The Impact of Hypofractionated Whole Breast Radiotherapy on Local Relapse in Patients With Grade 3 Early Breast Cancer: A Population-Based Cohort Study

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.

Clinical Outcomes of Hypofractionated Whole Breast Irradiation in Early-Stage, Biologically High-Risk Breast Cancer

PURPOSE

Adoption of hypofractionated whole breast irradiation (WBI) for patients with early-stage, biologically high-risk breast cancer remains relatively low. We compared clinical outcomes of conventionally fractionated versus moderately hypofractionated WBI in this patient population.

METHODS

We queried a prospectively maintained database for patients with early-stage (T1-2, N0, M0) breast cancer who received whole breast irradiation with either conventional fractionation (CWBI) or moderate hypofractionation (HWBI) at a single institution. We included only patients with biologically high-risk tumors (defined as either ER/PR/HER-2 negative, HER-2 amplified, and/or patients with a high-risk multi-gene assay) who received systemic chemotherapy. Inverse probability of treatment weighting (IPTW) was used to compare treatment cohorts and to estimate 5-year time to event endpoints. Hazard ratios (HR) and 95% CI were determined based on Cox Proportional Hazards Model.

RESULTS

We identified 300 patients, of whom 171 received CWBI and 129 received HWBI. There was a statistically significant difference in median age at diagnosis, 59 years for CWBI vs 63 years for HWBI (p = 0.004), and in median follow-up time, 97 months for CWBI vs 55 months for HWBI (p < 0.001). After accounting for differences in patient and tumor characteristics with IPTW, we found similar 5-year freedom from local recurrence (HR 0.76, 95% CI 0.14-4.1), freedom from regional recurrence (HR 3.3, 95% CI 0.15-69), freedom from distant metastasis (HR 3.9, 95% CI 0.86-17), and disease-free survival (HR 0.84, 95% CI 0.3-2.4), between those treated with CWBI and those treated with HWBI. Results were similar among each of the three high-risk subtypes.

CONCLUSION

Our data support the use of moderately hypofractionated whole breast irradiation in patients with early-stage, biologically high-risk breast cancer.

Ten-year outcomes of hypofractionated postmastectomy radiation therapy of 26 Gy in 6 fractions

PURPOSE

To investigate the efficacy and long-term side effects of hypofractionated postmastectomy radiation therapy (HFRT-PM) of 26 Gy in 6 fractions over 5 weeks.

MATERIALS & METHODS

We retrospectively reviewed characteristics and outcomes of patients with stage I-III breast cancer treated with HFRT-PM between 2000-2009. Treatment provided four fractions of 4 Gy (day (d)1, d3, d15, d17) then two fractions of 5 Gy (d29, d31) over 5 weeks. The treatment techniques were applied by using 3D conformal radiotherapy of chest wall with regional nodal volume if required.

RESULTS

454 patients were identified, with a median follow-up of 10.6 years (range 0.5-22.9). Regional nodal irradiation was made in 84.1 % of patients. At 10 years, the cumulative incidence of locoregional relapse was 15.1 %. In multivariate analysis, regional lymph nodes involvement (≥ 4 nodes) was associated with worse locoregional control (HR 1.68; [95% CI 1.06-2.67], p = 0.03) and overall survival (HR 2.16; [95% CI 1.59-2.95], p < 0.001). The toxicities were acceptable. The incidence of cardiac disorders (3.3 %), and symptomatic lung fibrosis (1.5 %) was low during follow-up. At 10 years, the cumulative rate of arm lymphedema was 9.5 % and considered severe in 20 patients (4.4 %).

CONCLUSION

The long-term results of this study show that HFRT-PM of 26 Gy in 6 fractions over 5 weeks seems safes but locoregional recurrence seems slightly higher than those observed in the literature, highlighting that long-term follow-up is needed and the need of randomized trials for hypofractionated radiotherapy therapy in postmastectomy situation.

[Radiation Oncology - Recent Status]

Radiation Oncology - Recent Status Abstract. We summarize the most important developments and innovations in the field over the past years and illustrate resulting external radiation treatment schedules and related treatment tolerance, focusing on hypofractionation.

Hypofractionated Adjuvant Radiation Therapy Is Effective for Patients With Lymph Node-Positive Breast Cancer: A Population-Based Analysis

PURPOSE

This study evaluated long-term, population-based, breast cancer-specific outcomes in patients treated with radiation therapy (RT) to the breast/chest wall plus regional nodes using hypofractionated (HF) (40-42.5 Gy/16 fractions) versus conventionally fractionated (CF) regimens (50-50.4 Gy/25-28 fractions).

