Q. Is HER2 injection required after chemo and radiotherapy in breast cancer patient?

Answered by
Dr. Pawar Satyajit Jalinder
and medically reviewed by iCliniq medical review team.
This is a premium question & answer published on Jan 29, 2019

Hello doctor,

For a person who has completed six chemotherapy sessions and month-long radiation for breast cancer treatment, how many HER2 injections are required after the above? ERPR/HER2 parameters are negative.



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Can you give information regarding a few details? What was the stage? What was the histopathology report? What chemotherapy was received? If ER/PR and HER 2 was negative, then was FISH (fluorescence in-situ hybridization) done?

If HER 2 is negative by FISH and histopathology, then HER 2 injection is not required. If HER 2 is positive, then if the disease is not metastatic then every three weekly injections for one year. If the disease is metastatic, then HER 2 injections are continued indefinitely till disease remains under control. I would be happy to help you if you have any further queries.

Thank you doctor,

It was stage 1. Six sittings of chemotherapy and six weeks of radiation were completed. How long does she require HER 2, is it for six sessions after chemo completions or 12 sessions? Three doses of HER 2 was also given along with the fourth, fifth and sixth chemo sessions. Does the count of HER 2 injections start after the chemo was completed or should the first three HER 2 given along with the chemo be included in the total count to calculate whether we need 6 or 12 HER2 injections? Does excessive HER 2 (Trastuzumab 440 mg) have any negative consequence on the heart, given her age? FISH was not done.



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I have gone through the report you had uploaded (attachment removed to protect patient identity). Can you provide me with some additional information?

1. As you have mentioned she had stage I cancer, could you provide a report of surgery? As very small tumors (less than 1 cm) can be treated with a shorter course of chemotherapy.

2. For details of chemotherapy, can you tell which chemotherapy she received? And whether it was received before or after surgery? And how many injections has she received till now? As per her report, and information provided by you, I was able to conclude that she must have received six cycles of TCH that is Trastuzumab, Carboplatin, and Docetaxel. So she should receive an additional one year of Trastuzumab after chemotherapy that is total 17 injections.

3. I could not get what you meant by excessive Trastuzumab? The schedule I have mentioned above is standard practice. Yes, Trastuzumab can cause a decrease in heart function in 10 % cases but usually, it is reversible.

Yes, there are newer studies which have tried to shorten the duration of Trastuzumab injection but these are not yet in standard practice and still have not shown equality with one year of Trastuzumab.

Thank you doctor,

She has completed six chemotherapy sessions and it started six months back, after the surgery which happened a month before that. HER 2 was started along with the fourth chemo session and it is continuing now. I want to know how many HER 2 are required as we are worried about any impact on the heart due to excessive HER 2 (Trastuzumab).

HER2 injections given along with fourth, fifth and sixth chemo cannot be counted in the total count, am I right? The count starts fresh for HER 2 after the complete chemotherapy is done which happens every 21 days. She can stop it if it is required only for six months or continue it for one year, depending on your advice considering any impact on the heart. In the past, she had many surgeries like gall bladder, hernia mesh, parathyroid.



Welcome back to

So as you have mentioned, she had Trastuzumab three injections during chemotherapy. So after chemotherapy she should receive it for total one year (that is 17 injections in total) with count staring from one again. Regarding impact on heart, echo is done every three months to see if any side effect is happening. And if any effect on the heart is there, injection is withheld for next cycle and echo is repeated. If everything is fine, then it is started again.

Duration of six months or one year can be decided depending on her risk of recurrence. For which I will need a full report of surgery. There are trials which have compared 6 vs 12 months and have found that six months is less effective. But I would not advice to decrease duration of Trastuzumab just because of risk of effect on the heart. As six months is less effective than one year. And risk of cardiac dysfunction is usually less and reversible. If she does not tolerate injections, then only I will think of reducing injections to six months.

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