benefit of adding herceptin to chemo is no different for small tumors

[Lani]

Adjuvant treatment strategy and results in small breast cancer tumors (pT1) with HER2 overexpression.


Sub-category:
HER2+

Category:
Breast Cancer - HER2/ER

Meeting:
2011 ASCO Annual Meeting

Abstract No:
607

Citation:
J Clin Oncol 29: 2011 (suppl; abstr 607)


Attend this session at the
ASCO Annual Meeting!
Session: Breast Cancer - HER2/ER

Type: General Poster Session

Time: Monday June 6, 1:00 PM to 5:00 PM

Location: McCormick Place Hall A

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Author(s): A. Hinke, P. Dall, G. Lenzen, C. Schumacher, D. Rezek, N. Gazawi, A. Ammon, F. G. Foerster, F. Beldermann, U. Cirrincione, J. Wilke; WiSP Research Institute, Langenfeld, Germany; Hospital Lueneburg, Lueneburg, Germany; Praxis, Osnabrueck, Germany; St. Elisabeth Hospital, Köln, Germany; Marienhospital, Wesel, Germany; Praxis, Leipzig, Germany; Praxis, Goettingen, Germany; Schwerpunktpraxis Gynakol Onkologie, Chemnitz, Germany; Brustzentrum, Stuttgart, Germany; Praxis, Fuerth, Germany


Abstract Disclosures


Abstract:

Background: Trastuzumab (T) was registered in 2006 for the treatment of early, HER2+ breast cancer (BC), after surgery, adjuvant chemotherapy (aCT) and/or radiotherapy, without specific tumor size restrictions. In a prospective observation study the routine practice of HER2 antibody treatment in this setting was examined, with a special focus on the pT1 subgroup. Methods: At present, 2,677 patients (pts) have been enrolled in this ongoing non-interventional study from 270 German centres. After exclusion of pts who were non-eligible due to M1 disease, negative HER2 status, pTis stage, unknown pT, or insufficient documentation at present, 2138 pts remained for this analysis. Results: The proportion of pT1 in the total group of pT1-4 primaries was 926/2138 (43%). Median age was similar in the pT1 and pT2-4 groups with 56 and 56.5 years (y), respectively. The mean number of involved nodes was 1.5±3.6/3.4±5.7 (pT1/pT2-4), p<0.0001, with >10 nodes in 4%/12%. G3 tumors were only slightly less frequent in the pT1 group (49%/55%), as were hormone receptor negative cases (34%/39%). Interestingly, no difference was detected in the proportion receiving aCT in addition to T (92%/93%). However, while the rate of aCT with anthracyclines was similar (91%/90%), only 54% of pT1 pts received taxanes, compared to 66% in the pT2-4 group (p<0.0001). 46%/58% of pts were treated with a taxane/anthracycline combination. Platin derivatives were administered in 6%/7% only. Adjuvant radiotherapy was slightly less common in pT1 tumors (76%/79%). No differences were observed in T dosing, median number of cycles (18/18) and mean duration (50.1/50.4 weeks). After a follow-up of up to 6 years, 161 relapses were hitherto reported. As expected the risk of recurrence in pT1 treated with T is considerably lower, indicated by a hazard ratio for relapse (pT2-4 as reference) of 0.44 (95% confidence interval: 0.30-0.63), with Kaplan-Meier estimations for relapse-free survival of 95%/87% after 3 y and 82%/71% after 5 y. Conclusions: These results from a large community-based study confirm the favorable findings on adjuvant T+aCT from the randomized trials, independent of tumor size. Patients with pT1 tumors treated accordingly had an excellent prognosis.