Omitting Radiotherapy after Breast-Conserving Surgery in Luminal A Breast Cancer.

Female Humans Breast Neoplasms / classification Canada Ki-67 Antigen / biosynthesis Mastectomy, Segmental Neoplasm Recurrence, Local / pathology Prospective Studies Radiotherapy, Adjuvant Prognosis Middle Aged Receptors, Estrogen / biosynthesis Receptors, Progesterone / biosynthesis Receptor, ErbB-2 / biosynthesis Antineoplastic Agents, Hormonal / therapeutic use

Journal

The New England journal of medicine

ISSN: 1533-4406

Titre abrégé: N Engl J Med

Pays: United States

ID NLM: 0255562

Informations de publication

Date de publication:
17 Aug 2023

Historique:

medline: 18 8 2023

pubmed: 16 8 2023

entrez: 16 8 2023

Statut: ppublish

Résumé

Adjuvant radiotherapy is prescribed after breast-conserving surgery to reduce the risk of local recurrence. However, radiotherapy is inconvenient, costly, and associated with both short-term and long-term side effects. Clinicopathologic factors alone are of limited use in the identification of women at low risk for local recurrence in whom radiotherapy can be omitted. Molecularly defined intrinsic subtypes of breast cancer can provide additional prognostic information. We performed a prospective cohort study involving women who were at least 55 years of age, had undergone breast-conserving surgery for T1N0 (tumor size <2 cm and node negative), grade 1 or 2, luminal A-subtype breast cancer (defined as estrogen receptor positivity of ≥1%, progesterone receptor positivity of >20%, negative human epidermal growth factor receptor 2, and Ki67 index of ≤13.25%), and had received adjuvant endocrine therapy. Patients who met the clinical eligibility criteria were registered, and Ki67 immunohistochemical analysis was performed centrally. Patients with a Ki67 index of 13.25% or less were enrolled and did not receive radiotherapy. The primary outcome was local recurrence in the ipsilateral breast. In consultation with radiation oncologists and patients with breast cancer, we determined that if the upper boundary of the two-sided 90% confidence interval for the cumulative incidence at 5 years was less than 5%, this would represent an acceptable risk of local recurrence at 5 years. Of 740 registered patients, 500 eligible patients were enrolled. At 5 years after enrollment, recurrence was reported in 2.3% of the patients (90% confidence interval [CI], 1.3 to 3.8; 95% CI, 1.2 to 4.1), a result that met the prespecified boundary. Breast cancer occurred in the contralateral breast in 1.9% of the patients (90% CI, 1.1 to 3.2), and recurrence of any type was observed in 2.7% (90% CI, 1.6 to 4.1). Among women who were at least 55 years of age and had T1N0, grade 1 or 2, luminal A breast cancer that were treated with breast-conserving surgery and endocrine therapy alone, the incidence of local recurrence at 5 years was low with the omission of radiotherapy. (Funded by the Canadian Cancer Society and the Canadian Breast Cancer Foundation; LUMINA ClinicalTrials.gov number, NCT01791829.).

Sections du résumé

BACKGROUND BACKGROUND

METHODS METHODS

We performed a prospective cohort study involving women who were at least 55 years of age, had undergone breast-conserving surgery for T1N0 (tumor size <2 cm and node negative), grade 1 or 2, luminal A-subtype breast cancer (defined as estrogen receptor positivity of ≥1%, progesterone receptor positivity of >20%, negative human epidermal growth factor receptor 2, and Ki67 index of ≤13.25%), and had received adjuvant endocrine therapy. Patients who met the clinical eligibility criteria were registered, and Ki67 immunohistochemical analysis was performed centrally. Patients with a Ki67 index of 13.25% or less were enrolled and did not receive radiotherapy. The primary outcome was local recurrence in the ipsilateral breast. In consultation with radiation oncologists and patients with breast cancer, we determined that if the upper boundary of the two-sided 90% confidence interval for the cumulative incidence at 5 years was less than 5%, this would represent an acceptable risk of local recurrence at 5 years.

RESULTS RESULTS

Of 740 registered patients, 500 eligible patients were enrolled. At 5 years after enrollment, recurrence was reported in 2.3% of the patients (90% confidence interval [CI], 1.3 to 3.8; 95% CI, 1.2 to 4.1), a result that met the prespecified boundary. Breast cancer occurred in the contralateral breast in 1.9% of the patients (90% CI, 1.1 to 3.2), and recurrence of any type was observed in 2.7% (90% CI, 1.6 to 4.1).

CONCLUSIONS CONCLUSIONS

Among women who were at least 55 years of age and had T1N0, grade 1 or 2, luminal A breast cancer that were treated with breast-conserving surgery and endocrine therapy alone, the incidence of local recurrence at 5 years was low with the omission of radiotherapy. (Funded by the Canadian Cancer Society and the Canadian Breast Cancer Foundation; LUMINA ClinicalTrials.gov number, NCT01791829.).

