Acute toxicity of intraoperative radiotherapy and external beam-accelerated partial breast irradiation in elderly breast cancer patients

A systematic review and meta-analysis of intraoperative electron radiation therapy delivered with a dedicated mobile linac for partial breast irradiation in early breast cancer

•PBI is valid alternative to WBI in patients at low-risk of local relapse. •PBI is delivered by means of various techniques, one of which is IOeRT. •After IOeRT, an unexpectedly high LR rate was observed in the only phase III RCT. •Patient selection impacts on LR rates after IOeRT. •With appropriate patient selection IOeRT outcomes overlap with other RT techniques.

Partial breast irradiation compared with whole breast irradiation: a systematic review and meta-analysis

BACKGROUND

Early-stage breast cancer is among the most common cancer diagnoses. Adjuvant radiotherapy is an essential component of breast-conserving therapy, and several options exist for tailoring its extent and duration. This study assesses the comparative effectiveness of partial-breast irradiation (PBI) compared with whole-breast irradiation (WBI).

METHODS

A systematic review was completed to identify relevant randomized clinical trials and comparative observational studies. Independent reviewers working in pairs selected studies and extracted data. Randomized trial results were pooled using a random effects model. Prespecified main outcomes were ipsilateral breast recurrence (IBR), cosmesis, and adverse events (AEs).

RESULTS

Fourteen randomized clinical trials and 6 comparative observational studies with 17 234 patients evaluated the comparative effectiveness of PBI. PBI was not statistically significantly different from WBI for IBR at 5 years (RR = 1.34, 95% CI = 0.83 to 2.18; high strength of evidence [SOE]) and 10 years (RR = 1.29, 95% CI = 0.87 to 1.91; high SOE). Evidence for cosmetic outcomes was insufficient. Statistically significantly fewer acute AEs were reported with PBI compared with WBI, with no statistically significant difference in late AEs. Data from subgroups according to patient, tumor, and treatment characteristics were insufficient. Intraoperative radiotherapy was associated with higher IBR at 5, 10, and over than 10 years (high SOE) compared with WBI.

CONCLUSIONS

Ipsilateral breast recurrence was not statistically significantly different between PBI and WBI. Acute AEs were less frequent with PBI. This evidence supports the effectiveness of PBI among selected patients with early-stage, favorable-risk breast cancer who are similar to those represented in the included studies.

Preliminary outcomes of accelerated partial breast irradiation by interstitial multicatheter brachytherapy with intraoperative free-hand catheter implantation in early breast cancer

BACKGROUND

To evaluate the clinical feasibility of interstitial brachytherapy by intraoperative free-hand catheter implantation in the treatment of early breast cancer after breast-conserving surgery (BCS).

METHODS

Between January 2018 and December 2019, 44 patients with early breast cancer after BCS who met the inclusion criteria ≥45 years old, invasive carcinoma ≤3 cm or ductal carcinoma in situ <2.5 cm, estrogen receptor positive, lymph node negative, surgical margin negative, no distant metastasis, and an ECOG performance score ≤1 were enrolled in this phase II single-arm study. The postoperative irradiation field includes the tumor bed plus 2-cm margin in all directions, except in the anterior-posterior direction. The total prescribed tumor dose was 3400 cGy delivered in 10 fractions twice daily at 6-hour intervals. The primary endpoints were acute side effects, late treatment-related toxicity, and cosmetic outcome. The secondary endpoints were local recurrence-free survival (LRFS), regional recurrence-free survival (RRFS), distant metastasis-free survival (DMFS), and overall survival (OS).

RESULTS

The median follow-up time was 33.5 months (mean, 32.9 months; range, 20-43 months). The cosmetic results were good to very good in 92.3% of the questionnaire respondents. The acute toxicities were mild, and no acute grade 3-4 toxicity was noted. Wound infection was noted in two patients (4.5%). There was only one event of regional lymph node recurrence in one patient. The 3-year LRFS, DMFS, and OS were 100%, and RRFS was 94.7%. For two patients who had a positive lymph node based on their final pathology reports, postoperative irradiation, including whole breast and regional lymph nodes, was added.

CONCLUSION

Accelerated partial breast irradiation using interstitial brachytherapy with the intraoperative free-hand catheter implantation technique provides an alternative method of postoperative radiotherapy for selected patients with early breast cancer after BCS with acceptable toxicities.

