Tumour bed boost radiotherapy for women after breast-conserving surgery

Practice of Tumor Bed Boost in Patients after Oncoplastic Breast-Conserving Surgery

The practice of boost to the tumor bed after treatment with oncoplastic breast-conserving surgery (BCS) remains variable. Using a survey, the present study evaluated the current practice of tumor bed boost administered in women after oncoplastic BCS. Actively practicing radiation oncologists across India were sent a questionnaire on the practice of adjuvant whole-breast radiotherapy and tumor bed boost after oncoplastic BCS via email and encouraged to participate. Of the 54 radiation oncologists who participated, most (98.1%) used a linear accelerator for radiotherapy. Hypofractionation was preferred by 59.26%, standard fractionation by 7.41%, and the remaining selected the fractionation strategy based on various patient factors. In addition, 83.33% participants reported that they always planned tumor boost, 51.85% preferred photons for the boost, and 75.93% administered sequential boost. The most common dose for the boost was 12.5 Gy in five fractions (40.74%). Most participants (77.78%) revealed that they used a combination of methods for identifying the tumor bed. With respect to clip placement, most surgeons (96%) at the participants' centers placed ≥ 4 clips at the tumor site, with both the base and margins being preferred by surgeons (81.48%) for placement. Finally, 12.96% participants revealed that the surgeons always involved them during surgical planning, whereas 7.4% participants reported that they always included the surgeons during radiotherapy planning, suggesting that radiation oncologists and oncoplastic surgeons do not involve each other during surgical and radiotherapy planning, possibly leading to suboptimal treatment. This may be attributed to the absence of guidelines regarding boost practices after oncoplastic BCS.

Stabilised Hyaluronic Acid (sHA) gel as a novel marker for breast cancer tumour bed cavity: Surgical feasibility

Introduction

Consistent delineation of the breast conserving surgery (BCS) tumour bed (TB) for breast cancer remains a challenge for radiation oncologists. Accurate delineation allows for better local control and reduces toxicity when planning partial breast or TB boost radiation therapy (RT).

Methods

In the operating theatre (OT) breast surgeons inserted stabilised hyaluronic acid (sHA) gel as small drops approximately one cm into the walls surrounding the resection cavity. Surgical feasibility was determined by the rate of successful sHA gel insertion procedure, the ease of insertion as rated by surgeons, the time required for insertion procedure, the quantity used, and any adverse events (AE) relating to sHA gel insertion.

Results

Thirty-five patients were enrolled. All patients underwent sHA gel insertion successfully. The procedure added a median of 2.8 min to the OT time and was rated as 'easy' in 89 % of patients. There were no immediate AE in OT. Five (14 %) patients experienced a grade 2 or higher AE. Three of the five patients were prescribed oral antibiotics for breast infection. Two of the five patients experienced a grade 3 AE - haematoma which required evacuation in OT day 1 post-BCS, and infected seroma which required drainage and washout in OT 2 months post-BCS. All five patients recovered and underwent the planned adjuvant therapies for their BC. The AE data reflects common risks with standard BCS and are not clearly attributed to sHA gel insertion alone.

Conclusion

We show that sHA gel is surgically feasible as a marker to help define the TB cavity for post-BCS adjuvant MRI-based RT planning.

Locoregional Therapy: From Mastectomy to Reconstruction, Targeted Surgery, and Ultra-Hypofractionated Radiotherapy

Background

The past 3 decades have seen an unprecedented shift toward treatment de-escalation in surgical therapy of breast cancer.

Summary

Radical mastectomy has been replaced by breast-conserving and oncoplastic approaches in most patients, and full axillary lymph node dissection by less radical staging procedures, such as sentinel lymph node biopsy and targeted axillary dissection. Further, attempts have been made to spare healthy tissue while increasing the probability of removing the tumor with clear margins, thus improving cosmetic results and minimizing the risk of local recurrence. In this context, modern probe-guided localization techniques have been introduced to guide surgical excision. This progress was accompanied by the development of targeted systemic therapies. At the same time, radiotherapy for breast cancer has undergone significant changes. The use of hypofractionation has decreased the typical length of a treatment course from 5-6 weeks to 1-3 weeks. Partial breast irradiation is now a valid option for de-escalation in patients with low-risk features. Axillary radiotherapy achieves similar recurrence rates and decreases the risk of lymphedema in patients with limited sentinel node involvement.

Key Messages

Taken together, these advances are important steps toward individualization of locoregional management strategies. This highlights the importance of interdisciplinary approaches for de-escalation of locoregional therapies.

Effect of adjuvant radiotherapy after breast-conserving surgery in elder women with early-stage breast cancer: a propensity-score matching analysis

Purpose

The study aimed to explore the role of adjuvant radiotherapy (RT) after breast-conserving surgery (BCS) in elder women with early-stage breast cancer (BC).

Methods

BC patients with 70-79 years of age, stage T1-2N0-1M0, undergoing BCS were screened in the Surveillance, Epidemiology and End Results (SEER) database between 2010 and 2015. The clinicopathological characteristics were balanced with propensity-score matching (PSM) method. Kaplan-Meier curves and Cox regression analyses were performed to determine the impact of adjuvant RT on BC patients.

Results

Ultimately, 12,310 patients treated with adjuvant RT and 4837 patients treated with no RT, were involved in the analysis. Overall, patients treated with adjuvant RT was associated with a better breast cancer-specific survival (BCSS) (HR: 1.980 [1.596- 2.456], P < 0.001) and overall survival (OS) (HR: 2.214 [1.966- 2.494], P < 0.001) than those who did not undergo RT. After 1:1 PSM, adjuvant RT still performed advantage in both BCSS (HR: 1.918 [1.439- 2.557], P < 0.001) and OS (HR: 2.235 [1.904- 2.624], P < 0.001). In the multivariate COX analysis of BCSS, widowed, divorced and separated patients, tumor grade III, T2 stage, N1 stage, no RT, molecular subtypes with luminal B and triple negative were associated with a shorter BCSS (P < 0.05). In the multivariate COX analysis of OS, age ≥74 years, widowed, divorced and separated patients, tumor grade II/III, T2 stage, no RT, no chemotherapy, molecular subtypes with triple negative were associated with a shorter OS (P < 0.05). Furthermore, the advantages of adjuvant RT were observed in all subgroup analysis.

