Abstract P5-15-09: Impact of oncotype dx genetic signature used in early breast cancer. Clinical and economic analisys of a 110 patient cohort treated in the Catalan Oncologic Institute (ICO), Spain

Introduction

Benefit from adjuvant chemotherapy (CT) is doubtful in a high percentage of patients with early breast cancer. The 21-gene recurrence-score (RS) assay (Oncotype DX, Genomic Health) is one gene-expression assay that provide prognostic and predictive information in hormone-receptor (RH) positive breast cancer. The results of the TAILORx study have confirmed that the majority of patients with tumors RH + and HER2 negative can avoid CT without increasing their risk of relapse. From 2012 to 2015 we used Mammaprint (MMP), in our institution and 60% of cases could avoided CT (communicated in SABCS 2015). Since 2017 we use RS for this purpose.

Primary Objective

To analyze the impact of using RS to change the indication of adjuvant CT.

Secondary Objectives

To analyze the association between different clinical pathological factors and the RS value, and calculate the difference between the cost of all RS test and the cost in direct expense of the treatment with CT of all patients who could avoid it thanks to the RS

Material and methods

We analyzed all RS test performed in the three ICO centers during 2017. We sent 112 tumor samples; in 2 samples adequated RNA for RS was not obtained. We compared the adjuvant treatment initially planned according to institutional treatment protocol with the treatment given after RS. We compared the direct economic costs of CT with the costs of the diagnostic test, and performed a logistic regression analysis of some pathological factors and RS value.

Results

The RS could be determined in 110 of 112 cases, in which there was indication of adjuvant CT. Only 14 patients received CT (12,72%) with the RS value, so CT was avoided in 96 patients (87,28%).

The clinical-pathological characteristics of the series are summarized in the table 1. Of the risk factors analyzed, only grade 3 (p 0.001) and PR <20% (p<0.002) showed a statistically significant relationship with a higher probability of RS> 25. No association was found between age, nodal status, tumor diameter, Ki67, Infiltrating Ductal Carcinoma vs neither Infiltrating Lobular Carcinoma nor Lympho-Vascular invasion.

The cost of the genetic studies was 180000€ (1636€ each). The cost of each CT schedule (EC x 4 followed by paclitaxel x 12) was 7214€ and the total cost of 96 cases 692590€. Direct costs savings estimated from the reduction in CT treatment were 512590€

Conclusion: Our series shows that RS avoided unnecessary CT in 87% of cases and was more cost-effective than a previous series with MMP. G3 and RP <20 were the only pathological factors associated with an increased risk of RS> 25.

Table 1.Patients characteristics and clinical-pathological details from the analyzed tumorsPatient characteristicsAge, mean (range)53,76 (19 – 75)≥50y72 (65.5%)<50y38 (34.5%)HistologyInfiltrating ductal carcinoma88 (80%)Infiltrating lobular carcinoma20 (18,2%)Others2 (1,8%)TNMTumor diameter (mm), mean (range)19,25 (1 – 160)pN058 (52,7%)pN1mic21 (19%)pN131 (28,3%)Hormone receptorsRE 2-100%110 (100%)RP <20%22 (20%)RP ≥20%88 (80%)Ki67 median, mean (range)20, 21 (2-75)Lymphovascular invasionyes9 (8%)no101 (92%)Adjuvant treatmentCT14 (12,72%)Hormonotherapy96 (87,28%)

Citation Format: Ferrer M, Dorcas J, Quiroga V, Margelí M, del Barco S, Stradella A, Petit A, Falo C, Viñas G, Romeo M, Villanueva R, Cirauqui B, Vázquez S, Fernández A, Recalde S, Vethencourt A, Soler T, Pérez-Martín X, Gil-Gil M. Impact of oncotype dx genetic signature used in early breast cancer. Clinical and economic analisys of a 110 patient cohort treated in the Catalan Oncologic Institute (ICO), Spain [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-15-09.