Identifiants

DOI: 10.1056/NEJMoa2302344 PMID: 37585627

pubmed: 37585627

doi: 10.1056/NEJMoa2302344

doi:

Substances chimiques

Ki-67 Antigen 0

Receptors, Estrogen 0

Receptors, Progesterone 0

Receptor, ErbB-2 EC 2.7.10.1

Antineoplastic Agents, Hormonal 0

Banques de données

ClinicalTrials.gov

['NCT01791829']

Types de publication

Journal Article

Langues

eng

Sous-ensembles de citation

Pagination

612-619

Subventions

Organisme : Canadian Cancer Society

ID : 705466

Investigateurs

Beverly Helen Lester (BH)

Michael Sia (M)

Dorothy L Uhlman (DL)

David Voduk (D)

Eric Tran (E)

Alan McVey Nichol (A)

Lorna M Weir (LM)

Hannah Mills Carolan (H)

Jean-Marc Bourque (JM)

Sarah Hamilton (S)

Scott Tyldesley (S)

Sally Smith (S)

Pauline Troung (P)

Elaine Sze-Sze Wai (ES)

Isabelle Vallieres (I)

Tanya Berrang (T)

Susan Tyler (S)

Hosam Kader (H)

Nelson Leong (N)

Robert Olson (R)

Allison Ye (A)

Tien Phan (T)

Ivo Olivotto (I)

Siraj Husain (S)

Theresa Trotter (T)

Peter Craighead (P)

Shazia Mahmood (S)

Philip Wright (P)

Mohamed Akra (M)

Andrew Cooke (A)

Bashir Bashir (B)

Shahida Ahmed (S)

Julian Kim (J)

Ramana Rachakonda (R)

Darin Gopaul (D)

Sofya Kobeleva (S)

Sundeep Shahi (S)

Vasanth Basrur (V)

Timothy J Whelan (TJ)

Iwa Kong (I)

Ian Dayes (I)

Barbara Strang (B)

Jonathan Sussman (J)

Julie Arsenault (J)

Mira Goldberg (M)

Do-Hoon Kim (DH)

Francisco Perera (F)

Abhirami Hallock (A)

Gordon Okawara (G)

William McMillan (W)

Brian Findlay (B)

Rachel VanderMeer (R)

Julie Bowen (J)

David Want (D)

Sarwat Shehata (S)

Ryan Calson (R)

Andrew Pearce (A)

Wayne Koll (W)

Medhat El-Mallah (M)

Sten Donald Myrehaug (SD)

Jose Chang (J)

Orit Freedman (O)

Laval Grimard (L)

Lynn Chang (L)

Jean-Michel Caudrelier (JM)

Peter Cross (P)

Catherin Lochrin (C)

Scott Morgan (S)

Krystine Lupe (K)

John Hilton (J)

Joanne Meng (J)

Shailendra Verma (S)

Susan F Dent (SF)

Anthony Fyles (A)

Wilfred Levin (W)

Christine Anne Koch (CA)

Tatiana Conrad (T)

Jennifer Croke (J)

Robert Edward Dinniwell (RE)

Kathy Han (K)

Fei-Fei Liu (FF)

Joelle Helou (J)

Conrad Falkson (C)

Catherine de Metz (C)

Sou Thain (S)

William MacKillop (W)

Carey Shenfield (C)

Silvana Spadafora (S)

Ioannis A Voutsadakis (IA)

Christiaan Stevens (C)

Mathew Follwell (M)

Tiffany Tam (T)

Oluwabunmi Ogundimu (O)

Margaret Anthes (M)

Kevin Ramchandar (K)

Eileen Rakovitch (E)

Ida Akerman (I)

Danny Vesprini (D)

Irene Karam (I)

Mary Doherty (M)

Hanny Soliman (H)

Gregory Czarnotia (G)

Justin Lee (J)

Sophie Lavertu (S)

Pierre Rousseau (P)

Jean-Pierre Guay (JP)

Pierre Del Vecchio (P)

Toni Vu (T)

Valerie Theberge (V)

Anne Dagnault (A)

Nathalie Lessard (N)

Melanie Gaudreault (M)

Melanie Letourneau (M)

Lucie Blondeau (L)

Isabelle Germain (I)

Thierry M Muanza (TM)

Khalil Sultanem (K)

Gary Mok (G)

Marie-Andree Fortin (MA)

Sebastien Clavel (S)

Moein Alizadeh (M)

Danny Duplan (D)

Annie Houle (A)

Levon Igidbashian (L)

Anne-Sophie Gautheir-Pare (AS)

Isabelle Roy (I)

Tarek Hijal (T)

Christine Lambert (C)

Valerie Panet-Raymond (V)

Marc David (M)

Commentaires et corrections

Type : CommentIn