Accelerated Partial Breast Irradiation using External-Beam or Intraoperative Electron Radiotherapy: 5 year oncological outcomes of a prospective cohort study

PURPOSE

To evaluate the ipsilateral breast tumor recurrence (IBTR) after two accelerated partial breast irradiation (APBI) techniques (intraoperative electron radiotherapy, IOERT and external-beam APBI, EB-APBI) in patients with early stage breast cancer.

PATIENTS AND METHODS

Between 2011 and 2016, women ≥60 years with breast carcinoma or DCIS of ≤30mm and cN0 undergoing breast conserving therapy were included in a two-armed prospective multi-center cohort study. IOERT (1 × 23.3Gy prescribed at the 100% isodose line) was applied in one hospital and EB-APBI (10 × 3.85Gy daily) in 2 other hospitals. Primary endpoint was IBTR (all recurrences in the ipsilateral breast irrespective of localization) at 5 years after lumpectomy. A competing risk model was used to estimate the cumulative incidences of IBTR, which were compared using Fine and Gray's test. Secondary endpoints were locoregional recurrence rate (LRR), distant recurrence, disease specific survival and overall survival. Univariate Cox-regression models were estimated to identify risk factors for IBTR. Analyses were performed of the intention to treat (ITT) population (IOERT n=305; EB-APBI n=295), and sensitivity analyses were done of the per-protocol population (PP) (IOERT n=270; EB-APBI n=207).

RESULTS

Median follow up was 5.2 years (IOERT) and 5 years (EB-APBI). Cumulative incidence of IBTR in the ITT population at 5 years after lumpectomy was 10.6% (95% confidence interval 7.0-14.2%) after IOERT and 3.7% (95%CI 1.2-5.9%) after EB-APBI (p=0.002). LRR was significantly higher after IOERT than EB-APBI (12.1% vs 4.5%, p=0.001). There were no differences between groups in other endpoints. Sensitivity analysis showed similar results. For both groups, no significant risk factors for IBTR were identified in the ITT population. In the PP population surgical margin status was the only significant risk factor for developing IBTR in both treatment groups.

CONCLUSION

Ipsilateral breast tumor recurrences and locoregional recurrence rates were unexpectedly high in patients treated with IOERT, and acceptable in patients treated with EB-APBI.

Breast surgical oncology in elderly and unfit patients: a systematic review

INTRODUCTION

Breast cancer treatment in elderly women remains a complex issue due to pre-existing comorbidities, therapy-related toxicities, and the lack of evidence-based data in this population, leading to both overtreatment and undertreatment.

EVIDENCE ACQUISITION

The aim was to investigate the literature on breast surgical oncology in the older woman as a major therapeutic challenge: the 86 more consistent articles amongst 1440 potential citations according to PRISMA guidelines were retained.

EVIDENCE SYNTHESIS

Studies demonstrated that despite low-grade tumor types, lower incidence of axillary lymph node involvement, ER+ disease, and less aggressive tumor biology, elderly breast cancer patients often receive less than the standard-of-care when compared to their younger counterparts. The surgery omission in elderlies and the preference for the primary endocrine treatment is associated with worse survival, especially in patients aged 80 years or over - a cohort with no specific recommendations concerning breast and axillary surgical procedures. On the other hand, a higher mastectomy rate is still considered the standard treatment in older women with higher T2:T1 tumor ratio and greater difficulties to attend radiotherapy due to severe comorbidities. Surgical de-escalation procedures even in an-ambulatory setting are recognized as a feasible option in these patients to prevent or palliate breast or chest wall symptoms.

CONCLUSIONS

Benefits and disadvantages from surgery only or coupled with adjuvant therapies for elderly women were analyzed in literature, outlining a growing need for a proper geriatric assessment and short-stay surgical programs which are feasible today owing to the availability of less invasive approaches.

Delivery of Adjuvant Radiation in 5 Days or Less After Lumpectomy for Breast Cancer: A Systematic Review

BACKGROUND

Recent data have been published supporting the application of ultra-short radiation therapy (RT) regimens for women with early stage breast cancer following breast conserving surgery (BCS). What has remained controversial is whether and how to apply accelerated whole breast irradiation (AWBI) or accelerated partial breast irradiation (APBI) approaches in these patients, as well as the consideration of intraoperative RT (IORT) for this population.

