Delay in herceptin dose

[anshul_15]

Dear all,

My mother , age 53 years, post menopausal, was diagnosed with breast cancer (in right breast) last year. She undergone BCS along with mammoplasty in Sept 2015. After surgery, she was given adjuvant chemotherapy (along with herceptin) and radiotherapy.

Her cancer was staged as:

pT2N0M0.

Tumor size- 4 cm

ER-- 1 to 15 percent positive (as per different reports)

PR- 0

Her2 neu-- Strong positive (3+) FISH positive,

Due to pyelonephritis along with septicaemia after surgery, she was given chemotherapy as under:

Weekly paclitaxel + weekly herclone (herceptin) for 12 weeks (4 cycles)

After that the weekly protocol of herceptin was shifted to once in three weeks for 13 more cycles.

Now when the weekly herceptin was getting shifted to once in three weeks protocol, the staff did a mistake.

The once in three weeks dose had to be started just after one week of the last weekly dose, but due to some misunderstanding, the once in three weeks dose started 21 days after the last weekly dose.

Hence the 21 day cycle of herceptin was disturbed.

After this, all subsequent dose of herceptin were administered at regular intervals of 21 days.

So now, my mother has completed total 17 shots of herceptin (4 with paclitaxel and 13 after paclitaxel).

Here i want to add that she is also taking Tamoxifen 20mg after the completion of chemotherapy.

I hope I am able to clarify the situation. Please let me know if something is not clear.

I want to ask:

1. Whether this extra gap of 21 days disrupted her herceptin 1 year protocol ? (when the dose was getting shifted from weekly to once in three weeks)

2. Should my mother take more shots of herceptin to compensate the gap ?

Just to add that we can easily afford herceptin and there are no financial issues for the purchase of medicine.

Thank you very much...

[roxboxfox RadiationOncologist]

Answer

1. If a dose of Herceptin therapy is missed by >1 week, Herceptin should be reloaded using the appropriate loading dose:

8 mg/kg for q 3w dosing (switching from weekly to 3 weekly)

This is a minor dosing error and would mean slight transient imbalance in the Herceptin levels in the blood with no clinically appreciable risk of relapse.

2. Additional shots of Herceptin unlikely to make any huge impact.

The license for Herceptin use is for 1 year (This is 17-18 cycles).

(Your mom sure has battled out this cancer for quite some long time, and hats off to her for fighting this with your support).

Whether one uses 17 cycles or 18 cycles, it does not make a huge impact.

The very fact, this seems to trouble your conscience and may/maynot give sleepless nights, one may offer you the 18th cycle (so that you have a peaceful future life).

Whereas if u have a patient, who says, doctor enough...its been so long 1 full year can we stop now, one would be happy to stop at 17 cycles.

Medicolegally your doctor is correct in both these situations and has managed both patients well.

At the end of the day,

Given her Medical Situation and theTumour Profile, as per NHS Predict v2.0

Benefit of Herceptin over 1 year

Is 2% at 5 years or 6% at 10 years (Provided you have had 2nd generation Chemo + Hormone Therapy for 5 years).

Please be assured your mom has been treated very appropriately as per modern International standards with :

1. Breast Conserving surgery with Mammoplasty

2. Adj Chemo

3. Adj RT

4. Targeted Therapy with Herceptin x 1 year

5. and Hormone Therapy

Hope this help !!!

[anshul_15 in reply to roxboxfox]

Thank you very much doctor for your valuable comments, very helpful indeed.

The only thing that makes me think is your statement regarding 2nd generation chemotherapy.

In my mother's case, initial protocols written for her chemotherapy were AC-TH or TCH but she was only given paclitaxel (4 Cycles) with herceptin due to pyelonephritis and septicaemia after BCS.

Now she is completely fine and healthy.

Should more chemotherapy be considered at this point ? or Paclitaxel is sufficient enough ? (as for the predict model, I guess, it take AC TH or TCH chemotherapy into account).

Does Paclitaxel (single agent, without prior anthracyclins) comes under the purview of 2nd generation chemotherapy ?

[roxboxfox RadiationOncologist in reply to anshul_15]

Weekly Paclitaxel x 12 cycles only is not a standard Adjuvant Chemotherapy Regimens which oncologists use as it falls neither as first, second or third generation in the model.

The reason it was used was due to the fact your mother had Pyelonephritis and Septicemia, many oncologists may have not offered chemo, however there is less evidence of using Herceptin without chemo.

So very smartly Weekly Paclitaxel was used along with Herceptin and there is one such prospective trial funded by Roche using such a regimen.

So its impossible to give it a category...

Using my best estimate that third generation regimens include Taxanes but I would not label your regimen to be 3rd generation, i have guessed and estimated it's benefit to be around somewhere between 2nd and 3rd generation and optimistically given it 2nd generation on the NHS predict model.(Though such a regimen does not exist on its model).

It's almost a year, there is no role of Adjuvant chemo at this point.

You have completed Adjuvant chemo and more so you cannot combine and give Tamoxifen and Chemotherapy together.

You are in a comfortable position and continue follow up as advised by your Oncologist.

All the best !

[anshul_15 in reply to roxboxfox]

Thanks a lot doctor.... always been my pleasure to talk to you.... you have always been very helpful.

Thanks once again.