Hypofractionated radiotherapy after conservative surgery for breast cancer: analysis of acute and late toxicity

Breast Cancer Adjuvant Radiotherapy and Chemotherapy Sequencing: Sequential, Concomitant, or What Else? A Comprehensive Review of the Adjuvant Combinations Journey

Background: To date, in breast cancer (BC) treatment, adjuvant chemotherapy (A-CT) has preceded adjuvant radiotherapy (A-RT). In the last twenty years, the adjuvant treatment of BC has quickly evolved due to better knowledge of its molecular biology, genetic profile, and α/β ratio of 3/4 Gy for tumor and normal tissue radiosensitivity. Thus, new schedules with hypofractionated radiotherapy have been tested, and a third generation of A-CT has been introduced, raising the question of whether it is time to rethink the sequencing between these two approaches. Methods: In the last 20 years, many attempts have been made worldwide to optimize the best sequencing strategy between these two approaches in terms of sequential CT-RT and RT-CT and concomitant and sandwich modalities using drugs and schedules. This paper presents a comprehensive review of the state of the art, analyzing all the available studies to assess the sequencing between A-CT and A-RT with different generations of chemotherapy schedules. Results: More than 8000 patients from 30 studies treated with adjuvant chemotherapy and whole breast radiotherapy who were enrolled in randomized, retrospective, and prospective studies were analyzed. Sequential, concomitant, and sandwich modalities of chemotherapy with conventional or hypofractionated RT schedules from the most important studies were included. The most used sequence was adjuvant chemotherapy followed by conventional or hypofractionated radiotherapy. In the concomitant approach, i.v. CMF has been the most important adopted schedule, while the concomitant use of anthracyclines and taxanes with conventional or hypofractionated radiotherapy has been found to be more toxic. One study analyzed the benefit in terms of reducing adjuvant treatment time with upfront hypofractionated radiotherapy and third-generation chemotherapy. Conclusions: At present, the best sequencing strategy has not yet been defined. This comprehensive review is a journey among the most important randomized, retrospective, and prospective studies that highlights the past, current, and novel time sequencing proposals between A-CT and A-RT to assess the state of the art and provide useful information for future adjuvant approaches in breast cancer treatment.

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.

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.

Development and optimisation of a machine-learning prediction model for acute desquamation following breast radiotherapy in the multi-centre REQUITE cohort

Purpose

Some patients with breast cancer treated by surgery and radiation therapy experience clinically significant toxicity, which may adversely affect cosmesis and quality of life. There is a paucity of validated clinical prediction models for radiation toxicity. We used machine learning (ML) algorithms to develop and optimise a clinical prediction model for acute breast desquamation after whole breast external beam radiation therapy in the prospective multicenter REQUITE cohort study.

Methods and Materials

Using demographic and treatment-related features (m = 122) from patients (n = 2058) at 26 centers, we trained 8 ML algorithms with 10-fold cross-validation in a 50:50 random-split data set with class stratification to predict acute breast desquamation. Based on performance in the validation data set, the logistic model tree, random forest, and naïve Bayes models were taken forward to cost-sensitive learning optimisation.

Results

One hundred and ninety-two patients experienced acute desquamation. Resampling and cost-sensitive learning optimisation facilitated an improvement in classification performance. Based on maximising sensitivity (true positives), the “hero” model was the cost-sensitive random forest algorithm with a false-negative: false-positive misclassification penalty of 90:1 containing m = 114 predictive features. Model sensitivity and specificity were 0.77 and 0.66, respectively, with an area under the curve of 0.77 in the validation cohort.

Conclusions

ML algorithms with resampling and cost-sensitive learning generated clinically valid prediction models for acute desquamation using patient demographic and treatment features. Further external validation and inclusion of genomic markers in ML prediction models are worthwhile, to identify patients at increased risk of toxicity who may benefit from supportive intervention or even a change in treatment plan.

A data science approach for early-stage prediction of Patient's susceptibility to acute side effects of advanced radiotherapy

The prediction by classification of side effects incidence in a given medical treatment is a common challenge in medical research. Machine Learning (ML) methods are widely used in the areas of risk prediction and classification. The primary objective of such algorithms is to use several features to predict dichotomous responses (e.g., disease positive/negative). Similar to statistical inference modelling, ML modelling is subject to the class imbalance problem and is affected by the majority class, increasing the false-negative rate. In this study, seventy-nine ML models were built and evaluated to classify approximately 2000 participants from 26 hospitals in eight different countries into two groups of radiotherapy (RT) side effects incidence based on recorded observations from the international study of RT related toxicity "REQUITE". We also examined the effect of sampling techniques and cost-sensitive learning methods on the models when dealing with class imbalance. The combinations of such techniques used had a significant impact on the classification. They resulted in an improvement in incidence status prediction by shifting classifiers' attention to the minority group. The best classification model for RT acute toxicity prediction was identified based on domain experts' success criteria. The Area Under Receiver Operator Characteristic curve of the models tested with an isolated dataset ranged from 0.50 to 0.77. The scale of improved results is promising and will guide further development of models to predict RT acute toxicities. One model was optimised and found to be beneficial to identify patients who are at risk of developing acute RT early-stage toxicities as a result of undergoing breast RT ensuring relevant treatment interventions can be appropriately targeted. The design of the approach presented in this paper resulted in producing a preclinical-valid prediction model. The study was developed by a multi-disciplinary collaboration of data scientists, medical physicists, oncologists and surgeons in the UK Radiotherapy Machine Learning Network.