Conclusion

Adjuvant RT after BCS can improve both BCSS and OS in elderly patients with early-stage BC. Additionally, all subgroups analysis-derived BCSS and OS were in support of RT.

Impact of Radiotherapy Volumes on Late-Term Cosmetic Outcomes and Quality of Life in Patients With Unifocal and Multifocal/Multicentric Breast Cancer After Breast-Conserving Surgery

Objective

Breast-conserving surgery (BCS) followed by radiotherapy (RT) is the standard treatment for early-stage breast cancer. The use of an additional RT dose (boost) to the tumour bed improves local control but may worsen quality of life (QOL) and cosmetic results. Multifocal/multicentric tumours (MMTs) pose a challenge as they require larger boost volumes. This study investigated the impact of RT volumes on late-term cosmetic outcomes and QOL in patients with unifocal and MMTs who underwent adjuvant RT after BCS.

Materials and Methods

Retrospective data of 367 patients who underwent BCS between 2012 and 2014 were reviewed. A cohort of 121 patients with at least six months of completed RT were prospectively included in the study. Cosmetic results were evaluated using a modified scoring system, and QOL was assessed using The European Cancer Treatment and Organization Committee tools.

Results

The results showed that the inclusion of regional lymphatics in the RT treatment field significantly affected QOL, particularly in terms of role functioning and social functioning. Higher boost volume ratios were associated with increased pain-related symptoms. However, the presence of MMTs did not significantly affect cosmetic outcomes compared to unifocal tumours.

Conclusion

The size of the boost and inclusion of regional lymphatics in RT significantly impact QOL in patients undergoing BCS. Tumour foci number does not affect cosmetic outcomes. These findings emphasize the need for careful consideration of RT volumes to minimize long-term adverse effects on QOL. Future prospective studies should evaluate early side effects and baseline QOL scores to provide a comprehensive assessment.

A Comparison Between Sequential Conventional and Hypofractionated Boost Following Whole-Breast Radiotherapy: A Propensity Score-Matched Analysis

BACKGROUND

The majority of local relapses after breast conservation therapy occur in the proximity of the primary lesion. Studies have shown that boost radiotherapy (RT) following conventional whole-breast radiotherapy (WBRT) of 50 Gy in five weeks improves outcomes. Boost RT also increases the risk of moderate skin reactions and fibrosis. The ideal boost RT dose and timing (sequential versus simultaneous) after hypofractionated radiotherapy schedules remain unclear. This retrospective propensity score-matched analysis assessed the outcome of sequential hypofractionated boost compared to conventional fractionated boost.

METHODS

The study was approved by the Institutional Review Board of the Regional Cancer Centre, Thiruvananthapuram, India. Patients with stage I-III breast cancer who have received adjuvant radiotherapy with a sequential boost of either hypofractionated RT (8 Gy in three fractions) or conventional fractionated RT (10 Gy in five fractions) after conservative breast surgery were identified from the radiotherapy planning records and included in this study. A 1:1 case matching was performed using a propensity score incorporating four known prognostic factors, namely, clinical and pathological composite stage, tumor grade, tumor biology (based on estrogen and/or progesterone and HER2 neu expression), and boost technique, which may have an impact on acute toxicity to make the two boost groups more homogenous.

RESULTS

After propensity score matching (PSM), there were a total of 166 patients, with 83 patients each in both conventional and hypofractionated boost RT groups. The median follow-up period was 30.7 months. At two years, locoregional recurrence-free survival (LRFS) was 98.8% in both groups. Disease-free survival (DFS) at two years for the hypofractionated group and conventional group was 91.5% and 96.3% (hazard ratio (HR): 2.5, 95% confidence interval (CI): 0.664-9.4, p = 0.161), respectively, with no statistically significant difference. Patients with grade 3 tumors who received hypofractionated boost had a statistically significant increased risk of recurrence (DFS: 88.9% versus 100%, HR: 60.559, 95% CI: 0.138-26613.2, p = 0.011). The overall survival (OS) at two years was 100% in both groups. There was no difference in acute skin toxicity between the two groups.

CONCLUSION

The present interim analysis shows similar locoregional recurrence-free survival, overall survival, and disease-free survival and acute skin toxicity for hypofractionated boost RT of 8 Gy in three fractions compared to the conventional boost of 10 Gy in five fractions. Hypofractionated boost is a feasible alternative option following hypofractionated whole-breast radiotherapy for women with breast conservation treatment. However, longer follow-up is required before forming definite conclusions.

Efficacy and Tolerance of IMRT Boost Compared to IORT Boost in Early Breast Cancer: A German Monocenter Study

The aim of this retrospective study is to compare the two boost subgroups, IORT or IMRT, in terms of overall survival (OS), progression-free survival (PFS), cosmesis, and acute and late toxicity. It shall be shown whether and which of the boost techniques offers better results with respect to the facial points, since there are already many studies on applying boost to the tumor bed after/during breast conserving surgery, and there are few which compare the different techniques. For this comparison, two subgroups of 76 patients each (n = 152), treated between 2002 and 2015, were enrolled in the study. In one subgroup, the 9 Gy boost was intraoperatively administered after complete removal of the primary tumor, while the other subgroup received the boost of 8.4 Gy percutaneously and simultaneously integrated into the tumor bed after breast conserving surgery. Both subgroups have subsequently undergone whole breast irradiation (WBI) of 50.4/50 Gy in 1.8−2 Gy per fraction. OS and the incidence of late toxicity did not differ between the two subgroups and no risk factor was found regarding PFS. Acute toxicities initially occurred significantly less (p < 0.001) in the IORT subgroup; however, after WBI took place, this difference vanished. Therefore, boost application by means of IORT or IMRT can be considered equivalent.

