B-type natriuretic peptide plasma level in 5-year breast cancer survivors after radiotherapy

Modern Radiotherapy and Risk of Cardiotoxicity

Despite the advancements of modern radiotherapy, radiation-induced heart disease remains a common cause of morbidity and mortality amongst cancer survivors. This review outlines the basic mechanism, clinical presentation, risk stratification, early detection, possible mitigation, and treatment of this condition.

Positive association between heart dosimetry parameters and a novel cardiac biomarker, solubleST-2, in thoracic cancer chest radiation

Background

Early screening and diagnosis of radiation‐induced heart disease (RIHD) is difficult in patients with chest radiation exposure. sST‐2 is involved in myocardial stress or injury. We evaluated the relationship between heart dose parameters and sST‐2 changes in chest malignant tumor patients who received chest radiation.

Methods

We prospectively collected thoracic malignancy cancer patients who had received chest radiotherapy. Heart dosimetry parameters were extracted from the treatment planning system. sST‐2 was measured at baseline, the middle stage, and after radiotherapy (recorded as pre‐ST‐2, mid‐ST‐2, and post‐ST‐2). sST‐2 change rate was calculated. Scatter plots showed the relationship between cardiac dose parameters and ST‐2 change rate. Multiple regression was used to analyze the relationship between cardiac dose parameters and ST‐2 change rate.

Results

Totally, 60 patients were enrolled. The mean V₅, V₁₀, V₂₀, V₃₀, V₄₀, and MHD was 60.93 ± 27.79%, 51.43 ± 25.44%, 39.17 ± 21.75%, 28.07 ± 17.15%,18.66 ± 12.18%, and 18.60 ± 8.63 Gy, respectively. The median M‐LAD was 11.31 (IQR 3.33‐18.76) Gy. The mean pre‐ST‐2, mid‐ST‐2, and post‐ST‐2 was 5.1 ± 3.8, 6.4 ± 3.9, and 7.6 ± 4.4, respectively. sST‐2 was elevated with thoracic irradiation (P < .001). Multivariate linear regression analyses showed that V₅, V₁₀, V₂₀, and MHD were independently and positively associated with ST‐2 change rate (β = .04, .04, .04, and .10, respectively, all P < .05).

Conclusion

Serum sST‐2 levels were elevated over time during radiotherapy. V₅, V₁₀, V₂₀ and MHD were independently and positively associated with the elevated ST‐2 change rate.

New therapeutic insights into radiation-induced myocardial fibrosis

Radiation therapy (RT) for the treatment of thoracic tumors causes radiation-induced heart disease (RIHD). Radiation-induced myocardial fibrosis (RIMF) is both an acute and chronic stage of RIHD, depending on the specific pathology, and is thought to be a major risk factor for adverse myocardial remodeling and vascular changes. With the use of more three-dimensional conformal radiation regimens and early screenings and diagnoses for RIMF, the incidence of RIHD is declining, but it still must be carefully investigated to minimize the mortality and morbidity of patients with thoracic malignancies after RT treatment. Effective methods for preventing RIMF involve a decrease in the direct radiation dose in the heart, and early screening and diagnosis. Medications remain as a useful adjunct for preventing or treating RIMF. This review mainly discusses the cellular and molecular mechanisms underlying RIMF, and new therapeutic drugs that can potentially be developed from this knowledge.