External Validation of a Predictive Model for Acute Skin Radiation Toxicity in the REQUITE Breast Cohort

Background: Acute skin toxicity is a common and usually transient side-effect of breast radiotherapy although, if sufficiently severe, it can affect breast cosmesis, aftercare costs and the patient's quality-of-life. The aim of this study was to develop predictive models for acute skin toxicity using published risk factors and externally validate the models in patients recruited into the prospective multi-center REQUITE (validating pREdictive models and biomarkers of radiotherapy toxicity to reduce side-effects and improve QUalITy of lifE in cancer survivors) study.

Methods: Patient and treatment-related risk factors significantly associated with acute breast radiation toxicity on multivariate analysis were identified in the literature. These predictors were used to develop risk models for acute erythema and acute desquamation (skin loss) in three Radiogenomics Consortium cohorts of patients treated by breast-conserving surgery and whole breast external beam radiotherapy (n = 2,031). The models were externally validated in the REQUITE breast cancer cohort (n = 2,057).

Results: The final risk model for acute erythema included BMI, breast size, hypo-fractionation, boost, tamoxifen use and smoking status. This model was validated in REQUITE with moderate discrimination (AUC 0.65), calibration and agreement between predicted and observed toxicity (Brier score 0.17). The risk model for acute desquamation, excluding the predictor tamoxifen use, failed to validate in the REQUITE cohort.

Conclusions: While most published prediction research in the field has focused on model development, this study reports successful external validation of a predictive model using clinical risk factors for acute erythema following radiotherapy after breast-conserving surgery. This model retained discriminatory power but will benefit from further re-calibration. A similar model to predict acute desquamation failed to validate in the REQUITE cohort. Future improvements and more accurate predictions are expected through the addition of genetic markers and application of other modeling and machine learning techniques.

Acute radiation-induced skin toxicity in hypofractionated vs. conventional whole-breast irradiation: An objective, randomized multicenter assessment using spectrophotometry

PURPOSE

Radiation dermatitis represents one of the most frequent side effects in breast cancer patients undergoing adjuvant whole-breast irradiation (WBI). Whether hypofractionated WBI induces comparable or less acute radiation-induced skin reactions than conventional WBI is still not fully clarified, as randomized evidence and objective assessments are limited. The aim of this study was to objectively determine frequency and severity of acute radiation-induced skin reactions during hypofractionated vs. conventionally fractionated adjuvant WBI.

METHODS

In this randomized multicenter study, a total of 140 breast cancer patients underwent either hypofractionated or conventional WBI following breast-preserving surgery. Maximum radiation dermatitis severity was assessed at completion and during follow-up by physician-assessed CTCAE v4.03 and the patient-reported RISRAS scale. Additionally, photospectrometric skin readings were performed to objectify skin color differences between both treatment arms.

RESULTS

Radiation dermatitis severity was significantly lower in patients receiving hypofractionation compared with conventional fractionation (mean 1.05 vs. 1.43, p = .024). Grade 0 radiation dermatitis occurred in 21.43% vs. 4.28%, grade ≥2 in 27.14% vs. 42.91% and grade ≥3 in 0% vs. 4.34% of patients following hypofractionated and conventional WBI, respectively. Objective photospectrometric measurements (n = 4200) showed both decreased erythema severity (p = .008) and hyperpigmentation (p = .002) in the hypofractionation arm. Patients allocated to hypofractionated WBI also reported less pain (p = .006), less hyperpigmentation (p = <0.001) and less limitations of day-to-day activities (p = <0.001).

CONCLUSION

Physician and patient-assessed toxicity scorings as well as objective photospectrometric skin measurements revealed that hypofractionated WBI yielded lower rates and severity of acute radiation-induced skin toxicity.

Impact of ATM rs1801516 on late skin reactions of radiotherapy for breast cancer: Evidences from a cohort study and a trial sequential meta-analysis