METHODS AND MATERIALS

A prospective provincial database was used to identify patients with lymph node-positive breast cancer treated with curative-intent breast/chest wall + regional nodal RT from 1998 to 2010. The effect of RT fractionation on locoregional recurrence-free survival (LRRFS), distant recurrence-free survival (DRFS), and breast cancer-specific survival (BCSS) was assessed for the entire cohort and for high-risk subgroups: grade 3, ER-/HER2-, HER2+, and ≥4 positive nodes. Multivariable analysis and 2:1 case-match comparison of HF versus CF were also performed.

RESULTS

A total of 5487 patients met the inclusion criteria (4006 HF and 1481 CF). Median age was 55 years, and median follow-up was 12.7 years. On multivariable analysis, no statistically significant differences were identified in 10-year LRRFS (hazard ratio [HR] 0.87; 95% confidence interval [CI], 0.59-1.27; P = .46), DRFS (HR 0.90; 95% CI, 0.76-1.06; P = .19), or BCSS (HR 0.92; 95% CI, 0.76-1.10; P = .36) between the HF and CF cohorts. There was no statistical difference in breast cancer-specific outcomes in the high-risk subgroups. On analysis of 2962 HF cases matched to 1481 CF controls, no statistical difference was observed in LRRFS (HR 0.98; 95% CI, 0.71-1.33; P = .87), DRFS (HR 0.97; 95% CI, 0.85-1.11; P = .68), or BCSS (HR 1.00; 95% CI, 0.87-1.16; P = .92).

CONCLUSIONS

This large, population-based analysis with long-term follow-up after locoregional RT demonstrated that modest HF provides similar breast cancer-specific outcomes compared with CF. HF is an effective option for patients with stage I to III breast cancer receiving nodal RT.

Hypofractionated radiation treatment for breast cancer: The time is now

While there is now Level I data with long-term follow-up supporting the routine use of hypofractionated (HF) whole-breast radiation therapy (WBRT) after breast-conserving surgery, its adoption has been slow and variable. This article will review the literature supporting the efficacy and safety of hypofractionated radiation for breast cancer, discuss the radiobiological rationale specific to breast tumors, and make an argument for justifying the routine adoption of shorter, HF-WBRT courses when delivering breast radiation. Data using HF with regional nodal irradiation and in the post-mastectomy setting will also be reviewed. The aim is to provide an in-depth understanding of the use of hypofractionated radiation therapy for breast cancer, its applicability, and topics warranting future research.

Recommendations for hypofractionated whole-breast irradiation

This recommendation consensus for hypofractionated whole-breast radiotherapy (RT) was organized by the Brazilian Society of Radiotherapy (SBRT) considering the optimal scenario for indication and safety in the technology applied. All controversies and contraindication matters (hypofractionated RT in patients who underwent chemotherapy [CT], hypofractionated RT in lymphatic drainage, hypofractionated RT after mastectomy with or without immediate reconstruction, boost during surgery, hypofractionated RT in patients under 50 years old, hypofractionated RT in large breasts, hypofractionated RT in histology of carcinoma in situ [DCIS]) was discussed during a meeting in person, and a consensus was reached when there was an agreement of at least 75% among panel members. The grade for recommendation was also suggested according to the level of scientific evidence available, qualified as weak, medium, or strong. Thus, this consensus will aid Brazilian radiotherapy experts regarding indications and particularities of this technique as a viable and safe alternative for the national reality.

Tumor grade and molecular subtypes on local control in breast cancer radiotherapy: Does fractionation really matter? A retrospective control study group

The aim of this current study was to assess whether the tumour grade and molecular subtypes have influenced local control in the whole breast hypofractionated radiotherapy (HRT) over standard radiotherapy (SRT) in early breast node negative cancer patients by a retrospective control group study.

Data of 215 patients treated with hypofractionated radiotherapy at our institution from 2008 to 2011 were prospectively collected and then compared with 215 pts treated with SRT in a control group study. The local relapse free survival (LRFS) in both arms was compared on the basis of variables defined by tumour grade (Nottingham Grading System), and Molecular subtypes. Kaplan-Meier method was applied to estimate the LRFS in both groups. Chi-squared and univariate Cox proportional hazards model were conducted for all variables in both groups to assess the impact on local control. Statistical significance was assumed at P < .05. Statistical significant variables at univariate analysis were then included in multivariate Cox proportional hazards model. The median follow up duration was 9.5 years (7–13 yrs); the Kaplan Meyer 8 year LRFS did not reach any statistical significant difference between the two groups (P = . 836). At univariate Cox analysis tumour grade 3 was significantly related to local relapse only in the SRT group (P = .041) while, among molecular subtypes, no differences were found for all groups; for Her2 + noL no difference was found (P = .233). Multivariate analysis confirmed Her2 non-luminal subtype as an independent variable for local relapse regardless the fractionation arm (P = .045). Breast cancer subtypes show a different radiosensitivity, which is independent by fractionation.