Comparison of Breast Cancer Radiotherapy Techniques Regarding Secondary Cancer Risk and Normal Tissue Complication Probability - Modelling and Measurements Using a 3D-Printed Phantom

Background

Radiotherapy after breast-conserving therapy is a standard postoperative treatment of breast cancer, which can be carried out with a variety of irradiation techniques. The treatment planning must take into consideration detrimental effects on the neighbouring organs at risk-the lung, the heart, and the contralateral breast, which can include both short- and long-term effects represented by the normal tissue complication probability and secondary cancer risk.

Patients and Methods

In this planning study, we investigate intensity-modulated (IMRT) and three-dimensional conformal (3D-CRT) radiotherapy techniques including sequential or simultaneously integrated boosts as well as interstitial multicatheter brachytherapy boost techniques of 38 patients with breast-conserving surgery retrospectively. We furthermore develop a 3D-printed breast phantom add-on to allow for catheter placement and to measure the out-of-field dose using thermoluminescent dosimeters placed inside an anthropomorphic phantom. Finally, we estimate normal tissue complication probabilities using the Lyman-Kutcher-Burman model and secondary cancer risks using the linear non-threshold model (out-of-field) and the model by Schneider et al. (in-field).

Results

The results depend on the combination of primary whole-breast irradiation and boost technique. The normal tissue complication probabilities for various endpoints are of the following order: 1%-2% (symptomatic pneumonitis, ipsilateral lung), 2%-3% (symptomatic pneumonitis, whole lung), and 1%-2% (radiation pneumonitis grade ≥ 2, whole lung). The additional relative risk of ischemic heart disease ranges from +25% to +35%. In-field secondary cancer risk of the ipsilateral lung in left-sided treatment is around 50 per 10,000 person-years for 20 years after exposure at age 55. Out-of-field estimation of secondary cancer risk results in approximately 5 per 10,000 person-years each for the contralateral lung and breast.

Conclusions

In general, 3D-CRT shows the best risk reduction in contrast to IMRT. Regarding the boost concepts, brachytherapy is the most effective method in order to minimise normal tissue complication probability and secondary cancer risk compared to teletherapy boost concepts. Hence, the 3D-CRT technique in combination with an interstitial multicatheter brachytherapy boost is most suitable in terms of risk avoidance for treating breast cancer with techniques including boost concepts.

Radiotherapy of Breast Cancer—Professional Guideline 1st Central-Eastern European Professional Consensus Statement on Breast Cancer

The international radiotherapy (RT) expert panel has revised and updated the RT guidelines that were accepted in 2020 at the 4th Hungarian Breast Cancer Consensus Conference, based on new scientific evidence. Radiotherapy after breast-conserving surgery (BCS) is indicated in ductal carcinoma in situ (stage 0), as RT decreases the risk of local recurrence (LR) by 50–60%. In early stage (stage I-II) invasive breast cancer RT remains a standard treatment following BCS. However, in elderly (≥70 years) patients with stage I, hormone receptor-positive tumour, hormonal therapy without RT can be considered. Hypofractionated whole breast irradiation (WBI) and for selected cases accelerated partial breast irradiation are validated treatment alternatives to conventional WBI administered for 5 weeks. Following mastectomy, RT significantly decreases the risk of LR and improves overall survival of patients who have 1 to 3 or ≥4 positive axillary lymph nodes. In selected cases of patients with 1 to 2 positive sentinel lymph nodes axillary dissection can be substituted with axillary RT. After neoadjuvant systemic treatment (NST) followed by BCS, WBI is mandatory, while after NST followed by mastectomy, locoregional RT should be given in cases of initial stage III–IV and ypN1 axillary status.

Risk factors and specific cancer types of second primary malignancies in patients with breast cancer receiving adjuvant radiotherapy: a case-control cohort study based on the SEER database

Patients with breast cancer can survive and live a long, cancer-free life; however, late complications of treatment, such as second primary malignancies (SPMs), have emerged as a competing cause of death and morbidity. We conducted a long-term population-based cohort study to identify the risk factors for SPMs and specific secondary cancer types after various latency periods of irradiated breast cancer. Cox proportional hazards regression was used to calculate the hazard ratio (HR) and 95% confidence interval (95% CI) for independent risk factors for SPM. We also calculated the HR of each specific cancer type and the latency time to specific SPMs. The risk of SPM was statistically significantly higher in patients with adjuvant RT than in patients without adjuvant RT (adjusted HR [aHR]: 1.105, 95% CI: 1.013-1.206). Compared with the control group, the case group had significantly increased risks of contralateral breast cancer (aHR: 1.268, 95% CI: 1.112-1.445), lung cancer (aHR: 1.218, 95% CI: 1.049-1.565), and urinary system cancer (aHR: 1.702, 95% CI: 1.140-2.543). Adjuvant RT for breast cancer increases the risk of SPM. Contralateral breast cancer, lung cancer, and bladder cancer were significant SPMs after breast RT, although the cumulative risk of SPM was low, at approximately 6, 10, and 13 cancers per 1000 women with irradiated breasts at latency periods of 5, 10, and 15 years, respectively, after breast RT.

Long-Term Outcomes of an International Cooperative Study of Intraoperative Radiotherapy Upfront Boost With Low Energy X-Rays in Breast Cancer

Purpose

The purpose of this study was to assess the effectivity of upfront kilovoltage intraoperative radiotherapy (IORT) as a boost in high-risk early-stage breast cancer patients from an international pooled cohort.

Materials/Methods

Patients from four centers in three different countries were retrospectively screened. Those with a minimum 1-year follow-up were included. Cumulative local (LR), regional (RR), and distant metastasis rates (DM) were analyzed. Additionally, the estimated overall survival (OS) was assessed. The Cox regression analysis was performed to identify failure predicting factors.