Abstract P6-09-04: Predictive factors for considering to avoid axillar lymphadenectomy in selected node positive breast cancer patients after neoadjuvant chemotherapy

Background:

To perform a systematic axillar lymphadenectomy (ALND) in clinical node positive (N+) patients after neoadjuvant chemotherapy (NACT) is currently under discussion. We aimed to study which factors are related to a pathological complete axillar response (ypN0) after NACT in order to select which patients could benefit from a sentinel lymph node biopsy without interfering with survival.

Material and methods

N+ patients who underwent ALND after NACT between June 2008 and December 2016 were retrospectively analyzed. Clinical features, molecular and histological factors, recurrence and specific mortality rates were compared between patients achieving a complete pathological axillary response vs not (ypN0 vs ypN+).

Results

345 N+ patients were reviewed. After NACT, 137 (39.6%) become ypN0[CF1] , 9 (2.6%) ypN1 mic, 113 (32.7%) ypN1, 60 (17.3%) ypN2 and 22 (6.4%) N3. Univariate analysis results regarding the predictive factors for ypN0 are detailed in [table 1]. Multivariate analyses showed molecular subtype (TN and Her2+) and clinical response as independent predictors of ypN0 [table 2]. After a mean follow-up of 58 months, overall survival was statistically superior in ypN0 vs ypN1 (p= 0.001).

Table 1.Predictive factors for ypN0 YpN0 (n = 137)YpN+ (n = 208)pAge (mean, years)58.3 ± 13.2758.59 ± 12.340.799BMI (mean)27.8±5.4927.8±5.360.973Dosis of QT (median)(%)  0.575IIA6 (31.6)13 (68.4) IIB71 (39.3)110 (60.8) IIIA28 (36.8)48 (63.2) IIIB24 (43.6)31 (56.4) IIIC7 (58.3)5 (41.7) Radiological image(%)  0.930Nodule77 (38.1)125 (61.9) Non-mass distortion10 (43.5)13 (56.5) Radiological size (median)32 (0-115)29 (0-130)0.246Suspicious a-LN by US(%)  0.486130 (30.9)37 (24.3) 25 (5.2)14 (9.2) >257 (58.8)91 (59.9) Histological subtype(%)  0.093Invasive Ductal Carcinoma133 (40.9)192 (59.1) Invasive Lobular Carcinoma2 (20)8 (80) Others2 (22.2)7 (78.8) Nottingham grade(%)  <0.001G11 (6.2)15 (93.8) G244 (28.6)110 (71.4) G386 (53.4)75 (46.6) Molecular-like subtype(%)  <0.001Luminal A-like2 (5.3)36 (94.7) Luminal B-like (Her2 -)21(18.1)95 (81.9) Luminal B-like (Her2 +)40 (63.5)23 (36.5) HER-2 enriched (non luminal)43 (74.1)15 (25.9) Triple Negative31 (44.9)38 (55.1) Vascular invasion19 (42.2)26 (57.8)0.889Clinical Response(%)  <0.001Complete61 (75.3)20 (24.7) Partial69 (31.8)148 (68.2) No response6 (20.7)23 (79.3) Progression1 (10)9 (90) Percentage are given per row.

Table 2.Multivariate analysis logistic regression of clinical predictive factors of ypN0. OR95% Confidence Intervalp valueMolecular subtype   No-luminal vs Luminal7,7483,913-15,343<0,001Clinical response   Response vs not response6,8491,834-25,5710,04OR: Odd ratio. No-luminal includes: luminal B (HER2 +), HER2 Henriched and triple negative. Luminal includes: Luminal A and Luminal B (HER2 -).

Conclusions

A remarkable percentage of N+ became ypN0 after NATC. Molecular subtype and complete clinical response were independent predictive factors of ypN0. We propose to offer the benefit of a targeted axillary procedure in those patients.

Citation Format: Fernandez-Gonzalez S, Falo Zamora C, Nuñez D, Vethencourt A, Pla MJ, Soler T, Guma A, Perez X, Gil M, Ponce J, Garcia A. Predictive factors for considering to avoid axillar lymphadenectomy in selected node positive breast cancer patients after neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-09-04.

