5-year Distant Disease-free Survival Research Articles

Abstract PO5-22-08: Comparison of long-term oncological outcomes in young women with breast cancer between BRCA-mutation carriers versus non-carriers: How genetic risk factors and tumor characteristics influence the prognosis

Abstract Objectives and rationale: Breast cancer (BC) arising at a young age is relatively uncommon; however, approximately 6 to 10% of women diagnosed with BC are younger than the age 40. This subgroup of young women presents different risk factors, tumor biology, and clinical outcomes. Moreover, the interpretation of the effects of inherited genetic factors on the prognosis of young patients with BC remains a subject of debate. The primary aim of this study was to evaluate the characteristics of young patients with BC and to compare the long-term oncological results between BRCA-mutation carriers and non-carriers. We retrospectively reviewed all the consecutive young (≤ 40 years old) BC patients treated at the Breast Unit of IRCCS Humanitas Research Hospital (Milan, Italy). All young patients underwent BRCA-mutation analysis. For further analysis young BC patients were divided into two groups: BRCA-mutation carriers versus non-carriers. Tumor, surgical treatment, and post-operative data were compared between the two groups. Primary end-points were: disease-free survival (DFS), distant disease-free survival (DDFS), and overall survival (OS). The Kaplan-Meier method was used to generate the recurrence and survival curves. Multivariate analyses were performed using the Cox proportional hazards model to identify independent risk and protective factors for DFS, DDFS, and OS. Results: The characteristics of 63 young BC patients with BRCA-mutation were compared with 339 young BC patients without BRCA-mutation. BRCA-mutation carriers tend to be younger (60.3% versus 34.8% if age ≤ 35 years, odds ratio (OR) = 17.699, 95% confidence interval (95%CI) = 33.871-35.568, p = 0.001) and present more aggressive tumors (66.7% versus 40.7% if G3, OR = 17.119, 95%CI = 2.549-2.828, p = 0.001; 57.2% versus 12.4% if biological subtype triple negative, OR = 52.727, 95%CI = 2.042-2.417, p = 0.001; 73.0% versus 39.2% if Ki67 ≥ 25%, OR = 58.981, 95%CI = 47.135-58.505, p = 0.001). Young BC patients without BRCA-mutation presented significantly better long-term oncological results in terms of DFS, DDFS, and OS compared with young BRCA-mutation carriers (10-years DFS rate 91.1% versus 58.1%, p < 0.001; 10-year DDFS rate 91.2% versus 76.1%, p = 0.003; 10-year OS rate 98.0% versus 87.8%, p = 0.002, respectively). Neo-adjuvant chemotherapy was found to be an independent protective factor for OS in young BRCA-mutated BC patients (hazard radio = 14.885, 95%CI = 2.343-94.566, p = 0.004). Conclusions: Breast cancer is more likely to present at a younger age (≤ 35 years) and with more aggressive characteristics (G3, triple negative, Ki67 ≥ 25%) in patients with BRCA-mutation compared with their non-mutated counterpart. Young BRCA-mutation carriers show a poorer prognosis in terms of recurrence and survival compared with non-carriers. The implementation of neo-adjuvant chemotherapy may improve survival in young BC patients with BRCA-mutation. Citation Format: Damiano Gentile, Simone Di Maria Grimaldi, Andrea Sagona, Erika Barbieri, Alberto Bottini, Giuseppe Canavese, Giulia Caraceni, Shadya Darwish, Corrado Tinterri. Comparison of long-term oncological outcomes in young women with breast cancer between BRCA-mutation carriers versus non-carriers: How genetic risk factors and tumor characteristics influence the prognosis [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-22-08.

Subtype-Specific Survival of Young Women with Breast Cancer and Its Interaction with the Germline BRCA Status.

Data are scarce on the role of pathogenic germline variants in BRCA1 and BRCA2 (gBRCAm) in subtype-specific survival in young women who develop breast cancer under the age of 40. This retrospective, real-world cohort study assessed the distant disease-free survival (DDFS) and overall survival (OS) of young women diagnosed with breast cancer between 2008 and 2019 while taking into consideration the interaction of clinical subtypes and the gBRCA status. Among 473 women, HR+/Her2- was the most common subtype (49.0%), followed by TNBC (31.3%), HR+/Her2+ (13.7%), and Her2+/HR- (5.9%). The gBRCA status was known for 319 cases (gBRCAwt (wild-type - without pathogenic variants in BRCA1 or BRCA2): 204, gBRCA1m: 83, gBRCA2m: 31, 1 patient with both). The distribution of clinical subtypes varied depending on the gBRCA status (p < 0.001). In survival analysis with a median follow-up of 43 months, the unadjusted DDFS and OS were worse for gBRCAwt TNBC compared to both HR+ subtypes, but not for gBRCAm TNBC patients. T-stage, nodal involvement, and the gBRCA status were identified as significant for survival in TNBC. In TNBC, gBRCAm was associated with better DDFS and OS than gBRCAwt (5-year DDFS 81.4% vs. 54.3%, p = 0.012 and 5-year OS 96.7% vs. 62.7%, p < 0.001). In contrast, in HR+/Her2- patients, gBRCAm patients showed a tendency for worse survival, though not statistically significant. Subtype-specific survival in young women with breast cancer needs to be evaluated in interaction with the gBRCA status. For TNBC, gBRCAm is of favorable prognostic value for overall survival, while patients with gBRCAwt TNBC need to be considered to have the highest risk for adverse survival outcomes.

