts in Ga-68 Prostate Specific Membrane Antigen (PSMA) PET/CT Imaging

Of course, there’s a lot of gobbledygook that goes way over my head in those papers, but the common theme is that PSMA-negative patients do exist and that affects imaging. They only possible distinction that I’ve come up with from briefly skimming those papers is that more aggressive cancers seem to express more PSMA than less aggressive cancers. Maybe the doctor could confirm that or educate me.

Of course, the Prostate Cancer Research Institute has a video on this very topic:

What’s next? I’m thinking that I’m going to pursue two parallel paths, one within the VA and one outside of it. Both will likely take weeks if not months to pursue. (I’m not panicking about this, but I also don’t want to keep kicking the can down the road without doing anything to guide our decision-making, especially seeing as my PSA doubling time seems to be shrinking.)

Within the VA, I’m going to:

  1. Write the urologist and let him know that I came away from our phone call with a completely different take.
  2. Push to get the appointment with Oncology and hope to enlist them as an ally in trying to get an alternate scan sooner rather than later. In the in-person meeting, the urologist seemed to be deferential to their opinion.
  3. If neither of those result in any action, I’ll meet with the patient advocate at the VA and see if that can break the log jam either within the VA or by allowing me to gain community care outside of the VA.

Outside the VA, I’ll look at:

  1. Identifying what’s needed to become a patient at UCSD. It may not require much, as they did my salvage radiation therapy almost four years ago.
  2. Try to set up an appointment with the medical oncologist that the VA consulted when we talked two years ago.
  3. Get his take on alternate imaging.

I will tread very carefully because I don’t want to screw up any eligibility for care within the VA by going outside the VA or create confusion as to who is really taking the lead on my care. That’s why it’s really best that, if the VA can’t or won’t pursue additional screening, that they are the ones who initiate the request for community care. It’s something I need to research.

So that’s how I’m going into the weekend. How about you?

Be well.

Header image: Anza-Borrego Desert, California

Day 5,615 – Doctor Call

On By DanIn imaging, Prostate Cancer, RecurrenceLeave a comment

As I was driving to the barber to get my hair cut (both of them), my phone rang. Normally, I avoid phone conversations when I’m driving—even the hands-free, Bluetooth variety—but when the Caller ID popped up on the infotainment screen as being the VA Medical Center, I answered because I thought it might be the Oncology scheduler calling to set up an appointment.

Instead, the call was from the urologist I met on Tuesday to talk about his research and efforts to pursue an Axumin scan. (I sent an email to him yesterday saying that I did a little legwork for him and learned that UCSD still does Axumin PET scans in case the VA didn’t.)

In a nutshell, he contacted the VA nuclear medicine department and, according to him, they were very elusive with him in saying whether they even had the ability to do the scan at the VA and, even if they did, if they would do it considering the PSMA PET scans have replaced it in their minds.

Then the doctor again put his faith in the PSMA PET scan and thought that the Axumin scan wouldn’t provide any useful information. He also mentioned that he looked at the 10% of patients not having PSMA protein and said, from his quick research, it seemed to only been identified in a single study. Unfortunately, that was said at a time when I was more focused on driving than listening, and I’m sure I didn’t fully understand what he was trying to convey.

I was finally able to safely park and give 100% of my attention to the conversation, and he said one other thing that puzzled me. He seemed confident that, because my PSA was rising, I did, in fact, have the PSMA protein. I’m not sure that I agree with that and need to do some digging.

We did talk about having a Pylarify PSMA PET scan which uses a different tracer than the 68-Ga-PSMA-11 PET scans. He thought that that could be a possibility, but wasn’t sure that the VA offered it yet. He knew it had been FDA-approved, but thought that the VA hadn’t developed the protocols for its use yet. I mentioned that when I spoke with UCSD yesterday, they said they had the ability to do Pylarify scans, too.

I asked him about how I might get a referral from him/the VA for me to get the scan on my own, and he thought that there may be a number of bureaucratic hoops to jump through to make that happen, including determining if something was “medically necessary.” He wasn’t exactly sure of the process, especially if I was going to use my own insurance (Medicare).

I just wanted him to confirm that, in his view, there was value in getting a scan to learn the location of the cancer and what it’s doing. He agreed.

I told him that my goal was to find the cancer and, if there were one or two lesions, to do spot radiation to knock them down if they’re in a suitable zapping location. That may help delay the start of ADT. (Or not. I’m not sure if they put patients on ADT when going after oligometastatic lesions.)

Finally, he did ask if I had been scheduled with the oncologist yet, and I have not. He was interested in hearing what they had to say about scans.

Needless to say, the waters have been muddied and I’m a little less confident that I know what’s going to happen next.

I’ll send him an email in the morning recapping our conversation, with an emphasis on his agreement that having a scan at this point is important. Translation: Medical necessity. I’ll also let him know that I’m open to trying any scan that he thinks will work.

I may also ask him to explain again why he is convinced that I have the PSMA protein and why he’s skeptical of the 10% number.

