Partial breast irradiation versus whole breast radiotherapy for early breast cancer

Non-irradiated area of intraoperative radiotherapy with electron technique: outcomes and pattern of failure in early-stage breast cancer from a single-center, registry study

INTRODUCTION

Intraoperative radiotherapy (IORT) with electrons has revealed to have higher rates of ipsilateral breast tumor recurrence (IBTR) than external beam radiotherapy in updated large-scale, randomized controlled trials in 2021. This study details the oncological outcomes of IORT with electron beams using our strict IORT policies. We have found new and important observations regarding the location of recurrence.

METHODS AND MATERIALS

This is a single institution registry of early-stage breast cancer patients who underwent lumpectomy and electron beam IORT with appropriate cone size. All patients met our pre-excision requirements. The primary endpoint was 5-year IBTR rate, with secondary endpoints being 5-year locoregional failure rate, 5-year distant metastasis rate, 5-year overall survival and, importantly, the failure patterns.

RESULTS

Between January 2011 and December 2022, 124 patients were recruited. The median follow-up was 6.7 years. The 5-year IBTR rate was 1.87% (95% CI 0.47-7.29%), which is much lower than the ELIOT trial and comparable with other accelerated partial breast irradiation (APBI) techniques. The 5-year locoregional failure rate was 3.68% (95% CI 1.40-9.52%), and the 5-year distant metastasis rate was 0.88% (95% CI 0.13-6.12%), while the 5-year overall survival rate was 97.52% (95% CI 92.44-99.19%). Six patients experienced IBTR. All recurrences were in surgical area, occurring superficial to the tumor bed and within 1 cm of the skin dermis. This failure pattern is very unique and might be explained by our hypothesis of the non-irradiated area beneath the skin.

CONCLUSIONS

IORT with electron beams with strict patient selection criteria and strict large cone size is still an acceptable treatment for select patients with early-stage breast cancer. However, our new findings support extreme caution in the non-irradiated area beneath the skin around the tumor cavity. Given the constraints of our sample size, these findings should be interpreted cautiously and warrant further investigation in larger, more comprehensive studies.

In-vitro cytotoxicity of biosynthesized nanoceria using Eucalyptus camaldulensis leaves extract against MCF-7 breast cancer cell line

Cerium oxide nanoparticles possess unique properties that make them promising candidates in various fields, including cancer treatment. Among the proposed synthesis methods for CNPs, biosynthesis using natural extracts, offers an eco-friendly and convenient approach for producing CNPs, particularly for biomedical applications. In this study, a novel method of biosynthesis using the aqueous extract of Eucalyptus camaldulensis leaves was used to synthesize CNPs. Scanning electron microscopy and Transmission electron microscopy (TEM) techniques revealed that the synthesized CNPs exhibit a flower-like morphology. The particle size of CNPs obtained using Powder X-ray diffraction peaks and TEM as 13.43 and 39.25 nm. Energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy confirmed the effect of biomolecules during the synthesis process and the formation of CNPs. The cytotoxicity of biosynthesized samples was evaluated using the MTT method demonstrating the potential of these samples to inhibit MCF-7 cancerous cells. The viability of the MCF-7 cell line conducted by live/dead imaging assay confirmed the MTT cytotoxicity method and indicated their potential to inhibit cancerous cells. Furthermore, the successful uptake of CNPs by MCF-7 cancer cells, as demonstrated by confocal microscopy, provides evidence that the intracellular pathway contributes to the anticancer activity of the CNPs. In general, results indicate that the biosynthesized CNPs exhibit significant cytotoxicity against the MCF-7 cancerous cell line, attributed to their high surface area.

The correlation study between TOP2A gene expression in circulating tumor cells and chemotherapeutic drug resistance of patients with breast cancer

BACKGROUND

Patients with breast cancer (BC) at advanced stages have poor outcomes because of high rate of recurrence and metastasis. Biomarkers for predicting prognosis remain to be explored. This study aimed to evaluate the relationships between circulating tumor cells (CTCs) and outcomes of BC patients.

PATIENTS AND METHODS

A total of 50 female were enrolled in this study. Their diagnoses were determined by clinical characteristics, image data, and clinical pathology. CTC subtypes and TOP2A gene expression on CTCs were detected by CanPatrol™ technology and triple color in situ RNA hybridization (RNA-ISH), which divided into epithelial CTCs (eCTCs), mesenchymal CTCs (MCTCs), and hybrid CTCs (HCTCs) based on their surface markers. Hormone receptor, including estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2) expression, was measured by immunohistochemistry (IHC) method before treatment. The risk factors for predicting recurrence and metastasis were calculated by COX risk regression model. The progression-free survival (PFS) of patients was determined using Kaplan-Meier survival curve.

