Neoadjuvant radiotherapy in the approach of locally advanced breast cancer

Abstract

BackgroundApproximately 4% of European patients are diagnosed with locally advanced breast cancer (LABC), a clinical condition commonly associated with poorer prognosis. Systemic therapy is the recommended initial treatment and when inoperability criteria prevails, radiotherapy (RT) should be used for tumour downstaging. This study intends to evaluate the impact of neoadjuvant radiotherapy (NART) in the treatment of inoperable LABC.MethodsA retrospective study of female patients, submitted to the NART between January 2014 and December 2018 at our institution. The evaluation of pathological response (pR) was made based on Pinder criteria. Primary endpoint: pR. Secondary endpoints: overall survival (OS) and progression-free survival (PFS). OS and PFS were calculated using the Kaplan-Meier method. Differences between groups were compared using Student’s t-test, ANOVA (Analysis of variance) and χ2 test. The statistical analyses were performed using Stata (V.13).ResultsA total of 76 patients were included, 18% with breast complete response. The 5 years OS was 54% and PFS was 61%. Subgroup analysis showed that pR >90% is correlated with a better OS (p=0.004). Basal-like intrinsic subtype is correlated with worse OS and PFS (p<0.05). No relation was found between response and age, intrinsic subtype, treatment performed and clinical T stage.ConclusionOur study confirms that NART is an effective downsizing treatment in inoperable LABC, allowing for a surgical resection regardless of the systemic treatment performed. Response to NART is independent of the intrinsic subtype and pR >90% is correlated with a better OS. Prospective studies to explore predictive response biomarkers are necessary in order to improve patient selection and optimisation of the treatment.

A Novel Approach for the Discovery of Biomarkers of Radiotherapy Response in Breast Cancer

“…A potential issue is that there could be differences in secreted biomarker levels when RT is given neoadjuvantly to shrink in situ cancers compared with levels seen after post-operative adjuvant RT dealing with residual tumour cells. However, RT does also have a role in the management of BC in the neoadjuvant setting, where it can be combined with chemotherapy in patients with locally advanced cancer [ 115 , 116 , 117 , 118 , 119 , 120 , 121 ]. Neoadjuvant RT alone has been used for the treatment of BCs that are unsuitable for primary conservative surgery [ 122 ].…”

Quantitative digital histopathology and machine learning to predict pathological complete response to chemotherapy in breast cancer patients using pre-treatment tumor biopsies

“…Due to the high risk of cancer progression, metastatic spread, and loco-regional recurrence, LABC is associated with a poorer prognosis compared to early-stage BC 3 – 5 . The 10-year survival is approximately 44%, which is dependent on BC subtype and response to therapies 6 . Definitive treatment for LABC includes neoadjuvant chemotherapy (NAC) followed by surgery 7 .…”

Primary Chemoradiotherapy Treatment (PCRT) for HER2+ and Triple Negative Breast Cancer Patients: A Feasible Combination

“…Concomitant administration of radiotherapy and chemotherapy preoperatively looking for potentiating synergies is a standard approach for different tumors such as rectal, pancreatic, oesophageal or lung cancer. Concurrent radiotherapy and chemotherapy or immunotherapy regimens have been proposed prior to surgery as a strategy to improve resectability rates [ 8 , 9 , 10 , 11 ], increase pCR in certain breast cancers [ 12 , 13 ], and facilitate breast reconstruction [ 14 ]. However, concerns about its tolerance and safety have made many oncologists reluctant.…”