Local recurrence outcomes after breast conserving surgery and adjuvant radiotherapy in ductal carcinoma in situ of the breast and a comparison with ECOG E5194 study

Outcomes from low-risk ductal carcinoma in situ: a systematic review and meta-analysis

PURPOSE

The current standard of treatment for ductal carcinoma in situ (DCIS) is surgery with or without adjuvant radiotherapy. With a growing debate about overdiagnosis and overtreatment of low-risk DCIS, active surveillance is being explored in several ongoing trials. We conducted a systematic review and meta-analysis to evaluate the recurrence of low-risk DCIS under various treatment approaches.

METHODS

PubMed, Embase, Web of Science, and Cochrane were searched for studies reporting ipsilateral breast tumour event (IBTE), contralateral breast cancer (CBC), and breast cancer-specific survival (BCSS) rates at 5 and 10 years in low-risk DCIS. The primary outcome was invasive IBTE (iIBTE) defined as invasive progression in the ipsilateral breast.

RESULTS

Thirty three eligible studies were identified, involving 47,696 women with low-risk DCIS. The pooled 5-year and 10-year iIBTE rates were 3.3% (95% confidence interval [CI]: 1.3, 8.1) and 5.9% (95% CI: 3.8, 9.0), respectively. The iIBTE rates were significantly lower in patients who underwent surgery compared to those who did not, at 5 years (3.5% vs. 9.0%, P = 0.003) and 10 years (6.4% vs. 22.7%, P = 0.008). Similarly, the 10-year BCSS rate was higher in the surgery group (96.0% vs. 99.6%, P = 0.010). In patients treated with breast-conserving surgery, additional radiotherapy significantly reduced IBTE risk, but not total-CBC risk.

CONCLUSION

This review showed a lower risk of progression and better survival in women who received surgery and additional RT for low-risk DCIS. However, our findings were primarily based on observational studies, and should be confirmed with the results from the ongoing trials.

The clinical significance of HER2 expression in DCIS

HER2 is an established prognostic and predictive marker for patients with invasive breast cancer. The clinical and biological significance of HER2 overexpression in patients with ductal carcinoma in situ (DCIS) remains poorly defined. DCIS is a heterogeneous disease and some patients with DCIS will not progress to invasive breast cancer. However, clinically significant recurrence rates have been reported after breast-conserving surgery for DCIS and approximately half of these cases will be life-threatening invasive recurrences. Since the incidence of DCIS is rising due to the widespread use of screening mammography, there is robust interest in selecting high-risk DCIS patients that may benefit from adjuvant therapies. Molecular prognostic and predictive models in early invasive breast cancer help clinicians identify patients that will benefit from chemotherapy. Molecular subtyping and profiling could also be useful in treating DCIS patients. According to current practice guidelines, HER2 testing is not recommended in DCIS patients. Nevertheless, evidence suggests that HER2-positive DCIS cases may be associated with adverse clinicopathological parameters and increased recurrence rates. This review summarizes the existing body of evidence linking HER2 expression and ipsilateral breast cancer recurrence in DCIS. HER2, as well as its correlation with other clinicopathological markers might be a useful prognostic and predictive marker, helping clinical decision-making in DCIS patients.

Delayed initiation of radiation therapy is associated with inferior outcomes for breast cancer patients with hormone receptor-negative tumors after breast-conserving surgery

Background

To investigate whether the interval between adjuvant chemotherapy (CT) completion and postoperative radiation therapy initiation (ICR) after breast-conserving surgery (BCS) affects ipsilateral breast tumor recurrence (IBTR) or survival.

Methods

All women who were diagnosed with invasive breast cancer and underwent BCS between 2005 and 2014 were included. In total, 1,472 patients underwent adjuvant CT followed by postoperative radiation therapy (RT) (CT+), whereas 402 patients received postoperative RT alone (CT-). Analyses were stratified by ICR and the interval between surgery and the initiation of postoperative RT (ISR) in these two cohorts. The cutoff points for treatment delay were 47 days in the CT+ cohort and 69 days in the CT- cohort. IBTR, local-regional failure (LRF), disease-free survival (DFS), and overall survival (OS) were assessed through Kaplan-Meier (K-M) analysis. Univariate and multivariate regression analyses were performed to determine the prognostic factors of survival outcomes.

Results

The median follow-up duration was 56 months. There was an association between a delay in ICR and an increase in IBTR in the CT+ group (P=0.014 for intervals ≤47 vs. >47 days). This association was confirmed by multivariate analyses [hazard ratio (HR) of 2.766; P=0.046] in the hormone receptor-negative subgroup. The 5-year cumulative incidence rates of IBTR were 1.3% and 3.3% (≤47 vs. >47 days, respectively) in the CT+ cohort. For patients in the CT- cohort, a longer delay of initiation of postoperative RT (≤69 vs. >69 days) significantly decreased DFS (HR of 6.430; P=0.002). The 5-year cumulative incidence rates of disease recurrence were 3.0% for RT starting ≤69 days after surgery and 12.6% for RT starting >69 days after surgery.

