PSA seasonality

[Justfor_]

I am mounting a theory that has to do with increased PSADT during winter vs summer time. For this reason I analyzed my old PSA readings during the 2+ years before starting Bicalutamide. I divided the year into two halfs assigning winter as the period starting on the autumnal equinox and ending on the vernal one. Summer is the remaining. The results support the theory that PSA marches faster during winter and relents during summer.

2019-20 Winter, PSADT = 8.2 months, (N=5 samples)

2020 Summer , PSADT = 12.4 months, (N=4 samples)

2020-21 Winter , PSADT = 4.0 months, (N=9 samples)

2021 Summer , PSADT = 13.9 months, (N=6 samples)

I theorize that it may be linked to the seasonal changes in blood pressure and circulation volume, by delivering more "nutrients" to the cancerous cells during winter compared to summer.

[FlyJ]

Do you think sun exposure/vitamin D production might play a role?

[Justfor_ in reply to FlyJ]

Check my reply to Scout4answers.

[Scout4answers]

seems like too simple an answer; vitamin D from increased exposure to sunshine?

[Justfor_ in reply to Scout4answers]

Reasonable thought, but in my case debatable as I supplemented with D3 all year round. Another suspect can be the ambient temperature. Now, I am looking into the possible influence of the Beta blockers that I take. In principal they lower the frequency of the cardiac-pulses and to a lesser degree the blood pressure. What we know for certain from mechanical engineering is that the flow in smaller diameter pipes is more affected by pressure variations than larger ones. Cancerous cells get their fuel from hair sized arteries during their early stages.

[FlyJ in reply to Scout4answers]

Certainly there are many references to Vitamin D and prostate cancer in Pub med (too many to list). Perhaps more activity/exercise during the warmer months may play a role too. I don't see anything in pubmed about seasonal rate changes in PSADT

[Justfor_ in reply to FlyJ]

Under the usual quarterely PSA sampling rate it is not possible to notice any seasonal variability. I have monthly samples that draw up a better picture.

[cujoe]

Justfor_, I never thought much about seasonality for PSA. Until the last several years the majority of my results came during two major run-ups in PSA (BCRs #1 & #2) and a 4-year treatment vacation when most of the results were in the > 0.1 "undetectable" form. Having ultra-labs for that entire vacation period would have possibly shed some light on your notion of seasonal fluctuation in PSA.

I agree that Vit D might well be a player in such a seasonal variation, esp. for those supplementing year-round and not adjusting dosage with periodic testing for time-of-year, geographical location, skin color, and time spent in the sun - with lower winter season Vit D levels due to less natural Vit D (diminished immune function) resulting in higher PSA results?

Regardless of cause, it is an interesting theory - and would lead one to wonder how many people might have been led to start a treatment cycle due to such a spurious fluctuation in PSA. I use a trend definition of 3 labs of sequential increases/decreases to define trend - and a fourth increase to confirm it. Under that definition, such a seasonal fluctuation might make it hard to both define and confirm a trend unless one was testing at something close to monthly.

BTW, I hope you are long past your recent longish COVID infection - and now keeping you and yours Safe & Well!

Ciao - Kaptin cujoe

[Justfor_ in reply to cujoe]

Thank you cujoe, I am fine now. Next week will see my September PSA test. After my latest dose reduction, anything lower than 0.020 will be a vote in favour of my fluid dynamics based theory regarding the influence of Beta blockers. To be continued ...

[cujoe in reply to Justfor_]

Glad to hear you are recovered. Where PCa is concerned, continuations are a good thing.

[Justfor_ in reply to Justfor_]

Today, the PSA test came back at 0.011, thing that made me very happy. My calculated Bicalutamide concentration has gone down to 83% on average due to this month's dosage reduction (25 mg every 5 days vs 25mg every 4 days previously). I did a search regarding Beta blockers and PCa and my findings are the following:

1) Early papers up to 2015 find some benefit in Cancer Specific Survival (HR 0.78 and 0.85) without making any distinction between selective and non-selective Beta blockers. The one I am on is selective.

2) Latest paper from Norway (2022) finds some benefit on BCR, but only for the non-selective variety.

3) There are another 2-3 papers that find no benefit whatsoever.

[cujoe in reply to Justfor_]

Thanks for sharing the good lab report. Seems you have mastered the bical min dosage for your situation. An n=1 definitely worthy of a case report paper.

As for beta-blockers, since going mostly WFPB, my BP is too low to consider them. However, I would think that is a topic that Patrick has looked into in some depth.

