Kadcyla vs Herceptin - anti HER2 targeted therapy


I was diagnosed with 21mm primary breast cancer (ER+, HER2+) in October 2022. I went through 5 cycles of chemo (EC and Docetaxel + PHESGO) from December and had a SLNB and WLE in April. The surgeon removed the tumour with clean margins and no LVI or node invasion was found. I am awaiting to start radiotherapy with booster and hormone therapy soon. 
As some remaining active cancer cells were detected in the removed tumour, my targeted anti HR2 treatment needs to change. I cannot carry on with the PHESGO injections (NICE does not allow use of Pertuzumab in adjuvant setting for node negative patients), and was offered to start on either Trastuzumab emtansine (Kadcyla) or single Trastuzumab (Herceptin). I am reluctant to take Kadcyla as it has a combined chemo agent and I do not want to go back to this part of the treatment unless there is a clear benefit to it over the second option. No doctor is willing to confirm this at this point.
I cannot find any research papers explaining the benefits of one over the other as Kadcyla is very recent and has been studied with a wider cohort of patients with different stages and degrees of nodes invasion. 
I would really appreciate it if somebody could point me out to specific literature or research so I can try to understand why I am being “pushed” in that direction.
Thank you! 

Hi Geri033  

Thanks for posting.  

It is understandable that you are seeking more information about further treatment recommendations after neo-adjuvant or primary chemotherapy for HER2 positive and ER positive breast cancer. When remaining cancer cells are found at the time of surgery following neo-adjuvant chemotherapy, the NICE guidance recommends further treatment of Kadcyla for women who have HER2 positive cancers.  

This recommendation is based on the findings of the Katherine study. The early results showed that Kadcyla was more effective than trastuzumab in reducing the risk of breast cancer returning. You can read more about the study here and the impact on patients taking part here.   

You may also find our information about radiotherapy to the breast and hormone therapy useful.  

We offer a range of free supportive services for anyone who has had a diagnosis of breast cancer which you may be interested in.  They include face to face and online courses and events.  

For more details about all of these services, please see the information on the link, or call our free helpline.   

We are currently evaluating this service and would appreciate your feedback. Please click here to the survey. It should take approximately 10 minutes to complete.   

Do call our helpline if you would like to talk this through or have any further questions. The helpline team have time to listen to your concerns, talk things through and signpost you to more support and information. Your call will be confidential, and the number is free from UK landlines and all mobile networks. The number is 0808 800 6000, (Relay UK - prefix 18001). 

If you would prefer one of our nurses to call you. To do this, please complete this form t** icking the box agreeing to a call back.**  

Our usual opening hours are Monday to Friday 9am - 4pm and 9am - 1pm on Saturday.   

We are closed Monday the 29th May for the bank holiday.  

Out of hours you can leave a message and we will call you back when we next open.   

Best wishes  


Breast Care Nurse   

Please read the Ask Our Nurses disclaimer  Full details on how we collect and use your data can be found in our Privacy Policy    

This thread will now be closed from further replies. If you have any additional questions or would like to provide feedback, please start a new thread.