METHODS

We performed a systematic review of the literature searching for randomized and prospective data published evaluating ultra-short RT delivered in 5-days or less with APBI, AWBI, or IORT.

RESULTS

We identified two randomized studies applying AWBI (n=5,011 patients) with 5 to 10 year follow up, which supported the use of ultra-short course AWBI (5 fractions in one week) as compared to hypofractionated WBI. We identified six randomized trials evaluating APBI (as compared to WBI) in 5 days or less (n= 8,415) with numerous (n=55) prospective studies as well, with the data supporting short course APBI as compared to WBI. Finally, we identified two randomized trials evaluating IORT; however, both trials demonstrated elevated rates of recurrence with IORT as compared to WBI.

CONCLUSIONS

The current body of data available for ultra-short adjuvant RT regimens delivered in 5-days or less after BCS overwhelming support their utilization. While data for both exists, APBI regimens have, by far, greater numbers of patients and longer follow-up as compared to AWBI. Also, given increased rates of recurrence seen with IORT with long-term follow-up, this should not be considered a standard approach at this time.

Wound Fluid from Breast Cancer Patients Undergoing Intraoperative Radiotherapy Exhibits an Altered Cytokine Profile and Impairs Mesenchymal Stromal Cell Function

Intraoperative radiotherapy (IORT) displays an increasingly used treatment option for early breast cancer. It exhibits non-inferiority concerning the risk of recurrence compared to conventional external irradiation (EBRT) in suitable patients with early breast cancer. Since most relapses occur in direct proximity of the former tumor site, the reduction of the risk of local recurrence effected by radiotherapy might partially be due to an alteration of the irradiated tumor bed's micromilieu. Our aim was to investigate if IORT affects the local micromilieu, especially immune cells with concomitant cytokine profile, and if it has an impact on growth conditions for breast cancer cells as well as mammary mesenchymal stromal cells (MSC), the latter considered as a model of the tumor bed stroma.42 breast cancer patients with breast-conserving surgery were included, of whom 21 received IORT (IORT group) and 21 underwent surgery without IORT (control group). Drainage wound fluid (WF) was collected from both groups 24 h after surgery for flow cytometric analysis of immune cell subset counts and potential apoptosis and for multiplex cytokine analyses (cytokine array and ELISA). It served further as a supplement in cultures of MDA-MB 231 breast cancer cells and mammary MSC for functional analyses, including proliferation, wound healing and migration. Furthermore, the cytokine profile within conditioned media from WF-treated MSC cultures was assessed. Flow cytometric analysis showed no group-related changes of cell count, activation state and apoptosis rates of myeloid, lymphoid leucocytes and regulatory T cells in the WF. Multiplex cytokine analysis of the WF revealed group-related differences in the expression levels of several cytokines, e.g., oncostatin-M, leptin and IL-1β. The application of WF in MDA-MB 231 cultures did not show a group-related difference in proliferation, wound healing and chemotactic migration. However, WF from IORT-treated patients significantly inhibited mammary MSC proliferation, wound healing and migration compared to WF from the control group. The conditioned media collected from WF-treated MSC-cultures also exhibited altered concentrations of VEGF, RANTES and GROα. IORT causes significant changes in the cytokine profile and MSC growth behavior. These changes in the tumor bed could potentially contribute to the beneficial oncological outcome entailed by this technique. The consideration whether this alteration also affects MSC interaction with other stroma components presents a promising gateway for future investigations.

APBI Versus Ultra-APBI in the Elderly With Low-Risk Breast Cancer: A Comparative Analysis of Oncological Outcome and Late Toxicity

PURPOSE

Accelerated partial breast irradiation (APBI) represents a validated technique for low-risk breast cancer. Recently, ultra-APBI (uAPBI) using fewer than 5 fractions was described in the literature. We compared clinical outcomes and late toxicity after APBI or uAPBI in older patients.

METHODS AND MATERIALS

Two cohorts of older patients (aged ≥70 years) with low-risk breast cancer treated with APBI (interstitial brachytherapy) were analyzed retrospectively. A total dose of 34 Gy in10 fractions (APBI) or 16 Gy in 1 fraction (uAPBI) was delivered from 2004 to 2012 and from 2013 to 2018, respectively. Oncologic outcome analyzed the cumulative incidence of local relapse, regional relapse, and distant metastases with disease-free survival, cause-specific survival, and overall survival. Late toxicity and cosmetic results were investigated.