Results

A total of 653 patients from centers in Peru, Spain, and Germany were included. The median follow-up was 55 (12–180) months, and age was 58 (27–86) years. Clinical tumor (T) staging was T1 65.85%, T2 30.17%, and T3 3.98%. Positive margins were found in 7.9% and in-situ component in 20.06%. The median IORT dose was 20 (6–20). The median time from IORT to EBRT was 74.5 (13-364) days. An overall 3.4% (n = 22) of patients developed local recurrence at some point during follow-up. The 12-, 60-, and 120-month cumulative LR were 0.3%, 2.3%, and 7.9%, respectively. After multivariate analysis, only age <50 remained to be a significant prognostic factor for local recurrence (HR 0.19, 95% CI 0.08–0.47; p < 0.05). The 10-year estimated OS was 81.2%.

Conclusion

Upfront boost with IORT yields similar local control outcomes to those EBRT-based reports. Results from prospective trials, regarding toxicity, cosmesis, and effectivity are awaited to confirm these findings.

Breast Radiotherapy after Oncoplastic Surgery—A Multidisciplinary Approach

Simple Summary

This article aims to review and summarize the current evidence for the role of oncoplastic breast surgery and the implications this may have on other therapies, such as radiotherapy and chemotherapy.

Abstract

Oncoplastic breast surgery encompasses a range of techniques used to provide equitable oncological outcomes compared with standard breast surgery while, simultaneously, prioritizing aesthetic outcomes. While the outcomes of oncoplastic breast surgery are promising, it can add an extra complexity to the treatment paradigm of breast cancer and impact on decision-making surrounding adjuvant therapies, like chemotherapy and radiotherapy. As such, early discussions at the multidisciplinary team meeting with surgeons, medical oncologists, and radiation oncologists present, should be encouraged to facilitate best patient care.

Implications of Oncoplastic Breast Surgery on Radiation Boost Delivery in Localized Breast Cancer

Background

Oncoplastic partial mastectomy (OPM) is a technique utilized to improve aesthetic and survivorship outcomes in patients with localized breast cancer. This technique leads to breast tissue rearrangement, which can have an impact on target definition for boost radiotherapy (BRT). The aim of this study was to determine if the choice of surgical technique independently affected the decision to deliver a radiation boost.

Materials and methods

This was a retrospective study of patients treated between January 2017 and December 2018. We selected consecutive patients based on surgical procedure: 50 undergoing standard breast-conserving surgery and 50 having had an OPM. The primary outcome was average treatment effect (ATE) of surgery type on reception of BRT. Secondary outcomes included ATE of surgery type on the time to reception of radiotherapy and incidence of ipsilateral breast tumor recurrence (IBTR). The ratio of boost clinical target volume (CTV) to pathologic tumor size was also compared between the two groups. Treatment effects regression adjustment and inverse-probability weighted analysis was used to estimate ATEs for both primary and secondary outcomes.

Results

For the entire cohort, the median age was 64 years (range: 37-88 years). The median tumor size was 1.5 cm (range: 0.1-6.5 cm). The majority of patients were with ≤ stage IIA (78%), invasive ductal subtype (80%), negative lymphovascular space invasion (78%), negative margin (90%), and positive ER/PR (estrogen receptor/progesterone receptor) (69%). Overall, surgical technique was not associated with differences in the proportion of patients receiving BRT (ATE: 6.0% [95% CI: -4.5 to 16.0]). There were no differences in delays to radiation treatment between the two groups (ATE: 32.8 days [95% CI: -22.1 to 87.7]). With a median follow-up time of 419 days (range: 30-793 days), there were only five recurrences, with one case of IBTR in each group. There was no difference in the ratio of CTV volume to tumor size between the two groups (p=0.38).

Conclusions

OPM did not affect the decision to offer localized BRT following standard whole breast radiotherapy or significantly affect treatment times or radiation volumes. The decision to offer OPM should include a multi-disciplinary approach.

Long-term results of hypofractionation with concomitant boost in patients with early breast cancer: A prospective study

Aim

To report the long-term local control and survival of patients with early breast cancer who had hypofractionated whole breast irradiation with concomitant boost (Hypo-CB).

Methods and materials

Between October 2009 and June 2010, 73 patients with early breast cancer (T1-3N0-1M0) who underwent breast conserving surgery were enrolled into the study. Thirty-six of these participants received 50 Gy of conventional irradiation in 25 fractions over 5 weeks to the whole breast with a sequential boost to the tumor bed with 10–16 Gy in 5–8 fractions (Conv-SEQ). The other 37 participants received a hypofractionated dose of 43.2 Gy in 16 fractions with an additional daily concomitant boost (CB) of 0.6 Gy over 3 weeks (Hypo-CB).

Results

At a median follow-up time of 123 months, ipsilateral local recurrence (ILR) was found in 3 participants, 1 of whom was in the hypofractionated group. All 3 ILR were true local recurrence (TR). There were no significant differences in the 10-year disease free survival (DFS) and 10-year overall survival rates (OS) between the conventional and hypofractionated groups (93.9% vs. 94.4%, p = 0.96 and 91.9% vs. 91.6%, p = 0.792, respectively).

Conclusion

This study showed that the effectiveness, DFS and OS were comparable between hypofractionated whole breast irradiation with a CB and the conventional irradiation with a sequential boost.

Hypofractionated whole breast irradiation after IORT treatment is safe in patients receiving adjuvant chemotherapy

INTRODUCTION

Hypofractionated whole breast irradiation (hWBI) and intraoperative radiotherapy (IORT) could be associated in breast cancer patients showing high-risk factors of local recurrence after breast conserving therapy (BSC). The aim of this trial was to evaluate, for the first time, the toxicity and cosmesis of hWBI after photon-IORT in high-risk patients treated by adjuvant chemotherapy.

MATERIALS AND METHODS

Thirty-one high-risk localized breast cancer patients treated by BCS, IORT (20 Gy), and adjuvant chemotherapy were included from February 2019 to August 2020 in this prospective trial, of hWBI (40.5 Gy/2.67 Gy/15 fractions). Acute and late toxicity (CTCAEv5.0) and cosmesis (Harvard scale), were assessed after treatment.