RESULTS

The patients with a large tumor size (≥ 3 cm) and advanced tumor node metastasis (TNM) stages had high total CTCs (TCTCs) (P < 0.05). These patients also had high TOP2A expression level. COX risk regression analysis indicated that TOP2A expression levels in TCTCs, ER + , HER-2 + , and TNM stages were critical risk factors for recurrence and metastasis of patients (P < 0.05). The PFS of patients with ≥ 5 TCTCs, ≥ 3 HCTCs, and positive TOP2A expression in ≥ 3 TCTCs was significantly longer than that in patient with < 5 TCTCs, < 3 HCTCs, and TOP2A expression in < 3 TCTCs (P < 0.05). In contrast, the PFS of patients with positive hormone receptors (ER + , PR + , HER-2 +) also was dramatically lived longer than that in patients with negative hormone receptor expression.

CONCLUSIONS

High TCTC, HCTCs, and positive TOP2A gene expression on CTCs were critical biomarkers for predicting outcomes of BC patients. Positive hormone receptor expression in BC patients has significant favor PFS.

The Japanese breast cancer society clinical practice guidelines for radiation treatment of breast cancer, 2022 edition

The Breast Cancer Clinical Practice Guidelines, organized by the Japanese Breast Cancer Society (JBCS), were published in 2022. We present the English version of the Radiation Therapy (RT) section of the guidelines. The JBCS formed a task force to update the 2018 version of the JBCS Clinical Practice Guidelines. The Background Questions (BQs) contain the standard treatments for breast cancer in clinical practice, whereas the Clinical Questions (CQs) address daily clinical questions that remain controversial. Future Research Questions (FRQs) explore the subjects that are considered important issues, despite there being insufficient data for inclusion as CQs. The task force selected the 12 BQs, 8 CQs, and 6 FRQs for the RT section. For each CQ, systematic literature reviews and meta-analyses were conducted according to the Minds Manual for Guideline Development 2020, version 3.0. The recommendations, strength of recommendation, and strength of evidence for each CQ were determined based on systematic reviews and meta-analyses, and finalized by voting at the recommendation decision meeting.

Comparison of partial-breast irradiation and intraoperative radiation to whole-breast irradiation in early-stage breast cancer patients: a Kaplan-Meier-derived patient data meta-analysis

PURPOSE

Partial breast irradiation (PBI) and intraoperative radiation (IORT) represent alternatives to whole breast irradiation (WBI) following breast conserving surgery. However, data is mixed regarding outcomes. We therefore performed a pooled analysis of Kaplan-Meier-derived patient data from randomized trials to evaluate the hypothesis that PBI and IORT have comparable long-term rates of ipsilateral breast tumor recurrence as WBI.

METHODS

In February, 2023, PubMed, EMBASE and Cochrane Central were systematically searched for randomized phase 3 trials of early-stage breast cancer patients undergoing breast-conserving surgery with PBI or IORT as compared to WBI. Time-to-event outcomes of interest included ipsilateral breast tumor recurrence (IBTR), overall survival (OS) and distant disease-free survival (DDFS). Statistical analysis was performed with R Statistical Software.

RESULTS

Eleven randomized trials comprising 15,460 patients were included; 7,675 (49.6%) patients were treated with standard or moderately hypofractionated WBI, 5,413 (35%) with PBI and 2,372 (15.3%) with IORT. Median follow-up was 9 years. PBI demonstrated comparable IBTR risk compared with WBI (HR 1.20; 95% CI 0.95-1.52; p = 0.12) with no differences in OS (HR 1.02; 95% CI 0.90-1.16; p = 0.70) or DDFS (HR 1.15; 95% CI 0.81-1.64; p = 0.43). In contrast, patients treated with IORT had a higher IBTR risk (HR 1.46; 95% CI 1.23-1.72; p < 0.01) compared with WBI with no difference in OS (HR 0.98; 95% CI 0.84-1.14; p = 0.81) or DDFS (HR 0.91; 95% CI 0.76-1.09; p = 0.31).

CONCLUSION

For patients with early-stage breast cancer following breast-conserving surgery, PBI demonstrated no difference in IBTR as compared to WBI while IORT was inferior to WBI with respect to IBTR.

