Hypofractionated versus conventional intensity-modulated radiation irradiation (HARVEST-adjuvant): study protocol for a randomised non-inferior multicentre phase III trial

Chinese Society of Clinical Oncology (CSCO) Breast Cancer guidelines 2024

Background

Developing guidelines for the diagnosis and treatment of common cancers in China based on the evidence-based practice, the availability of diagnosis and treatment products, and the up-to-date advances in precision medicine is one of the basic tasks of the Chinese Society of Clinical Oncology Breast Cancer (CSCO BC) Committee.

Methods

Protocols with high evidence level and good availability are used as the Level I recommendations; protocols with relatively high evidence level but slightly lower expert consensus or with poor availability are used as the Level II recommendations; and protocols that are clinically applicable but with low evidence level are regarded as the Level III recommendations. Based on the findings of clinical research at home and abroad and the opinions of CSCO BC experts, the CSCO BC guidelines determine the levels of recommendations for clinical application.

Results

For human epidermal growth factor receptor 2 (HER2)-positive breast cancer, a combination of trastuzumab and pertuzumab regimen were recommended as Level I recommendation for neoadjuvant and first line metastatic breast cancer. Pyrotinib is also recommended as Level I recommendation in first line and second line therapy according to the latest studies conducted in China. Antibody drug conjugates was also recommended for patients with trastuzumab progression. For triple negative breast cancer, immunotherapy in early and metastatic breast cancer was highlighted and listed as new chapters in this version of guideline. For hormone receptor (HR)-positive breast cancer, cyclin dependent kinase 4/6 (CDK4/6) was recommended in different stages, especially in adjuvant therapy. There was also a new chapter for HER2-low breast cancer stratified by HR status.

Conclusions

We firmly believe that evidence-based, availability-concerned, and consensus-based guidelines will be more feasible for clinical practice in China and in other countries with similar situations.

Hypofractionation for Regional Nodal Irradiation in Breast Cancer: Best of Both the Worlds

Locoregional radiotherapy play an important role in controlling the disease after surgery in patients with breast cancer. Radiotherapy schedules vary from conventional fraction to hypofractionation. The purpose of this review is to get an insight into the data on regional nodal irradiation (RNI) with hypofractionation in patients with breast cancer. This systematic review was constructed in accordance with Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) framework. Electronic databases such as PubMed, Cochrane and EMBASE were searched from January 1, 2023 to March 31, 2023 to identify studies published in English language on hypofractionated RNI in post mastectomy patients. The search was carried out with the National Library of Medicine's Medical Subject Heading (MeSH) terms like "regional nodal irradiation," "hypofractionated" and "hypofractionation in breast cancer" with different Boolean operators (and/or). A manual search of reference lists of included articles was also performed to make sure there were no additional cases unidentified from the primary search. Studies deemed potentially eligible were identified and assessed by same independent reviewers to confirm eligibility. RNI data are mainly from a randomized study from Beijing and pooled data from START trials. There are also data from retrospective and single institutional studies and a few phase II studies with limited number of patients using different dose fractionations and techniques of radiotherapy. Doses used in these trials ranged from 26-47.7 Gy in 5-19 fractions over 1-4 weeks. Grade ≥ 2 pulmonary fibrosis and lymphedema rate ranged from 2%-7.9% and 3%-19.8% respectively. Grade ≥ 2 shoulder dysfunction and brachial plexopathy ranged from 0.2%-28% and 0%-< 1%, respectively. Late effects with a dose range of 26-40 Gy delivered in 5 to 15 fractions over 1-3 weeks were less/similar to conventional fraction. Current data showed lower/similar rates of toxicity with hypofractionated RNI compared with conventional fractionation RNI. Doses of 26 Gy to 40 Gy delivered in 5 to 15 fractions over 1-3 weeks are safe for RNI. With limited data, ultra-hypofractionation 26 Gy/5 fractions/1 week also seems to be safe. However, long-term outcome is awaited and many trials are going on to address its efficacy and safety.

Toxicity Evaluation of Dose-Escalation in Hypofractionated Regional Nodal Irradiation for Breast Cancer: A Retrospective Study

PURPOSE

Regional nodal irradiation (RNI) to the axilla and supraclavicular area presents distinct toxicities, such as lymphedema and shoulder stiffness, compared with whole-breast irradiation. There is insufficient evidence on the safety of dose-escalation in hypofractionated RNI. We aimed to evaluate and compare toxicity rates in patients with breast cancer who received hypofractionated RNI with and without dose-escalation.

METHODS AND MATERIALS

We retrospectively analyzed 381 patients with breast cancer treated with hypofractionated RNI between March 2015 and February 2017. Patients received either the standard-dose to the regional nodal area (43.2 Gy/16 fx; 48.7 Gy3.5 equivalent dose [EQD2], 2 Gy equivalent dose with α/β= 3.5 Gy) or dose-escalation with a median dose of 54.8 Gy3.5 EQD2 (range, 51.7-60.9 Gy3.5 EQD2), depending on clinical and pathologic nodal stage. Toxicity rates of lymphedema and shoulder stiffness were assessed, and statistical analyses were conducted to identify associated factors.

RESULTS

The median follow-up time was 32.3 months (5.7-47.0 months). After radiation therapy, 71 (18.6%) patients developed lymphedema, and 48 (12.6%) developed shoulder stiffness. Patients who received dose-escalation exhibited significantly higher rates of lymphedema (32.1% vs 14.8%; odds ratio, 2.72, P = .0004) and shoulder stiffness (23.8% vs 9.4%; odds ratio, 2.01, P = .0205) compared with the standard-dose group. Moreover, dose-escalation showed a tendency to increase the severity of lymphedema and shoulder stiffness.