The relationship between the ataxia-telangiectasia mutated (ATM) rs1801516 gene polymorphism and risk of radiation-induced late skin side effects remains a highly debated issue. In the present study, we assessed the role of ATM rs1801516 as risk factor for radiation-induced fibrosis and telangiectasia, using the LENT-SOMA scoring scale in 285 breast cancer patients who received radiotherapy after breast conserving surgery. A systematic review with meta-analysis and trial sequential analysis (TSA) was then conducted to assess reliability of the accumulated evidence in breast cancer patients. In our cohort study, no association was found between ATM rs1801516 and grade ≥ 2 telangiectasia (GA+AA vs GG, HR_adjusted: 0.699; 95%CI: 0.273–1.792, P = 0.459) or grade ≥ 2 fibrosis (GA+AA vs GG, HR_adjusted: 1.175; 95%CI: 0.641–2.154, P = 0.604). Twelve independent cohorts of breast cancer patients were identified through the systematic review, of which 11 and 9 cohorts focused respectively on the association with radiation-induced fibrosis and radiation-induced telangiectasia. Pooled analyses of 10 (n = 2928 patients) and 12 (n = 2783) cohorts revealed, respectively, no association of ATM rs1801516 with radiation-induced telangiectasia (OR: 1.14; 95%CI: 0.88–1.48, P = 0.316) and a significant correlation with radiation-induced fibrosis (OR: 1.23; 95%CI: 1.00–1.51, P = 0.049), which however did not remain significant after TSA adjustment (TSA-adjusted 95%CI: 0.85–1.78). These results do not support an impact of ATM rs1801516 on late skin reactions of radiotherapy for breast cancer, nevertheless further large studies are still required for conclusive evidences.

Cosmesis in patients with breast neoplasia submitted to the hypofractionated radiotherapy with of intensity-modulated beam

OBJECTIVE

To assess the cosmetic satisfaction of patients diagnosed with breast cancer submitted to the hypofractionated radiotherapy with IMRT (hIMRT) technique and its correlation with dosimetric data of the radiotherapy planning.

METHODS

The retrospective cohort study that assessed women with a diagnosis of malignant breast neoplasia submitted to the conservative treatment or radical mastectomy and treated with hIMRT. In the period between August 2007 to December 2014, in a philanthropic / private institution, 170 records were selected. The cosmetic assessment was carried out by means of the Harvard/RTOG/NSABP scale with one-year minimum range after treatment. The collected dosimetric data were: breast / chest wall volume, volume that received 95% (V95%) and 107% (V107%) of the prescribed dose.

RESULTS

The volume of the treated breasts ranged from 169 to 2.103 ml (median = 702; IQR: 535 to 914 ml). Median V95% was 86.7% (54.6-96.6%; IQR: 80.0% to 90.6%); eight (5.7%) patients had V95% higher than 95%. Median V107% was 0% (0%-16.3%; IQR: 0.0% to 0.3% and 13); 9.3% patients had V107% higher than 2%. One hundred and thirty-three (78.2%) patients responded to the cosmetic assessment: 99 (74.4%) considered the cosmetic results excellent. Significant associations between cosmetic assessment and breast volume (p=0.875), V95% (p=0.294) e V107% (p=0.301) were not found.

CONCLUSION

The cosmetic results showed favorable when using hIMRT, and the lack of correlation with usual the dosimetric data illustrates the capacity of hIMRT to minimize the heterogeneity of the dose in this endpoint, even in voluminous breasts.

Hypofractionated whole breast radiotherapy with or without hypofractionated boost in early stage breast cancer patients: a mono-institutional analysis of skin and subcutaneous toxicity

BACKGROUND

Our study evaluated skin and subcutaneous toxicity analyzing its correlation with patient- and treatment-related factors in a large mono-institutional series of women with early stage breast cancer treated with adjuvant hypofractionated whole breast radiotherapy (WBRT) with or without a sequential hypofractionated boost (HB).

METHODS

Two hundred and nineteen patients, median age 62 years, received adjuvant hypofractionated WBRT in 16 fractions to a total dose of 42.4 Gy. Patients with negative prognostic factors received a HB of 2.65 Gy for 4 or 5 (patients with focal positive surgical margins) fractions. Systemic adjuvant treatments were hormonal therapy (HT) and/or chemotherapy (CHT) and/or Trastuzumab. Toxicities were assessed using the Common Terminology Criteria for Adverse Events (CTCAE 4.03) scale at 5th, 10th, 16th, 20th day from the start of radiotherapy (RT) and 1, 6 and 12 months after the end of RT. Univariate and multivariate analysis estimated toxicity predictive factors.

RESULTS

No case of treatment interruption and no acute or late G3 toxicities occurred. In the univariate analysis HB administration resulted a risk factor for acute toxicity, while CHT administration and number of excised lymph nodes ≥ 10 resulted a risk factor for late toxicity. In the multivariate analysis none of the evaluated factors emerged a risk factor for acute and/or late toxicity.

CONCLUSIONS

Our results confirmed that hypofractionated WBRT even followed by a HB resulted safe and well tolerated. Longer follow-up is warranted to estimate late toxicity and treatment outcomes.

Predictive parameters in hypofractionated whole-breast 3D conformal radiotherapy according to the Ontario Canadian trial

AIM

To evaluate the possible role of dosimetric parameters according Normal Tissue Complication Probability (NTCP) model as predictive of late toxicity and cosmesis in hypofractionated whole-breast three-dimensional conformal radiotherapy.