Molecular subtypes of breast cancer predicting clinical benefits of radiotherapy after breast-conserving surgery: a propensity-score-matched cohort study

BACKGROUND

Based on the molecular expression of cancer cells, molecular subtypes of breast cancer have been applied to classify patients for predicting clinical outcomes and prognosis. However, further evidence is needed regarding the influence of molecular subtypes on the efficacy of radiotherapy (RT) after breast-conserving surgery (BCS), particularly in a population-based context. Hence, the present study employed a propensity-score-matched cohort design to investigate the potential role of molecular subtypes in stratifying patient outcomes for post-BCS RT and to identify the specific clinical benefits that may emerge.

METHODS

From 2006 to 2019, the present study included 59,502 breast cancer patients who underwent BCS from the Taiwan National Health Insurance Research Database. Propensity scores were utilized to match confounding variables between patients with and without RT within each subtype of breast cancer, namely luminal A, luminal B/HER2-negative, luminal B/HER2-positive, basal-like, and HER2-enriched ones. Several clinical outcomes were assessed, in terms of local recurrence (LR), regional recurrence (RR), distant metastasis (DM), disease-free survival (DFS), and overall survival (OS).

RESULTS

After post-BCS RT, patients with luminal A and luminal B/HER2-positive breast cancers exhibited a decrease in LR (adjusted hazard ratio [aHR] = 0.18, p < 0.0001; and, 0.24, p = 0.0049, respectively). Furthermore, reduced RR and improved DFS were observed in patients with luminal A (aHR = 0.15, p = 0.0004; and 0.29, p < 0.0001), luminal B/HER2-negative (aHR = 0.06, p = 0.0093; and, 0.46, p = 0.028), and luminal B/HER2-positive (aHR = 0.14, p = 0.01; and, 0.38, p < 0.0001) breast cancers. Notably, OS benefits were found in patients with luminal A (aHR = 0.62, p = 0.002), luminal B/HER2-negative (aHR = 0.30, p < 0.0001), basal-like (aHR = 0.40, p < 0.0001), and HER2-enriched (aHR = 0.50, p = 0.03), but not luminal B/HER2-positive diseases. Remarkably, when considering DM, luminal A patients who received RT demonstrated a lower cumulative incidence of DM than those without RT (p = 0.02).

CONCLUSION

In patients with luminal A breast cancer who undergo BCS, RT could decrease the likelihood of tumor metastasis. After RT, the tumor's hormone receptor status may predict tumor control regarding LR, RR, and DFS. Besides, the HER2 status of luminal breast cancer patients may serve as an additional predictor of OS after post-BCS RT. However, further prospective studies are required to validate these findings.

Long-term outcomes of intraoperatively-placed applicator brachytherapy for rapid completion of breast conserving treatment: An analysis of a prospective registry data

Background and purpose

To evaluate the long-term outcome of accelerated partial breast irradiation utilizing intraoperatively placed applicator-based brachytherapy (ABB) in early-stage breast cancer.

Materials and methods

From our prospective registry, 223 patients with pTis-T2, pN0/pN1mic breast cancer were treated with ABB. The median treatment duration including surgery and ABB was 7 days. The prescribed doses were 32 Gy/8 fx BID (n = 25), 34 Gy/10 fx BID (n = 99), and 21 Gy/3 fx QD (n = 99). Endocrine therapy (ET) adherence was defined as completion of planned ET or ≥ 80% of the follow-up (FU) period. Cumulative incidence of ipsilateral breast tumor recurrence (IBTR) was estimated and influencing factors for IBTR-free survival rate (IBTRFS) were analyzed.

Results

218/223 patients had hormone receptor-positive tumors, including 38 (17.0%) with Tis and 185 (83.0%) with invasive cancer. After a median FU of 63 months, 19 (8.5%) patients had recurrence [17 (7.6%) with an IBTR]. Rates of 5-year IBTRFS and DFS were 92.2% and 91.1%, respectively. The 5-year IBTRFS rates were significantly higher for post-menopausal women (93.6% vs. 66.4%, p = 0.04), BMI < 30 kg/m2 (97.4% vs. 88.1%, p = 0.02), and ET-adherence (97.5% vs. 88.6%, p = 0.02). IBTRFS did not differ with dose regimens.

Conclusions

Postmenopausal status, BMI < 30 kg/m2, and ET- adherence predicted favorable IBTRFS. Our results highlight the importance of careful patient selection for ABB and encouragement of ET compliance.