The long-term outcome of adjuvant hypofractionated radiotherapy and conventional fractionated radiotherapy after breast-conserving surgery for early breast cancer: a prospective analysis of 107 cases

Background

This study aimed to evaluate the long-term outcomes of hypofractionated and conventional fractionated radiotherapy after breast-conserving surgery in patients with early-stage breast cancer. In addition, cosmetic and delayed toxic effects in the breast were also investigated.

Methods

A total of 107 female patients were recruited and randomly classified into the hypofractionated radiotherapy (HF) group (53 participants) and the conventional fractioned radiotherapy (CF) group (54 participants). The HF group was subjected to the following treatments: whole-breast irradiation (± irradiation of the infra-supraclavicular region) at 42.56 Gy/16 fractions + tumor bed boost at 7.98 Gy/3 fractions. The CF group received the following treatments: whole-breast irradiation (± irradiation of the infra-supraclavicular region) at 50 Gy/25 fractions + tumor bed boost at 10 Gy/5 fractions.

Results

The 10-year local recurrence (LR) rate, tumor-specific survival rate, disease-free survival rate, and overall survival rate of the HF and CF groups were 9.6% vs. 7.9% (P=0.712); 88.1% vs. 90.1% (P=0.738); 81.1% vs. 82.9% (P=0.792); and 86.5% vs. 88.5% (P=0.748), respectively. The 10-year rates of patients with good or excellent cosmetic results in the HF and CF groups were 72.7% vs. 67.4% (P=0.581), respectively. The 10-year rates of patients with delayed toxicity-free effects in the skin and the rates of patients with toxicity-free subcutaneous tissues in the HF and CF groups were 70.5% vs. 65.2% (P=0.595) and 52.3% vs. 47.8% (P=0.673), respectively.

Conclusions

Hypofractionated and CF showed comparable long-term efficacy, cosmetic effects, and delayed toxic effects. Hence, HF may be used as an alternative to conventional fractionated radiotherapy.

Utilization of hypofractionated whole-breast radiation therapy in patients receiving chemotherapy: a National Cancer Database analysis

PURPOSE

Results from four major hypofractionated whole-breast radiotherapy (HF-WBRT) trials have demonstrated equivalence in select patients with early-stage breast cancer when compared with conventionally fractionated WBRT (CF-WBRT). Because relatively little data were available on patients receiving neoadjuvant or adjuvant chemotherapy, consensus guidelines published in 2011 did not endorse the use of HF-WBRT in this population. Our goal is to evaluate trends in utilization of HF-WBRT in patients receiving chemotherapy.

METHODS AND MATERIALS

We retrospectively analyzed data from 2004 to 2013 in the National Cancer DataBase on breast cancer patients treated with HF-WBRT who met the clinical criteria proposed by consensus guidelines (i.e., age >0 years, T1-2N0, and breast-conserving surgery), regardless of receipt of chemotherapy. We employed logistic regression to delineate and compare clinical and demographic factors associated with utilization of HF-WBRT and CF-WBRT.

RESULTS

A total of 56,836 women were treated with chemotherapy and WBRT (without regional nodal irradiation) from 2004 to 2013; 9.0% (n = 5093) were treated with HF-WBRT. Utilization of HF-WBRT increased from 4.6% in 2004 to 18.2% in 2013 (odds ratio [OR] 1.21/year; P < 0.001). Among patients receiving chemotherapy, factors most dramatically associated with increased odds of receiving HF-WBRT on multivariate analysis were academic facilities (OR 2.07; P < 0.001), age >80 (OR 2.58; P < 0.001), west region (OR 1.91; P < 0.001), and distance >50 miles from cancer reporting facility (OR 1.43; P < 0.001). Factors associated with decreased odds of receiving HF-WBRT included white race, income <$48,000, lack of private insurance, T2 versus T1, and higher grade (all P < 0.02).