PATIENTS AND METHODS

A retrospective analysis on 215 consecutive early breast cancer patients treated with breast conserving surgery and adjuvant hypofractionated whole-breast radiotherapy (according the Ontario Canadian trial), with a 6 years median follow-up was conducted. To assess the impact of 10%-20% dose hotspots on different percent values of planning target volume (PTV) of the breast, we retrospectively employed the NTCP model of Lyman. PTV breast (PTVbr), V110 were identified. For statistical analysis the χ² and paired t-test were used to find a correlation between late skin and subcutaneous toxicity and cosmetic outcome with dosimetrical parameters Multivariate analysis was performed with the aim to assess independently the impact of dosimetric and clinical parameters on late toxicity and cosmesis using Pearson's covariance.

RESULTS

Late skin toxicity was recorded in 47/215 (22%); and G3 toxicity occurred in 11 patients (5%). Cosmesis with excellent-good score was found in 172 patients (80%) while fair-poor score was found in 43 patients (20%). In univariate χ² analysis the V110 >10% of the PTV breast significantly correlated with higher toxicity (P<0.005, OR 9.60 [CI 3.89-23.72]). Cosmesis related to V110 >10% and PTV breast volume over 1,300 cc was significant at multivariate analysis (P<0.005, OR 6.07 [CI 2.36-15.59]).

CONCLUSION

To safely use one of the most important whole-breast hypofractionated radiotherapy schedules, we found some predictive paramaters on the basis of NTCP model by Lyman. These parameters may be useful in selection of elegible patients.

In vitro cellular radiosensitivity in relationship to late normal tissue reactions in breast cancer patients: a multi-endpoint case-control study

PURPOSE

A minority of patients exhibits severe late normal tissue toxicity after radiotherapy (RT), possibly related to their inherent individual radiation sensitivity. This study aimed to evaluate four different candidate in vitro cellular radiosensitivity assays for prediction of late normal tissue reactions, in a retrospective matched case-control set-up of breast cancer patients.

METHODS

The study population consists of breast cancer patients expressing severe radiation toxicity (12 cases) and no or minimal reactions (12 controls), with a follow-up for at least 3 years. Late adverse reactions were evaluated by comparing standardized photographs pre- and post-RT resulting in an overall cosmetic score and by clinical examination using the LENT-SOMA scale. Four cellular assays on peripheral blood lymphocytes reported to be associated with normal tissue reactions were performed after in vitro irradiation of patient blood samples to compare case and control radiation responses: radiation-induced CD8+ late apoptosis, residual DNA double-strand breaks, G0 and G2 micronucleus assay.

RESULTS

A significant difference was observed for all cellular endpoints when matched cases and controls were compared both pairwise and grouped. However, it is important to point out that most case-control pairs showed a substantial overlap in standard deviations, which questions the predictive value of the individual assays. The apoptosis assay performed best, with less apoptosis seen in CD8+ lymphocytes of the cases (average: 14.45%) than in their matched controls (average: 30.64%) for 11 out of 12 patient pairs (p < .01). The number of residual DNA DSB was higher in cases (average: 9.92 foci/cell) compared to their matched control patients (average: 9.17 foci/cell) (p < .01). The average dose response curve of the G0 MN assay for cases lies above the average dose response curve of the controls. Finally, a pairwise comparison of the G2 MN results showed a higher MN yield for cases (average: 351 MN/1000BN) compared to controls (average: 219 MN/1000BN) in 9 out of 10 pairs (p < .01).

CONCLUSION

This matched case-control study in breast cancer patients, using different endpoints for in vitro cellular radiosensitivity related to DNA repair and apoptosis, suggests that patients' intrinsic radiosensitivity is involved in the development of late normal tissue reactions after RT. Larger prospective studies are warranted to validate the retrospective findings and to use in vitro cellular assays in the future to predict late normal tissue radiosensitivity and discriminate individuals with marked RT responses.

Hypofractionated boost after whole breast irradiation in breast carcinoma: chronic toxicity results and cosmesis

PURPOSE

To evaluate the impact of hypofractionated boost after hypofractionated whole breast irradiation in breast carcinoma.

METHODS AND MATERIALS

Patients after breast conservative surgery were treated all time with hypofractionation of 2.67 Gy/day. Whole breast dose was 40.05 Gy followed in case of risk of local relapse by a boost of 16.02 Gy or 8.01 Gy. Acute and chronic toxicity results were evaluated including cosmetic software-assisted assessment and objective evaluation of fibrosis parameters (elasticity and hydration) by means of a skin tester.

RESULTS

A total of 362 patients were evaluated. Acute toxicities comprised grade 1 dermatitis in 48.1 %, grade 2 in 44.5 % and grade 3 in 17 patients 4.7 %, respectively. After a median follow-up of 4.5 years, in 308 cases (86.6 %) there was no chronic skin or subcutaneous changes. In the first consecutive 50 patients, measures with skin tester showed no statistical differences in parameters for skin and subcutaneous fibrosis. Cosmetic results were considered excellent and good in 26 and 62 %, respectively.

CONCLUSIONS

Boost to tumour bed with hypofractionated doses is well tolerated and acute and chronic toxicities are mild with good cosmetic results. Objective systems are encouraging methods to assess skin quality and cosmesis.