Risk factors for late recurrence and postrelapse survival in estrogen receptor (ER)-positive, human epidermal growth factor receptor (HER) 2-negative breast cancer after 5 years of endocrine therapy

It is unclear which patients with ER-positive, HER2-negative breast cancer benefit from extended endocrine therapy beyond 5 years. Prognostic factors for late-recurring breast cancer postrelapse survival have been reported. We retrospectively analyzed data from 892 patients with ER-positive and HER2-negative invasive breast cancer who were disease-free after completing a 5-year adjuvant endocrine therapy. Patients were then classified as high-risk (positive lymph nodes, large tumor size, high tumor grade) or low-risk. High-risk patients were divided into extended endocrine therapy and stop groups. Comparisons were made using propensity score matching, and the benefits of extended endocrine therapy for high-risk patients and prognostic factors for postrelapse survival were assessed. The high- and low-risk groups comprised 444 and 448 patients, respectively. The 10-year distant disease-free survival (DDFS) rates were 96.3 % (95 % confidence interval [CI] 0.912–0.985) and 86.5 % (95 % CI 0.798–0911) in the extended and stop groups, respectively (P = 0.00382). Cox proportional hazards model revealed that extended endocrine therapy promoted greater reduction in distant metastasis risk than 5-year endocrine therapy in high-risk populations (hazard ratio [HR] 0.27; 95 % CI 0.11–0.68; P = 0.0054). Postrelapse survival was significantly different in patients with DDFS ≥7 years (HR 0.24; 95 % CI 0.072–0.81; P = 0.021) and those with better response to first-line treatment (HR 0.072; 95 % CI, 0.058–0.90; P = 0.041). Patients with risk factors for late recurrence should be considered for extended endocrine therapy. Longer DDFS and response to first-line treatment may be a prognostic factor for postrelapse survival after late recurrence.

Phase III study of HR-positive/HER2-negative/lymph node-positive breast cancer non-responsive to primary chemotherapy: a randomized trial

There are few studies focus on post-neoadjuvant treatment in hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-)/lymph node-positive (LN+) breast cancer, a multi-center, open-label, randomized, controlled phase III trial was conducted to evaluate pathological response-guided non-cross-resistant adjuvant chemotherapy in patients with HR+/HER2-/LN+ breast cancer who were non-responsive to primary chemotherapy. Patients received four cycles of non-cross-resistant adjuvant chemotherapy plus endocrine therapy (ET), or ET alone. Forty patients responsive to neoadjuvant chemotherapy and with Miller and Payne G4 or G5 and LN- status were assigned to the observation group. Distant disease-free survival was the primary endpoint. The final intention-to-treat analysis comprised 379 patients. After a median follow-up period of 72.4 months, the 5-year distant disease-free survival was 92% and 90% in the chemotherapy plus ET and ET-alone groups, respectively. Comparatively, the observation group showed a trend towards better distant disease-free survival. For patients non-responsive to neoadjuvant chemotherapy, adjuvant non-cross-resistant chemotherapy did not significantly improve distant disease-free survival compared to ET alone.

Management of the axilla in postmenopausal patients with cN0 hormone receptor-positive/HER2-negative breast cancer treated with neoadjuvant endocrine therapy and its prognostic impact.

To evaluate the differences in nodal positivity if the sentinel lymph node biopsy (SLNB) is performed before or after neoadjuvant endocrine therapy (NET) in breast cancer patients, and its impact on prognosis. A retrospective cohort study was performed in a single center including 91 postmenopausal cases with clinically node-negative and hormone receptor-positive/HER2-negative (HR + /HER2-) breast cancer, treated with NET and SLNB. SLNB was done pre-NET until 2014, and post-NET thereafter. Axillary lymph node dissection (ALND) was indicated only in SLNB macrometastasis, although in selected elderly patients, it was omitted. Kaplan-Meier survival curves were estimated in relation to the status of the axilla, and the differences assessed using the log-rank test. Between December 2006 and March 2022, SLNB was performed pre-NET in 14 cases and post-NET in 77. Both groups were similar in baseline tumor and patient characteristics. SLNB positivity was similar regardless of whether SLNB was performed before (5/14, 35.7%) or after NET (27/77, 37%), with 2/14 SLN macrometastases in the pre-NET cohort and 17/77 in the post-NET cohort. Only three patients (18.7%) with SLN macrometastasis had > 3 positive nodes following ALND. The 5-year overall survival and distant disease-free survival were 92.4% and 94.8%, respectively, with no significant differences according to SLNB status (p 0.5 and 0.8, respectively). SLN positivity did not differ according to its timing (before or after NET). Therefore, NET has no effect on lymph node clearance. Furthermore, the prognosis is good regardless of the axillary involvement. Therefore, factors other than axillary involvement may affect the prognosis in these patients.