CONCLUSIONS

Despite the absence of consensus guideline recommendations, the use of HF-WBRT in patients receiving chemotherapy has increased fourfold (absolute = 13.6%) over the last decade. Increased utilization of HF-WBRT should result in institutional reports verifying its safety and efficacy.

External radiotherapy for breast cancer in the elderly

BACKGROUND

Breast cancer is the most common malignancy amongst elderly women and the main cause of mortality. A specific management for elderly woman is not clear because clinical trials are usually not customized for this subset of patients.

AIMS

The aim of this paper is to provide an overview of the available information on the main issues in the field of breast cancer radiotherapy in the elderly population.

MATERIALS AND METHODS

Authors discuss on different radiation treatments for breast cancer in the elderly, based on the data of the literature with a focus on new strategy: hypo-fractionation, accelerated partial breast irradiation, and the utility of a dose boost.

DISCUSSION

The treatment of breast cancer is not standardized in the elderly. The optimal management in this population often requires complex multidisciplinary supportive care due to multiple comorbidities to optimize their cancer care.

CONCLUSIONS

New options such as APBI or HyRT regimens should be taken into consideration and offered as a breach of duty to the elderly population. Furthermore, they should be extensively investigated through randomized clinical trials.

Accelerated whole breast irradiation in early breast cancer patients with adverse prognostic features

Purpose

Accelerated whole breast irradiation (AWBI) and conventional whole breast irradiation (CWBI) were compared to determine whether AWBI is as effective as CWBI in patients with early breast cancer and adverse prognostic features.

Patients and methods

We included 330 patients who underwent breast-conserving surgery (BCS) and post-operative radiation therapy (RT) using AWBI for pT1-2 and pN0-1a breast cancer from 2007 to 2010. These patients were matched with 330 patients who received CWBI according to stage, age (±3 years), and the year of BCS. AWBI of 39 Gy and CWBI of 50.4 Gy were given in 13 and 28 fractions, respectively.

Results

Median follow-up time was 81.9 months. There were no statistically significant differences between the AWBI and CWBI groups in terms of age, stage, tumor grade, or molecular subtype. More patients with Ki-67 index ≥ 14% were present in the AWBI group (AWBI 47.0% vs. CWBI 10.3%; P<0.01). The 5-year ipsilateral breast tumor relapse (IBTR) rates for the AWBI and CWBI groups were 0.8% and 1.8%, respectively (P=0.54). High tumor grade was a statistically significant risk factor for IBTR (5-year IBTR rate: 2.9%; P=0.01). Ki-67 ≥ 14% was marginally related to IBTR (5-year IBTR rate: 2.2%; P=0.07). There were no statistically significant differences in the hazard ratios between the AWBI and CWBI groups according to any of the risk factors. There were no acute grade 3 toxicities in the AWBI group. There were no late grade 3 toxicities in either group.

Conclusions

AWBI is comparable to CWBI in early breast cancer with adverse prognostic features.

Comparison of Conventional and Hypofractionated Radiotherapy in Breast Cancer Patients in Terms of 5-Year Survival, Locoregional Recurrence, Late Skin Complications and Cosmetic Results

Bckground:

Adjuvant radiation therapy is commonly administered following breast-conserving surgery for breast cancer patients. Hypofractionated radiotherapy can significantly reduce the waiting time for radiotherapy, working load on machines, patient visits to radiotherapy departments and medical costs.

Material/Methods:

Fifty-two patients with operable breast cancer (pT1-3pN0M0) who underwent breast conservation surgery in Tehran Cancer Institute during January 2011 to January 2012, were randomly assigned to undergo radiotherapy in two arms (hypofractionated radiotherapy arm with 30 patients, dose 42.5 Gy in 16 fractions; and conventional radiotherapy arm with 22 patients, dose 50 Gy in 25 fractions). W compared these two groups in terms of overall survival, locoregional control, late skin complications and cosmetic results.

Results:

At a median follow-up of 52.4 months (range: 0–64 months), the follow-up rate was 82.6%. Overall, after 60 months, there was no detectable significant differences between groups regarding cosmetic results (p = 0.857), locoregional control or survival.

Conclusions:

The results confirm that hypofractionated radiotherapy with a subsequent boost is as effective as conventional radiotherapy, is well-tolerated and can be used as an alternative treatment method following breast conservation surgery.