RESULTS

All patients completed their treatment and were evaluable after treatment. No patients showed severe (G3) acute/late toxicity. Excellent/good cosmesis at least 6 months after completing the treatment, was present in 93.6% of the patients.

CONCLUSION

hWBI in high-risk localized breast cancer patients treated by chemotherapy seems to have similar toxicity and cosmetic results than conventionally fractionated WBI in combination to photon-IORT after BCS.

Short-term outcomes and safety of radiotherapy for immediate breast reconstruction with autologous flap transfer following breast-conserving surgery

BACKGROUND

The outcomes of immediate autologous breast reconstruction (IABR) after partial mastectomy followed by postoperative radiotherapy (RT) in terms of aesthetics, treatment-related complications, and local control are unclear. In this study, we evaluated the efficacy of IABR after partial mastectomy with or without breast RT, and thus the impact of radiation on autologous flap transfer.

METHOD

A retrospective cohort study involving consecutive breast cancer patients who underwent IABR after partial mastectomy between July 2011 and December 2017 at Shengjing Hospital was performed. Patients were divided into two groups based on whether or not they received RT after IABR. We compared aesthetic outcomes and changes in the flap size over the three-dimensional coordinates at various timepoints (pre-RT, 1, 6, and 12 months post-RT), as well as postoperative complications, survival, and recurrence rates between the two groups.

RESULTS

In total, 84 breast cancer patients were enrolled, with 32 patients in the RT group and 52 in the non-RT group. At a median follow-up time of 33.3 months, no significant difference was found in the rate of regional recurrence between the two groups (3.13% vs. 3.85%, P = 1.00), and no local recurrences occurred in either group. At the timepoints pre-RT, 1, and 6 months post-RT (approximately 4, 7, and 12 months after IABR, respectively), 77 (91.7%), 70 (83.3%), and 83 (98.8%) patients, respectively, had achieved very good or good cosmetic outcomes, and only changes in breast skin color at 1 month after RT significantly differed between the RT and non-RT groups, with very good or good cosmetic result rates of 62.5% vs. 96.2%, respectively (P < 0.001). No significant difference in the reduction of flap size was observed at any timepoint between the two groups. There were no significant differences between the two groups in the rates of postoperative complications including necrosis of the flap, infection, hematoma, or seroma (all P > 0.05). Additionally, no grade 3 or greater RT-associated adverse events occurred during or after RT.

CONCLUSION

RT following IABR provides aesthetically satisfactory results without intolerable adverse complications and may safely be performed in patients who underwent IABR after partial mastectomy.

The prognostic value of lymph node ratio in survival of non-metastatic breast carcinoma patients

PURPOSE

This study was conducted to assess the correlation between lymph node ratio (LNR) and prognosis of non-metastatic invasive breast carcinoma.

METHOD

This retrospective study examined 455 patients who were diagnosed with non-metastatic, unilateral invasive breast carcinoma and underwent either breast conservative surgery (BCS) or modified radical mastectomy (MRM) with axillary lymph node dissection (ALND) with at least one lymph node identified in the ALND specimen. Receiver operating characteristics (ROC) curve analysis was used to find out predictive cut-off values of the LNR and negative lymph nodes (NLN).

RESULTS

The median follow-up duration was 38 months. The median DFS and OS were 68 months and 72 months, respectively. 25.1% of patients had reported recurrence. The optimal cut-off value of LNR was 0.40. LNR was found to correlate significantly with pathological T (p < 0.001), pathological N (p < 0.001), and NLN (p < 0.001). Univariate analysis of the patients showed that the age group ≤ 35 years, menstrual status, pathological T, nodal status, lymphovascular invasion (LVI), perineural invasion (PNI), tumor grade, estrogen receptor (ER), progesterone receptor (PR), molecular subtypes, LNR, and NLN can affect disease-free survival (DFS) (p < 0.05) and OS (p < 0.05). Multivariate analysis showed that the pathological T (p < 0.001), menstrual status (p = 0.030), and LNR (p < 0.001) were the independent prognostic factors for DFS. Pathological T (p < 0.001) and LNR (p < 0.001) were the independent prognostic factors affecting OS.

CONCLUSION

LNR is the independent prognostic factor of DFS and OS for non-metastatic breast carcinoma.

Radiation Boost After Adjuvant Whole Breast Radiotherapy: Does Evidence Support Practice for Close Margin and Altered Fractionation?

Adding a boost to whole breast radiation (WBI) following breast-conserving surgery (BCS) may help improve local control, but it increases the total cost of treatment and may worsen cosmetic outcomes. Therefore, it is reserved for patients whose potential benefit outweighs the risks; however, current evidence is insufficient to support comprehensive and consistent guidance on how to identify these patients, leading to a potential for significant variations in practice. The use of a boost in the setting of close margins and hypofractionated radiotherapy represents two important areas where consensus guidelines, patterns of practice, and current evidence do not seem to converge. Close margins were previously routinely re-excised, but this is no longer felt to be necessary. Because of this recent practice change, good long-term data on the local recurrence risk of close margins with or without a boost is lacking. As for hypofractionation, although there is guidance recommending that the decision to add a boost be independent from the whole-breast fractionation schedule, it appears that patterns-of-practice data may show underutilization of a boost when hypofractionation is used. The use of a boost in these two common clinical scenarios represents important areas of future study for the optimization of adjuvant breast radiation.

Adaptive radiation therapy of breast cancer by repeated imaging during irradiation

Breast cancer is the most frequent cancer among females and also a leading cause of cancer related mortality worldwide. A multimodality treatment approach may be utilized for optimal management of patients with combinations of surgery, radiation therapy (RT) and systemic treatment. RT composes an integral part of breast conserving treatment, and is typically used after breast conserving surgery to improve local control. Recent years have witnessed significant improvements in the discipline of radiation oncology which allow for more focused and precise treatment delivery. Adaptive radiation therapy (ART) is among the most important RT techniques which may be utilized for redesigning of treatment plans to account for dynamic changes in tumor size and anatomy during the course of irradiation. In the context of breast cancer, ART may serve as an excellent tool for patients receiving breast irradiation followed by a sequential boost to the tumor bed. Primary benefits of ART include more precise boost localization and potential for improved normal tissue sparing with adapted boost target volumes particularly in the setting of seroma reduction during the course of irradiation. Herein, we provide a concise review of ART for breast cancer in light of the literature.

