Endocrine Therapy for Ductal Carcinoma In Situ (DCIS) of the Breast with Breast Conserving Surgery (BCS) and Radiotherapy (RT): a Meta-Analysis

Reimagining Deintensification for Low-Risk Breast Cancer

As outcomes for low-risk breast cancer continue to improve, research and clinical paradigms are increasingly focused on appropriate deintensification with the goal of improving the therapeutic ratio of breast cancer treatment. These deintensification approaches span across disciplines including breast surgery, radiation therapy, and systemic therapy. With regard to breast surgery, studies have continued to push deintensification when it comes to surgical margins with breast conservation, reducing re-excision rates, whereas deintensification of axillary surgery has reduced the rates of axillary lymph node dissection and increasingly the need for any axillary surgery, including sentinel lymph node biopsy for low-risk patients. With regard to radiation therapy, studies have allowed for a drastic reduction in treatment duration, whereas approaches that reduce the target of treatment have led to a change from from treatment daily for 5-7 weeks to many low-risk patients completing treatment in just five treatments. With regard to systemic therapy, use of genomic assays and tumor biology has led to reduced utilization of cytotoxic chemotherapy, with studies also allowing for dose reduction of endocrine therapy for patients with ductal carcinoma in situ. Moving forward, greater focus should be placed on interdisciplinary deintensification approaches such as the consideration of radiation therapy alone as compared with endocrine therapy alone for low-risk breast cancers.

Management of Ductal Carcinoma In Situ: An Ontario Health (Cancer Care Ontario) Clinical Practice Guideline

(1) Background: To make recommendations on the most effective therapy options for Ductal Carcinoma of the Breast (DCIS) patients; (2) Methods: MEDLINE, EMBASE, Cochrane Library, PROSPERO databases, and main relevant guideline websites were searched. Draft versions of the guideline went through formal internal and external reviews, with a final approval by the Program in Evidence Based Care and the DCIS Expert Panel. The Grading of Recommendations, Assessment, Development, and Evaluation approach was followed; (3) Results: Based on the current evidence from the systematic review and this guideline authors' clinical opinions, initial draft recommendations were developed to improve the management of patients with DCIS. After a comprehensive internal and external review process, ten recommendations and 27 qualifying statements were eventually made. This guideline includes recommendations for the primary treatment of DCIS with surgical treatment and/or radiation therapy and the management of DCIS after primary treatment for patients with DCIS, including DCIS with microinvasion (<1 mm through the duct); (4) Conclusions: The current guideline was created after a systematic review and a comprehensive internal and external review process. We believe this guideline provides valuable insights that will be useful in clinical decision making for health providers.

Ductal Carcinoma In Situ in Borderline Phyllodes Tumor: A Diagnostic and Treatment Dilemma

The co-existence of breast carcinoma in the form of ductal carcinoma in situ (DCIS) in a case of Phyllodes tumor (PT) is extremely rare. We present a case of a pre-menopausal lady with a large breast lump diagnosed as benign PT on her initial biopsy. Wide local excision and breast conservation with round block oncoplasty were done. A post-operative diagnosis of borderline PT with sclerosing adenosis and high-grade DCIS were made. Adjuvant radiotherapy and hormonal therapy were given, and the patient had no recurrence after three years of follow-up. DCIS in PT is very rare, and hence no standard protocol for treating such cases exists. So proper histopathological diagnosis, treatment with multidisciplinary involvement, and regular follow-up can help us conserve the breast and prevent recurrence in such cases.

Evolution of publicly available large language models for complex decision-making in breast cancer care

PURPOSE

This study investigated the concordance of five different publicly available Large Language Models (LLM) with the recommendations of a multidisciplinary tumor board regarding treatment recommendations for complex breast cancer patient profiles.

METHODS

Five LLM, including three versions of ChatGPT (version 4 and 3.5, with data access until September 3021 and January 2022), Llama2, and Bard were prompted to produce treatment recommendations for 20 complex breast cancer patient profiles. LLM recommendations were compared to the recommendations of a multidisciplinary tumor board (gold standard), including surgical, endocrine and systemic treatment, radiotherapy, and genetic testing therapy options.

RESULTS

GPT4 demonstrated the highest concordance (70.6%) for invasive breast cancer patient profiles, followed by GPT3.5 September 2021 (58.8%), GPT3.5 January 2022 (41.2%), Llama2 (35.3%) and Bard (23.5%). Including precancerous lesions of ductal carcinoma in situ, the identical ranking was reached with lower overall concordance for each LLM (GPT4 60.0%, GPT3.5 September 2021 50.0%, GPT3.5 January 2022 35.0%, Llama2 30.0%, Bard 20.0%). GPT4 achieved full concordance (100%) for radiotherapy. Lowest alignment was reached in recommending genetic testing, demonstrating a varying concordance (55.0% for GPT3.5 January 2022, Llama2 and Bard up to 85.0% for GPT4).

