Neoadjuvant chemotherapy (NACT) with dual HER2 targeting improved pCR rates (ypT0ypN0) compared with Herceptin plus chemotherapy in the TRYPHAENA and NeoSphere registration trials. Pertuzumab-containing regimens were adopted at KOC following NICE approval (December 2016).
A retrospective case notes study of 110 (stage 1-3) HER2+ breast cancer patients receiving HER2-directed NACT at KOC was conducted. Age, clinical stage, ER status, treatment regimen and pCR status were recorded.
Single targeting treatment (S) used FEC-TH. Dual targeting (D) regimens were FEC-THP or TCHP. Patients were well matched for age, clinical stage and ER status. Overall, dual targeting increased pCR rates: 62% vs 31% (S). pCR rates were higher with dual targeting regardless of ER or nodal status. The highest pCR rate was seen amongst ER negative patients receiving D (81%). Amongst D regimens, an excess of ER+ patients was seen in the TCHP group (75% TCHP vs 37% FEC-THP). Despite this, pCR rates were comparable (61% TCHP vs 63% FEC-THP). All 9 ER negative patients treated with TCHP achieved pCR (100%) compared with FEC-THP (67%). Table: Demographics and pCR rates for single and dual HER2 targeted NACT.
Single targeting (S) Dual targeting (D) Time period Oct 15-Nov 17 Dec 16-Nov 17 N 55 55 Age Median (range) 55 (36-78) 53 (29-77) Regimen FEC-TH 55 FEC-THP 19 TCHP 36 ER status ER + 31 (56%) 34 (62%) ER - 24 (44%) 21 (38%) Node status at diagnosis N + 37 (67%) 29 (53%) N - 18 (33%) 26 (47%) pCR [n (%)] 17 (31%) 34( 62%) ER + 11 (35%) 17 (50%) ER - 6 (25%) 17 (81%) N + 11 (30%) 22 (76%) N - 6 (33%) 12 (46%)
A substantial increase in pCR rates was observed with dual targeting, regardless of ER and nodal status, reproducing the registration trial data in real world clinical practice. pCR rates were greatest in ER negative patients, regardless of regimen. The small subgroup most likely to achieve pCR were ER negative patients treated with TCHP.
Kent Oncology Centre, Maidstone Hospital.
Has not received any funding.
R. Burcombe: Honorarium and advisory board: Roche in 2017 for writing an article (BJN) on HER2 directed therapy for MBC. All other authors have declared no conflicts of interest.