Abstract P2-08-58: Prognostic factors of survival in node positive breast cancer patients after neoadjuvant chemotherapy in a large series after 5y follow-up: Can response overcome the poor prognosis of nodal stage?

Background: Status of the axilla is one of the most significant prognostic factors in breast cancer (BC) patients. On the other hand, response to neoadjuvant chemotherapy (NACT) is related to survival. The aim of the present study is to analyze which prognostic factors impact most on Node positive (N+) BC patient survival after NATC. Material and methods: Retrospective analyses on a series of N+ BC patients treated with NATC based on anthracyclines and taxanes +/- trastuzumab if HER2 positive tumors, between June 2008 and December 2016. Clinical, radiological and pathological outcomes have been evaluated. Residual cancer burden (RCB) 1 and the neoadjuvant response index (INR) 2 have been recorded. Survival was calculated with Kaplan-Meier survival curve since the start of NATC to the first documented disease recurrence (DFS) or death (OS). Hazard ratios (HRs) with 95% CIs were estimated with cox proportional hazards regression analysis and subgroups were compared with a two-sided log-rank test. Results: A total of 345 N+ BC patients were included. Pathological complete response was achieved in 72 (20.8%) patients. After NACT, 137 (39.6%) become ypN0, 9 (2.6%) ypN1 mic, 113 (32.7%) ypN1, 60 (17.3%) ypN2 and 26 (7.6%) N3. Those independent predictive factor of ypN0 were molecular subtype (TN and Her2+) with OR: 7.7, p<0.001 and clinical response with OR 6.88, p: 0.04. At a mean follow-up of 58 months there have been 73 (21.1%) recurrences: 9 (2.3%) local, 45 (13%) systemic, 15 (4.3%) systemic+ local, 3 (0.9%) axilla, 1 (0.3%) supraclavicular. The estimated 5y OS was 87.8%. The univariate analysis according to DSF is detailed in Table1.

Adjusted univariate anaalysis cox regression of clinical and pathological factors of desease free survivalBMI10.989-1.010.963AGE0.9960.953-1.0420.876Dose NATC0.9940.979-1.0080.402Clinical Stage1.4021.077-1.8260.012Rx Image1.260.803-1.9940.311Rx size1.0090.995-1.0240.217Number suspicious ALN1.0950.801-1.4970.57Molecular subtype TN,HER20.8800.534-1.450.616Nottinghan grade1.0460.753-1.4530.789Histological subtype1.4651.044-2.0570.27MOlecular subtype1.1510.956-1.3850.137Vascular invasion1.6761.137-24710.009Clinical response2.3691.709-3.284<0.001Fibrosis tumor bed0.980.972-0.989<0.001Nodal fibrosis>50%1.7950.874-3.6860.111Pathological tumoral response1.6861.175-2.4180.005ypN03.561.853-6.838<0.001NRI0.330.192-0.565<0.001RCB1.2741.106-1.4680.001

In the multivariate model those parameters that were independently prognostic were clinical response HR: 5.44 (IC95% 2.275-13.042, p<0.001) and clinical stage HR: 2.364 (IC95% 1.018-5.490, p: 0.045). Conclusions: The most significant prognostic factor in our N+ series was response to NATC, followed by clinical stage. Those independently predictive factors of axillar response (ypN0) were molecular subtype (TN and Her2+) and clinical response. In conclusion, in those patients with chemo sensitive tumors, lymphadenectomy could be safely spared with a more selective axillary approach.

Citation Format: Fernandez S, Garcia A, Vethencourt A, Vazquez S, Petit A, Pla MJ, Ortega R, Pérez J, Gil M, Ponce J, Pernas S, Lopez A, Falo C. Prognostic factors of survival in node positive breast cancer patients after neoadjuvant chemotherapy in a large series after 5y follow-up: Can response overcome the poor prognosis of nodal stage? [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-08-58.