Abstract P5-02-53: P95HER2 Expression in HER2-Positive Breast Cancer

Abstract Background: -HER2-positive breast cancer subtype accounted for around 15-20% of all breast cancer. -The introduction of HER2-targeted therapy such as trastuzumab and pertuzumab has remarkably increased the patients’ prognosis of HER2-positive breast cancer. -However, resistance exists due to impaired drug binding to HER2 receptor and constitutive activation of HER2 downstream signaling pathways. -P95HER2 isoform is a truncated form of HER2 that retains the C terminal domain but lacks an N terminal trastuzumab binding site, leading to trastuzumab resistance in HER2-positive breast cancer. -A new P95HER2 antibody is developed to target the extracellular domain of p95HER2 in formalin-fixed paraffin-embedded (FFPE) HER2-positive breast cancer tissues by using hematoxylin and eosin (HE) staining method. Objectives: To evaluate the expression of P95HER2 and its clinicopathological characteristics in HER2-positive breast cancer. Methods: We assessed 68 HER2-positive patients (IHC 3+ or IHC 2+/in situ hybridization [ISH]+) from Fudan University Shanghai Cancer Center (FUSCC) who underwent breast cancer surgery and were treated with adjuvant chemotherapy (taxane or anthracycline or combination) plus trastuzumab from 2014 to 2016. P95HER2 HE antibody is provided by Simcere Pharma. In this study, we compared 27 patients with primary trastuzumab resistance with 41 non-relapse breast cancer patients. 14 patients have not received trastuzumab targeted therapy. P95HER2 staining of either 1+, 2+ or 3+ observed in any tumor area in HE slides was considered to be P95 HER2 positive. Chi-square test was used to determine the relationship between P95HER2 expression of patients’ characteristics. The main outcome measures were disease free-survival (DFS), distant disease-free survival (DDFS) and overall survival (OS) by using log-rank test. Univariable and multivariable Cox regression analyses were used to identify independent factors related to prognosis. Results: From 2014 to 2016, we assessed the expression of P95HER2 expression in 68 HER2 positive breast cancer patients from FUSCC. Median follow-up was 45 months. In our study, 19 (27.9%) were P95HER2 positive. P95HER2 positive expression rate is higher in premenopausal patients than in postmenopausal patients (68.4% vs 38.8%, P= 0.028). Univariable analysis showed that higher T-stage (P= 0.018), higher N-stage (P= 0.001) and P95HER2 positive expression (P= 0.033) were associated with worse DDFS. Multivariable analysis showed that higher T-stage (hazard ratio, 6.019; 95% CI, 1.205-30.078; P= 0.029) and P95HER2 positive (hazard ratio, 2.349; 95%CI, 1.03-5.358; P= 0.042) independently predicted worse DDFS. P95HER2 positive was significantly associated with shorter 5-year DDFS (42.1% vs 67.6%, P= 0.028), but has no significant difference in DFS (36.8% vs 59.5%, P= 0.072) and OS (74.8% vs 81.2%, P= 0.685). Conclusions: P95HER2 positive was found more in premenopausal patients and was associated with a higher metastasis rate, indicating that P95HER2 expression tends to be a more aggressive isoform type of HER2-positive breast cancer. P95HER2 may serve as a therapeutic target for anti-HER2 therapy. Citation Format: Chih Wan Goh, Liyi Zhang, Wei-Ru Chi, Bingqiu Xiu, Jiajian Chen, Wenqing Yang, Chunxia Ao, Jianxing Tang, Jingyan Xue, Yayun Chi, Jiong Wu. P95HER2 Expression in HER2-Positive Breast Cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-02-53.

Clinicopathologic Features and Prognosis of Female Early Breast Cancer With HER2 Low Expression: A Propensity Score Matched Analysis.

Metastatic breast cancer (MBC) patients with low expression of human epidermal growth factor 2 (HER2) have been proven to benefit from HER2 targeted therapy. We aimed to determine how HER2-low status affected survival and metastatic risk as well as how it affected pathological complete response (pCR) in neoadjuvant chemotherapy (NAC) patients. According to the results of immunohistochemistry (IHC) and in situ hybridization (ISH) testing, 321 female patients were sorted into HER2-low (IHC 1+/2+ with ISH negative) and HER2-zero (IHC 0) groups using propensity score matching (PSM). Overall survival (OS), disease-free survival (DFS), and distant disease-free survival (DDFS) were compared for both groups, while pCR was only analyzed for NAC patients. In total, 97 patients in each group after PSM were included. We discovered that pCR was not associated with HER2 expression status in 45 patients who underwent NAC. Five-year OS in the HER2-low group was significantly higher (98.99%) than in the HER2-zero group (95.87%, P = .044); however, this difference was not reflected in the 5-year DFS (90.61 vs 90.52%, P = .868) and 5-year DDFS (93.67 vs 91.53%, P = .757). Meanwhile, multivariate analysis revealed that HER2-low expression could indicate better OS (P = .047, hazard ratios [HRs] = 16.121, 95% confidence interval [CI] = 1.035-251.046), but it had no prognostic value for DFS or DDFS. When compared with HER2-zero expression, HER2-low expression was not connected to pCR and could not modify metastasis risk in female patients with early-stage breast cancer (BC), but it may prolong patient survival.

William Lindsay Morrison

Background/Aim: The value of androgen receptor (AR) in breast cancer has gained renewed interest as a prognostic and treatment predictive biomarker. The aims of this work were to study the...

Prognostic role of the stromal tumor-infiltrating lymphocytes (TILs) in women with early ER+/HER2+ breast cancer (BC) in whom adjuvant chemotherapy (ChT) was omitted.

e12526 Background: Adjuvant systemic therapy in women with early ER+/HER2+ BC usually includes ChT, trastuzumab (T) and endocrine therapy (ET). High level of TILs is associated with better outcome in HER2+ disease. Here we explore the outcome and prognostic role of TILs in women with early ER+/HER2+ BC in whom ChT was omitted. Methods: Women with ER+ (IHC ≥ 1%) and HER2+ (IHC3+ and/or FISH ratio ≥ 2.0) early BC who underwent surgery between years 2006 and 2016 at the Institute of Oncology Ljubljana and did not receive adjuvant ChT were eligible for this study. Hematoxilin and eosin slides of primary tumors were retrieved and evaluated for the percentage of stromal TILs. Distant disease-free survival (DDFS) was estimated by the Kaplan-Meier method. The association between DDFS and TILs level was explored in the Cox proportional hazard model. Relative survival was used for estimating the probability of dying due to the breast cancer or other causes. Results: During the 10-year period 86 (29.4%) out of 292 women with early ER+/HER2+ BC who underwent surgery did not receive adjuvant ChT. ChT was omitted due to the stage I disease (n=30), comorbidities (n=25), older age (n=19), refusal of treatment (n=9) and other causes (n=3). Five (5.8%) and 81 (94.1%) women received T and ET, respectively. Their median age was 65.8 yrs (IQR 55.7, 75.6 yrs) and 45 (52.3%) had stage I disease. There were 53 (61.6%), 24 (27.9%) and 9 (10.4%) women with low (&lt;10%), intermediate (≤10% to &lt;40%) and high (≥ 40%) level of TILs, respectively. After median follow-up of 10 years 28 events (distant recurrence or death) occurred. The 10-year DDFS for those who did not receive ChT due to the stage I disease, comorbidities and older age was 91% (95% CI, 0.79 to 1.00), 38% (95% CI, 0.18 to 0.75]) and 26% (95% CI, 0.10 to 0.66) (p˂0.0001), respectively. After excluding women with stage I disease the estimated probability of dying due to the breast cancer and due to other causes was 26.7% and 26.5%, respectively. Overall, for every 10% increase in TILs the risk of distant recurrence or death was reduced for 18% (HR=0.82; 95% CI, 0.64 to 1.05) (p=0.11). In the multivariable Cox model, higher TILs level was a significant predictor of better DDFS (HR 0.75; 95% CI, 0.57 to 0.98) (p=0.041) (Table). Conclusions: Women with stage I ER+/HER2+ BC who do not receive adjuvant ChT and T but do receive adjuvant ET may still have a very good outcome. In contrast, survival of women who do not receive adjuvant ChT and T for other reasons is poor; however, only a half of those deaths are related to BC. TIL is a favourable prognostic biomarker which might be helpful when de-escalation of systemic therapy in women with ER+/HER2+ BC is considered.[Table: see text]

