How Long until Herceptin Kicks in??

[sabpri]

I have the most unusual situation. At diagnosis, I had 2 Tumors, totally pathologically different, one ER/PR+ Her2-, and the other this weird Triple Negative with a small subpopulation within it that was very Her2+ amplified. No one knew what to really do with me, and the Oncs disagreed as to whether I was really Her2+ or not, but decided in the end since that weird sub pop was Her2+, they would give me Herceptin. At diagnosis, I had 2 small bone mets.

I stayed on herceptin for one year, then my Onc took me off since it was standard protocal and we never knew if I was truly her2+. That one year mark was 10/06, and by January 2007, my tumor markers started rising. After additional TM rise in April, scans showed major bone mets and a spot on the lining of my lung. I started cabro/abraxane and after 3 months, TM dropped some and although lung spot is gone, bones are worse. Bone biopsy showed path to be ER/PR/HER2-. I just thought it was very coincidental that I went off Herceptin in October and for the first time in over a year my TM went up and then my cancer came back. I know it was peak recurrance time, so maybe it was just the timing. Now we are going to be switching chemo to see if we can stop the bone mets, but I have successfully won my plea to at least "try" the Herceptin. Maybe my path was weird and it didn't get the small subset that showed Her2+ like before, or maybe herceptin just works for me.

Anyway, I told Onc I wanted to try one or two cycles of the Herceptin before switching chemo treatments, because if I switch and the bone mets go away, I won't know if it was the Herceptin or the new chemo (I am still on the Abraxane). I just had my first 3 week dose one week ago. Does anyone know how long it would take to work if it was going too? I don't want to wait too long to see if it is going to do something, but I want to give it enough time as well. My TM are pretty reliable, and have been hanging around upper 30's (normal is 12) since the lung spot disappeared (was 70's). I would hope that if it dropped to 20 or less, than I could assume it was working, but I don't know how long that might take. I don't know if anyone would even know, but I am trying to decide how long I should try it before adding a new chemo to it.

Thoght I would pose this question here and see if anyone would have any insights. I feel half of this medical practice of cancer is a total crap shoot!!

Thanks,
Natalie

[BonnieR]

I don't have an answer for you. I am very new at this myself. But I was thinking it is really a shame that we have to ask other patients to explain things that medical professionals should be addressing for us. It just makes me all the more grateful for this site though. I have certainly learned all sorts of things in my short time here and it gives me question to ask next time I am seeing the doctor....

[Lani]

You might want to follow your her2 ECD serum test (too bad you didn't test it before you started herceptin again)

It usually goes down 20% within the first 3-4 weeks if herceptin is working

THEY found it to be positive even in some cases where the primary was her2-(infering that the mets were her2+ or something about the tissue her2 testing was erroneous).{ Papers on this topic include several by Walter Carney.}

You don't say what kind of scans showed your bone mets ie, bone scan vs CT scan vs MRI scan. From my reading, I think each has a different time interval before effect of medication shows up and it may also be individual ie, not the same for everyone.

Has anyone suggested getting serial Circulating tumor cells? Dr. Cristanofelli (?sp) of MD Anderson has championed this as a way of following the effectiveness of treatments for metastatic bc just as they take serial core biopsies of those undergoing neoadjuvant bc to see if the treatment is working.

It is also felt that herceptin works not only on those patients whose tumors are her2+(amplified) but also on those who have low her2(?negative) but lots of heregulin.( a her family ligand--the thing that stimulates the receptor)

Hope some of this helped!

[BonnieR]

well, Lani, you just proved the point of my earlier posting!! I wonder if everyone's doctors are as well informed!!!

[Lani]

I don't think it is just a problem of being well-informed.

The papers I discussed are just papers. What they discuss (using serum her2ECD testing to ensure her2- is indeed her2-, following CTCs to evaluate efficacy of a line of treatment) have not yet gone throughthe of randomized clinical trials with large numbers of patients needed to become the "accepted" treatment that everyone/ or a subset of everyone gets.

In the end, they may not pan out.

But when no treatment is "the best" for everyone, not everyone is a round peg (trying to fit into a round hole)as you well know with your unusual history, and your oncologist(s) admit they don't know which direction to go with you, how can it hurt to seek out the best information you can and ask all the questions you can.

[Lani]

Were you ever able to find the oncologist whose interview with Breast Cancer pdate I encouraged you to listen to in Palm Springs (the one who had breast cancer herself)?

I would think she would be both as well-read and up-to-date as she could possibly be as well open-minded.