Allergic reaction to Herceptin

[jpuk]

I was diagnosed in December 2004 with Inflammatory Breast Cancer, a rare and particularly aggressive variety of this vile dsease; there followed chemotherapy, mastectomy and currently radiotherapy. Post-op pathology revealed 5 of 13 nodes positive but mercifully no evidence of extranodal or vascular invasion.

Because of the advanced nature of the diagnosis I have been put on Herceptin and have now had 3 treatments. I was warned to expect a 'flu-type reaction, but each session has been completely uneventful. My consultant oncologist has now told me that this is a good sign, and indicates there must be few if any cancer cells left as it is the interaction of the Herceptin antibody with the protein on the cancer cells which causes allergic reaction, i.e. it is not what it is but what it does that sets up reaction. This sounded like good news, but after the consultation I recalled that the more less senior doctor who went throught he consenting process with me before treatment started had said that an allergic reaction is caused because Herceptin is a "humanised" product based on a substance originally derived from mice!

I shall raise the issue when I see the consultant again next week but meanwhile I wonder if anyone else has discussed or read about the causes of allergic reaction to Herceptin?

[jpuk]

Should have typed "less senior doctor" who consented me!

[Christine MH-UK]

Hi JP,

On the product insert, it specifically mentions that people who are allergic to 'murine proteins' may have problems with herceptin. Murine means rat or mouse, although I think with herceptin it is actual chinese hamster ovarian cells that are used The less senior doctor is definitely on to something.

Of course, maybe I'm just trying to cheer myself up because herceptin makes my nose run.

I am sure that other people on this board know more about this, though.

[PatS]

A few weeks ago, at a local support group meeting, there were two reps from Genentech and a local onc who did a talk on Herceptin. They also said it was the small amount of mouse that caused an allergic reaction in some people.


Pat

[kk1]

I don't think I would use that consulting onc again!---it was not a very bright thing to say even for a first year med student. Statements like that would make me really worry about anything he/she might say in the future.

[jpuk]

I have great faith in him. He is in fact the most senior clinical oncologist at one of the leading hospitals in London: a centre of excellence for breast cancer medicine where the pool of medical expertise is second to none in the world. Moreover he has put himself out to prescribe the most up-to-date leading edge medicine for me, with drugs which are not usually available in the UK. He is a careful Scot, and my guess is that there was some truth in what both he and his registrar have said.

By the way, in the UK we cannot just switch about between hospitals like changing supermarkets. It is possible to transfer, but only for good cause and it requires a referral from one consultant to another. Transfer can also risk building in delays to treatment, as the second consultant can decline the transfer, especially if the lists are full. Of course, if you pay privately you can shop around as you please until you find someone who will tell you what you want to hear (although as a lawyer I must say that shopping around will not necessarily procure the best professional advice) but thank goodness I do not have to pay the colossal costs of my treatment.

[Lisa]

EEK! I had no idea I was injecting mouse weekly. That explains why my cats have become so needy.


Whatever the reason it works, it does work for most women, especially combined with chemo. My onc just said a couple of weeks ago, that he has seen a definite increase in the lifespan of his patients on Herceptin. Like the others, I too have a constantly runny nose (2 years now). My heart is tested regularly and never been a problem.

I don't know why it works, but I focus more on the fact that I'm still around to not worry why.

Love and light,

Lisa

[Sandy H]

You were put on Herceptin because you are Her2 positive. I am inflammatory breast cancer and Her2 positive. There are many on this board who are not inflammatory and are on Herceptin because of the Her2. I have never heard this reason given for a reaction. I was told by my oncologist that there is no way of really knowing if Herceptin works or not. Its best to stay on it unless there is a heart problem because with the right chemo sometimes it will work. It may prevent reoccurence, progression or slow the disease down. Good luck to you. hugs, Sandy

[StephN]

Hi -
We are always saying on this board that each one of us will have some individual twist in how our bodies use and react to the various drugs we are subjected to.

My first dose of Herceptin was as a Stage IV patient with rampant liver mets and a climbing CA27-29 tumor marker that reached over 100 at times. I also had it with my first doses of Taxol and Navelbine. Now you have to admit that this is quite a slam to one's system.

As I recall (it was about 4 years ago this took place) I had some slight fever that first evening but did eat the dinner my hubby fixed. The next day I felt fine - and was pleasantly surprised at how good I felt. No flu -like feelings, but LOTS of cancer cells running around!
I proceeded to the cancer center to have a bone scan and saw my nurse case manager. She was glad I did not have any ill effects and said they like to check up on us as each patient will react differently.

So, my experience does NOT match with what your consultant said about the cancer cells being a reason for a reaction. I also am allergic to all sorts of furry animals as well as horses. Guess a little side of "mouse" with my drug is tolerated ok due to my taking regular allergy meds.

Glad you are doing well within the UK medical system - we have some women who post real problems over there.