CONCLUSION

This early feasibility study is the first to compare different LLM in breast cancer care with regard to changes in accuracy over time, i.e., with access to more data or through technological upgrades. Methodological advancement, i.e., the optimization of prompting techniques, and technological development, i.e., enabling data input control and secure data processing, are necessary in the preparation of large-scale and multicenter studies to provide evidence on their safe and reliable clinical application. At present, safe and evidenced use of LLM in clinical breast cancer care is not yet feasible.

Treatments and Prognosis of the Breast Ductal Carcinoma In Situ

INTRODUCTION

With progress in treatments, breast ductal carcinoma in situ (DCIS) outcomes have substantially improved. However, as various treatment methods are used in different countries and institutions, consensus on the optimal treatment method is lacking. This study aimed to analyze the prognostic factors and provide a reference for optimizing the clinical treatment of DCIS.

PATIENTS AND METHODS

This retrospective clinical study collected data from DCIS patients at the Sun Yat-sen University Cancer Center from 2010 to 2017. The Kaplan-Meier method and Cox regression model were used to assess disease-free survival (DFS), overall survival (OS), and local control (LC) rates.

RESULTS

Among the 483 included patients, 83.6% (404) underwent mastectomies. The median follow-up time was 101 months. The number of patients undergoing breast-conserving surgery (BCS) with radiotherapy has gradually increased. Axillary lymph node dissection was the main surgery performed from 2010 to 2015, and the proportion of sentinel lymph node biopsies (SLNBs) has increased. LC and DFS rates with BCS without radiotherapy were significantly lower than those with mastectomy (P = .002; P < .001). Additionally, the patients who did not undergo axillary surgery had worse LC and OS rates than those who underwent SLNB (P = .028 and P = .038). Endocrine therapy (ET) or its duration had no significant effect on prognosis.

CONCLUSION

In conclusion, BCS without radiotherapy and lack of axillary surgery were independent prognostic factors. We recommend performing BCS with radiotherapy and SLNB more in clinical practice, as well as shortening the ET duration.

Trends and variation in treatment of early breast cancer in European certified breast centres: an EUSOMA-based analysis

BACKGROUND

Practice indicators (PI) measure provided care making use of real-world data. This study describes trends and variations in adjuvant treatment of early breast cancer (EBC) using the European Society of Breast Cancer Specialists (EUSOMA) database.

METHODS

The analysis was conducted on anonymous cumulative data registered by 56 certified breast centres, which all entered at least 500 new diagnoses in the database in the 10-year period 2010-2019. Practice trends of radiotherapy, endocrine treatment, chemotherapy, and anti-HER2 therapy were evaluated. The association with age group (<50, 50-69, ≥70) and geographical area of the centre (Northern, Central, Southern Europe; NE, CE, SE) was assessed with the Pearson Chi2 test for independence in contingency tables.

RESULTS

In total, 150,150 patients with EBC were selected. Overall, radiotherapy was administered more frequently in NE centres, and conversely, endocrine, chemo-, and anti-HER2 therapy were used more frequently in SE centres (p<0.001). 46.9% of the pN1 patients received postmastectomy radiotherapy, with significant differences by age and geographical region (p < 0.001). Adjuvant endocrine treatment for endocrine-sensitive carcinoma in situ was administered in 46.1%, with a decreasing trend during the study period (58.5-34.5%; p < 0.001). Anti-HER2 therapy was delivered in 75.6% of all patients with HER2BC T1a/bN0, patients older than 70 received anti-HER2 in 67.6% in SE compared to 31.3% in NE centres.

CONCLUSION

Important variations in EBC management between European certified breast centres have been demonstrated. PI using real-world data can help to monitor, evaluate, and eventually guide and align good clinical practice in the management of breast cancer.

Cost-Effectiveness of Adjuvant Treatment for Ductal Carcinoma In Situ

PURPOSE

Ductal carcinoma in situ (DCIS) accounts for 20% of breast cancer cases in the United States and is potentially overtreated, leading to high expenditures and low-value care. We conducted a cost-effectiveness analysis evaluating all adjuvant treatment strategies for DCIS.

METHODS

A Markov model was created with six competing treatment strategies: observation, tamoxifen (TAM) alone, aromatase inhibitor (AI) alone, radiation treatment (RT) alone, RT + TAM, and RT + AI. Baseline recurrence rates were modeled using the NSABP B17 and RTOG 9804 trials for standard-risk and good-risk DCIS, respectively. Relative risk reductions and adverse event rates for each treatment strategy were derived from meta-analyses of large randomized trials. We used a willingness-to-pay threshold of $100,000 in US dollars/quality-adjusted life-year and a lifetime horizon for two cohorts of women, age 40 and 60 years. Comprehensive sensitivity analyses evaluated the robustness of base-case results.