I’ll also try to connect with the oncology schedulers and get that appointment on the books.

I may also look at what it takes to get myself in as a patient at UCSD through either their urology or medical oncology departments. Because UCSD did my salvage radiation therapy in 2022, I may still be in their system, so it may be less difficult than starting from scratch. I’ll have to figure out how to share my VA health records with UCSD if needed.

The saga goes on…

Be well.

Header image: Anza-Borrego Desert, California

Day 5,613 – Doctor Appointment

On By DanIn Hormone Therapy, imaging, Prostate Cancer, Recurrence6 Comments

Those of us of a certain age may remember the “Stump the Band” segment on the Johnny Carson show, where audience members asked the band to play some obscure song. Well, today was my turn at “Stump the Urologist.”

It was a very productive meeting that lasted nearly 40 minutes which was unusual. I came equipped with hard copies of my PSA chart, the MSKCC PSA doubling time (PSA-DT) calculator results, and my list of questions. He was impressed and really pleased with the chart in particular.

We started talking about how my four PSMA PET scans were all inconclusive, and I steered the conversation to whether I might be one of the 10% for whom PSMA PET scans don’t work. He seemed to be a bit skeptical at first, but he also said it was a possibility.

Given that my PSA increased substantially and my PSA-DT was decreasing, I wondered if it would be better to jump into ADT sooner or if there’s still value in trying to find the cancer’s location with imaging. He was of the opinion to continue to try to find it before starting ADT.

I had a series of questions that really dealt specifically with ADT, and he said it was a bit premature to think about those and that they would be better answered by a medical oncologist. I knew that I was jumping the gun with some of them, but I thought I’d ask anyway. During that part of the conversation, I did mention that I tolerated the ADT probably better than most when I had it for my salvage radiation therapy, but that I wasn’t eager to jump into it earlier than necessary.

After that, he took control of the conversation and asked me about my status when it came to sexual function and incontinence, and offered up options to deal with both if I was interested.

Then we returned to the topic of next steps, and that’s where I played “Stump the Urologist.” (Who, by the way, was a full-blown internist and not a resident.) He grabbed my PSA chart and excused himself for a few minutes as he went off to consult with the department head.

When he returned, I was a bit surprised when he put his faith in the results of the PSMA PET scan, saying it has the best sensitivity and the best specificity of any scan out there. He said that they had moved away from the Axumin scans because they were the old technology.

I politely pushed back, reminding him that a PSMA PET scan should have had an 80% – 90% chance of finding my cancer at my PSA level if I had the PSMA protein for the 68-Gallium tracer to lock onto. But if I don’t have that PSMA protein, the sensitivity and specificity of the scan won’t matter because nothing will ever light up. He really couldn’t argue against that.

I went back to the topic of ADT and mentioned that I met with a medical oncologist (MO) two years ago, and received conflicting opinions on when to start ADT. The MO said she would start my ADT when my PSA hit 2.0 ng/mL (a urologist said she wouldn’t start it until there was evidence of metastasis). Today’s urologist said he looks for one of three “triggers” to begin ADT: PSA > 10.0 ng/mL 😲; PSA-DT less than six months; or evidence of metastasis.

I also mentioned that the VA MO that I saw two years ago was a general oncologist and not someone who specialized in genitourinary cancers and, as helpful as she was, she had to consult with a UCSD MO who specifically deals with prostate cancer. I sowed the seed of eliminating the VA MO as a middleman if they have to consistently consult the UCSD doctor (who is highly regarded in the field), and suggested that I could just see him directly. I’m not sure if that will take root.

Finally, I did ask a very basic question given how elusive this has been: Is this even cancer? He said that, if I hadn’t had a prostatectomy, that there might be other explanations for the rising PSA. But he was confident that we are, in fact, dealing with cancer.

That led to a follow-up question of: Is it metastatic? Based on the information we have, he said it’s not. He seemed to squirm a bit when I asked about it being micro-metastatic, because, in his mind, that wasn’t very well-defined.

Before mapping out a plan, I have to admit that my ego puffed up a tad when he said, “You’re the best educated patient I’ve seen in weeks.” He also admitted that my case was a bit puzzling to them and not something they routinely see.

We agreed on three actions:

  • The doctor is going to explore how and where I can get an Axumin scan, and if the VA will authorize it if I have to go outside the VA. That may take a day or two to get an answer. I mentioned that I’d be willing to use Medicare and go out on my own if necessary.
  • He is doing a referral to get me seen by the VA oncology team to get them familiar with my case. I suspect it will take a few days to hear from the scheduler.
  • We do another PSA test in June and meet to see where we’re at.

All in all, this was a good meeting with a robust discussion about my case that has all of us scratching our heads as to what’s going on and what to do next. Frustrating? Yes, to a degree. But, as we discussed during the meeting, nothing is black-and-white in the world of prostate cancer.

More to come.

Be well!