DNA Methyltransferase Gene Polymorphisms for Prediction of Radiation-Induced Skin Fibrosis after Treatment of Breast Cancer: A Multifactorial Genetic Approach

Purpose

This study was conducted to investigate the role of four polymorphic variants of DNA methyltransferase genes as risk factors for radiation-induced fibrosis in breast cancer patients. We also assessed their ability to improve prediction accuracy when combined with mitochondrial haplogroup H, which we previously found to be independently associated with a lower hazard of radiation-induced fibrosis.

Materials and Methods

DNMT1 rs2228611,DNMT3A rs1550117,DNMT3A rs7581217, and DNMT3B rs2424908 were genotyped by real-time polymerase chain reaction in 286 Italian breast cancer patients who received radiotherapy after breast conserving surgery. Subcutaneous fibrosis was scored according to the Late Effects of Normal Tissue–Subjective Objective Management Analytical (LENT-SOMA) scale. The discriminative accuracy of genetic models was assessed by the area under the receiver operating characteristic curves (AUC).

Results

Kaplan-Meier curves showed significant differences among DNMT1 rs2228611 genotypes in the cumulative incidence of grade ≥ 2 subcutaneous fibrosis (log-rank test p-value= 0.018). Multivariate Cox regression analysis revealed DNMT1 rs2228611 as an independent protective factor for moderate to severe radiation-induced fibrosis (GG vs. AA; hazard ratio, 0.26; 95% confidence interval [CI], 0.10 to 0.71; p=0.009). Adding DNMT1 rs2228611 to haplogroup H increased the discrimination accuracy (AUC) of the model from 0.595 (95% CI, 0.536 to 0.653) to 0.655 (95% CI, 0.597 to 0.710).

Conclusion

DNMT1 rs2228611 may represent a determinant of radiation-induced fibrosis in breast cancer patients with promise for clinical usefulness in genetic-based predictive models.

Hypofractionated Radiation Therapy for Breast Cancer: Long-Term Results in a Series of 85 Patients

Purpose

Whole-breast irradiation after conservative surgery is the standard treatment for early breast cancer. The purpose of this study is to report the late toxicity, cosmetic result, and disease control in a group of patients treated with hypofractionated radiotherapy (RT) comparing results with retrospective data of a control group who underwent conventional RT.

Methods

From 2006 to 2008, 85 patients were treated with hypofractionated schedule to dose of 45 Gy, 2.25 Gy/fr, followed by a boost. We evaluated late toxicity, cosmetic result, and disease control. The data were compared to a control group of 70 patients who underwent conventional RT before 2006.

Results

At 8 years of follow-up, the cumulative incidence of late skin toxicity was 6.2 in the hypofractionated RT group and 7.5 in the standard RT group (p = 0.94). The cumulative incidence of late subcutaneous tissue toxicity was 11.6 in the hypofractionated RT group and 18.7 in the standard RT group (p = 0.23). Cosmetic outcome was rated as excellent or good in 84/85 patients of the hypofractionated RT group and in 68/70 patients of the conventional RT group (p = 0.7). No statistically significant differences were found in terms of local control (p = 0.05), disease-free survival (p = 0.06), or overall survival (p = 0.17) between the 2 groups.

Conclusions

The present analysis, focused on long-term effects, disease control, and survival, confirms, in a daily practice setting, the low incidence of skin atrophy and fibrosis, the satisfactory cosmetic outcome, and the high grade of local and distant disease control with hypofractionated schedule.

Hypofractionated irradiation in elderly patients with breast cancer after breast conserving surgery and mastectomy : Analysis of 205 cases

Background

Several randomized trials and meta-analyses confirmed a wide benefit of radiotherapy (RT), both after breast conserving surgery (BCS) and mastectomy. However, many elderly women don't receive RT. Hypofractionated (HF) RT allows « simplified » and more accessible treatments with equivalent results to classic RT in three large randomized trials. However, there are few available data on HF-RT for nodal irradiation, as well as for the boost.

Methods

We evaluated patients treated for IBC by HF-RT between 2004 and 2012 in two regional cancer centres. We used an original scheme delivering 45 Gy in 15 fractions three times a week, both after BCS or mastectomy, with or without nodal irradiation. After BCS, a 9 Gy boost in 3 fractions was delivered. Local, regional and distant recurrences were assessed, as well as acute and late cutaneous, cardiac or pulmonary toxicities.

Results

205 patients were analysed, 116 after BCS (57 %) and 89 after mastectomy (43 %). Median age was 81 years (range: 52-91); 44 % had axillary nodal involvement (pN+). The Nottingham Prognostic Index (NPI) scored 0, 1, 2 and 3 in 10 %, 27 %, 44 % and 19 % of the cases. A nodal HF-RT was delivered in 65 patients (32 %) and boost in 98 patients (84 % of BCS) by 9 Gy/3 fr scheme. Fifty (24 %) patients underwent chemotherapy and 156 (75 %) hormonal treatment.

