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Jul 10, 2017 12:12PM
Jul 11, 2017 10:58AM
Although you are in the right forum (for people with DCIS plus HER2-positive Microinvasion(s)), the title of your thread does not correspond very well to your question. You aren't asking about the DCIS component, but about the node-negative, ER+ PR- HER2+ microinvasion(s). You might get more replies from others with similar diagnoses with a revised thread title. If you wish to revise the title, you can send a Private Message to the Moderators and request that they revise the title of your thread to something like, "Node-negative ER+ PR- HER2+ microinvasion(s)" or even more generally, "Node-negative Hormone receptor-positive, HER2+ microinvasion(s)".
By the way, your treatment plan (Tamoxifen alone) appears to be within our current local clinical consensus guidelines for breast cancer from NCCN (Version 2.2017). Assuming the histology of the microinvasions was ductal, lobular, metaplastic or mixed, then for hormone receptor-positive (ER+ and/or PR+), HER2-positive, node-negative (pN0) disease, where the tumor is ≤ 0.5 cm (including microinvasive), the guidelines provide (emphasis added):
>> "Consider adjuvant endocrine therapy [x,y] ± adjuvant chemotherapy [z,aa] with trastuzumab [bb,cc] (category 2B)"
Thus, for the above situation, treatment plans either with or without (±) chemotherapy plus trastuzumab (HERCEPTIN) are within guidelines.
The results from the APT Trial (ClinicalTrials.gov number, NCT005424510), which influenced treatment guidelines for small, node-negative HER2-positive tumors, were published in late 2015:
>>Tolaney (2015), "Adjuvant Paclitaxel and Trastuzumab for Node-Negative, HER2-Positive Breast Cancer"
>>Main Page: http://www.nejm.org/doi/full/10.1056/NEJMoa1406281#t=articleDiscussion
>>PDF version: http://www.nejm.org/doi/pdf/10.1056/NEJMoa1406281
In the above 2015 publication, "The median follow-up time was 4.0 years. . . "
Note that it appears that only 9 patients (2.2 %) in the study had microinvasive disease (Table 1).
The discussion of the paper indicates that patients may decide this question differently, after a personalized risk/benefit analysis.
Just recently, seven-year follow-up data was recently released at ASCO 2017:
>>Tolaney (ASCO 2017), Abstract No. 511, "Seven-year (yr) follow-up of adjuvant paclitaxel (T) and trastuzumab (H) (APT trial) for node-negative, HER2-positive breast cancer (BC)"
This abstract reports after "a median follow-up of 6.5 yrs . . ."
Results from abstracts may be preliminary in nature. Those with pending treatment decisions should be certain to discuss any outside information with their medical oncologist to ensure accurate understanding and applicability to their particular situation.
"T1" = Tumor ≤ 20 mm in greatest dimension
The T1 size category is further subdivided as follows:
T1mi Tumor ≤ 1 mm in greatest dimension
T1a Tumor > 1 mm but ≤ 5 mm in greatest dimension
T1b Tumor > 5 mm but ≤ 10 mm in greatest dimension
T1c Tumor > 10 mm but ≤ 20 mm in greatest dimension
CORRECTION: The full-length paper of the APT Trial was published in the January 8, 2015 issue of the New England Journal of Medicine. Per my copy of Version 2.2015 of the NCCN guidelines for breast cancer (published in the April 1, 2015 of JNCCN ), the option of chemotherapy plus trastuzumab for very small HER2-positive tumors was first introduced into Version 1.2015 of the guidelines.
Stage IA IDC, 9/2013 BMX. Right: IDC (1.5 mm, grade 2) with DCIS (5+ cm), 0/4 nodes, pN0. Left: DCIS (5+ cm), 0/1 node, pN0(i+).