RESULTS

One hundred fifty-seven patients (APBI, n = 109 patients; uAPBI, n = 48 patients) underwent APBI according to the same selection criteria. Apart from the median follow-up (97 vs 72 months for APBI and uAPBI; P < .002), no significant difference was noted between the 2 groups. Regarding 6-year oncologic outcome, no significant difference was observed between APBI and uAPBI for local recurrence (1.3% vs 0%; P = .4), regional recurrence (2.5% vs 2.3%; P = .9), distant metastases (4.3% vs. 2.4%; P = .6), disease-free survival (85.2% vs. 82.2%; P = .8), cause-specific survival (96.7% vs. 96.2%; P = .9), and overall survival (86.7% vs. 82.2%; P = .7). Regarding late toxicity, no significant difference was observed between APBI and uAPBI (total complication number, 45 vs 33%; P = .173) with only grade 1 (88.4% vs. 95%) and grade 2 (11.6% vs. 5%) late toxicities (P = .677). Similarly, no significant difference was observed for excellent/good cosmetic results between the 2 cohorts (P = .98).

CONCLUSIONS

We report the first study comparing APBI versus uAPBI in a cohort of older patients with low-risk breast cancer. No significant difference was found between the 2 treatment groups regarding oncologic outcome, late toxicity, and cosmetic result. uAPBI based on a single fraction of brachytherapy represents an attractive option for therapeutic de-escalation in older patients with breast cancer.

Breast cancer in the oldest old (≥ 89 years): Tumor characteristics, treatment choices, clinical outcomes and literature review

INTRODUCTION

Risk of breast cancer increases with age and very few data are available in patients older than 89.

METHODS

A retrospective analysis on patients aged 89 and older treated between 2008 and 2019 at our certified breast center. The aim was to analyze clinical characteristics, decision-making, treatment, outcomes and open questions regarding this subpopulation for which there is a lack of guidelines.

RESULTS

58 patients included. Tumor characteristics were analyzed, 85% patients underwent surgery of which 44% had a mastectomy. The median follow-up and overall survival were 20 and 76 months, respectively.The median survival of metastatic and non-metastatic patients were 14 and 50 months, respectively. Most patients did not receive any adjuvant treatment and among these 14% had a relapse.

CONCLUSIONS

Elderly patients should not be under or over-treated because of their age; they represent a large heterogeneous group deserving a sub-stratification for a better tailored treatment.

Impact of intraoperative radiotherapy on the perioperative period of patients after breast-conserving surgery

BACKGROUND

To investigate the effect of intraoperative radiotherapy (IORT) in the perioperative period of patients after breast-conserving surgery (BCS).

METHODS

The clinical data of 100 patients with early breast cancer undergoing breast-conserving surgery (BCS) followed by treatment with IORT using the Intrabeam system (Carl Zeiss Meditec, Oberkochen, Germany) (BCS + IORT group, n=100) between June 2016 and December 2019 were analyzed and compared with the data of 60 matched patients who only underwent breast-conserving therapy over the same period (BCS group, n=60). The surgical settings and postoperative acute complications between the groups were assessed.

RESULTS

There was no significant statistical difference between the groups in terms of age, tumor size, grading, lymph node status, hormone receptor status, and human epidermal growth factor receptor 2 (HER-2) status (P>0.05). The BCS + IORT group had a significantly longer surgery duration (P<0.05), but there was no significant statistical difference in terms of intraoperative blood loss, amount of bleeding, drainage tube removal time, postoperative length of hospitalization, incision suture removal time, or incidence of postoperative complications (P>0.05).

CONCLUSIONS

IORT using the Intrabeam system safely delivers radiation therapy, is well-tolerated, has acceptable acute toxicity, and does not significant increase the risk of surgery or the incidence of perioperative complications.

Efficacy analysis of intraoperative radiotherapy in patients with early-stage breast cancer

Background

To analyze the clinical efficacy of intraoperative radiotherapy (IORT) after breast-conserving surgery (BCS) in patients with early-stage breast cancer (BC), and to investigate the relationship between its influencing factors and clinical efficacy and prognosis.

Methods

A total of 73 patients with early-stage BC who underwent IORT after BCS in our hospital were selected in this research.