Abstract P2-12-06: Pathological response-guided postoperative treatment strategy for positive HR/negative HER2 and positive lymphnodes breast cancer patients with non-responsive pathological results to neoadjuvant chemotherapy

Abstract Objective: No consensus up to date suggesting whether patients with positive HR/negative HER-2 and positive lymph nodes breast cancer should receive additional adjuvant chemotherapy following a poor response to neoadjuvant chemotherapy to acquire a better DDFS. The main aim of this trial is to compare the 5-year DDFS between additional adjuvant chemotherapy plus endocrine therapy group and endocrine alone group following 4 cycles neoadjuvant chemotherapy. Method: A multicenter, open-label, randomized, controlled, phase 3 trial was conducted. All patients enrolled in the study were HR+ HER2- LN+ breast cancer patients completing four cycles neoadjuvant chemotherapy, with a non-responsive pathological result to neoadjuvant chemotherapy. The non-responsive criterion was defined as Miller and Payne staging grade1 to grade 3, or any grade of Miller and Payne staging but residual positive lymph nodes were found in surgical specimen. All enrolled patients were randomly assigned to receive four cycles non-cross resistant regimen plus endocrine therapy, or endocrine therapy alone. The primary endpoint was DDFS, and the secondary endpoint was iDFS and OS. Result: From October 2010 to September 2018, a total of 391 patients were enrolled for eligibility. The final ITT analysis compromised 379 patients (187 in adjuvant chemotherapy plus endocrine therapy group, and 192 in endocrine therapy alone group). After a median follow-up of 72.4 months, the 5-year distant disease free survival estimate was 92% (95% CI 88-96) in the adjuvant chemotherapy group and 90% (86-94) in the endocrine therapy alone group (HR 0.79, 95% CI 0.45-1.37) (P=0.401). In the prespecified CEF subgroup, the 5-year DDFS was 94% (95% CI 90-98) in adjuvant chemotherapy group, and 91% (95% CI 87-94) in endocrine group (HR 0.68, 95% CI 0.36-1.30) (P=0.249). In the exploratory analysis, we found a better 5-year DDFS trend in adjuvant chemotherapy group in ypN+ patients in CEF subgroup (P=0.196). Conclusion: A better 5-year DDFS trend in additional adjuvant chemotherapy plus endocrine therapy can be found for patients with positive HR/negative HER-2 and positive lymph nodes following a poor response to neoadjuvant chemotherapy. Citation Format: Yang Yang, Xue Chen, Zhaoqing Fan, Yingjian He, Yuntao Xie, Jinfeng Li, Tianfeng Wang, Tao Ouyang. Pathological response-guided postoperative treatment strategy for positive HR/negative HER2 and positive lymphnodes breast cancer patients with non-responsive pathological results to neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-12-06.

Abstract P3-18-16: Breast conserving surgery in BRCA-mutation carriers. A single Institution experience

Abstract BackgroundBRCA-mutation carriers have a lifetime risk of breast cancer (BC) that ranges from 36 to 70%. For patients (pts) without mutation, breast conserving surgery (BCS) (followed by radiation therapy) is the treatment of choice since it offers similar survival to that of unilateral mastectomy. However, the optimal local management in BRCA-mutation carriers remains a matter of debate and the role of bilateral salpingo-oophorectomy (BSO) in reducing BC risk might be influenced by age and medical BC treatments (such as GnRH analogues). Patients and methodsWe retrieved clinical pathologic characteristics of 124 BRCA-mutated BC pts, consecutively tested at our Institution from 2008 to 2018. Primary end-point was recurrence-free survival (RFS) evaluation in terms of disease-free survival (DFS), distant DFS (DDFS) and overall survival (OS). Secondary end-point was identification of independent predictive factors for BCS. Clinical pathologic characteristics were evaluated and compared using univariate and multivariate analysis. Kaplan-Mayer curves were used to describe DFS, DDFS and OS. ResultsMedian age at BC surgery was 41 years (range 24-74), most of the pts (79%) were pre-menopausal and presented with ductal invasive carcinoma (91.9%). As per biological subtype, 63 (50.8%) pts had luminal-like BC, 52 (41.9%) triple negative (TN) BC and 9 (7.3%) HER2 enriched-like BC. More than half pts (62.9%) presented with G3 tumors and median Ki-67 was 40% (range 5-95). 17 (13.7%) and 80 (64.5%) pts underwent neo-adjuvant and adjuvant chemotherapy, respectively; 64 (51.6%) pts received adjuvant endocrine therapy, 39 (31.5%) with the addition of GnRH analogue. When comparing BCS to mastectomy, regardless of BSO, we could not observe any statistically significant difference in all the RFS end-points. 10-year DFS rate was 56.4% and 79.5%, respectively (p=0.187); 10-year DDFS rate was 83.7% and 82.3%, respectively (p=0.689); 10-year OS rate was 87.7% and 85.1%, respectively (p=0.947). At a multivariate analysis, age ≤41 years (p=0.008; OR 0.309; 95% CI 0.190-0.513) and primary tumor dimension ≤21 mm (p=0.008; OR 0.320; 95% CI 0.114-0.426), were the only predictors of breast surgery type (BCS compared to any other surgical treatment). ConclusionsOur data suggest that young pre-menopausal BRCA-mutated pts with small tumors may not need up-front mastectomy and BSO might be postponed, when ovarian cancer risk epidemiologically rises and potential reproductive desire is fulfilled. Citation Format: Agnese Losurdo, Damiano Gentile, Monica Zuradelli, Andrea Sagona, Erika Barbieri, Monica Barile, Paolo Bianchi, Rosalba Torrisi, Wolfgang Gatzemeier, Marta Scorsetti, Corrado Tinterri, Armando Santoro. Breast conserving surgery in BRCA-mutation carriers. A single Institution experience [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-18-16.

