Long-term outcomes of implant-based immediate breast reconstruction with and without radiotherapy: a population-based study

Identification of sentinel lymph node macrometastasis in breast cancer by deep learning based on clinicopathological characteristics

The axillary lymph node status remains an important prognostic factor in breast cancer, and nodal staging using sentinel lymph node biopsy (SLNB) is routine. Randomized clinical trials provide evidence supporting de-escalation of axillary surgery and omission of SLNB in patients at low risk. However, identifying sentinel lymph node macrometastases (macro-SLNMs) is crucial for planning treatment tailored to the individual patient. This study is the first to explore the capacity of deep learning (DL) models to identify macro-SLNMs based on preoperative clinicopathological characteristics. We trained and validated five multivariable models using a population-based cohort of 18,185 patients. DL models outperform logistic regression, with Transformer showing the strongest results, under the constraint that the sensitivity is no less than 90%, reflecting the sensitivity of SLNB. This highlights the feasibility of noninvasive macro-SLNM prediction using DL. Feature importance analysis revealed that patients with similar characteristics exhibited different nodal status predictions, indicating the need for additional predictors for further improvement.

A BRILLIANT-BRCA study: residual breast tissue after mastectomy and reconstruction

INTRODUCTION

Different types of mastectomies leave different amounts of residual breast tissue. The significance of the residual breast volume (RBV) is not clear. Therefore, we developed an MRI tool that allows to easily assess the RBV. In this study we evaluated factors associated with RBV after skin or nipple sparing mastectomy (SSM/NSM) in breast cancer BRCA pathogenic variant (PV) carriers who underwent both therapeutic and risk reducing SSM/NSM and its relation to breast cancer outcomes using an innovative MRI-based tool.

METHODS

Data of breast cancer BRCA PV who were treated between 2006 and 2020 were retrieved from of the oncogenetics unit databases. Only patients who underwent SSM/NSM and had a postoperative breast MRI available for analysis were included. Data collected included demographics, clinicopathological features, and outcomes. The MRI tool was developed by a breast cancer imaging laboratory. A logistic regression test and 95% confidence interval (CI) were used to assess the associated risk of increased RBV. A forward stepwise linear regression was used to correlate tumour-patient specific factors and RBV, and a Kaplan-Meier curve to show the probability of locoregional relapse.

RESULTS

A total of 84 patients undergoing 89 mastectomies were included. At a median follow-up of 98 months, 5 local, 2 regional, and 4 distant recurrences were observed. RBV was not significantly related with breast cancer outcomes (p value = NS). A higher body mass index (BMI) was associated with a higher RBV (p < 0.0001). A larger number of involved axillary nodes was associated with a smaller RBV (p = 0.025). The RBV on the risk-reducing mastectomy side was significantly higher compared to the breast cancer side (p value = 0.007). Local recurrences occurred in the vicinity of the primary tumour.

Residual breast tissue after mastectomy and reconstruction: A substudy of the Spatial location of breast cancer local rECurRence aftEr masTectomy (SECRET) project

The current project is part of the Spatial location of breast cancer local rECurRence aftEr masTectomy (SECRET) study (NCT06130111). Herein we compared the chest wall thickness after non-skin sparing mastectomy (non-SSM) with the chest wall thickness after SSM, as a surrogate for residual breast tissue after mastectomy.

METHODS

The study was approved by the ethics committee of relevant institutions. Data of patients with a local recurrence (LR) after non-SSM was collected from the Netherlands Cancer Registry (NCR); data of patients undergoing SSM were collected from Sheba Medical Center. Student's t-test was used to evaluate the difference between the cohorts. Chest wall thickness was measured on postoperative images.

RESULTS

Out of 4949 patients who underwent mastectomy from the NCR cohort, a total of 173 (3.5 %) had a LR at 5 years, of these a total of 153 patients included in the non-SSM cohort. The median age was 59 years (age 33-92), LR occurred at a median of 23.6 months (2.5-60 months). The SSM cohort included 84 patients, with a median age of 38.4 years (28-63.5), overall, 5 LRs occurred at a median of 15 months (5-46 months). The SSM cohort had significantly thicker chest walls compared to non-SSM (p < 0.001). Most LRs in both groups occurred in the subcutis.

CONCLUSION

The chest wall thickness differed according to mastectomy procedures. Most of the LR occurred at the subcutis. The role of residual breast tissue and residual cancer in relation to type of mastectomy should be further investigated.

Surgical complications after immediate implant-based breast reconstruction for breast cancer in women over 65 years

BACKGROUND

While immediate breast reconstruction rates in breast cancer are increasing, they remain low in women over 65 years old. The aim was to investigate surgical outcomes in women older than 65 years receiving implant-based immediate breast reconstruction.