[Hypofractionated whole breast irradiation (WBRT): Results and indications]

Breast irradiation after breast-conserving surgery is essential for maximizing local control and overall survival. The increase of breast cancer (BC) incidence, constraints of classical five weeks (w) radiation regimens and scarcity of radiotherapy units have led to test short hypofractionated WBRT schemes. One pilot study and three prospective randomized trials have tested various hypofractionated regimens of WBRT. About 7000 patients were included and follow-up ranged from 5 to 12 years. The conclusion of these trials is similar, showing local control and toxicity equivalent to these of the standard regimens. Three schemes are now clearly validated: 42.5Gy/16fr/3w, 40Gy/15fr/3w, or 42Gy/13fr/5w. However, the majority of included patients had favorable prognostic factors, were treated to the breast only and the boost dose, when indicated, was delivered with a standard fractionation. Therefore, we recommend the regimens preferentially in patients treated to the breast only, and without nodal involvement. These studies did not evaluate the addition of a boost dose with a hypofractionated scheme. If a boost is to be given, a standard fractionation should be used. Particular care should be taken to avoid heterogeneities leading to high fraction doses to organs at risk (lung and heart).

Hypofractionated whole breast irradiation: new standard in early breast cancer after breast-conserving surgery

Hypofractionated whole breast irradiation (HF-WBI) has been proved effective and safe and even better for late or acute radiation toxicity for early breast cancer. Moreover, it improves patient convenience, quality of life and is expected to be advantageous in the medical care system by reducing overall cost. In this review, we examined key randomized trials of HF-WBI, focusing on adequate patient selection as suggested by the American Society of Therapeutic Radiology and Oncology (ASTRO) guideline and the radiobiologic aspects of HF-WBI in relation to its adoption into clinical settings. Further investigation to identify the current practice pattern or cost effectiveness is warranted under the national health insurance service system in Korea.

Short-course radiotherapy in elderly women with breast cancer: Comparison by age, comorbidity index and toxicity

BACKGROUND

Breast cancer is the most common malignancy amongst elderly women. It represents the main cause of mortality for those women and it is steadily increasing. The primary therapeutic approach remains surgery, as in other age groups. The role of radiotherapy following surgery is still debated. The use of hypofractionated schedules is challenging the standard fractionation and has now been considered an advantageous option within this subgroup of patients. Results from randomized controlled trials have not been shown to be inferior to standard fractionation in terms of local recurrence, disease-free survival and overall survival. Acute and late side effects were not increased by hypofractionated regimens.

PATIENTS AND METHODS

60 elderly women treated by hypofractionated radiotherapy after breast conserving surgery were stratified by age. Comorbidities associated compliance and toxicity correlation to age were the first endpoints of the study. Comorbidity associated compliance was calculated by Cumulative Illness Rating Scale Geriatric.

RESULTS

At a median follow-up of 15 months overall survival was 100%, without severe late toxicity. No statistical significant differences were found between Cumulative Illness Rating Scale-Geriatric, systemic therapy and toxicity.

CONCLUSION

In our experience hypofractioned regimens seem to be safe and reliable in the elderly setting, although longer follow up is needed.

Hypofractionated whole breast radiotherapy: current perspectives

Adjuvant radiotherapy (RT) is an important part of breast cancer management but the dose and fractionation schedules used are variable. A total of 50 Gy in 25 daily fractions delivered over 5 weeks is often considered the “standard” adjuvant RT prescription. Hypofractionated regimes such as 42.5 Gy in 16 daily fractions or 40 Gy in 15 daily fractions following breast-conserving surgery have proven to be equally effective and achieve similar or better cosmetic and normal tissue outcomes for both invasive and in situ diseases and when treating the regional nodes. Hypofractionation is more convenient for patients and less costly. However, certain patients at higher risk of RT late effects may benefit from a less intense, even more extended fractionation schedule. This review describes the indications for whole breast hypofractionated adjuvant RT for patients with breast cancer following breast-conserving surgery and proposes that hypofractionation should be the new “standard” for adjuvant breast cancer RT.

Similar Outcomes of Standard Radiotherapy and Hypofractionated Radiotherapy Following Breast-Conserving Surgery

Background

Adjuvant radiation therapy is commonly administered to breast cancer patients who received breast-conserving surgery. However, lengthy treatment times of standard radiotherapy pose certain challenges. Here, we performed a prospective controlled study comparing standard radiation to hypofractionated radiotherapy in terms of efficacy and outcome.

Material/Methods

Eighty breast cancer patients (tumor stage pT1-2N0-1M0) who had undergone breast-conservation surgery were randomly divided into 2 groups (40 patients/group). The experimental group received 43.2 Gy to the whole breast in 18 fractions for 24 days with a concomitant boost (50.4 Gy) to the tumor bed. The control group received 45 Gy to the whole breast in 25 fractions for 44 days with a boost to the tumor bed of 59 Gy. Survival, locoregional recurrence, adverse effects, and aesthetic results were all considered for analysis.