With a 49-month median follow-up, 3/116 (2.6 %) patients and 4/89 (4.5 %) had local recurrence (LR) after BCS and mastectomy, respectively. The overall 5-year LR rate was 4.4 %. In univariate and multivariate analysis, LR risk factors were: high NPI (HR 5.46; p = 0.028), and triple negative tumour (HR 9.78; p = 0.006). Only 8 (4.5 %) patients had grade III skin toxicity; 29 (14 %) late fibrosis and 16 (8 %) telangiectasia. No pulmonary or cardiac toxicity was observed.

Conclusion

Our HF-RT scheme (with or without nodal irradiation) confirms in elderly patients the data from randomized trials, both after BCS or mastectomy. Toxicity seems very acceptable but requires a longer follow-up. A larger evaluation is still ongoing in several other centres in France.

Preoperative hypofractionated radiotherapy in the treatment of localized soft tissue sarcomas

BACKGROUND

The primary treatment of soft tissue sarcomas (STS) is a radical resection of the tumor with adjuvant radiotherapy. Conventional fractionation of preoperative radiotherapy is 50 Gy in fraction of 2 Gy a day. The purpose of the conducted study was to assess the efficacy and safety of hypofractionated radiotherapy in preoperative setting in STS patients.

METHODS

272 patients participated in this prospective study conducted from 2006 till 2011. Tumors were localized on the extremities or trunk wall. Median tumor size was 8.5 cm, 42% of the patients had tumor larger than 10 cm, whereas 170 patients (64.6%) had high grade (G3) tumors. 167 patients (61.4%) had primary tumors. Patients were treated with preoperative radiotherapy for five consecutive days in 5 Gy per fraction, with an immediate surgery. Median follow up is 35 months.

RESULTS

79 patients died at the time of the analysis, the 3-year overall survival was 72%. Local recurrences were observed in 19.1 % of the patients. Factors that had a significant adverse impact on local recurrence were tumor size of 10 cm or more and G3 grade. 114 patients (42%) had any kind of treatment toxicity, vast majority with tumors located on lower limbs. 7% (21) of the patients required surgery for treatment of the complications.

CONCLUSION

In this non-selected group of locally advanced STS use of hypofractionated preoperative radiotherapy was associated with similar local control (81%) when compared to previously published studies. The early toxicity is tolerable, with small rate of late complications. Presented results warrant further evaluation.

Evaluating the effects of aluminum-containing and non-aluminum containing deodorants on axillary skin toxicity during radiation therapy for breast cancer: a 3-armed randomized controlled trial

PURPOSE

Deodorant use during radiation therapy for breast cancer has been controversial as there are concerns deodorant use may exacerbate axillary skin toxicity. The present study prospectively determined the use of both aluminum-containing and non aluminum containing deodorants on axillary skin toxicity during conventionally fractionated postoperative radiation therapy for breast cancer.

METHODS AND MATERIALS

This 3-arm randomized controlled study was conducted at a single center, tertiary cancer hospital between March 2011 and April 2013. Participants were randomized to 1 of 2 experimental groups (aluminum-containing deodorant and soap or non-aluminum containing deodorant and soap) or a control group (soap). A total of 333 participants were randomized. Generalized estimating equations were used to estimate and compare the odds of experiencing high levels of sweating and skin toxicity in each of the deodorant groups to the odds in the control group. The study evaluated a range of endpoints including objective measurements of axilla sweating, skin toxicity, pain, itch and burning. Quality of life was assessed with a validated questionnaire.

RESULTS

Radiation characteristics were similar across all groups. Patients in the deodorant groups did not report significantly different ratings for axillary pain, itch, or burning compared with the control group. Patients in the aluminum-containing deodorant group experienced significantly less sweating than the control; the odds of their sweating being barely tolerable and frequently or always interfering with their daily activities was decreased by 85% (odds ratio, 0.15; 95% confidence interval, 0.03-0.91).

CONCLUSIONS

We found no evidence that the use of either aluminum-containing or non-aluminum containing deodorant adversely effects axillary skin reaction during conventionally fractionated radiation therapy for breast cancer. Our analysis also suggests patients in the aluminum-containing deodorant arm had significantly less sweating without increased symptoms of axillary radiation skin toxicity. These results add to the evidence that the prescription of deodorants during radiation therapy for breast cancer is now questionable.

Pneumonitis and pulmonary fibrosis associated with breast cancer treatments

To review the available published data regarding the incidence, mechanisms of pathogenesis, clinical presentations and management of pneumonitis caused by anti-cancer treatments (radiotherapy (RT) and systemic agents) that are included in the guidelines of the treatment of breast cancer (BC) and address the issues on the current grading classification of pneumonitis. A literature search was performed between July and October 2013 using PubMed for papers published from January 1989 to October 2013. Any clinical trial, case report, case series, meta-analysis or systematic review that reported on pulmonary toxicity of any BC therapeutic modality was included (only papers published in English). Most of anticancer treatments currently used in the management of BC may induce some degree of pneumonitis that is estimated to have an incidence of 1-3 %. There is an obvious distinction between chemotherapy- and targeted treatment-related lung toxicity. Moreover, the current classification of pneumonitis needs to be modified as there is a clear diversity in grade 2. As pneumonitis is relatively common and reported as side effect of new anticancer agents, physicians need to be aware of the clinical and radiological manifestations of drug- and RT-induced toxicities in patients with BC. A key recommendation is the subdivision of grade 2 cases to two subgroups. We provide an algorithm, along with real life cases as managed in the breast Unit of Royal Marsden Hospital, with the aim to guide physicians in managing all possible eventualities that may come across in clinical practise.