Recent advances in de-intensification of radiotherapy in elderly cancer patients

Cancer in the elderly remains an evolving issue and a health challenge. Several improvements in the radiotherapy field allow the delivery of higher doses/fractions with a safe toxicity profile, permitting the reduction of radiation treatment protocols in the elderly. Regarding breast, prostate, and lung cancer, the under-representation of older patients in clinical trials limits the extension of treatment recommendations to elderly patients in routine clinical practice. Among the feasible alternatives to standard whole breast radiotherapy (WBRT) in older patients are shorter courses using higher hypofractionation (HF) and accelerated partial breast irradiation (APBI). The boost continues to be used in women at high risk of local recurrence but is less widely accepted for women at lower risk and patients over 70 years of age. Regarding prostate cancer, there are no published studies with a focus on the elderly. Current management decisions are based on life expectancy and geriatric assessment. Regimens of HF and ultra-HF protocols are feasible strategies for older patients. Several prospective non-randomized studies have documented the safe delivery of ultra-HF for patients with localized prostate cancer, and multiple phase III trials and meta-analyses have confirmed that the HF regimen should be offered with similar acute toxicity regardless of patient age and comorbidity. A recent pooled analysis from two randomized trials comparing surgery to stereotactic body radiation therapy (SBRT) in older adult patients with early stage non-small cell lung cancer did show comparable outcomes between surgery and SBRT. Elderly cancer patients are significantly under-represented in all clinical trials. Thus, the inclusion of older patients in clinical studies should be strongly encouraged to strengthen the evidence base for this age group. We suggest that the creation of oncogeriatric coordination units may promote individualized care protocols, avoid overtreatment with aggressive and unrecommended therapies, and support de-escalating treatment in elderly cancer patients.

Precision Medicine and the Role of Biomarkers of Radiotherapy Response in Breast Cancer

Radiotherapy remains an important treatment modality in nearly two thirds of all cancers, including the primary curative or palliative treatment of breast cancer. Unfortunately, largely due to tumor heterogeneity, tumor radiotherapy response rates can vary significantly, even between patients diagnosed with the same tumor type. Although in recent years significant technological advances have been made in the way radiation can be precisely delivered to tumors, it is proving more difficult to personalize radiotherapy regimens based on cancer biology. Biomarkers that provide prognostic or predictive information regarding a tumor's intrinsic radiosensitivity or its response to treatment could prove valuable in helping to personalize radiation dosing, enabling clinicians to make decisions between different treatment options whilst avoiding radiation-induced toxicity in patients unlikely to gain therapeutic benefit. Studies have investigated numerous ways in which both patient and tumor radiosensitivities can be assessed. Tumor molecular profiling has been used to develop radiosensitivity gene signatures, while the assessment of specific intracellular or secreted proteins, including circulating tumor cells, exosomes and DNA, has been performed to identify prognostic or predictive biomarkers of radiation response. Finally, the investigation of biomarkers related to radiation-induced toxicity could provide another means by which radiotherapy could become personalized. In this review, we discuss studies that have used these methods to identify or develop prognostic/predictive signatures of radiosensitivity, and how such assays could be used in the future as a means of providing personalized radiotherapy.

A Prospective Study of Cosmetic Outcomes for Patients Treated with Breast Conservation and Radiation Therapy using Shorter Fractionation Schedules at Auckland Hospital, New Zealand

AIMS

Breast cosmesis is an important outcome for women after breast conservation. It has been shown to be correlated with better patient satisfaction, sexuality and self-esteem. This study reports the subjective and objective breast cosmesis outcomes for women treated at Auckland Hospital Radiation Oncology Department using hypofractionated radiation therapy.

MATERIALS AND METHODS

Breast cosmesis was evaluated using a subjective questionnaire and standardised photographs before radiation, at 6 weeks, 1 year, 3 years and 5 years after radiation. Objective evaluation of the photographs and completion of questionnaires were undertaken by clinicians at the same time points. The questionnaire evaluated global cosmesis on a four-point scale - excellent (E), good (G), fair (F) and poor (P). Patient, tumour and treatment factors were evaluated to assess the impact on cosmesis.

RESULTS

Three hundred and fifty-eight patients completed the baseline assessments and two hundred and two patients completed the 5-year assessments. Sixty-eight per cent of patients at baseline and 70% at 5 years scored their cosmesis as E/G compared with 52% and 51%, respectively, by clinician assessment. Age >50 years, separation ≤25 cm, non-diabetic, T1 tumours, node negative, quadrant of the scar, no boost and no adjuvant endocrine therapy were correlated with E/G cosmesis. On multivariate analysis at baseline, the individual breast factors that were significantly associated with a score of E/G cosmesis were breast shape (P = 0.028) and scar appearance (P = 0.001). At 5 years, breast shape (P = 0.003), nipple shape (P = 0.019) and scar appearance (P = 0.001) were found to be significant.

CONCLUSION

This study shows that most women reported no significant change in their breast cosmesis after hypofractionated radiation treatment over 5 years and that a number of patient, tumour and treatment factors may impact on breast cosmesis.

Increasing Role of Oncoplastic Surgery for Breast Cancer

PURPOSE OF REVIEW

The goals of surgery for breast cancer have remained the same over the years, to eliminate breast cancer from the breast with the least degree of deformity. With the current expectation of long-term survival after breast cancer treatment, more attention has turned to the cosmetic result of the surgical treatment. Whether lumpectomy or mastectomy, the need for aesthetic improvement was recognized by surgeons both in and outside the USA.