METHOD

The population-based Stockholm Breast Reconstruction Database includes all adult women with breast cancer receiving an implant-based immediate breast reconstruction in Stockholm, Sweden, 2005-2015. Primary outcomes within 30 days from immediate breast reconstruction were: infection requiring antibiotics and reoperation on. Implant removal was a secondary outcome. Women more than 65 years were compared with younger age groups. Chi-square tests and multivariable logistic regression were applied for the primary outcomes, and Kaplan-Meier analysis for the secondary outcome.

RESULTS

Among 1749 cases of immediate breast reconstruction, 140 (8.0%) were in women more than 65 years. Median follow-up was 74 months (1-198). Postoperative infection was not more common in women older than 65 years old (22 of 140, 15.7%) than in women under 65 years old (303 of 1609, 18.8%; P = 0.221). Reoperation on was more frequent in women older than 65 years than in other age groups (more than 65: 8.6%; 50-64: 6.5%; 40-49: 3.5%; less than 40: 1.6%; P < 0.001), however, age older than 65 years was not an independent risk factor in the multivariable analysis (OR 1.00, 95% c.i. 0.44 to 2.28). Overall, 6-year probability of implant removal was 11.4%, (8.1% due to complications and 3.3% due to patient preference). There was no statistically significant difference between age groups for either reason (P = 0.085 and P = 0.794 respectively).

CONCLUSION

Older age alone was not associated with worse surgical outcomes after implant-based immediate breast reconstruction in highly selected patients older than 65 years when compared with their younger counterparts.

Patient-Reported Outcomes and Complication Profiles of Implant-Based Breast Reconstruction in Patients With Postmastectomy Radiation Therapy

OBJECTIVE

This study aims to investigate the patient-reported outcomes (PROs) and complications of distinct implant-based breast reconstruction modality for patients with postmastectomy radiation therapy (PMRT).

METHODS

A retrospective review was conducted on breast cancer patients with stage II-III disease who performed implant-based breast reconstruction following with PMRT between September 2016 and April 2022. The patients were categorized into two matched groups: (1) patients receiving prepectoral breast reconstruction (PBR) or (2) subpectoral breast reconstruction (SBR) followed by PMRT. Following reconstruction, the patients were further compared for PMRT with the tissue expander (PMRT-TE) versus PMRT with permanent implant (PMRT-PI). PROs were measured with BREAST-Q questionnaire. Early and late complications were recorded and analyzed.

RESULTS

A total of 55 eligible patients were recruited. Patients who underwent PBR reported significantly higher satisfaction with breasts scores (P = 0.003) compared with the SBR group. The PMRT-TE group had higher satisfaction with breasts (P = 0.001) but lower physical well-being (P = 0.029) scores compared with PMRT-PI group. Moreover, patients in SBR cohort had a higher risk of capsular contracture (Baker grade III or IV) (20.5% vs 6.3%) and implant dislocation (48.7% vs 12.5%) than patients in PBR cohort. Patients in PMRT-PI group had a slightly higher rate of capsular contracture (Baker grade III or IV) than PMRT-TE group (20.8% vs 12.9%).

CONCLUSIONS

PBR was associated with lower rates of late complications, especially for implant dislocation, and higher satisfaction with breasts scores compared to SBR. In addition, compared to PMRT-TE with PMRT-PI, patients in PMRT-TE cohort reported superior PROs of satisfaction with breasts.

Immediate Breast Reconstruction With Latissimus Dorsi Myocutaneous Flap and Silicone Implant Followed by Adjuvant Radiotherapy for Breast Cancer

BACKGROUND

About 30% to 50% of women with breast cancer undergo mastectomy, and approximately 50% of them will receive adjuvant radiotherapy (ART). This study evaluates the medium- and long-term impact of ART after immediate breast reconstruction (IBR) with latissimus dorsi myocutaneous (LDM) flap and silicone implants.

METHODS

Clinical, surgical, and oncological data were retrospectively collected and analyzed based on the medical records of 176 patients who had undergone IBR with LDM flap and silicone implants.

RESULTS

The data showed that 7.4% of patients had a history of previous radiotherapy, 56.3% received ART, 31.8% developed capsular contracture with a mean follow-up of 58.1 months, and 14.2% of surgeries were categorized as procedures with a prolonged operating time, lasting above 1 SD of the observed mean. Those who experienced prolonged operating time (odds ratio, 4.72; 95% confidence interval, 1.72-12.93; P = 0.003) and those who received ART (odds ratio, 7.38; 95% confidence interval, 3.18-17.10; P < 0.001) were more likely to develop capsular contracture. Thirty-two patients (18%) underwent capsulectomy with implant replacement, and 7 patients (4%) had the implant removed. The mean time between IBR and reoperation was 29.1 months. Patients who received ART were 2.84 times more likely to experience reconstruction failure or undergo implant-related reoperation ( P = 0.002).