Impact of dose-dense neoadjuvant chemotherapy on pathologic response and survival for HER2-positive breast cancer patients who receive trastuzumab

To compare outcomes in patients with human epidermal growth factor receptor-2 (HER2)-positive breast cancer who received either dose-dense neoadjuvant chemotherapy (NAC) with trastuzumab or standard-interval chemotherapy with trastuzumab. Patients with HER2-positive breast cancer who received NAC, including epirubicin and cyclophosphamide followed by paclitaxel with trastuzumab were included. Patients were divided into either the dose-dense or standard-interval group. We compared pathologic complete remission (pCR), distant disease-free survival (DDFS), event-free survival (EFS), and breast cancer-specific survival (BCSS) between the two groups. Two hundred (49.6%) patients received dose-dense NAC, and 203 (50.4%) received standard-interval NAC. The pCR rate was 38.4% in the dose-dense group and 29.2% in the standard-interval group (P = 0.052). In patients with lymph node (LN) metastases, the LN pCR rate was 70.9% in the dose-dense group and 56.5% in the standard-interval group (P = 0.037). After a median follow-up of 54.6 months, dose-dense chemotherapy presented an improvement on DDFS (hazard ratio [HR] = 0.49, 95% confidence interval [CI]: 0.19–1.28, EFS (HR = 0.54, 95% CI: 0.24–1.21), and BCSS (HR = 0.41, 95% CI: 0.11–1.51), but the difference was not significant. Compared with standard-interval chemotherapy, dose-dense chemotherapy resulted in a superior 5-year DDFS (100% vs. 75.3%, P = 0.017) and 5-year EFS (96.9% vs. 78.3%, P = 0.022) in patients younger than 40 years. HER2-positive patients can achieve a higher LN pCR rate with dose-dense NAC than with standard-interval NAC with trastuzumab. Better survival may also be achieved with dose-dense chemotherapy with trastuzumab than with standard-interval chemotherapy with trastuzumab among young patients (age ≤ 40 years).

Abstract PD3-03: Continued efficacy of neratinib in patients with HER2-positive early-stage breast cancer: Final overall survival analysis from the randomized phase 3 ExteNET trial

Abstract Background: Neratinib (NERLYNX®) is an irreversible pan-HER inhibitor that significantly improves invasive disease-free survival (iDFS) compared with placebo when given as extended adjuvant therapy in patients with HER2-positive (HER2+) early breast cancer after trastuzumab-based adjuvant therapy. In the phase 3 ExteNET trial, an absolute iDFS benefit of 2.5% and distant disease-free survival (DDFS) benefit of 1.7% were observed with neratinib after 5 years’ follow-up. As reflected in the approved indication by the European Medicines Agency (EMA), patients with hormone receptor-positive (HR+) disease who initiated neratinib treatment within 1 year of completing trastuzumab (HR+/≤1 year) experienced an absolute iDFS benefit of 5.1% and DDFS benefit of 4.7% at 5 years. In HR+/≤1 year patients with residual disease after neoadjuvant therapy, absolute 5-year iDFS and DDFS benefits of 7.4% and 7.0%, respectively, were observed. Here we report the final protocol-defined, event-driven analysis of overall survival (OS) from ExteNET, and provide descriptive analyses of subgroups of primary interest according to the EU label and current clinical practice in early-stage HER2+ disease. Methods: ExteNET was a multicenter, randomized, double-blind, placebo-controlled phase 3 trial of women with early-stage HER2+ breast cancer who had completed neoadjuvant or adjuvant trastuzumab plus chemotherapy (NCT00878709). Patients were randomly assigned to oral neratinib 240 mg/day or placebo for 1 year. Hazard ratios (HR) for OS were estimated from Cox proportional hazards models, and survival rates by the Kaplan-Meier method. The OS analysis was event-driven and powered for the intention-to-treat (ITT) population with a target of 248 events. Descriptive analyses were performed in the HR+/≤1 year subgroup per the approved indication in the EU, and in higher-risk patients, i.e. HR+/≤1 year who have residual disease after neoadjuvant therapy [i.e. those who did not achieve a pathologic complete response (pCR)]. Cut-off date: July 2019. Results: 2840 patients were randomized to study treatment (1420 per group). After a median follow-up of 8.1 years, 127 (8.9%) and 137 (9.6%) patients in the neratinib and placebo ITT groups had died, respectively. The 8-year OS rates were 90.1% (95% CI, 88.3–91.6) in the neratinib group and 90.2% (95% CI, 88.4–91.7) in the placebo group (absolute difference at 8 years -0.1%; stratified HR=0.95; 95% CI, 0.75–1.21; p=0.6914). A positive trend was seen in the prespecified HR+ subgroup (n=1631; absolute difference at 8 years 1.5%; HR=0.80; 95% CI, 0.58–1.12), and within this population, descriptive analyses suggested greater benefits with neratinib in the HR+/≤1 year subgroup (n=1334; absolute difference at 8 years 2.1%; HR=0.79; 95% CI, 0.55–1.13) and in the HR+/≤1 year subset with no pCR after neoadjuvant therapy (n=295; absolute difference at 8 years 9.1%; HR=0.47; 95% CI, 0.23–0.92). No new safety signals were reported with this long-term follow-up to 8 years. Conclusions: In this final OS analysis of ExteNET, there were fewer deaths with neratinib than placebo in the ITT population, but the results did not reach statistical significance. Analyses showed greater OS improvements with neratinib in subgroups including HR+/≤1 year, and HR+/≤1 year with residual disease after neoadjuvant therapy. These findings are consistent with the results based on the primary endpoint of iDFS, and support the use of neratinib in clinical practice in these patients. Citation Format: Frankie Ann Holmes, Beverly Moy, Suzette Delaloge, Stephen Chia, Bent Ejlertsen, Janine Mansi, Hiroji Iwata, Michael Gnant, Mark Buyse, Carlos Barrios, Tajana Silovski, Robert Separovic, Anna Bashford, Angel Guerrero-Zotano, Neelima Denduluri, Debra Patt, Erhan Gokmen, Ira Gore, John Smith, Richard Bryce, Feng Xu, Alvin Wong, Miguel Martin, Arlene Chan. Continued efficacy of neratinib in patients with HER2-positive early-stage breast cancer: Final overall survival analysis from the randomized phase 3 ExteNET trial [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD3-03.

