Particle radiotherapy for breast cancer

Understanding changes in pulmonary function and functional status in breast cancer patients after systemic chemotherapy and radiotherapy: a prospective study

BACKGROUND

Respiratory complications in breast cancer (BC) patients after chemotherapy (CT) and radiotherapy (RT) have been well acquainted and these complications should be investigated to prevent secondary problems and/or improve BC patients' clinical outcomes. Therefore, this study aimed to assess the potential acute effect of systemic chemotherapy and radiotherapy on respiratory function and functional status of patients with breast cancer.

METHODS

A total of 25 BC patients who were candidates for systemic chemotherapy and radiotherapy were recruited after oncological examination and included in this study. Respiratory function and functional status were assessed with the Pulmonary Function Test (PFT) and the Six-Minute Walk Test (6MWT), respectively. Patients were assessed before CT (c0), after CT (c1), and after RT (r1).

RESULTS

25 BC patients were assessed in c0 and c1 while only 15 out of 25 patients (60%) were assessed in r1. The actual values of Forced vital capacity (FVC) (t = 2.338, p =.028), Forced expiratory volume in 1s (FEV1 (t = 2.708, p =.012), and the forced expiratory flow of between 25% and 75% of vital capacity (FEF25-75%) (t = 2.200, p =.038) were found significantly different after systemic CT. Inspiratory (MIP) and expiratory (MEP) muscle strength also did not show a significant change from c0 to c1. A significant effect of the type of surgery was found (Wilks' lambda, F [1, 19] = 6.561, p =.019, ηp2 = 0.25) between c0 and c1 in actual FVC value. The main effect of time was found significant in FVC (F [2, 28] = 4.840, p =.016, ηp2 = 0.25) from c0 to r1. Pairwise comparisons with Bonferroni correction showed that there was a significant difference between c0 and r1 (p =.037).

DISCUSSION

The present study showed decreased FVC and FEV1 actual values and percent predicted rates from baseline to the completion of treatment. Since the interactional effect of the type of surgery was significant, we suggest that clinical and demographic factors such as age should be considered when interpreting the early changes in PFT. In addition, the significant linear trend of decreasing in some specific outcomes in respiratory function also highlighted the need for continuous monitoring of potential respiratory problems in patients with BC from baseline to the completion of chemotherapy and radiotherapy.

New Approaches in Breast Cancer Radiotherapy

Breast cancer stands as the most prevalent malignancy, necessitating a well-established approach to its management due to its sustained prevalence over decades. The implementation of intensive treatments, combining various modalities, has yielded excellent survival outcomes. Consequently, the optimization of quality of life and the mitigation of long-term side effects emerge as critical considerations for clinicians. As a result, discussions regarding treatment de-intensification strategies have been initiated for all treatment modalities, including surgery, radiotherapy (RT), and chemotherapy. RT plays a crucial role in adjuvant therapy. The efficacy of RT in disease control and overall survival across all stages of breast cancer has been demonstrated in numerous clinical trials and meta-analyses utilizing extensive datasets. However, advancements in genetic tumor profiling and improved identification of disease subgroups have prompted a reevaluation of RT omission in low-risk groups as a strategy for treatment de-intensification. Conversely, technological improvements and shortened total treatment times with hypofractionation make RT a secure and feasible option for enhancing local control and survival with minimal impact on the quality of life.

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.