Toxicity and cosmetic outcome of hypofractionated whole-breast radiotherapy: predictive clinical and dosimetric factors

Purpose

The objective of this study is to evaluate toxicity and cosmetic outcome in breast cancer patients treated with adjuvant hypo fractionated radiotherapy to the whole breast, and to identify the risk factors for toxicity.

Methods and materials

Two hundred twelve women with early breast cancer underwent conserving surgery were enrolled in the study. The patients received 40.05 Gy in 15 daily fractions, 2.67 Gy per fraction. The boost to the tumor bed was administered with a total dose of 9 Gy in 3 consecutive fractions in 55 women. Physician-rated acute and late toxicity and cosmetic outcome (both subjective and objective) were prospectively assessed during and after radiotherapy.

Results

In our population study the mean age was 63 with the 17% (36 pts) of the women younger than 50 years.

The median follow-up was 34 months. By the end of RT, 35 patients out of 212 (16%) no acute toxicity, according to the RTOG criteria, while 145 (68%) and 31 patients (15%) developed grade 1 and grade 2 acute skin toxicity, respectively.

Late skin toxicity evaluation was available for all 212 patients with a minimum follow up of 8 months. The distribution of toxicity was: 39 pts (18%) with grade 1 and 2 pts (1%) with grade 2. No worse late skin toxicity was observed.

Late subcutaneous grade 0-1 toxicity was recorded in 208 patients (98%) and grade 2 toxicity in 3 patients (2%), while grade 3 was observed in 1 patient only. At last follow up, a subjective and objective good or excellent cosmetic outcome was reported in 93% and 92% of the women, respectively. At univariate and multivariate analysis, the late skin toxicity was correlated with the additional boost delivery (p=0.007 and p=0.023). Regarding the late subcutaneous tissue, a correlation with diabetes was found (p=0.0283).

Conclusion

These results confirm the feasibility and safety of the hypofractionated radiotherapy in patients with early breast cancer. In our population the boost administration was resulted to be a significant adverse prognostic factor for acute and late toxicity. Long-term follow up is need to confirm this finding.

Evidence from a breast cancer hypofractionated schedule: late skin toxicity assessed by ultrasound

Background

Feasibility of whole breast hypofractionated radiotherapy schedules in breast conserving therapy is recognized however concerns remain about the role of the boost dose on the overall treatment’s potential toxicity. In this study we report on the possibility to quantitatively evaluate radiation induced toxicity in patients treated with an abbreviated course with major concern in the irradiated boost region.

Methods

Eighty-nine patients who underwent conservative surgery for early-stage breast cancer followed by adjuvant accelerated hypofractionated whole breast radiotherapy were included in this study to assess skin and subcutaneous tissue late toxicity by means of ultrasonographic quantitative examination. For each patient the skin thickness was measured at four positions: on the irradiated breast, in the boost region and in the corresponding positions in the contra-lateral not treated breast. All patients were scanned by the same radiologist to reduce potential inter-operator variability, the operator was blind to the scoring of the patient CTCv3 late toxicity as well as patient treatment characteristics. Ultrasound assessment and clinical evaluation were compared.

Results

The median time between the end of adjuvant radiotherapy and ultrasound examination was 20.5 months. The measured mean skin thickness in the irradiated breast was 2.13 ± 0.72 mm while in the mirror region of the contra-lateral healthy breast was 1.61 ± 0.29 mm. The measured mean skin thickness in the irradiated boost region was 2.25 ± 0.79 mm versus 1.63 ± 0.33 mm in the corresponding region of contra-lateral healthy breast. The mean increment in skin thickness respect to the counterpart in the healthy breast was 0.52 ± 0.67 mm and 0.62 ± 0.74 mm for the breast and the boost region respectively. A significant direct correlation was found between the increment in skin thickness in the irradiated breast and in the boost region with fibrosis (G ≥ 1).

Conclusions

In this study results from a breast cancer hypofractionated schedule in terms of late skin toxicity are reported. In particular our study confirms that late cutaneous reactions can be reliably assed by ultrasonographic examination, also discriminating between regions irradiated at different doses, and that this instrumental evaluation is in agreement with clinical stated toxicity.