Keep those good labs coming and Μείνετε ασφαλείς και καλά.

Ciao - Kaptin K9

[KocoPr]

This would be a perfect scenario for AI to parse volumes of data.

[Justfor_ in reply to KocoPr]

Well, information like energy can't be created out of nothing. Boat loads of quarterly PSAs can't give even a single seasonal reliable pair of PSADTs. AI can't achieve the impossible. Sorry.

[Maxone73 in reply to KocoPr]

I can do that easily, it's just I can't find the data! 😀

[KocoPr]

hmmm, i see what you’re thinking “energy metabolism”. That is interesting as biologic reactions require specific temperatures. I don’t think our core body temperatures drop because of winter. Sure we do shiver and feel cold but that is our bodies maintaining a certain temperature.

[Justfor_ in reply to KocoPr]

I am not thinking temperature. I am thinking blood flows and pressure. Hormones, where from cancerous cells get the energy to divide and proliferate, are conveyed by blood streams. More heart pulses, more blood flow, more hormone deliverables. The issue with pressure has to do with fluid dynamics in capillary tubes. Less pressure, less flow through fine arteries, less hormone deliverables.

[Nfler in reply to Justfor_]

Maybe consider bat as it seems to be very effective in exposing Pca n then killing it intermittently…

[KocoPr]

Ok got it. From personal experience living in AK and visiting family in Florida after 40 and 50 below you would think I would die of heat but i was actually better suited to deal with the heat at least for a few weeks because my blood was thicker or more viscouse. Also going from Fla to AK in winter the thinner blood allowed me to take the sub zero temps for a few weeks. This was just my experience so I don’t know if it is scientifically proven that cold thickens the blood while heat thins it.

[Justfor_ in reply to KocoPr]

Ok, additionally to pumping power (heart pulses) and distribution network (arteries) you are raising the subject of blood viscosity. Valid addition, no doubt. Registered.

[jackcop]

Interesting hypothesis.

[ElRanchoDePoisonIvy]

Probably not vitamin D, as you would see a lot of systematic latitudinal variation as well. Could be linked in some way to activity levels which will usually be higher in the warmer months, depending on where you live. As for myself, I haven't seen any seasonal variation.

[Nfler in reply to ElRanchoDePoisonIvy]

Also Vit D is not well absorbed in vitamin form as opposed to sun exposure…

[kainasar]

So many variables.

[Maxone73 in reply to kainasar]

number is not a problem, I designed neural networks with over 120 variables (input features) and that size is considered very very small in current AI scenario

[Maxone73]

I was thinking about melatonin production, but then it should work the opposite way considering this study ncbi.nlm.nih.gov/pmc/articl...

where melatonin was administered during summer only...bah

[Justfor_ in reply to Maxone73]

In my case 20 mg supplementation daily all year round.

[Maxone73 in reply to Justfor_]

is it working?

[Justfor_ in reply to Maxone73]

Can't produce any tangible proof it does.

[Maxone73 in reply to Justfor_]

I am in a phase where “at least it does not hurt” sounds good enough for trying! 😀

[Justfor_ in reply to Maxone73]

It doesn't hurt, that's for sure. You only sleep more hours. I have a theory of mine claiming that the immune system does its housekeeping more efficiently when all other body activities/distractions are at minimum. So, longer sleep time, better housekeeping. Hint: When we get the flu, doesn't our body guide us towards the bed?

[Maxone73 in reply to Justfor_]

Well yes, for sure better sleep= better health and it’s better if all your body energy is focused on fighting cancer only rather than splitting it with different conditions. Rest is medicine per se.

[NanoMRI]

For past six years been testing nearly every month since my salvage extended pelvic lymph node surgery nadir of <0.010. My usPSA was <0.010 during first two years then rose through 0.01X, 0.02X into 0.03X range; holding 0.03x range for past two years. I am not seeing seasonal variances and I did winter in Europe first years and rest of time has been wandering the Rockies; last few winters on Texas coast. I did self-directed bicalutamide the first year, after establishing the <0.010 post ePLND nadir, for added insurance, with guidance of Royal Marsden onc and Belgium center that did the ePLND. My US docs recommended Stampede trial; I said no, not yet. For past three years I have been taking supps to combat cancer stem cells, Vit D to get my levels up and therapeutic blood draws to lower my ferritin. Don't know if these efforts are helping but trying, as my goal is to defer/delay long-term ADT/chemo/castration resistance as long as possible.