Breast Conservation Therapy Decreases Heart-Specific Mortality

Melissa Nelson

August 29, 2022

The study covered in this summary was published in as a preprint and has not yet been peer reviewed.

Key Takeaways

  • Cardiovascular disease is a frequent complication of treatment of breast cancer. Heart disease is the leading cause of death among elderly patients with breast cancer.

  • Mastectomy, in comparison with breast conservation therapy, was significantly associated with higher risk for death from heart disease.

  • The risk of mortality from heart disease was higher among Black patients and unmarried patients.

Why This Matters

  • While survival rates for people with breast cancer have greatly improved, treatment complications are increasing. These complications include cardiotoxicity, which leads to cardiovascular disease.

  • Breast conservation therapy with chemoradiotherapy, endocrine therapy, and targeted therapy and mastectomy are currently the standard of care. Breast conservation therapy results in better patient satisfaction and overall survivability. However, the impact on heart-specific mortality of these two treatment regimens is unclear.

Study Design

  • The study included 132,616 people with primary breast cancer. The investigators used data from the Surveillance, Epidemiology, and End Results (SEER) program for the period from January 1998 to December 2015.

  • The study included only people with primary breast cancer. Patients were divided into two cohorts: those who received breast conservation therapy, and those who underwent mastectomy. The study's primary endpoint was heart-specific survival.

  • Factors that were evaluated included sex, race, age at diagnosis, marital status, surgery type, cancer stage, laterality, estrogen receptor and progesterone receptor status, survival time, and cause of mortality.

Key Results

  • Breast conservation therapy was given to 64.3% of patients; 35.7% of patients underwent mastectomy. The median age at diagnosis was 53.26 years. White patients made up 77.2% of the population; Black patients, 13.2%. The majority of patients (89.2%) had stage I or stage II disease.

  • During a median 88.4 months' follow-up, overall heart-specific mortality was second to breast cancer mortality. As age increased, mortality increased; heart-specific mortality was the leading cause of death among patients older than 80 years.

  • Risk factors significantly associated with death from heart disease included age, race, marital status, and surgery type.

  • Heart-specific mortality was higher among patients older than 50. Black patients were at highest risk of heart-specific mortality. Married people were less likely to die from heart disease. Mastectomy was significantly associated with higher risk of death from heart disease in comparison with breast conservation therapy.


  • The study was retrospective, which may have had a bearing on data quality.

  • The investigators were not able to evaluate the effects of chemotherapeutic agents and targeted therapy because of a lack of data in the SEER database. The SEER database also lacked comorbidity data.


  • The study received no commercial funding.

  • The authors have disclosed no relevant financial relationships.

This is a summary of a preprint research study, "Breast Conservation Therapy Decreased Heart-Specific Mortality in Breast Cancer Patients Compared With Mastectomy," published July 6 on and led by Ruipeng Zhao of Nanjing Medical University in China. It is provided to you by Medscape. The study has not yet been peer reviewed. The full text of the study can be found on

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