Sucralfate gel as a radioprotector against radiation induced dermatitis in a hypo-fractionated schedule: a non-randomized study

External beam radiotherapy with high doses provokes many acute skin reactions, such as erythema and moist desquamation. Many topical preparations are used in radiation oncology departments in the skin care. Sucralfate humid gel, a colloidal physical form of the anti-ulcer drug sucralfate, promotes epithelial regeneration and activates cell proliferation. Based on this knowledge, we performed a non-randomized clinical trial to evaluate the efficacy of topical sucralfate gel in 30 breast cancer patients receiving postoperative accelerated hypofractionated photon beam therapy. The comparison was performed with 30 patients as historical controls. The acute reaction of the skin was significantly lower in the group receiving the sucralfate gel (p<0.05, Mann Whitney test), while 90% of the patients had no evidence of radiation induced skin toxicity. There was no sucralfate gel related toxicity reported by any patient in this study. More patients in a randomized way are needed for more definite results.

Abbreviated course of radiotherapy (RT) for breast cancer

The use of RT as a component of breast-conserving therapy or after mastectomy has been proven to reduce the risk of local-regional recurrence (LRR) and to improve long-term breast cancer-specific and 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 1.8-2 Gray (Gy). However, due to geographic limitations, patient preferences and financial considerations, there have been continued attempts to evaluate the efficacy and toxicity of abbreviated courses of breast RT. 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 that have resulted in substantially improved dose homogeneity in the target volume. As an alternative to approximately five weeks of daily treatment at 1.8-2 Gy, delivering radiobiologically-equivalent total doses in hypofractionated, abbreviated schedules has been evaluated in five randomized controlled trials, as well as many prospective and retrospective experiences. These studies have generally demonstrated equivalent rates of LRR, disease-free survival and overall survival with the use of hypofractionated regimens. Despite theoretical and historic concerns that hypofractionated regimens could increase damage to normal tissue, the rates of acute and long-term toxicities have generally not been increased in most recent series. Some toxicities, however, may take years to decades to manifest. Questions still remain regarding which patients are appropriate for abbreviated treatment. The majority of patients included in the studies supporting hypofractionated treatment were of older age with early-stage invasive ER+ disease of predominantly lower histological grade. This favorable subset of patients is also the most eligible for other alternative treatment approaches, such as partial-breast irradiation or hormonal therapy alone. Additionally, few to none of the patients included in most studies were treated with mastectomy, lymph node irradiation, a lumpectomy cavity radiation boost, or adjuvant chemotherapy. The existing evidence prompted the American Society for Radiation Oncology (ASTRO) to convene a task force to issue an evidence-based guideline in 2010 delineating the patients for whom an abbreviated radiation course is most supported by the current evidence [Smith et al. 2010, Int J Radiat Oncol Biol Phys]. Ongoing and future studies will further clarify the suitability of a hypofractionated treatment approach for the patient subgroups underrepresented in available trials. Additionally, alternative abbreviated treatment regimens, including those in which treatment is given once weekly and treatments that include an integrated lumpectomy cavity boost, are actively being investigated. Finally, innovative radiation techniques, such as the use of higher energies, prone treatment, and breathing-adapted therapy have further increased the homogeneity of breast irradiation and minimized dose delivered to nearby critical normal structures. Consequently, increasing experience with these techniques may expand the population of patients amenable to hypofractionated therapy.

Feasibility and acute toxicity of hypofractionated radiation in large-breasted patients

PURPOSE

To determine the feasibility of and acute toxicity associated with hypofractionated whole breast radiation (HypoRT) after breast-conserving surgery in patients excluded from or underrepresented in randomized trials comparing HypoRT with conventional fractionation schedules.

METHODS AND MATERIALS

A review was conducted of all patients consecutively treated with HypoRT at the University of Chicago. All patients were treated to 42.56 Gy in 2.66 Gy daily fractions in either the prone or supine position. Planning was performed in most cases using wedges and large segments or a "field-in-field" technique. Breast volume was estimated using volumetric measurements of the planning target volume (PTV). Dosimetric parameters of heterogeneity (V105, V107, V110, and maximum dose) were recorded for each treatment plan. Acute toxicity was scored for each treated breast.

RESULTS

Between 2006 and 2010, 78 patients were treated to 80 breasts using HypoRT. Most women were overweight or obese (78.7%), with a median body mass index of 29.2 kg/m(2). Median breast volume was 1,351 mL. Of the 80 treated breasts, the maximum acute skin toxicity was mild erythema or hyperpigmentation in 70.0% (56/80), dry desquamation in 21.25% (17/80), and focal moist desquamation in 8.75% (7/80). Maximum acute toxicity occurred after the completion of radiation in 31.9% of patients. Separation >25 cm was not associated with increased toxicity. Breast volume was the only patient factor significantly associated with moist desquamation on multivariable analysis (p = 0.01). Patients with breast volume >2,500 mL experienced focal moist desquamation in 27.2% of cases compared with 6.34% in patients with breast volume <2,500 mL (p = 0.03).

CONCLUSIONS

HypoRT is feasible and safe in patients with separation >25 cm and in patients with large breast volume when employing modern planning and positioning techniques. We recommend counseling regarding expected increases in skin toxicity in women with a PTV volume >2,500 mL.