title: Secondary Breast Cancer Risk by Radiation Volume in Women With Hodgkin Lymphoma.
abstract: To determine whether the risk of secondary breast cancer (SBC) is reduced in women with Hodgkin lymphoma (HL) treated with smaller field radiation therapy (SFRT) versus mantle field radiation therapy (MRT).
  
  
  
  We used the BC Cancer Agency (BCCA) Lymphoid Cancer Database to identify female patients treated for HL between January 1961 and December 2009. Radiation therapy volumes were categorized as MRT or SFRT, which included involved field, involved site, or involved nodal radiation therapy. SBC risk estimates were compared using competing risk analysis and Fine and Gray multivariable model: MRT ± chemotherapy, SFRT ± chemotherapy, or chemotherapy-only.
  
  
  
  Of 734 eligible patients, 75% of the living patients have been followed up for more than 10 years, SBC has developed in 54, and 15 have died of breast cancer. The 20-year estimated risks (competing risk cumulative incidence) for SBC differed significantly: MRT 7.5% (95% confidence interval [CI] 4.4%-11.5%), SFRT 3.1% (95% CI 1.0%-7.7%), and chemotherapy-only 2.2% (95% CI 1.0%-4.8%) (P=.01). Using a Fine and Gray model to control for death and patients lost to follow-up, MRT was associated with a higher risk of SBC (hazard ratio [HR] = 2.9; 95% CI 1.4%-6.0%; P=.004) compared with chemotherapy-only and with SFRT (HR = 3.3; 95% CI 1.3%-8.4%; P=.01). SFRT was not associated with a greater risk of SBC compared with chemotherapy-only (HR = 0.87; 95% CI 0.28%-2.66%; P=.80).
  
  
  
  This study confirms that large-volume MRT is associated with a markedly increased risk of SBC; however, more modern small-volume RT is not associated with a greater risk of SBC than chemotherapy alone.
authors.affiliation: Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, British Columbia, Canada; Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Conway
authors.affiliation: Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Connors
authors.affiliation: Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, British Columbia, Canada; Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Scott
authors.initials: S
authors.lastname: Tyldesley
authors.affiliation: Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
authors.forename: Kerry J
authors.initials: KJ
authors.lastname: Savage
authors.affiliation: Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.
authors.forename: Belinda A
authors.initials: BA
authors.lastname: Campbell
authors.affiliation: Department of Cancer Surveillance and Outcomes, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
authors.forename: Yvonne Y
authors.initials: YY
authors.lastname: Zheng
authors.affiliation: Department of Cancer Surveillance and Outcomes, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Hamm
authors.affiliation: Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, British Columbia, Canada; Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada. Electronic address: TPickles@bccancer.bc.ca.
authors.forename: Tom
authors.initials: T
authors.lastname: Pickles
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D000970:Antineoplastic Agents / Q000009:adverse effects; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D001955:British Columbia / Q000453:epidemiology; D002423:Cause of Death; D002648:Child; D016001:Confidence Intervals; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006689:Hodgkin Disease / Q000188:drug therapy / Q000532:radiotherapy*; D006801:Humans; D015994:Incidence; D059012:Lost to Follow-Up; D015182:Lymphatic Irradiation / Q000009:adverse effects; D008466:Mechlorethamine / Q000008:administration & dosage / Q000009:adverse effects; D008594:Menopause, Premature; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D016609:Neoplasms, Second Primary / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D010049:Ovarian Diseases / Q000209:etiology; D011241:Prednisone / Q000008:administration & dosage / Q000009:adverse effects; D011344:Procarbazine / Q000008:administration & dosage / Q000009:adverse effects; D011878:Radiotherapy / Q000009:adverse effects / Q000379:methods; D018570:Risk Assessment; D017741:Survivors; D013997:Time Factors; D014750:Vincristine / Q000008:administration & dosage / Q000009:adverse effects; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents; D011344:Procarbazine; D008466:Mechlorethamine; D014750:Vincristine; D011241:Prednisone