Results

The following criteria were included as part of study follow-up: local control, survival, adverse skin reactions, cosmetic outcome, and hematological toxicity. At a median follow-up of 27 months (follow-up rate 100%), there were no statistical differences in any of the categories between the 2 groups. The 2-year survival rate of both groups was 100% without any locoregional recurrence. Although there was some skin toxicity, these instances were not severe and they cleared on their own within 6 weeks. The most common problems encountered by patients were breast fibrosis and altered pigmentation.

Conclusions

A shortened whole-breast hypofractionated irradiation schedule with a concomitant boost is as effective as standard radiation and may be a reasonable alternative following breast conservation surgery.

Systematic review and meta-analysis comparing hypofractionated with conventional fraction radiotherapy in treatment of early breast cancer

BACKGROUND

The purpose of this meta-analysis is to evaluate the efficacy and safety of altered radiation fraction size on outcomes for early breast cancer patients.

METHODS

A search of MEDLINE, EMBASE, WEB OF SCIENCE, Cochrane Library and ClinicalTrials.gov was conducted. Quality of the randomized controlled trials (RCTs) or non-RCTs were evaluated according to Cochrane's risk of bias tool or Methodological Index for non-Randomized Studies (MINORS). Pooled risk ratio (RR) and 95% confidence interval (CI) were calculated. Subgroup analysis was applied according to different fraction dose and sensitivity analysis was performed according to RCTs or non-RCTs.

RESULTS

23 studies were included in this systematic review. Meta-analysis demonstrated hypofractionation radiotherapy (HFRT) was associated with decreased grade 2/3 acute skin reactions compared with conventional fraction RT (CFRT), either 2.5-3.0 Gy per fraction or 5.0-6.5 Gy per fraction. HFRT with 2.5-3.0 Gy per fraction significantly decreased moderate/marked photographic changes in breast appearance compared with CFRT [RR = 0.80, 95% CI (0.70, 0.91), P = 0.001], while HFRT with more than 3.0 Gy per fraction significantly increased moderate/marked photographic changes [RR = 1.21, 95% CI (1.06, 1.38), P = 0.004]. In addition HFRT cost one-third lower than CFRT. Regarding to local regional recurrence, distant metastasis, overall survival, disease free survival, excellent/good cosmetic comes, symptomatic radiation pneumonitis, ischemic heart disease and symptomatic rib fracture, there was no significant difference between two arms.

CONCLUSIONS

Based on available evidence, HFRT with 2.5-3.0 Gy per fraction should be the better choice for treatment of early breast cancer patients.

Adoption of hypofractionated whole-breast irradiation for early-stage breast cancer: a National Cancer Data Base analysis

PURPOSE

To evaluate the relationship of patient, hospital, and cancer characteristics with the adoption of hypofractionation in a national sample of patients diagnosed with early-stage breast cancer.

METHODS AND MATERIALS

We performed a retrospective study of breast cancer patients in the National Cancer Data Base from 2004-2011 who were treated with radiation therapy and met eligibility criteria for hypofractionation. We used logistic regression to identify factors associated with receipt of hypofractionation (vs conventional fractionation).

RESULTS

We identified 13,271 women (11.7%) and 99,996 women (88.3%) with early-stage breast cancer who were treated with hypofractionation and conventional fractionation, respectively. The use of hypofractionation increased significantly, with 5.4% of patients receiving it in 2004 compared with 22.8% in 2011 (P<.001 for trend). Patients living ≥50 miles from the cancer reporting facility had increased odds of receiving hypofractionation (odds ratio 1.57 [95% confidence interval 1.44-1.72], P<.001). Adoption of hypofractionation was associated with treatment at an academic center (P<.001) and living in an area with high median income (P<.001). Hypofractionation was less likely to be used in patients with high-risk disease, such as increased tumor size (P<.001) or poorly differentiated histologic grade (P<.001).

CONCLUSIONS

The use of hypofractionation is rising and is associated with increased travel distance and treatment at an academic center. Further adoption of hypofractionation may be tempered by both clinical and nonclinical concerns.