Postoperative Adjuvant Anastrozole for 10 Rather than 5 Years in Patients with Oestrogen Receptor-Positive Breast Cancer: AERAS, a Randomised Multicentre Open-Label Phase III Trial

Background: Treatment with an aromatase inhibitor for 5 years is the standard treatment for postmenopausal hormone receptor-positive breast cancer. We investigated the effects of extending this treatment to 10 years on the risk of breast cancer recurrence. Methods: This prospective, randomised, multicentre open-label phase III study assessed the effect of extending anastrozole treatment for an additional 5 years in postmenopausal patients with stage I–IIIA hormone receptor-positive breast cancer who were disease-free after treatment with either 5 years of anastrozole alone or 2–3 years of tamoxifen followed by 2–3 years of anastrozole. Patients were allocated randomly (1:1) to continue anastrozole (1 mg/day orally) for an additional 5 years or stop anastrozole, using the central computer at the Comprehensive Support Project for Oncology Research Data Centre. Randomisation was stratified by type of postoperative endocrine therapy, nodal status, prior adjuvant chemotherapy, and facility. The primary endpoint was disease-free survival, including breast cancer recurrence, second primary cancers, and death from any cause. This study is registered with UMIN clinical trials registry, number UMI00818. Findings: We enrolled 1697 patients from 117 facilities between November 2007 and November 2012. Patients were assigned randomly to the continue group (n=849) or the stop group (n=848). Follow-up information was available for 1593 patients (n=787 in the continue group, n=806 in the stop group) as the full analysis set. After a median follow-up of 5·1 years, there were 172 events involving disease recurrence or the occurrence of contralateral breast cancer (75 in the continue group and 97 in the stop group) and 40 deaths (21 in the continue group and 19 in the stop group). The 5-year disease-free survival rates were 91% (95% confidence interval [CI] 89–93) in the continue group and 86% (95% CI 83–88) in the stop group (hazard ratio [HR] for disease-free survival 0·61, 95% CI 0·46–0·82; p<0·0010, two-sided log-rank test). The 5-year overall survival rates were 98% in the continue group and 98% in the stop group (HR 1·13, p=0·7042). The 5-year distant disease-free survival rates were 95% in the continue group and 93% in the stop group (HR 0·68, p=0·0553). Sixty-seven second primary cancers occurred, including 24 in the continue group and 43 in the stop group. Menopausal or bone-related all-grade adverse events were more frequent among patients in the continue group than in the stop group, including higher incidences of hot flashes (111 [14%] vs 81 [10%]), stiff joints (162 [21%] vs 98 [12%]), arthralgia (294 [37%] vs 236 [29%]), and new-onset osteoporosis (370 [47%] vs 355 [44%]). Interpretation: Continuing adjuvant anastrozole for an additional 5 years after 5 years’ initial treatment with anastrozole or tamoxifen is safe and beneficial in postmenopausal patients with hormone receptor-positive breast cancer. Trial Registration: This study is registered with UMIN clinical trials registry, number UMI00818. Funding: The Comprehensive Support Project for Oncology Research of the Public Health Research Foundation Declaration of Interest: None to declare. Ethical Approval: Ethical approval was provided by local ethics committees in each hospital.

