Long-Term Cardiac Safety and Survival Outcomes of Neoadjuvant Pegylated Liposomal Doxorubicin in Elderly Patients or Prone to Cardiotoxicity and Triple Negative Breast Cancer. Final Results of the Multicentre Phase II CAPRICE Study

Background

The CAPRICE trial was designed to specifically evaluate neoadjuvant pegylated liposomal doxorubicin (PLD) in elderly patients or in those with other cardiovascular risk factors in whom conventional doxorubicin was contraindicated. The primary analysis of the study showed a pathological complete response (pCR) of 32% and no significant decreases in LVEF during chemotherapy. Here, we report important secondary study objectives: 5-year cardiac safety, disease-free survival (DFS), overall survival (OS) and breast cancer specific survival (BCSS).

Methods

In this multicentre, single-arm, phase II trial, elderly patients or those prone to cardiotoxicity and high risk stage II-IIIB breast cancer received PLD (35 mg/m²) plus cyclophosphamide (600 mg/m²) every 4 weeks for 4 cycles, followed by paclitaxel for 12 weeks as neoadjuvant chemotherapy (NAC). Left ventricular ejection fraction (LVEF) monitorization, electrocardiograms and cardiac questionnaires were performed at baseline, during treatment and at 9, 16, 28 and 40 weeks thereafter. The primary endpoint was pCR and 5-year cardiac safety, DFS, BCSS and OS were also analyzed.

Results

Between Oct 2007, and Jun 2010, 50 eligible patients were included. Median age was 73 (35-84) years, 84% were older than 65; 64% of patients suffered from hypertension, and 10% had prior cardiac disease. Most of tumors (88%) were triple negative. No significant decreases in LVEF were observed. The mean baseline LVEF was 66.6% (52-86) and after a median follow-up of 5 years, mean LVEF was 66 (54.5-73). For intention to treat population, 5-year DFS was 50% (95% CI 40.2-68.1) and 5-year OS was 56% (95%CI 41.2-68.4). There were 8 non-cancer related deaths, achieving a 5 years BCSS of 67.74% (CI 95%:54.31%- 81.18%).

Conclusion

At 5-year follow-up, this PLD-based NAC regimen continued to be cardiac-safe and effective in a population of very high-risk breast cancer patients. This scheme should be considered as an option in elderly patients or in those with other risks of developing cardiotoxicity.

Trial Registration Number

ClinicalTrials.gov reference NCT00563953.

Abstract P1-15-09: Histological patterns of response to neoadjuvant chemotherapy in breast cancer and breast conservation

Introduction

Neoadjuvant chemotherapy (NAC) in breast cancer is an in vivo marker of chemosensitivity and pathological complete response (pCR) an independent prognostic factor. When there is response, NAC downstages the tumour and may allow for or facilitate a conservative surgery. There are three histological patterns of response to NAC: a concentric pattern in which tumour regression takes place from the periphery to the center, a scatter pattern, where fibrosis is placed between tumoral cells, and a mixed pattern.

Objective

To determine which clinical and histological variables define the type of response to neoadjuvant chemotherapy that facilitates and allows for breast conservation in women with breast cancer.

Material and methods

A retrospective observational study was made including 170 patients with breast cancer who underwent NAC in the Hospital Universitari de Bellvitge between February 2010 and October 2013. Different clinicopathological parameters were recorded: age, menopausal, stage, surrogate molecular subtype, histological pattern of response, and pCR.

Median age was 50 (23-78),Stage I (1.1%) IIA (27.1%) IIB (35%), IIIA (20.9%), IIIB (11.4%), IIIC (4.5%). Molecular subrogated types: Triple negative (30.7%), Luminal B Her 2 negative like (26.2%), Her 2 positive (17.7%), Luminal B Her 2 positive like (16.4%) and Luminal A like tumours (9.0%).NAC included Anthracyclines, Taxanes, and Trastuzumab if Her 2 +++.

Results:

Histological pattern of response: 25,5% of cases achieved a pCR. When residual tumour was observed, 42% of the cases were as scatter pattern, 21.9% as concentric pattern and 8.9% as mixed pattern.

The predictive factors of pCR were in the univariate analysis: absence of multicentricity, negative estrogen receptor, negative progesterone receptor, histological grade 3, Ki 67 > 20%, and her 2 overexpression. In the multivariate analysis, only negative estrogen receptor and her 2 overexpression were predictive factors. The molecular surrogate type Her 2 positive was predictive of pCR.

The predictive factors of the concentric response were in the univariate analysis: tumour size of < 5 cm, absence of nodal involvement, negative estrogen receptor, negative progesterone receptor, presence of tumour necrosis and inflammatory infiltration. In the multivariate analysis, tumour size < 5 cm, absence of lymph node involvement, Ki 67 > 20% and tumour necrosis were statistically significative. The molecular surrogated type predictive of a concentric response was triple negative. Conservative surgery was more frequent in the concentric pattern group (78.4%) than in the scatter pattern (58.1%) (p=0.032) but the histological pattern of response to NAC is not correlated to survival.

Conclusions

Tumour size < 5 cm, absence of lymph node involvement, Ki 67 > 20% and tumour necrosis were predictive of concentric pattern of response to NAC. Triple negative tumours were related to concentric histological pattern, meanwhile Her 2 overexpressed was predictive of pCR. The conservative treatment was more frequent in the concentric pattern. Histological pattern of response to NAC is not correlated to outcome. Only pCR was related to survival.

Citation Format: Pla Farnós M-J, García Tejedor A, Fernández Montolí ME, Campos Delgado M, Soler Monsó T, Petit Montserrar A, Morilla Ruiz I, Gil Gil M, Falo Zamora C, Ortega Martinez R, Gumà Martinez A, Perez Martin X, Ponce Sebastià J. Histological patterns of response to neoadjuvant chemotherapy in breast cancer and breast conservation [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 P1-15-09.