How to monitor cardiac toxicity of chemotherapy: time is muscle!

Lung-heart toxicity in a randomized clinical trial of hypofractionated image guided radiation therapy for breast cancer

Background

TomoBreast hypothesized that hypofractionated 15 fractions/3 weeks image-guided radiation therapy (H-IGRT) can reduce lung-heart toxicity, as compared with normofractionated 25-33 fractions/5-7 weeks conventional radiation therapy (CRT).

Methods

In a single center 123 women with stage I-II operated breast cancer were randomized to receive CRT (N=64) or H-IGRT (N=59). The primary endpoint used a composite four-items measure of the time to 10% alteration in any of patient-reported outcomes, physician clinical evaluation, echocardiography or lung function tests, analyzed by intention-to-treat.

Results

At 12 years median follow-up, overall and disease-free survivals between randomized arms were comparable, while survival time free from alteration significantly improved with H-IGRT which showed a gain of restricted mean survival time of 1.46 years over CRT, P=0.041.

Discussion

The finding establishes TomoBreast as a proof-of-concept that hypofractionated image-guided radiation-therapy can improve the sparing of lung-heart function in breast cancer adjuvant therapy without loss in disease-free survival. Hypofractionation is advantageous, conditional on using an advanced radiation technique. Multicenter validation may be warranted.

Trial registration

https://clinicaltrials.gov/ct2/show/NCT00459628. Registered 12 April 2007.

Cardiopulmonary-related patient-reported outcomes in a randomized clinical trial of radiation therapy for breast cancer

Background

Long-term prospective patient-reported outcomes (PRO) after breast cancer adjuvant radiotherapy is scarce. TomoBreast compared conventional radiotherapy (CR) with tomotherapy (TT), on the hypothesis that TT might reduce lung-heart toxicity.

Methods

Among 123 women consenting to participate, 64 were randomized to CR, 59 to TT. CR delivered 50 Gy in 25 fractions/5 weeks to breast/chest wall and regional nodes if node-positive, with a sequential boost (16 Gy/8 fractions/1.6 weeks) after lumpectomy. TT delivered 42 Gy/15 fractions/3 weeks to breast/chest wall and regional nodes if node-positive, 51 Gy simultaneous-integrated-boost in patients with lumpectomy. PRO were assessed using the European Organization for Research and Treatment of Cancer questionnaire QLQ-C30. PRO scores were converted into a symptom-free scale, 100 indicating a fully symptom-free score, 0 indicating total loss of freedom from symptom. Changes of PRO over time were analyzed using the linear mixed-effect model. Survival analysis computed time to > 10% PRO-deterioration. A post-hoc cardiorespiratory outcome was defined as deterioration in any of dyspnea, fatigue, physical functioning, or pain.

Results

At 10.4 years median follow-up, patients returned on average 9 questionnaires/patient, providing a total of 1139 PRO records. Item completeness was 96.6%. Missingness did not differ between the randomization arms. The PRO at baseline were below the nominal 100% symptom-free score, notably the mean fatigue-free score was 64.8% vs. 69.6%, pain-free was 75.4% vs. 75.3%, and dyspnea-free was 84.8% vs. 88.5%, in the TT vs. CR arm, respectively, although the differences were not significant. By mixed-effect modeling on early ≤2 years assessment, all three scores deteriorated, significantly for fatigue, P ≤ 0.01, without effect of randomization arm. By modeling on late assessment beyond 2 years, TT versus CR was not significantly associated with changes of fatigue-free or pain-free scores but was associated with a significant 8.9% improvement of freedom from dyspnea, P = 0.035. By survival analysis of the time to PRO deterioration, TT improved 10-year survival free of cardiorespiratory deterioration from 66.9% with CR to 84.5% with TT, P = 0.029.

Conclusion

Modern radiation therapy can significantly improve long-term PRO.

Trial registration

Trial registration number ClinicalTrials.govNCT00459628, April 12, 2007 prospectively.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08916-z.

One-Month Global Longitudinal Strain Identifies Patients Who Will Develop Pacing-Induced Left Ventricular Dysfunction over Time: The Pacing and Ventricular Dysfunction (PAVD) Study

Background

Predicting which individuals will have a decline in left ventricular (LV) function after pacemaker implantation remains an important challenge. We investigated whether LV global longitudinal strain (GLS), measured by 2D speckle tracking strain echocardiography, can identify patients at risk of pacing-induced left ventricular dysfunction (PIVD) or pacing-induced cardiomyopathy (PICMP).

Methods

Fifty-five patients with atrioventricular block and preserved LV function underwent dual-chamber pacemaker implantation and were followed with serial transthoracic echocardiography for 12 months for the development of PIVD (defined as a reduction in LV ejection fraction (LVEF) ≥5 percentage points at 12 months) or PICMP (reduction in LVEF to <45%).

Results

At 12 months, 15 (27%) patients developed PIVD; of these, 4 patients developed PICMP. At one month, GLS was significantly lower in the 15 patients who subsequently developed PIVD, compared to those who did not (n = 40) (GLS -12.6 vs. -16.4 respectively; p = 0.022). When patients with PICMP were excluded, one month GLS was significantly reduced compared to baseline whereas LVEF was not. One-month GLS had high predictive accuracy for determining subsequent development of PIVD or PICMP (AUC = 0.80, optimal GLS threshold: <−14.5, sensitivity 82%, specificity 75%); and particularly PICMP (AUC = 0.86, optimal GLS threshold: <−13.5, sensitivity 100%, specificity 71%).

Conclusions

GLS is a novel predictor of decline in LV systolic function following pacemaker implantation, with the potential to identify patients at risk of PIVD before measurable changes in LVEF are apparent. GLS measured one month after implantation has high predictive accuracy for identifying patients who later develop PIVD or PICMP.

Cardiovascular surveillance in breast cancer treatment: A more individualized approach is needed

Newly developed treatment strategies for breast cancer have reduced mortality rates over the past decades. Patients with breast cancer represent a heterogeneous population. Differences in the severity of the disease require diverse treatment options. Women have distinct individual risk patterns for cardiovascular disease that may affect their susceptibility to cardiotoxicity during therapy. While breast cancer treatment is targeted more on tumor and patient characteristics, a tailored individual approach with early and late cardiosurveillance is not yet implemented in routine care. Newly available cardiac imaging techniques are better suited to the early detection of cardiotoxicity and should be used more often in those patients at highest risk, as the early intervention afforded will improve their quality of life and prognosis.