306 - Oncotype DX - the Srio-Libans Hospital Cancer Center Experience

Date 28 September 2012
Event ESMO Congress 2012
Session Publication Only
Topics Breast Cancer, Early Stage
Diagnostics
Presenter Allan Pereira
Authors A.A.L. Pereira1, A.K. Shimada2, F.C. Santini2, E.C. Nascimento3, K.B. Ribeiro4, R.J. Marques2, M.S. Mano2, A. Katz5
  • 1Sirio Libanes Hospital, 01308-050 - Sao Paulo/BR
  • 2Centro De Oncologia - 2º Andar, Sirio Libanes Hospital, 01308-050 - Sao Paulo/BR
  • 3Imunohistoquímica E Biologia Molecular, Diagnostika, 01307-003 - Sao Paulo/BR
  • 4Instituto De Ensino E Pesquisa, Sirio Libanes Hospital, 01308-050 - Sao Paulo/BR
  • 5Centro De Oncologia, Sirio Libanes Hospital, 01308-050 - Sao Paulo/BR

Abstract

Background

The Oncotype Dx® recurrence score (RS) assay quantifies the risk of distant recurrence (rDR) and its use has increased despite the lack of prospective studies.

Methods

This is a cross-sectional study of consecutive patients (PTS) from our Institution with histologically confirmed invasive breast cancer (IBC) who underwent surgery with curative intent and in whom Oncotype Dx (ODx) was performed. The main objectives were to compare (1) the predicted rDR by RS and Adjuvant! (2) Risk allocation by RS and St Gallen Criteria and (3) the agreement between histological grading (HG) and RS.

Results

From October/2006 to April/2012, 105 PTS with ER positive IBC were evaluated. Median age: 55y. Sixty-eight (64.8%) were EC IA; axillary lymph node involvement was seen in 25 PTS (14 micro and 11 macrometastasis). The rDR by RS was low in 64 PTS (60.9%), intermediate in 34 (32.4%) and high in 7 (6.7%). According to Saint Gallen, 12 (12%), 68 (68%) and 20 PTS (20%) were classified as low, intermediate and high risk, respectively, among 100 classifiable PTS. There was no statistically significant agreement between risk allocation by RS and Saint Gallen criteria (Kappa coefficient = -0.043; p = 0.401). Ki-67 data was available for 89 PTS: <15% in 46; 15-19% in 9 and ≥20% in 34 PTS. There was correlation between RS and Ki-67 (Pearson chi-Square = 6.472; p= 0.167). Among the 80 node-negative PTS, there was no significant correlation between the predicted average rDR, using ODx, and Adjuvant!OnLine (Pearson correlation coefficient = 0.082, p = 0.792) with median risk of 10% vs 15.6%, respectively. HG was available in 103 PTS: 28 (27.2%) were grade 1, 69 (67%) grade 2 and 6 (5.8%) grade 3. A linear trend association between HG and RS was observed, ie, for increasing levels of the RS, we observed lower frequencies of grade 1 and higher frequencies of PTS with grade 2 (Linear trend chi-square = 4.62; p = 0.032).

Conclusions

We found no statistically significant agreement between Oncotype Dx®, the Saint Gallen criteria, Adjuvant!Online, or Ki-67. However, a potential association between HG and RS was noted. The rDR may be overestimated by clinicopathological-based classifications

Disclosure

All authors have declared no conflicts of interest.