Hypofractionation in the era of modulated radiotherapy (RT)

The use of radiation therapy (RT) as a component of breast-conserving therapy (BCT) has been shown to reduce the risk of local-regional recurrence and improve overall survival. As has been the common practice in the United States and Continental Europe, the majority of studies that demonstrated these benefits utilized daily radiation doses ranging from 1.8 to 2.0 Gray (Gy) per day given for approximately 5 weeks. However, due to geographic limitations, patient preferences, and financial considerations, there have been continued attempts to evaluate the efficacy and safety of abbreviated or hypofractionated courses of whole-breast radiation. Two key factors in these attempts have been: 1) advances in radiobiology allowing for a more precise estimation of equivalent dosing, and 2) advances in the delivery of RT ('modulation') that have resulted in substantially improved dose homogeneity in the target volume. Hypofractionated schedules have been compared to conventional radiation courses in several randomized controlled trials, as well as many prospective and retrospective experiences. These studies, now with about 10 years of follow-up, have demonstrated equivalent rates of local-regional recurrence, disease-free survival, and overall survival. The rates of toxicity have generally not been increased with hypofractionated regimens; however, certain toxicities may take decades to manifest. The generalizability of these results is unclear, as the majority of patients in the trials were elderly with early-stage hormone-receptor positive disease. Nevertheless, there is now sufficient evidence to recommend hypofractionated whole breast RT for a substantial percentage of patients.

Local recurrence in women with stage I breast cancer: declining rates over time in a large, population-based cohort

PURPOSE

To evaluate whether local recurrence (LR) risk has changed over time among women with stage I breast cancer treated with breast-conserving therapy.

METHODS AND MATERIALS

Subjects were 5974 women aged ≥50 years diagnosis with pT1N0 breast cancer from 1989 to 2006, treated with breast-conserving surgery and radiation therapy. Clinicopathologic characteristics, treatment, and LR outcomes were compared among 4 cohorts stratified by year of diagnosis: 1989 to 1993 (n=1077), 1994 to 1998 (n=1633), 1999 to 2002 (n=1622), and 2003 to 2006 (n=1642). Multivariable analysis was performed, with year of diagnosis as a continuous variable.

RESULTS

Median follow-up time was 8.6 years. Among patients diagnosed in 1989 to 1993, 1994 to 1998, 1999 to 2002, and 2003 to 2006, the proportions of grade 1 tumors increased (16% vs 29% vs 40% vs 39%, respectively, P<.001). Surgical margin clearance rates increased from 82% to 93% to 95% and 88%, respectively (P<.001). Over time, the proportions of unknown estrogen receptor (ER) status decreased (29% vs 10% vs 1.2% vs 0.5%, respectively, P<.001), whereas ER-positive tumors increased (56% vs 77% vs 86% vs 86%, respectively, P<.001). Hormone therapy use increased (23% vs 23% vs 62% vs 73%, respectively, P<.001), and chemotherapy use increased (2% vs 5% vs 10% vs 13%, respectively, P<.001). The 5-year cumulative incidence rates of LR over the 4 time periods were 2.8% vs 1.7% vs 0.9% vs 0.8%, respectively (Gray's test, P<.001). On competing risk multivariable analysis, year of diagnosis was significantly associated with decreased LR (hazard ratio, 0.92 per year, P=.0003). Relative to grade 1 histology, grades 2, 3, and unknown were associated with increased LR. Hormone therapy use was associated with reduced LR.

CONCLUSION

Significant changes in the multimodality management of stage I breast cancer have occurred over the past 2 decades. More favorable-risk tumors were diagnosed, and margin clearance and systemic therapy use increased. These changes contributed to the observed declining LR rates among patients treated with breast-conserving therapy.

The UK Standardisation of Breast Radiotherapy (START) trials of radiotherapy hypofractionation for treatment of early breast cancer: 10-year follow-up results of two randomised controlled trials

BACKGROUND

5-year results of the UK Standardisation of Breast Radiotherapy (START) trials suggested that lower total doses of radiotherapy delivered in fewer, larger doses (fractions) are at least as safe and effective as the historical standard regimen (50 Gy in 25 fractions) for women after primary surgery for early breast cancer. In this prespecified analysis, we report the 10-year follow-up of the START trials testing 13 fraction and 15 fraction regimens.

METHODS

From 1999 to 2002, women with completely excised invasive breast cancer (pT1-3a, pN0-1, M0) were enrolled from 35 UK radiotherapy centres. Patients were randomly assigned to a treatment regimen after primary surgery followed by chemotherapy and endocrine treatment (where prescribed). Randomisation was computer-generated and stratified by centre, type of primary surgery (breast-conservation surgery or mastectomy), and tumour bed boost radiotherapy. In START-A, a regimen of 50 Gy in 25 fractions over 5 weeks was compared with 41·6 Gy or 39 Gy in 13 fractions over 5 weeks. In START-B, a regimen of 50 Gy in 25 fractions over 5 weeks was compared with 40 Gy in 15 fractions over 3 weeks. Eligibility criteria included age older than 18 years and no immediate surgical reconstruction. Primary endpoints were local-regional tumour relapse and late normal tissue effects. Analysis was by intention to treat. Follow-up data are still being collected. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN59368779.

