Neoadjuvant Trastuzumab and Pertuzumab for Early HER2-Positive Breast Cancer: A Real World Experience.

Background: Randomized studies of neoadjuvant (NA) trastuzumab and pertuzumab combined with chemotherapy for HER2-positive breast cancers (BC) have reported pathological complete response (pCR) rates of 39 to 61%. This study aimed to determine the real-world efficacy and toxicity of NA trastuzumab and pertuzumab combined with chemotherapy in a UK tertiary referral cancer centre. Methods: HER2-positive early BC patients given neoadjuvant chemotherapy with trastuzumab and pertuzumab between October 2016 and February 2018 at our tertiary referral cancer centre were identified via pharmacy records. Clinico-pathological information, treatment regimens, treatment-emergent toxicities, operative details, and pathological responses and outcomes were recorded. Results: 78 female patients were identified; 2 had bilateral diseases and 48 of 78 (62%) were node positive at presentation. 55 of 80 (71%) tumours were ER-positive. PCR occurred in 37 of 78 (46.3%; 95% CI: 35.3-57.2%) patients. 14 of 23 (60.8%) patients with ER-negative tumours achieved pCR; 23 of 55 (41.8%) were ER-positive and 6 of 19 (31.6%) were ER-positive and PgR-positive. No cardiac toxicity was documented. Diarrhoea occurred in 53 of 72 (74%) patients. Grade 3-4 toxicity occurred in ≥2% patients. These were diarrhoea, fatigue, and infection. The Median follow up period was 45.2 months (95% CI 43.8-46.3) with 71 of 78 (91.0%) remaining disease-free and 72 of 78 (92.3%) alive. Estimated OS at 2 years 86% (95% CI: 75-99%). Conclusion: This data confirms the efficacy of neoadjuvant chemotherapy combined with dual HER2 directed therapy. While no cardiac toxicity was observed, diarrhoea occurred frequently. The low pCR rate observed in ER and PgR-positive BCs warrants further investigation and consideration of strategies to increase the pCR rate.

The impact of the 21-gene recurrence score (Oncotype DX) on concordance of adjuvant therapy decision making as measured by the Liverpool Systemic Therapy Adjuvant Decision Tool.

PURPOSE: The 21-gene recurrence score (Oncotype DX) (RS) informs systemic therapy decision making in ER-positive HER2-negative early breast cancer (BC). To date no study has described the more nuanced discussions that take place regarding systemic therapy or the impact of the RS on concordance in such decision making. Here we utilized a novel decision making tool to assess the impact of the RS on decision making as well as concordance of treatment recommendations. PATIENTS AND METHODS: The clinicopathological information (CPI) of 50 BCs without and with the RS were presented to a panel of breast oncologists in a simulated MDT. The Liverpool Adjuvant Systemic Therapy Decision Tool (LASTDT) was developed and used to categorize treatment recommendations. Outcome measures included the impact of the RS on decisiveness and concordance in decision making and its impact on treatment recommendations. RESULTS: Availability of the RS increased definitive decision making from 8% (4/50) to 56% (28/50) [χ2 = 79.35, p < 0.001] and altered the LASTDT category in 68% (34/50) of cases (p < 0.001), 74% of which were to forgo chemotherapy. With knowledge of RS, universal concordance rose from 14% to 64% [K = 0.328: K = 0.729]. CONCLUSIONS: The RS improves certainty of decision making as well as concordance amongst oncologists. This provides evidence that the availability of the RS can improve consistency of decision making amongst oncologists and thus helps to ensure patients are managed consistently. This is particularly important when patients are managed in a loco-regional, multidisciplinary team manner where heterogeneous decisions can lead to disparity in care.