Effect of Capecitabine Maintenance Therapy Using Lower Dosage and Higher Frequency vs Observation on Disease-Free Survival Among Patients With Early-Stage Triple-Negative Breast Cancer Who Had Received Standard Treatment

Among all subtypes of breast cancer, triple-negative breast cancer has a relatively high relapse rate and poor outcome after standard treatment. Effective strategies to reduce the risk of relapse and death are needed. To evaluate the efficacy and adverse effects of low-dose capecitabine maintenance after standard adjuvant chemotherapy in early-stage triple-negative breast cancer. Randomized clinical trial conducted at 13 academic centers and clinical sites in China from April 2010 to December 2016 and final date of follow-up was April 30, 2020. Patients (n = 443) had early-stage triple-negative breast cancer and had completed standard adjuvant chemotherapy. Eligible patients were randomized 1:1 to receive capecitabine (n = 222) at a dose of 650 mg/m2 twice a day by mouth for 1 year without interruption or to observation (n = 221) after completion of standard adjuvant chemotherapy. The primary end point was disease-free survival. Secondary end points included distant disease-free survival, overall survival, locoregional recurrence-free survival, and adverse events. Among 443 women who were randomized, 434 were included in the full analysis set (mean [SD] age, 46 [9.9] years; T1/T2 stage, 93.1%; node-negative, 61.8%) (98.0% completed the trial). After a median follow-up of 61 months (interquartile range, 44-82), 94 events were observed, including 38 events (37 recurrences and 32 deaths) in the capecitabine group and 56 events (56 recurrences and 40 deaths) in the observation group. The estimated 5-year disease-free survival was 82.8% in the capecitabine group and 73.0% in the observation group (hazard ratio [HR] for risk of recurrence or death, 0.64 [95% CI, 0.42-0.95]; P = .03). In the capecitabine group vs the observation group, the estimated 5-year distant disease-free survival was 85.8% vs 75.8% (HR for risk of distant metastasis or death, 0.60 [95% CI, 0.38-0.92]; P = .02), the estimated 5-year overall survival was 85.5% vs 81.3% (HR for risk of death, 0.75 [95% CI, 0.47-1.19]; P = .22), and the estimated 5-year locoregional recurrence-free survival was 85.0% vs 80.8% (HR for risk of locoregional recurrence or death, 0.72 [95% CI, 0.46-1.13]; P = .15). The most common capecitabine-related adverse event was hand-foot syndrome (45.2%), with 7.7% of patients experiencing a grade 3 event. Among women with early-stage triple-negative breast cancer who received standard adjuvant treatment, low-dose capecitabine maintenance therapy for 1 year, compared with observation, resulted in significantly improved 5-year disease-free survival. ClinicalTrials.gov Identifier: NCT01112826.

Is Survival with Conservative Breast Therapy Becoming Superior to That with Modified Radical Mastectomy Alone for the Treatment of Early Breast Cancer in This Era?

This study aims to assess survival rates in early breast cancer patients treated by conservative breast therapy (CBT), including radiotherapy, compared with those treated by modified radical mastectomy (MRM) alone. The South Egypt Cancer Institute and the Assiut University Oncology Department patients' records, from January 2010 to December 2017, were searched for T1-2N0-1M0 breast cancer patients treated by CBT or MRM. Patients who did not receive chemotherapy were excluded to reduce the treatment variation. The 5-year locoregional disease-free survival (LRDFS) was 97.3% for the CBT patients was and 98.0% for the MRM patients (P = .675). The 5-year distant disease-free survival (DDFS) was 93.6% for CBS and 85.7% for MRM (P = 0.033). The DFS was 91.9% for the BCT patients and 85.3% for the MRM patients (P = 0.045). The 5-year OS was 98.2% for the CBT patients and 94.3% for the MRM patients, (P = 0.02). By Cox regression analysis, the CBT resulted in significantly better OS, (P = 0.018) and the HR = 0.350, 95% CI 0.146-0.837. The adjusted OS, estimated by the propensity score-based weights, remained superior in CBT than in MRM patients (P < 0.001). CBT resulted in better DDFS, DFS, and OS than MRM. Future randomized trials are needed to confirm these findings and determine the cause.

Phase III trial of metronomic capecitabine maintenance after standard treatment in operable triple-negative breast cancer (SYSUCC-001).

507 Background: Triple-negative breast cancer (TNBC) has a relatively high relapse rate and poor outcome after standard therapy among all subtypes of breast cancer. Effective strategies to reduce risk of relapse and death are unmet medical needs. Methods: In this phase III trial, patients with operable TNBC were randomly assigned to receive metronomic capecitabine (650 mg/m2 twice daily continuously for one year) as maintenance therapy or observation after standard local and systemic treatment for curative intent. The primary end point was disease-free survival (DFS). Secondary end points included distant disease-free survival (DDFS), overall survival (OS) and safety. Results: A total of 434 patients were randomly assigned to capecitabine group (n = 221) or observation group (n = 213). At a median follow-up of 56.5 months, 5-year DFS was significantly better in capecitabine group than in observation group (83% vs. 73%, HR, 0.63; 95% CI, 0.42 to 0.96; p = 0.027). 5-year DDFS was also significantly better in capecitabine group than in observation group (85% vs. 76%, HR, 0.56; 95% CI, 0.37 to 0.90; p = 0.016). However, 5-year OS was not significantly different between two groups (85% vs. 81%, HR, 0.74; 95% CI, 0.47 to 1.18; p = 0.203). Two hundred and two (91.4%) of patients completed one year of capecitabine therapy as planned. The most common capecitabine-related adverse events were hand-foot syndrome (46%), leukopenia (24%), Hyperbilirubinemia (13%), gastrointestinal pain (7%) and elevated serum transaminases (5%). Conclusions: Maintenance therapy with metronomic capecitabine for one year following standard treatment significantly improved DFS in operable TNBC, which was safe and well tolerated. (SYSUCC-001, Clinical trial information: NCT01112826 .