FINDINGS

START-A enrolled 2236 women. Median follow-up was 9·3 years (IQR 8·0-10·0), after which 139 local-regional relapses had occurred. 10-year rates of local-regional relapse did not differ significantly between the 41·6 Gy and 50 Gy regimen groups (6·3%, 95% CI 4·7-8·5 vs 7·4%, 5·5-10·0; hazard ratio [HR] 0·91, 95% CI 0·59-1·38; p=0·65) or the 39 Gy (8·8%, 95% CI 6·7-11·4) and 50 Gy regimen groups (HR 1·18, 95% CI 0·79-1·76; p=0·41). In START-A, moderate or marked breast induration, telangiectasia, and breast oedema were significantly less common normal tissue effects in the 39 Gy group than in the 50 Gy group. Normal tissue effects did not differ significantly between 41·6 Gy and 50 Gy groups. START-B enrolled 2215 women. Median follow-up was 9·9 years (IQR 7·5-10·1), after which 95 local-regional relapses had occurred. The proportion of patients with local-regional relapse at 10 years did not differ significantly between the 40 Gy group (4·3%, 95% CI 3·2-5·9) and the 50 Gy group (5·5%, 95% CI 4·2-7·2; HR 0·77, 95% CI 0·51-1·16; p=0·21). In START-B, breast shrinkage, telangiectasia, and breast oedema were significantly less common normal tissue effects in the 40 Gy group than in the 50 Gy group.

INTERPRETATION

Long-term follow-up confirms that appropriately dosed hypofractionated radiotherapy is safe and effective for patients with early breast cancer. The results support the continued use of 40 Gy in 15 fractions, which has already been adopted by most UK centres as the standard of care for women requiring adjuvant radiotherapy for invasive early breast cancer.

FUNDING

Cancer Research UK, UK Medical Research Council, UK Department of Health.

DEGRO practical guidelines: radiotherapy of breast cancer I: radiotherapy following breast conserving therapy for invasive breast cancer

BACKGROUND AND PURPOSE

The aim of the present paper is to update the practical guidelines for postoperative adjuvant radiotherapy of breast cancer published in 2007 by the breast cancer expert panel of the German Society for Radiooncology (Deutsche Gesellschaft für Radioonkologie, DEGRO). The present recommendations are based on a revision of the German interdisciplinary S-3 guidelines published in July 2012.

METHODS

A comprehensive survey of the literature concerning radiotherapy following breast conserving therapy (BCT) was performed using the search terms "breast cancer", "radiotherapy", and "breast conserving therapy". Data from lately published meta-analyses, recent randomized trials, and guidelines of international breast cancer societies, yielding new aspects compared to 2007, provided the basis for defining recommendations according to the criteria of evidence-based medicine. In addition to the more general statements of the DKG (Deutsche Krebsgesellschaft), this paper addresses indications, target definition, dosage, and technique of radiotherapy of the breast after conservative surgery for invasive breast cancer.

RESULTS

Among numerous reports on the effect of radiotherapy during BCT published since the last recommendations, the recent EBCTCG report builds the largest meta-analysis so far available. In a 15 year follow-up on 10,801 patients, whole breast irradiation (WBI) halves the average annual rate of disease recurrence (RR 0.52, 0.48-0.56) and reduces the annual breast cancer death rate by about one sixth (RR 0.82, 0.75-0.90), with a similar proportional, but different absolute benefit in prognostic subgroups (EBCTCG 2011). Furthermore, there is growing evidence that risk-adapted dose augmentation strategies to the tumor bed as well as the implementation of high precision RT techniques (e.g., intraoperative radiotherapy) contribute substantially to a further reduction of local relapse rates. A main focus of ongoing research lies in partial breast irradiation strategies as well as WBI hypofractionation schedules. The potential of both in replacing normofractionated WBI has not yet been finally clarified.

CONCLUSION

After breast conserving surgery, no subgroup even in low risk patients has yet been identified for whom radiotherapy can be safely omitted without compromising local control and, hence, cancer-specific survival. In most patients, this translates into an overall survival benefit.