Impact of molecular subtype on 1325 early-stage breast cancer patients homogeneously treated with hypofractionated radiotherapy without boost: Should the indications for radiotherapy be more personalized?
Andrei Fodor,
Chiara Brombin,
Paola Mangili,
Fulvio Borroni,
Marcella Pasetti,
Roberta Tummineri,
Flavia Zerbetto,
Barbara Longobardi,
Lucia Perna,
Italo Dell’Oca,
Chiara L. Deantoni,
Aniko M. Deli,
Anna Chiara,
Sara Broggi,
Roberta Castriconi,
Pier Giorgio Esposito,
Najla Slim,
Paolo Passoni,
Simone Baroni,
Stefano L. Villa,
Paola M.V. Rancoita,
Claudio Fiorino,
Antonella Del Vecchio,
Giampaolo Bianchini,
Oreste D. Gentilini,
Mariaclelia S. Di Serio,
N.G. Di Muzio
Affiliations
Andrei Fodor
Department of Radiation Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy; Corresponding author.
Chiara Brombin
University Center for Statistics in the Biomedical Sciences, Vita-Salute San Raffaele University, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy
Paola Mangili
Medical Physics, IRCCS San Raffaele Scientific Institute, Milan, Italy
Fulvio Borroni
Department of Radiation Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy
Marcella Pasetti
Department of Radiation Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy
Roberta Tummineri
Department of Radiation Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy
Flavia Zerbetto
Department of Radiation Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy
Barbara Longobardi
Medical Physics, IRCCS San Raffaele Scientific Institute, Milan, Italy
Lucia Perna
Medical Physics, IRCCS San Raffaele Scientific Institute, Milan, Italy
Italo Dell’Oca
Department of Radiation Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy
Chiara L. Deantoni
Department of Radiation Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy
Aniko M. Deli
Department of Radiation Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy
Anna Chiara
Department of Radiation Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy
Sara Broggi
Medical Physics, IRCCS San Raffaele Scientific Institute, Milan, Italy
Roberta Castriconi
Medical Physics, IRCCS San Raffaele Scientific Institute, Milan, Italy
Pier Giorgio Esposito
Medical Physics, IRCCS San Raffaele Scientific Institute, Milan, Italy
Najla Slim
Department of Radiation Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy
Paolo Passoni
Department of Radiation Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy
Simone Baroni
Department of Radiation Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy
Stefano L. Villa
Department of Radiation Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy
Paola M.V. Rancoita
University Center for Statistics in the Biomedical Sciences, Vita-Salute San Raffaele University, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy
Claudio Fiorino
Medical Physics, IRCCS San Raffaele Scientific Institute, Milan, Italy
Antonella Del Vecchio
Medical Physics, IRCCS San Raffaele Scientific Institute, Milan, Italy
Giampaolo Bianchini
Department of Medical Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy
Oreste D. Gentilini
Department of Breast Surgery, IRCCS San Raffaele Scientific Institute, Milan, Italy
Mariaclelia S. Di Serio
University Center for Statistics in the Biomedical Sciences, Vita-Salute San Raffaele University, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy
N.G. Di Muzio
Department of Radiation Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy
Aim: We report molecular subtype impact on 1325 early breast cancer (BCa) patients treated with whole breast hypofractionated (WBH) adjuvant forward-planned intensity modulated radiotherapy (F-IMRT) without boost. Methods and materials: From 02/2009-05/2017 1325 patients with pTis-pT3, pNx-N1aM0 BCa who underwent breast conservation surgery were treated with WBHF-IMRT in our institute, to a total dose of 40 Gy/15 fractions, without boost. Median age: 62 (interquartile range-IQR-:51.14–70.53) years. Histology: 8% in situ carcinoma (ISC), 92% invasive tumors. Molecular subtypes (invasive tumors): 49.9% Luminal A, 33.1% Luminal B Her2 negative (−), 6.2% Luminal B Her2 positive (+), 3.6% Hormone Receptor (HR)- Her2+, 7.1% Triple negative (TNBC), and 0.2% HR+. Chemotherapy (CT) was prescribed in 28% of patients, hormonal therapy in 80.3%, monoclonal antibodies (MAb) in 86.8% of Luminal B Her2+ and 97.7% of HR- Her2+ patients. Results: Median follow up was 72.43 (IQR: 44.63–104.13) months. The 5-year Kaplan-Meier estimates of local relapse-free survival (LRFS) was 97.8%, regional-(RRFS) 98.6%, loco-regional- (LRRFS) 96.9%, distant- (DRFS) 96.6%, disease-free survival (DFS) 94.8% and overall survival (OS) 95.5%. Considering molecular subtypes, 5-year LRFS was: 99.8% for Luminal A, 96.7% for Luminal B Her2-, 94.1% for Luminal B Her2+, 87.9% for HR- Her2+, 95.1% for TNBC and 99.1% for in situ carcinoma. Conclusion: While the overall estimated probability of LR within 5 years after WBHF-IMRT without boost is good (2.2%), molecular subtypes have a strong impact, despite MAb therapy in Her2+ patients, and CT for TNBC patients, and could be used as a parameter in deciding the boost prescription.