For my readers outside the U.S. who may not be familiar with Johnny Carson, I was going to link a random video clip of his “Stump the Band” segment above and, when I searched YouTube, this—of all clips—was the one that popped up first. I think you’ll see the related humor in it once you watch it. 😂

Header image: Anza-Borrego Desert State Park, California

Month 184 – PSMA Explained & Next Steps

On By DanIn Hormone Therapy, imaging, Prostate Cancer6 Comments

After last week’s PSMA PET scan, I did a little more digging into how the scans work, and why they don’t work for 10% to 20% of patients.

Prostate specific membrane antigen (PSMA) is a protein that’s found in healthy prostate cells, and it continues to exist in prostate cancer cells in most, but not all, cases.

PSMA in Imaging

Researchers found a way to attach a radioactive tracer to the PSMA proteins which would light up when seen in a PET scan, indicating the presence of cancer. Gallium-68 is the most commonly used tracer, with fluorine-18 also being used.

When the tracer is injected into the patient, it seeks out cells that have expressed the PSMA protein and attaches to them. The PET scanner then looks for areas where there is a build-up of the tracer to indicate where the cancer is located.

I’m going to use a grossly over-simplified analogy based on my reading as a lay person.

We all know that magnets are attracted to steel or iron. Imagine that the cancer cells with the PSMA protein are small steel ball bearings, and the radioactive tracer is a bunch of tiny magnets. Inject the magnets into your system, and they go in search of the steel ball bearings. When they find them, they attach, and the PET scan can see where all the magnets are located.

But for those patients whose cancer cells do not have the PSMA protein, that essentially means that the cancer cells are plastic balls, and the magnets that were injected will never attach to them. The PET scan won’t see any build-up of magnets/cancer cells.

Based on my experience with four PSMA PET scans, I believe that I’m in that 10% group and that my cancer cells do not express the PSMA protein—they’re the plastic balls.

PSMA in Treatment

In addition to using PSMA positive cells for imaging purposes, researchers have also recently developed a treatment that uses the PSMA positive cells. It goes by the brand name Pluvicto, but also known as Lutetium-177–PSMA-617.

It’s only used on patients with castration-resistant prostate cancer that have PSMA proteins.

The difference between using gallium-68 or fluorine-18 and lutetium-177 is that the lutetium is a radioactive material that attaches to the PSMA protein cells and delivers beta particle radiation to kill the cells.

This means that for those patients whose cancer doesn’t express the PSMA protein, this treatment option would not be available.

Alternative Imaging

On the good news front, there are other imaging options out there, one of which is Axumin (18F-fluciclovine). Instead of targeting PSMA in the cancer cells, it looks at the amino acids.

Axumin scans aren’t as sensitive as PSMA PET scans, but they are more sensitive than choline-11 scans.

At my current PSA level (2.52 ng/mL), the Axumin scan should have a decent chance of finding something.

In a conversation in a prostate cancer forum, I learned that one patient had used the gallium-68 tracer for his PSMA PET scans with the same results as mine, but they switched to PYLARIFY (piflufolastat F 18) as the tracer (which also attaches to the PSMA) and found four lesions using the different radiotracer. I know that one anecdotal case doesn’t mean much, but it’s something I can ask my team about.

Skip Imaging?

You may recall that, at one point, I had conflicting guidance from the urologist and oncologist on when to start androgen deprivation (hormone) therapy (ADT). One said when we saw metastasis, and the other said when my PSA hit 2.0 ng/mL. Clearly, I’ve passed the 2.0 threshold with my latest PSA results.

I went back and recalculated my PSA doubling time using only the last four values dating back to 10 March 2025. (The fourth and fifth values that I used before are 0.94 (January 2025) and 0.95 (March 2025), so having them so close may have skewed the results a little. When I used all five data points, my PSADT was 10.1 months; when I use the last four data points, it’s 8.9 months.

Given I’m past the PSA threshold (for one doctor) and the fact my PSADT is less than 10 months, I’m also wondering if there’s any value in continuing in the efforts to try and find the lesions. Or is is better, given how my PSA is increasing, to go ahead and just resign myself to the fact that I have micrometastases someplace and start the ADT sooner rather than later? In the time that it takes to schedule another scan, regardless of the type, my PSA could be well over 3.0 and even pushing 4.0.

That leads me to another question. If we do start the ADT and it knocks my PSA down to <0.1 like it did when I had it for salvage radiation therapy, does that mean that scans wouldn’t be able to locate the cancer while on ADT?

To my way of thinking, knowing where the cancer is at is important, even if it means letting the PSA run unabated for a short while longer. But what the hell do I know? I’m all ears for experiences from others that may have been in the same or similar situation.

Summary

Again, this is my lay person interpretation of things that I’ve researched, so please take this with a pound of salt. If you know I’m wrong on my interpretation, please let me know and provide references as to why I’m wrong. I want to learn.

You can rest assured, though, that this will be a part of my conversation with my team on 24 March.

Stay tuned for more.

Be well.

Header image: Desert wildflowers, Anza-Borrego Desert State Park, California