RECENT FINDINGS

Oncoplastic surgery combines the skills of the cancer surgeon with those of the plastic surgeon. Sometimes, this means a team approach with a breast surgeon and a plastic surgeon both performing their mutual skills for the patient. Other times, the properly trained breast surgeon may perform some of the plastic techniques at the time of cancer surgery. Breast surgeons are rapidly gaining the ability to improve the post-cancer treatment appearance. To simplify the classification of oncoplastic techniques, we have used lower level, upper level, and highest level. The assignment of techniques to levels is based on both the technique and the surgeon's training and experience. Much data has accumulated demonstrating the safety and efficacy of the "aesthetic cancer cure." We describe the development of oncoplastic surgery, the techniques available, matching the right candidate with the right technique, and some comments about the future. It is clear from both clinical benefit and patient satisfaction that oncoplastic breast cancer procedures are here to stay. Plastic surgeons will likely focus on the upper- and highest-level procedures while breast/general surgeons will learn lower-level procedures and some of upper-level procedures as needed by their locale. Opportunities to educate breast/general surgeons in these techniques will continue to increase over the next several years. Formal education in oncoplastic surgery during breast fellowships will be necessary to catch up with the rest of the surgical world outside the USA.

Long-term outcome after intraoperative radiotherapy as a boost in breast cancer

PURPOSE

To investigate long-term oncological outcome and incidence of chronic side effects in patients with breast cancer and intraoperative radiotherapy given as an upfront boost (IORT boost).

METHODS

Retrospective analysis of 400 patients with an IORT boost with low-energy X‑rays (20 Gy), subsequent whole-breast irradiation (46-50 Gy), and annual oncological follow-up. Side effects were prospectively evaluated (LENT-SOMA scales) over a period of up to 15 years. Side effects scored ≥grade 2 at least three times during follow-up were judged to be chronic.

RESULTS

The median age was 63 years (30-85) and the median follow-up was 78 months (2-180) after IORT boost. In 15 patients a local recurrence occurred, resulting in a local recurrence rate at 5, 10, and 15 years of 2.0%, 6.6%, and 10.1%, respectively. The overall survival rates at 5, 10, and 15 years were 92.1%, 81.8%, and 80.7%, respectively. The most common high-grade side effects were fibrosis (21%) and pain (8.6%). The majority of side effects occurred within the first 3 years. The actuarial rates of chronic fibrosis were 19.1% and 21.1% at 5 and ≥8 years, of chronic pain 8.6% at ≥4 years, of chronic edema of the breast 2.4% at ≥2 years, of chronic lymphedema 0.0% at 5 and 10 years, and of chronic hyperpigmentation 0.5% at ≥2 years. Side effects were similar or less than expected from an external beam boost.

CONCLUSION

IORT boost appears to be a highly efficient and safe method for upfront delivery of the tumor bed boost in high-risk breast cancer patients.

Correlation of radiotherapy with prognosis of elderly patients with hormone receptor-positive breast cancer according to immunohistochemical subtyping

Objective

The present study examined the effect of radiotherapy on recurrence and survival in elderly patients with hormone receptor-positive early breast cancer.

Methods

A retrospective analysis of 327 patients aged ≥65 years, with stage I−II, hormone receptor-positive breast cancer who underwent breast-conserving surgery and received endocrine therapy (ET) or radiotherapy plus endocrine therapy (ET+RT) was performed. Both groups were divided into luminal A type and luminal B type subgroups. Evaluation criteria were 5-year disease-free survival (DFS), local relapse rate (LRR), overall survival (OS), and distant metastasis rate (DMR).

Results

There were significant differences in 5-year DFS [hazard ratio (HR)=1.59, 95% confidence interval (95% CI), 1.15−2.19; P=0.005] and LRR (HR=3.33, 95% CI, 1.51−7.34; P=0.003), whereas there were no significant differences in OS and DMR between ET group and ET+RT group. In luminal A type, there was no significant difference in 5-year DFS, LRR, OS and DMR between ET group and ET+RT group. In luminal B type, there were statistically significant differences in 5-year DFS (HR=2.19, 95% CI, 1.37−3.49; P=0.001), LRR (HR=5.45, 95% CI, 1.65−17.98; P=0.005), and OS (HR=1.75, 95% CI, 1.01−3.05; P=0.048) between ET group and ET+RT group. In the ET group, there were significant differences between luminal A type and luminal B type in 5-year DFS (HR=1.84, 95% CI, 1.23−2.75; P=0.003) and OS (HR=1.76, 95% CI, 1.07−2.91; P=0.026).

Conclusions

After breast-conserving surgery, radiotherapy can reduce the LRR and improve the DFS and OS of luminal B type elderly patients, whereas luminal A type elderly patients do not benefit from radiotherapy. Without radiotherapy, luminal A type patients have better DFS and OS than luminal B type patients.

The impact of age on the risk of ipsilateral breast tumor recurrence after breast-conserving therapy in breast cancer patients with a > 5 mm margin treated without boost irradiation

BACKGROUND

The boost irradiation to the tumor bed following whole-breast irradiation (WBI) reduced the risk of ipsilateral breast tumor recurrence (IBTR). However, in Japan, almost all patients with a margin ≤5 mm receive boost irradiation to the tumor bed, but the decision to perform boost irradiation for those with a margin > 5 mm is dependent on the institution. Thus, institutional guidelines on utilizing boost irradiation for patients aged ≤40 or ≤ 50 years vary. We investigated the IBTR rate to assess the appropriate age for boost irradiation to the tumor bed with a margin > 5 mm.

METHODS

From January 1993 to December 2010, 419 patients with early-stage breast cancer and negative margins (> 5 mm) after breast-conserving surgery received WBI without boost irradiation. The Gray test was used to compare the cumulative incidence of IBTR among patients aged ≤40, 41-50, and ≥ 51 years. Hazard ratios were estimated using the Fine and Gray models. Furthermore, as a subgroup analysis, we investigated whether IBTR depended on the use of systemic therapy, such as anthracycline or taxane regimens.