Results

Kaplan-Meier survival analysis was used to analyze the related factors of BCS and IORT of disease-free survival (DFS) and overall survival (OS). It was found that only age (χ² = 14.035, P = 0.003) was statistically positively correlated with the patient’s DFS, and local recurrence and metastasis rate and mortality were higher in patients over 70 years old. Log rank test was used to analyze multiple factors. Only the diameter of the applicator (χ² = 70.378, P < 0.05) was statistically significant with wound complications, and the larger the diameter, the higher incidence of wound complications. The remaining risk factors did not increase the incidence of wound complications. COX multivariate analysis showed that age was an independent risk factor for DFS rate and the risk factor had no significant effect on the OS rate of patients undergoing IORT after BCS.

Conclusions

IORT may be a safe form of treatment for the selected patients with early-stage BC, and can achieve satisfactory esthetic effect. Larger applicator diameters may increase the incidence of wound complications. Age is an independent risk factor for DFS in early-stage BC patients undergoing IORT after BCS.

Multicenter Phase II Study of Intraoperative Radiotherapy of Early Breast Cancer: Ipsilateral Tumor Recurrence

BACKGROUND

We performed a multicenter phase II study on the efficacy and safety of intraoperative radiotherapy (IORT) as partial breast irradiation using multiple devices.

METHODS

The primary endpoint was ipsilateral breast tumor recurrence (IBTR). Key inclusion criteria were T < 2.5 cm, age > 50 years, surgical margin > 1 cm, intraoperative pathologically free margins, and sentinel node negative. After resection of the tumor, radiation at 21 Gy was delivered directly to the mammary gland employing an electron linear accelerator in the operating room, otherwise the patient was transported from the surgical suite to the radiation room.

RESULTS

Overall, 142 patients were enrolled in this study and 129 underwent IORT. Stage 0: n = 4 (3.1%); stage I: n = 98 (76.0%); and stage IIA: n = 27 (20.9%). Luminal type: n = 116 (89.9%); triple-negative: n = 9 (7.0%); and human epidermal growth factor receptor 2: n = 4 (3.1%). Median follow-up time was 59.5 months (range 27.5-99.0), and the rate of IBTR was 3.1% (95% confidence interval 0.9-7.8). The toxicities included fibrosis in deep-connective tissue: grade 1, 78.1%; wound infection: grade 3, 1.6% and grade 2, 1.6%; and soft tissue necrosis: grade 3, 0.8% and grade 2, 0.8%. Recurrence in the breast occurred in four cases; the site of recurrence was just under the skin near the primary tumor site, with similar histology and subtype.

CONCLUSIONS

In this multicenter phase II study, the rate of IBTR was low and IORT at 21 Gy was feasible in properly selected patients. It is important to use a careful surgical technique to reduce local recurrence because the skin is not included in the radiation field of IORT.

Health-related quality of life of breast cancer patients after accelerated partial breast irradiation using intraoperative or external beam radiotherapy technique

PURPOSE

To compare health-related quality of life (HRQL) in elderly breast cancer patients between two types of Accelerated Partial Breast Irradiation: intraoperative radiotherapy (IORT) and external beam APBI (EB-APBI).

METHODS

Between 2011 and 2016 women ≥60 years undergoing breast conserving therapy for early stage breast cancer were included in a prospective multi-centre cohort study. Patients were treated with electron IORT (1 × 23.3 Gy) or photon EB-APBI (10 × 3.85 Gy daily). HRQL was measured by the EORTC-QLQ C30 and BR23 questionnaires before surgery and at several time points until 1 year.

RESULTS

HRQoL data was available of 204 IORT and 158 EB-APBI patients. In longitudinal analyses emotional functioning and future perspective were significantly, but not clinically relevantly, worse in IORT-treated patients, and improved significantly during follow-up in both groups. All other aspects of HRQL slightly worsened after treatment and recovered within 3 months with an improvement until 1 year. Cross-sectional analysis showed that postoperatively fatigue and role functioning were significantly worse in IORT patients compared to EB-APBI patients who were not yet irradiated, but the difference was not clinically relevant. At other timepoints there were no significant differences. Multivariable analysis at 1 year identified comorbidity and systemic therapy as risk factors for a worse global health score (GHS).

CONCLUSIONS

EB-APBI and IORT were well tolerated. Despite a temporary deterioration after treatment, all HRQL scales recovered within 3 months resulting in no clinically relevant differences until 1 year between groups nor compared to baseline levels.