oserdu/elacestrant and the tumor marker spike

[Maraki]

good morning!

I want to start off by saying that in this site I have gotten so much support and I am forever greatful for this.

I just finished my first 30 days of oserdu and got my appointment with my Oncologist yesterday. All my bloods came back great! But the tumor markers SPIKED like never ever before and for me the tumor marker test (CA 15-3) have been accurate.

I feel fine… my doctor commented and said that he sees this “spike with patients on oserdu and he def wants to wait before changing.

Has anyone else gotten similar experiences?

Thank you so much. I am have the ESR1 mutation and I just hope that this works🥹

[TammyCross]

Yes. I didn't believe my oncologist, since the 15-3 and even more the somewhat redundant but more sensitive 27-29 have been accurate for me. Not a huge increase, but just into the 60's has reliably signaled progression confirmed by a scan. Right away. That happened with Orserdu - markers were going up, not down -- and I was sure I would be switching yet again, but lo and behold, tumor markers are normal, now that I am entering my fourth month.

[Maraki in reply to TammyCross]

Omg they have never jumped this high ever! And my markers are very very accurate just like You… as soon as there was even a small jump there was sure to be progression.

But from 257 to 975??? I saw it and immediately just panicked. How were your tumor marker tends ?

[Maraki in reply to Maraki]

Trends***

[TammyCross in reply to Maraki]

Not that much. Only up into the 60's. That always signaled progression other times. Not this time. I was in the hundreds only when I was initially diagnosed, very belatedly, when I had a lot of tumors in many places. So, yeah, I would be alarmed, too. Some people are relieved when it goes down to 600. That is not the case for me. Doesn't sound like that is your pattern, either.

Will you get a scan now to follow up? I don't know how to help with freaking out, except to say that when I was initially diagnosed and 15-3 was over 800, after a week on fulvestrant and Ibrance, I went from too weak to walk to able to run uphill, and went to NEAD within months.

[Best521]

Yes I have had this happen twice, first time Trodelvy (Sazituzamab Govitican) and now Taxol. It was due to Tumor Flares as a result of cancer cell die off. 20% of patients experience Tumor Flares in the first 6 to 8 weeks due to treatment that is effectively treating the cancer. My tumor markers have always been accurate. In each case my tumor markers went up then dropped lower after the first two cycles. Hopefully this is good news for you too

Dana Farber has an excellent presentation on Tumor Markers through their Embrace program. It is posted on YouTube and called Biomarkers for Treatment and Progression

They discuss Tumor Flares around 15 minutes into the video

youtu.be/1CDU3gg8PN0(Not working as expected?)

[Proudmetsmama]

hello, yes that happened to me. It spikes like 100 points. I wish my doctor would have told me that this could happen on orsurdu. I was diagnosed metastatic and December 23 and this is my fifth line of therapy. I also have an ESR one mutation I really I’m terrified that this is not working. Little worse.

[Maraki in reply to Proudmetsmama]

But mine went from 250 to 900s 😫😆😆