Validation of the AJCC prognostic stage for HER2-positive breast cancer in the ShortHER trial

BackgroundThe 8th edition of the American Joint Committee on Cancer (AJCC) staging has introduced prognostic stage based on anatomic stage combined with biologic factors. We aimed to validate the prognostic stage in HER2-positive breast cancer patients enrolled in the ShortHER trial.MethodsThe ShortHER trial randomized 1253 HER2-positive patients to 9 weeks or 1 year of adjuvant trastuzumab combined with chemotherapy. Patients were classified according to the anatomic and the prognostic stage. Distant disease-free survival (DDFS) was calculated from randomization to distant relapse or death.ResultsA total of 1244 patients were included. Compared to anatomic stage, the prognostic stage downstaged 41.6% (n = 517) of patients to a more favorable stage category.Five-year DDFS based on anatomic stage was as follows: IA 96.6%, IB 94.1%, IIA 92.4%, IIB 87.3%, IIIA 81.3%, IIIC 70.5% (P < 0.001). Five-year DDFS according to prognostic stage was as follows: IA 95.7%, IB 91.4%, IIA 86.9%, IIB 85.0%, IIIA 77.6%, IIIC 67.7% (P < 0.001). The C index was similar (0.69209 and 0.69249, P = 0.975).Within anatomic stage I, the outcome was similar for patients treated with 9 weeks or 1 year trastuzumab (5-year DDFS 96.2% and 96.6%, P = 0.856). Within prognostic stage I, the outcome was numerically worse for patients treated with 9 weeks trastuzumab (5-year DDFS 93.7% and 96.3%, P = 0.080).ConclusionsThe prognostic stage downstaged 41.6% of patients, while maintaining a similar prognostic performance as the anatomic stage. The prognostic stage is valuable in counseling patients and may serve as reference for a clinical trial design. Our data do not support prognostic stage as guidance to de-escalate treatment.Trial registrationEUDRACT number: 2007-004326-25; NCI ClinicalTrials.gov number: NCT00629278.

Tumor characteristics and outcome by androgen receptor expression in triple-negative breast cancer patients treated with neo-adjuvant chemotherapy.

To assess clinical pathological characteristics and outcome of triple-negative breast cancers (TNBC) by androgen receptor (AR) protein expression. We retrospectively evaluated AR by immunohistochemistry on core-needle biopsy, (CNB) and residual disease (RD) in a consecutive institutional series of TNBC patients treated with neo-adjuvant chemotherapy (NACT) between 2000 and 2017. We investigated univariate associations between AR-expression on CNB (using different cut-offs), clinical pathological variables, and pathologic complete response (pCR). Next, we used multiple correspondence analysis (MCA) to investigate the relationships between AR on CNB and standard clinical and pathological variables, including stromal tumor infiltrating lymphocytes (sTILs). Finally, we investigated the prognostic value of AR-expression on CNB and RD using the Fine and Gray model. We included 71 patients; median follow-up was 6.7years. Considering the ≥ 1% cut-off, AR was present in 32% on the CNB and 14% on RD. AR-low (1-34% positive tumor cells) patients were associated with younger (premenopausal) age and AR-high (≥ 34% positive tumor cells) with older (postmenopausal) age. AR on CNB did not correlate with other features nor was it predictive for pCR or prognostic for metastatic outcome, regardless of the used cut-off. The MCA suggested that body mass index (BMI) affects the predictive role of AR-low and -highfor pCR differently. AR-loss on RD was prognostic for a better 5-year distant disease-free survival (DDFS) as compared to RD with retained AR-expression (61.6% (95% CI 44.26-79.14) and 25.0% (95% CI 3.94-87.21), respectively; p = 0.01). Low and high AR-expression on CNB of TNBCwere correlated with age and menopausal status but qualitative AR wasnot predictive for pCR. AR-loss on RD was prognostic for DDFS in TNBC patients treated with NACT.

Comparative efficacy of neoadjuvant to adjuvant chemotherapy for the treatment of early-stage HER2 negative breast cancer: A population-based analysis.

e12100 Background: The use of neoadjuvant treatment has increased over the past decade due to its ability to assess tumour sensitivity to systemic treatment in vivo, and to downstage women for increased breast conserving surgery. Recent studies have stratified patients with residual disease to receive additional treatment, which has resulted in meaningful improvements in survival. However, meta-analysis data suggest similar long-term outcomes for patients treated with neoadjuvant chemotherapy (NACT) compared to adjuvant chemotherapy (ACT) in historical randomized trials. The comparative efficacy in a real-world setting utilizing modern chemotherapy regimens is unknown. Methods: A retrospective review of the BC Cancer Breast Cancer Outcomes Unit (BCOU) was performed to identify patients with stage I-III HER-2 negative breast cancer treated with chemotherapy at the BC Cancer Agency from 2005-2010. Patients were then divided into 2 groups: those who received neoadjuvant chemotherapy (NACT) and those who received adjuvant chemotherapy (ACT). A matched analysis (age, stage, subtype) for patients treated with NACT vs ACT (matched 1:3) was then performed using a propensity scoring method to compare distant disease-free survival (DDFS), breast cancer specific survival (BCSS) and overall survival (OS). No patients received adjuvant chemotherapy for residual disease after NACT. Results: A total of 656 patients met the inclusion criteria, consisting of 164 NACT and 492 ACT cases. Median age was 49 years (37-68) in the NACT group vs 49 (37-65) in the ACT group (p = 0.71). The majority had stage 3 disease, 64% in both groups (p = 1.0). Most were hormone receptor positive (HR+), 67.1% vs 70.7% in the NACT vs ACT groups, respectively (p = 0.41). 5-year DDFS was 75% with NACT (95%CI 67, 82) and 77% with ACT (95%CI 72, 81), p = 0.87. 5-year OS for patients treated with NACT was 77% (95%CI 71, 84) and 80% (95%CI 75, 85) for patients treated with ACT, p = 0.33. 5-year BCSS was 80% with NACT (95% CI 70, 86) and 82% (95%CI 77, 86) with ACT, p = 0.75. Multivariate analysis for tumour size, nodal involvement and subtype are ongoing. Conclusions: The use of NACT compared to ACT in a population-based setting did not result in significant differences in DDFS, OS or BCSS. Acknowledging the comparative efficacy of these approaches will be informative to determine if the addition of subsequent adjuvant treatment for patients with residual disease after NACT will lead to differential benefits in a population-based setting.