RESULTS

RT alone was cost-effective for patients with standard-risk DCIS, and observation was cost-effective for patients with good-risk DCIS, across both age groups. Strategies including TAM or AI resulted in fewer quality-adjusted life-years than observation, because of the prolonged decrement in quality of life outweighing the modest benefit in ipsilateral risk reduction. In sensitivity analysis, RT alone was cost-effective for age 40, good-risk patients when ipsilateral risk reduction matched that of the RTOG 9804 trial, there was minimal increased risk of contralateral breast secondary malignancy, or there was strong patient willingness to pursue RT.

CONCLUSION

Our findings suggest that cost-effective and clinically optimal treatment strategies are RT alone for standard-risk DCIS and observation for good-risk DCIS, with personalization on the basis of patient age and preference for RT. Hormonal therapy is likely suboptimal for most patients with DCIS.

Long-term Survival Comparison of Repeated Breast-conserving Surgery Versus Mastectomy for Patients with DCIS with Ipsilateral Breast Tumor Recurrence: A Real-world Longitudinal Study

BACKGROUND

Although patients diagnosed with ductal carcinoma in situ (DCIS) harbor excellent overall survival (OS) after breast-conserving therapy, the evidence regarding to surgical management for ipsilateral breast tumor recurrence (IBTR) is scarce. This study aimed to assess the prognosis of repeated breast-conserving surgery (BCS) versus mastectomy for IBTR in DCIS survivors.

MATERIALS AND METHODS

Herein, 5344 DCIS cases with IBTR were identified during 702,748 person-years of follow-up, 3532 (66.09%) received mastectomy, and 1812 (33.91%) received repeated BCS. Cox regression and competing risk regression were employed to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for OS and breast cancer-specific survival (BCSS), which was respectively calculated within spontaneous and matched cohorts.

RESULTS

After adjustment for confounders, no statistically significant survival difference was observed between the repeated BCS and mastectomy for patients with DCIS with IBTR. The stratified analyses further revealed that patients with DCIS with IBTR receiving repeated BCS combined with radiation therapy were associated with both superior OS (HR, 0.79; CI, 0.64-0.98; P = .04) and BCSS (HR, 0.54; CI, 0.33-0.90; P = .02) compared with counterparts undergoing mastectomy. Furthermore, patients with DCIS who were age older than 60 years at IBTR diagnosis benefit from repeated BCS with radiotherapy (HR, 0.44; CI, 0.24-0.84; P = .01) than mastectomy.

CONCLUSION

We suggest that repeated BCS with radiation therapy deserves consideration when DCIS survivors suffered IBTR. The choice of surgical management should be tailored based on patients' age at IBTR diagnosis and size of recurrent disease.

Risk of hematologic malignancies after breast ductal carcinoma in situ treatment with ionizing radiation

The increased incidence of secondary hematologic malignancies (SHM) is a well-known, potentially fatal, complication after cancer treatment. It is unknown if patients with ductal carcinoma in situ (DCIS) of the breast treated with external beam radiotherapy (RT) and who survive long-term have increased risks of secondary hematologic malignancies (SHM), especially for low/intermediate-risk subsets with limited benefits from RT. DCIS patients in Surveillance, Epidemiology, and End Results (SEER) registries (1975-2016) were identified. Relative risks (RR), hazard ratio (HR), and standardized incidence ratios (SIR) were calculated to assess the SHM risk and subsequent survival times. SHM development, defined as a nonsynchronous SHM occurring ≥1 year after DCIS diagnosis, was our primary endpoint. Of 184,363 eligible patients with DCIS, 77,927 (42.3%) in the RT group, and 106,436 (57.7%) in the non-RT group, 1289 developed SHMs a median of 6.4 years (interquartile range, 3.5 to 10.3 years) after their DCIS diagnosis. Compared with DCIS patients in the non-RT group, RT was associated with increased early risk of developing acute lymphoblastic leukemia (ALL; hazard ratio, 3.15; 95% CI, 1.21 to 8.17; P = 0.02), and a delayed risk of non-Hodgkin lymphoma (NHL; hazard ratio, 1.33; 95% CI, 1.09 to 1.62; P < 0.001). This increased risk of ALL and NHL after RT was also observed in subgroup analyses restricted to low/intermediate-risk DCIS. In summary, our data suggest that RT after breast conserving surgery for DCIS patients should be cautiously tailored, especially for low and intermediate-risk patients. Long-term SHM surveillance after DCIS diagnosis is warranted.