RESULTS

The median follow-up time was 9.3 years. In multivariate analysis, only age predicted IBTR (p = 0.047). The 10-year IBTR rate was 15.7% in patients aged ≤40, 3.8% in those aged 41-50, and 2.0% in patients aged ≥51 years. The difference between patients aged ≤40 and 41-50 years was statistically significant (p = 0.045), whereas the difference between patients aged 41-50 and ≥ 51 years was not significant (p = 0.21).

CONCLUSIONS

In our institutional surgical setting, when boost irradiation is performed only for patients with a margin ≤5 mm, the IBTR rate after WBI without boost irradiation was significantly higher in patients aged ≤40 years, suggesting that boost irradiation should be used for patients in this age group.

A comparison of a brachytherapy and an external beam radiotherapy boost in breast-conserving therapy for breast cancer: local and any recurrences

PURPOSE

Adding a tumour bed boost to whole-breast irradiation in breast-conserving therapy reduces local recurrence rates. The purpose of the present study was to investigate whether the boost technique influences the magnitude of the effect.

METHODS

Patients treated with breast-conserving therapy for invasive breast cancer between 2000 and 2007 were included in the analysis. Three groups were considered according to the applied boost technique: electrons, brachytherapy or photons. The endpoints were local recurrence and any recurrence. Cox regression models were used and correction for the confounders in the association between boost technique and outcome was performed using multivariable models.

RESULTS

1879 tumours were included in the analysis. 1448 tumours (77.1%) were treated with an electron boost, 334 (17.8%) with a brachytherapy boost and 97 (5.2%) with a photon boost. Median follow-up was 13.1 years. The 10-year local recurrence rate was 2.2%. In multivariable analysis with correction for age, pathological Tumour or Node stage (pT, pN), chemotherapy and hormonal therapy, there was no significant difference between the three groups for the local recurrence risk (p = 0.89). 10-year any recurrence rate was 10.8%. In multivariable analysis with correction for age, pT, pN, resection margins, radiotherapy, year of diagnosis, chemotherapy and hormonal therapy, there was no significant difference between the brachytherapy group and the electron group or the photon group (p = 0.11 and p = 0.28, respectively). The photon group had more recurrences compared to the electron group (Hazard Ratio 1.81, 95% Confidence Interval 1.12; 2.92, p = 0.02).

CONCLUSIONS

The local recurrence risk reduction of the tumour bed boost in breast-conserving therapy is not influenced by the applied boost technique.

Results of a nationwide survey on Japanese clinical practice in breast-conserving radiotherapy for breast cancer

The Breast Cancer Group of the Japanese Radiation Oncology Study Group conducted a nationwide questionnaire survey on the clinical practice of postoperative radiotherapy for breast-conserving treatment for breast cancer. This questionnaire consisted of 18 questions pertaining to the annual number of treated patients, planning method, contouring structure, field design, dose-fractionated regimen, application of hypofractionated radiotherapy, boost irradiation, radiotherapy for synchronously bilateral breast cancer, and accelerated partial breast irradiation. The web-based questionnaire had responses from 293 Japanese hospitals. The results indicated the following: treatment planning is performed using relatively similar field designs and delivery methods; the field-in-field technique is used at more than one-third of institutes; the commonest criteria for boost irradiation is based on the surgical margin width (≤5 mm) and the second commonest criteria was age (≤40 or ≤50 years), although some facilities applied a different age criterion (>70 years) for omitting a tumor bed boost; for conventional fractionation, almost all institutes delivered 50 Gy in 25 fractions to the conserved whole breast and 10 Gy in 5 fractions to the tumor bed. This survey revealed that 43% of hospitals offered hypofractionated radiotherapy, and the most common regimens were 42.56 Gy in 16 fractions for whole-breast irradiation and 10.64 Gy in 4 fractions for boost irradiation. Almost all of the facilities irradiated both breasts simultaneously for synchronously bilateral breast cancer, and accelerated partial breast irradiation was rarely offered in Japan. This survey provided an overview of the current clinical practice of radiotherapy for breast-conserving treatment of breast cancer in Japan.

Evolution of radiotherapy techniques in breast conservation treatment

Radiation therapy (RT) is an important component of breast cancer treatment that reduces local recurrence and improves survival after breast conservation. Breast conservation rates have increased significantly since the late 1980s and techniques have improved with greater awareness of the impact of radiation on the heart. An overview of randomized controlled trials of breast conservation using standard whole breast irradiation, whole breast hypofractionation, accelerated partial breast irradiation (APBI) and intraoperative radiation are reviewed. Selection criteria for breast conservation and the utility of adding a boost dose to the primary tumor site are reviewed. Modern dose constraints are documented and 10 different radiation techniques from the 1980s through to modern volumetric modulated arc therapy (VMAT) are compared for a patient where the breast and internal mammary nodes are treated. A radiation boost reduces the risk of a recurrence for most, but not all patients. Short courses of RT over 3-4 weeks are generally as effective as longer courses. Short-term follow-up of trials of APBI show promise for selected good prognosis subgroups. The role of intraoperative radiation remains controversial. In the last 30 years, there have been significant advances in radiation techniques. Modern radiotherapy equipment and techniques will reduce complications and improve survival rates.

Recent Developments in Radiation Oncology: An Overview of Individualised Treatment Strategies in Breast Cancer

Radiation therapy (RT) for breast cancer has dramatically changed over the past years, leading to individualized risk-adapted treatment strategies. Historically, the choice of RT regimen was limited to conventional fractionation protocols using standard tangential fields. Nowadays, technological and technical improvements in modern RT have added a variety of other RT modalities, different fractionation schedules, and individualised treatment volumes to the portfolio of breast RT. This review aims to give a short overview on the main topics which have recently found their way into clinical practice: hypofractionated treatment protocols, accelerated partial breast irradiation (APBI) for low-risk patients, deep inspiration breath hold (DIBH) for maximal heart protection, extent of regional nodal irradiation for high-risk patients, and the implementation of new radiation techniques such as intensity modulated RT (IMRT) and volumetric modulated RT (VMAT).