Early-stage breast cancer, HER2-positive, Subcentimeter tumors, T1aN0M0, Very small tumors

APT Trial

The APT trial is highly cited for treatment possibilities in early stage HER2-positive breast cancer. This medical trial used a cocktail of drugs to treat small tumors, with small defined as under 3 centimeters. The drug combination given in this trial is like a “lighter” version of chemotherapy,with lower toxicity, along with trastuzumab.

I think it’s commendable doctors are working hard to see if women can be cured of early stage breast cancer with a lower toxicity risk from adjuvant therapy. Yet, for patients with T1a tumors, this study has limitations.

First, everyone in the APT trial took the drugs, so any recurrences of cancer cannot be compared to people who didn’t take the drugs. And second, only 17% of patients had “T1a tumors that already have a very favorable prognosis.” (Source here.) So 69 people out of the 406 in the study had T1a tumors. That’s not a lot, and yet it is more than any other current trial.

So far, recurrences were presumably lower in all groups, including in patients with T1a and T1b tumors. I’m curious to see is what the neoadjuvant therapy was for these women. For example, how many had a double mastectomy versus a lumpectomy? That information has not been shared (at least, not that I can see).

The final report is scheduled for December 2021, because researchers are waiting longer to see who gets cancer again.

Genentech, the maker of Herceptin (trastuzumab), is one sponsor and collaborator in the APT trial.

APT trial interview (2014) cited above: http://www.ascopost.com/issues/march-1-2014/her2-positive-breast-cancer-patients-with-small-tumors-benefit-from-low-toxicity-regimen/

Trial update published in the New England Journal of Medicine (2015): https://www.nejm.org/doi/10.1056/NEJMoa1406281?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dwww.ncbi.nlm.nih.gov

Seven-year trial follow up at ASCO meeting (abstract, 2017): https://meetinglibrary.asco.org/record/145548/abstract

APT trial information filed with the U.S. government: https://clinicaltrials.gov/ct2/show/NCT00542451

Catch all — overview of HER2-positive T1a/T1b retrospective studies and current studies, including the APT trial, plus conclusions: https://www.gotoper.com/publications/ajho/2015/2015jan/a-review-of-the-management-of-t1abn0-her2-overexpressed-breast-cancer



The information contained in this blog is not intended to be used for medical diagnosis or treatment. It should not be used in place of the advice of your doctor or other qualified health care provider.






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