376P - Long-term outcome of patients (pts) with HER2-positive (HER2+) metastatic breast cancer (MBC) who achieved a Complete Response (CR) after antiHER2...

Date 27 September 2014
Event ESMO 2014
Session Poster Display session
Topics Anti-Cancer Agents & Biologic Therapy
Biomarkers
Breast Cancer, Metastatic
Presenter Giuseppe Gullo
Citation Annals of Oncology (2014) 25 (suppl_4): iv116-iv136. 10.1093/annonc/mdu329
Authors G. Gullo1, A. De Giorgi2, N. O'Donovan3, D. Fennelly2, J. Walshe2, J. Ballot4, E. McDermott5, D. Evoy5, E.J. Jordan2, J.P. Crown2
  • 1Medical Oncology Unit, St Vincents University Hospital, 4 - Dublin/IE
  • 2Medical Oncology, St Vincents University Hospital, IE-4 - Dublin/IE
  • 3National Institute For Cellular Biotechnology,, Molecular Therapeutics for Cancer Ireland, Dublin City University, 9 - Dublin/IE
  • 4Medical Oncology Clinical Research Unit, St Vincents University Hospital, IE-4 - Dublin/IE
  • 5Department Of Surgery, St Vincents University Hospital, IE-4 - Dublin/IE

Abstract

Aim

The primary objectives of this study were to analyze the long-term outcome of pts with HER2+ MBC who achieved a CR after anti-HER2 therapy (HER2Tx) and to investigate potential impact of duration of HER2Tx on remission duration.

Methods

We performed a systematic retrospective review of a database of all pts with HER2+ MBC treated at our Institution with any HER2Tx. To be included in the present study pts must have received HER2Tx for at least 6 consecutive weeks and have adequate information on response and survival follow up (FU). CR was defined according to RECIST 1.1 criteria.

Results

Between January 2000 and November 2013 198 consecutive pts with HER2+ MBC were commenced on HER2Tx. A total of 24 pts (12%) achieved a CR lasting for at least 6 months. Pts characteristics: median age 52yrs (range 25-68), oestrogen receptors (ER): pos 54%/neg 46%, distant metastases: visceral 50%/bone or non-visceral 50%. All pts received trastuzumab (T). Associated systemic Tx was: docetaxel + carboplatin (50%), single agent taxane (29%), docetaxel + lapatinib (13%), capecitabine 8%. All pts received continued HER2Tx post CR. Median FU is 64.5 months (12-164). At the database cut-off date (1/5/2014) 22 pts (11%) are alive and with ongoing CR. Two pts had MBC relapse while on maintenance T (at 49 and 53 months) both ER/PgR-pos. Out of 154 pts with FU > 36 months, 17 (11%) remain alive and in CR. All pts were 1st-line HER2Tx, ER-neg 59%, single site of distant metastases 71%, median duration of HER2Tx 63 months (37-127). The rate of CR > 36months among ER-neg pts is 17% (9/52). No late relapse has been observed in ER-neg CR pts who were in CR > 36 months.

Conclusions

These mature results on a larger database confirm our previous (Gullo ECCO 2011) observation. Prolonged CRs after HER2Tx are not anecdotal and our data strongly suggest that overtly metastatic HER2+ MBC is a potentially curable disease, especially in pts with ER-neg disease, a limited number of metastatic sites and no prior HER2Tx. Prolonging HER2Tx might play a role in increasing durable CR. We are currently investigating the molecular profile of this subset of pts.

Disclosure

All authors have declared no conflicts of interest.