Conclusions

A high IBTR rate was related to an ICR beyond 47 days. Delay of RT after CT or surgery among patients who undergo BCS should be avoided, especially among patients in the hormone receptor-negative subgroup.

[Overall survival and survival without local recurrence in case of radiotherapy of the tumor bed of ductal carcinomas in situ of the breast: Review of the literature]

INTRODUCTION

Carcinomas in situ represent more than 15 to 20% of breast cancers. Radiotherapy of whole breast is part of the therapeutic standard and follows surgery. However, the indication of tumor bed irradiation is still controversial and heterogeneous according to international practice even though it is a very frequent clinical situation. The aim of this study is to define the indications of tumor bed irradiation in the context of ductal carcinomas in situ and to discuss accelerated partial irradiation of the breast.

METHOD

The selected papers were published between 2015 and 2020 and included as MeSH terms "ductal carcinoma in situ" and "boost" for the analysis of tumor bed irradiation, and "ductal carcinoma in situ" and "accelerated partial breast irradiation" for the analysis of accelerated partial irradiation.

RESULTS

Boost was more often performed when risk factors for local recurrence were present, such as age less than 40 or 50 years old, clinical mode of detection, tumor size greater than 15 to 20mm, high nuclear grade, presence of necrosis, positive or insufficient surgical margins, associated atypical hyperplastic lesions, and lobular carcinoma in situ. Accelerated partial irradiation is an option for favorable or intermediate prognosis CCIS, further studies involving more patients are required.

CONCLUSION

Radiotherapy of the mammary gland in the context of DCIS has shown its effectiveness in terms of local and locoregional control of the disease, thus reducing in situ and infiltrating recurrences. However, the indication of operating bed irradiation is still debated, and the practice is very heterogeneous depending on the country. Another possible alternative for patients with a favorable prognosis and a small tumor bed volume would be IPA.

Types of Mastectomies and Immediate Reconstructions for Ipsilateral Breast Local Recurrences

Purpose: Ipsilateral-breast-local-recurrence (ILBLR) is a rare event with little data on immediate-breast-reconstruction (IBR). We report post-operative results of different types of mastectomy for ILBLR with or without IBR performed during a period of 40 months in order to analyze post-operative complications as main objective. Methods: We analyzed mastectomies performed for ILBLR after initial breast conservative treatment from January 2016 to April 2019. The characteristics of patients, surgery, complication rate, postoperative hospitalization have been determined. Results: Of the 207 mastectomies, 32.8% had an IBR: 31 nipple-sparing-mastectomy (NSM) and 37 skin-sparing-mastectomy (SSM) with 37 latissimus-dorsi-flap (LDF) IBR and 31 implant-IBR. Few reconstruction was performed for patients with body-mass-index ≥30 (OR = 0.214), infiltrating ductal carcinomas (OR = 0.272) and ASA-3 patients (OR = 0.254). In multivariate analysis, LDF-IBR was more often realized for NSM and for patients with BMI ≥25. The overall complication rate was 37.4%: 45.6 and 33.1% with and without IBR, respectively (p = 0.056). In multivariate analysis, BMI ≥25 (OR 2.02, p = 0.023), IBR (OR 1.9, p = 0.046) and tobacco (OR 2.17, p = 0.055) were correlated with higher risk of complications. There was no difference for Grade 2-3 complications rates for IBR and no IBR, respectively (14.7%: 10/68 and 9.3%: 13/139). In multivariate analysis, overall survival from date of mastectomy for local recurrence was significantly associated with interval time to local recurrence (OR 6.981). Conclusion: Salvage mastectomy and IBR is a good choice for ILBLR, particularly using flap reconstruction. NSM can be considered as a good option in selected patients for ILBLR for NSM and/or LDFR.

The challenge of avoiding over- and under-treatment in older women with ductal cancer in situ: A scoping review of existing knowledge gaps and a meta-analysis of real-world practice patterns

Ductal cancer in situ (DCIS) is mainly a screen-detected disease and although the risk for breast cancer is age-dependent, most screening programs do not include women over the age of 75 years. Older women are usually excluded from clinical trials and treatment practices are largely based on observational studies or extrapolation of trial results from younger patients, leading to either over- or under-treatment of this population. We systematically reviewed available electronic databases for DCIS treatment patterns and outcomes in older patients 15 years. Inclusion criteria allowed for randomised controlled trials, cohort studies, case-control and cross-sectional studies, as well as meta-analyses, systematic reviews and position papers. Results showed that, although elderly are not necessarily frail, they are generally treated as such by physicians, aiming to de-escalate therapeutic interventions. After adjusting for frailty, age seems to be a significant factor for less surgery; however, older women with DCIS are more probable to receive surgery than their counterparts with early invasive cancer. DCIS biology and subtypes are independent risk factors for local recurrence or progression to invasive carcinoma, if DCIS is under-treated. The end-benefit of surgery, radio- and endocrine-therapy depend on additional parameters, such as life expectancy, co-morbidities and competing risks of death. Screen-detected DCIS in older women is a challenging clinical problem, mainly due to the lack of high-level data. Therapeutic strategies should be tailored to life expectancy and performance status, DCIS features and patient preference, aiming at combining optimal oncological outcomes with maintenance of quality of life.