Triple + recurrence risk without chemo in T1A, node negative BC

My oncologist said that being HER2+ meant that I had a higher risk of recurrence so I looked it up to find out exactly what my recurrence risk is. She also said it was highest during the first 2 years

"Small, Node-Negative Cancers

What is the outcome for HER2-positive patients with node-negative disease and very small tumors?

In the British Columbia Tumor Registry, 10-year recurrence-free survival for untreated patients with T1, N0 cancers was 78.7% if they were HER2-negative and 71.6% if they were HER2-positive.8 The study confirmed that HER2-positive untreated patients had worse outcomes than HER2-negative patients.

The benefit of trastuzumab in node-negative disease was shown in BCIRG-006. The disease-free survival rate at 5 years in this cohort, half of whom had T2 and T3 tumors, was 93% with AC-TH (HR 0.47, P = .003) and 90% with TCH (HR = 0.64, P = .057), compared to 85% with AC-T.9 A US Oncology phase II trial looked specifically at low-risk T1/2, N0/1a HER2-positive tumors in patients receiving docetaxel/cyclophosphamide plus trastuzumab, finding that 2-year disease-free survival approached 98%, with overall survival of approximately 99%.10 These good outcomes were confirmed by the APT trial of patients with HER2-positive, node-negative tumors ≤ 3 cm, where 3-year recurrence-free survival after paclitaxel plus trastuzumab was 99.2%.11 Only 2 of 406 patients had a distant recurrence.

Should patients with very small (≤ 1 cm) node-negative breast cancers (T1a/b) receive trastuzumab?

In the US Oncology phase II trial mentioned previously, patients with tumors ≤ 1 cm had a 100% disease-free and overall survival rate at 3 years.10 This raises the question: Do all patients with T1a/b tumors benefit from trastuzu­mab? Or is there a low-risk limit below which trastuzumab therapy does not make an appreciable difference? Most studies of patients with tumors ≤ 1 cm do not separate T1a from T1b lesions.

However, an examination of 16,975 breast cancer patients treated from 2000 to 2006 at Kaiser Permanente Northern California has been informative.12 Of them, 237 had HER2-positive, node-negative T1a or T1b tumors, mostly untreated (prior to trastuzu­mab's approval in the adjuvant setting). After a median 6 years of follow-up, there were 15 (6.3%) invasive recurrences, of which 4 (3.5%) were in T1a tumors and 11 (6.3%) in T1b tumors, and of these tumors, there were 7 (2.9%) distant recurrences, 6 of which were in patients with T1b tumors. The 5-year distant relapse–free rate was 94% for T1b and 99.1% for T1a tumors. Only 1 patient out of 101 with a T1a tumor not treated with chemotherapy experienced a distant recurrence. Half of the T1a cancers were hormone receptor–negative.

This 1% risk of the cancer spreading is the figure we also quote to our patients with ductal carcinoma in situ. The guidelines indicate that for node-negative, T1a and T1b tumors, chemotherapy plus trastuzumab can be considered. But we discuss with our patients who clearly have T1a cancers whether a risk for distant recurrence approaching 1% is worth a year of treatment..."

http://www.ascopost.com/issues/december-10-2016/treatment-of-early-her2-positive-breast-cancer-one-size-does-not-fit-all/