CONCLUSIONS

The results indicated that IBR with LDM flap and silicone implant followed by ART is a safe procedure, resulting in low rates of reconstruction failure. However, ART increased the likelihood of capsular contracture development and implant-related reoperation, having a negative effect on reconstructed breasts.

Pathology and resection margins following mastectomy prior to immediate breast reconstruction

Risk of local recurrence (LR) (and even distant disease-free survival) after mastectomy is associated with margin status. Furthermore, the vast majority of LR are located at the anterior (superficial) margin. Margins in mastectomy are considered anatomical borders and not true resection margins; such a conception may erroneously lead to underestimation of the risk of LR after mastectomy. If dissection is accurate along the fascia, only skin, subcutaneous tissue and minimal residual breast gland tissue (rBGT) are expected to remain in the patient. However, the subcutaneous fascia is an inconsistent anatomical structure that may be absent in almost half of patients. Studies and routine clinical practice suggest that resection may frequently, though often focally, be within the breast glandular tissue leaving various amounts of rBGT. Such areas may be nidus for subsequent de novo or recurrent premalignant or malignant disease. There is no consensus on handling of close/positive margins and intervention is extrapolated from studies on breast conserving surgery with subsequent radiotherapy. Handling of a close/positive margin is complicated by poor correlation between the ex vivo findings on the specimen and the attempt to relocate the area of concern in a patient with reconstructed breasts. In this clinical practice review, we strongly advocate for reporting of the lesion-to-margin distance in mastectomies to collect further evidence on the association between LR and margin status.

The King is in the altogether: Radiation therapy after oncoplastic breast surgery

Breast cancer is the most common malignancy, and the majority of the patients are diagnosed at an early disease stage. Breast conservation is the preferred locoregional approach, and oncoplastic breast conservation surgery is becoming more popular. This narrative review aims to discuss the challenges and uncertainties in target volume definition for postoperative radiation after these procedures, to improve radiation therapy decisions and encourage multidisciplinary.

Protocol for the T-REX-trial: tailored regional external beam radiotherapy in clinically node-negative breast cancer patients with 1-2 sentinel node macrometastases - an open, multicentre, randomised non-inferiority phase 3 trial

INTRODUCTION

Modern systemic treatment has reduced incidence of regional recurrences and improved survival in breast cancer (BC). It is thus questionable whether regional radiotherapy (RT) is still beneficial in patients with sentinel lymph node (SLN) macrometastasis. Postoperative regional RT is associated with an increased risk of arm morbidity, pneumonitis, cardiac disease and secondary cancer. Therefore, there is a need to individualise regional RT in relation to the risk of recurrence.

METHODS AND ANALYSIS

In this multicentre, prospective randomised trial, clinically node-negative patients with oestrogen receptor-positive, HER2-negative BC and 1-2 SLN macrometastases are eligible. Participants are randomly assigned to receive regional RT (standard arm) or not (intervention arm). Regional RT includes the axilla level I-III, the supraclavicular fossa and in selected patients the internal mammary nodes. Both groups receive RT to the remaining breast. Chest-wall RT after mastectomy is given in the standard arm, but in the intervention arm only in cases of widespread multifocality according to national guidelines. RT quality assurance is an integral part of the trial.The trial aims to include 1350 patients between March 2023 and December 2028 in Sweden and Norway. Primary outcome is recurrence-free survival (RFS) at 5 years. Non-inferiority will be declared if outcome in the de-escalation arm is not >4.5 percentage units below that with regional RT, corresponding to an HR of 1.41 assuming 88% 5-year RFS with standard treatment. Secondary outcomes include locoregional recurrence, overall survival, patient-reported arm morbidity and health-related quality of life. Gene expression analysis and tumour tissue-based studies to identify prognostic and predictive markers for benefit of regional RT are included.

ETHICS AND DISSEMINATION

The trial protocol is approved by the Swedish Ethics Authority (Dnr-2022-02178-01, 2022-05093-02, 2023-00826-02, 2023-03035-02). Results will be presented at scientific conferences and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05634889.

Optimising post-operative radiation therapy after oncoplastic and reconstructive procedures

Surgical techniques for breast cancer have been refined over the past decades to deliver an aesthetic outcome as close as possible to the contralateral intact breast. Current surgery further allows excellent aesthetic outcome even in case of mastectomy, by performing skin sparing or nipple sparing mastectomy in combination with breast reconstruction. In this review we discuss how to optimise post-operative radiation therapy after oncoplastic and breast reconstructive procedures, including dose, fractionation, volumes, surgical margins, and boost application.