CONCLUSIONS

Patients who received dose-escalation in hypofractionated RNI face a higher risk of developing lymphedema and shoulder stiffness compared with those who received standard-dose hypofractionated RNI. Therefore, it is crucial to implement close and frequent monitoring for early detection, along with timely rehabilitation interventions for these patients.

Efficacy and safety analysis of hypofractionated and conventional fractionated radiotherapy in postoperative breast cancer patients

OBJECTIVES

In this meta-analysis, we conducted a comparative analysis of the safety and efficacy of hypofractionated and conventional fractionated radiotherapy in individuals who had undergone surgery for breast cancer.

METHODS

This study involved a systematic and independent review of relevant research articles published in reputable databases such as PubMed, Embase, Cochrane Library, and Web of Science. Two investigators conducted the review, which included studies published up to January 3, 2023. The quality of the eligible studies was evaluated and data were extracted using Review Manager software 5.4 (RevMan 5.4) to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The analysis comprised 35 studies and encompassed a collective sample of 18,246 individuals diagnosed with breast cancer. We did not find a statistically significant disparity in efficacy between conventional fractionated (CF) radiotherapy and hypofractionated (HF) radiotherapy regarding local recurrence (LR; OR = 0.91, 95% CI: 0.76-1.09, P = 0.30), disease-free survival (DFS; OR = 1.20, 95% CI: 1.01-1.42, P = 0.03), and overall survival (OS; OR = 1.08, 95% CI: 0.93-1.26, P = 0.28). Concerning safety, there was no significant difference between the HF and CF regimens in terms of breast pain, breast atrophy, lymphedema, pneumonia, pulmonary fibrosis, telangiectasia, and cardiotoxicity. However, the HF regimen resulted in lower skin toxicity (OR = 0.43, 95% CI: 0.33-0.55, P < 0.01) and improved patient fatigue outcomes (OR = 0.73, 95% CI: 0.60 - 0.88, P < 0.01).

CONCLUSIONS

Although there is no substantial difference in LR, DFS, OS, or many other side effects between the HF and CF regimens, the HF regimen reduces skin toxicity and relieves patient fatigue. If these two issues need to be addressed in clinical situations, the HF regimen may be a superior alternative to conventional radiotherapy in postoperative breast cancer patients.

Evaluation of complexity and deliverability of IMRT treatment plans for breast cancer

This study aimed to predict the outcome of patient specific quality assurance (PSQA) in IMRT for breast cancer using complexity metrics, such as MU factor, MAD, CAS, MCS. Several breast cancer plans were considered, including LBCS, RBCS, LBCM, RBCM, left breast, right breast and the whole breast for both Edge and TrueBeam LINACS. Dose verification was completed by Portal Dosimetry (PD). The receiver operating characteristic (ROC) curve was employed to determine whether the treatment plans pass or failed. The area under the curve (AUC) was used to assess the classification performance. The correlation of PSQA and complexity metrics was examined using Spearman's rank correlation coefficient (Rs). For LINACS, the most suitable complexity metric was found to be the MU factor (Edge Rs = - 0.608, p < 0.01; TrueBeam Rs = - 0.739, p < 0.01). Regarding the specific breast cancer categories, the optimal complexity metrics were as follows: MAD (AUC = 0.917) for LBCS, MCS (AUC = 0.681) for RBCS, MU factor (AUC = 0.854) for LBCM and MAD (AUC = 0.731) for RBCM. On the Edge LINAC, the preferable method for breast cancers was MCS (left breast, AUC = 0.938; right breast, AUC = 0.813), while on the TrueBeam LINAC, it became MU factor (left breast, AUC = 0.950) and MCS (right breast, AUC = 0.806), respectively. Overall, there was no universally suitable complexity metric for all types of breast cancers. The choice of complexity metric depended on different cancer types, locations and treatment LINACs. Therefore, when utilizing complexity metrics to predict PSQA outcomes in IMRT for breast cancer, it was essential to select the appropriate metric based on the specific circumstances and characteristics of the treatment.

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.

The influence of axillary surgery and radiotherapeutic strategy on the risk of lymphedema and upper extremity dysfunction in early breast cancer patients

PURPOSE

To explore the risk factors for breast cancer-related lymphedema (BCRL) and upper extremity dysfunction (UED) in patients with early breast cancer after modern comprehensive treatment and to compare the toxicity of different treatment strategies.

METHODS

From 2017 to 2020, a total of 1369 female patients with pT1-3N0-1M0 breast cancer who underwent adjuvant radiotherapy in our centre were retrospectively reviewed. BCRL and UED were identified by the Norman and QuickDASH questionnaires. The incidence, severity and risk factors for BCRL and UED were evaluated.

RESULTS

After a median follow-up of 25 months, a total of 249 patients developed BCRL; axillary lymph node dissection (ALND), increased number of dissected nodes, right-sided and hypofractionated radiotherapy containing RNI were found to be significant risk factors (all p values < 0.05). The sentinel lymph node biopsy (SLNB)+ regional nodal irradiation (RNI) group had a significantly lower BCRL risk than the ALND + RNI group (10.8% vs. 32.5%, HR = 0.426, p = 0.020), while there was no significant difference between ALND vs. ALND + RNI or SLNB vs. SLNB + RNI. A total of 193 patients developed UED, and ALND (p = 0.02) was the only significant risk factor. The SLNB + RNI group had a significantly decreased risk of UED compared with the ALND + RNI group (7.5% vs. 23.9%, HR = 0.260, p = 0.001), and there was no significant difference between SLNB vs. SLNB + RNI or ALND vs. ALND + RNI.

CONCLUSION

Aggressive ALND remains the primary risk factor for BCRL and UED while RNI does not. Thus, replacing ALND with tailored radiotherapy would be an effective preventive strategy in early breast cancer patients.