BACKGROUND: Current guidelines do not recommend routine sentinel node biopsy (SLNB) for ductal carcinoma in situ (DCIS), except in the setting of mastectomy or microinvasive disease. This study aimed to evaluate national SLNB utilization in women undergoing upfront mastectomy for DCIS, identify predictors of SLNB utilization, and determine the percentage with a positive SLNB.
METHODS: A retrospective cohort analysis was performed using the NCDB of women with clinical DCIS who underwent upfront mastectomy between 2012 and 2017. Demographic and clinicopathologic variables were compared between patients who underwent SLNB and those who did not. Multivariate logistic regression models were used to identify factors associated with SLNB utilization and positive SLNB.
RESULTS: About 38,973 patients met inclusion criteria: 34,231 (88%) underwent SLNB and 4742 (12%) had no surgical axillary staging. Most patients were age 50-69 (51%), non-Hispanic White (71%), with private insurance (66%). On multivariate analysis, older patients were less likely to receive SLNB (P < .01), while patients with higher grade DCIS were more likely to undergo SLNB (P < .01). In those who underwent SLNB (n = 34,231), only 1,149 (3.4%) had nodal involvement. Non-Hispanic Black patients had increased odds of a positive SLNB (P < .01), while those with estrogen receptor positive disease were less likely to be node positive (OR 0.68, P < .001).
CONCLUSIONS: While 88% of patients had a SLNB, only 3.4% were found to be node positive. Given this low rate, it is reasonable to consider SLNB omission in select patients with low grade, hormone receptor positive DCIS undergoing upfront mastectomy.

OBJECTIVE: Recent studies have established the safety and efficacy of Superparamagnetic Iron Oxide (SPIO, Magtrace®) for delayed sentinel lymph node biopsy (SLNB) in patients with ductal carcinoma in situ (DCIS) who are undergoing mastectomy. The aim of our study was to measure cost containment with use of Magtrace® in comparison to upfront SLNB with traditional technetium-99 lymphatic tracer.
METHODS: A total of 41 patients at our institution underwent mastectomy with Magtrace® injection for DCIS and were included in our single-institution, retrospective analysis. For comparison, total charges data were obtained for an upfront SLNB at the time of mastectomy. Cost comparison analysis was then performed against charges for intraoperative Magtrace® injection with additional charges incorporated for those patients who required return to the operating room for delayed SLNB. Total cost containment for the cohort with use of Magtrace® was then measured.
RESULTS: Of the 41 patients who underwent Magtrace® injection, two patients required return to the operating room for a delayed SLNB for invasive disease. Including these charges for a second encounter into our cost analysis, the use of Magtrace® still yielded an overall cost containment of $205,793.55 in our cohort when comparing to patients who underwent upfront SLNB. For patients who underwent Magtrace® injection and did not require return to the operating room, charges were reduced by $6,768.52 per patient.
CONCLUSIONS: The use of Magtrace® for delayed SLNB in patients with DCIS undergoing mastectomy yielded a significant overall cost containment, further supporting its use in this patient population.

BACKGROUND: Consensus guidelines recommend ≥ 2 mm margins in patients undergoing partial mastectomy (PM) for ductal carcinoma in situ (DCIS). It is unknown whether the number or proximity of margins less than 2 mm is associated with an increased mastectomy rate in patients attempting breast conservation therapy (BCT) for DCIS. The aim of this study is to examine this relationship.
METHODS: An institutional database review identified 208 patients with DCIS who underwent PM at a tertiary referral center and community hospitals from July 2020 to June 2023. Patients with a history of breast cancer, previous surgery for breast cancer, ipsilateral invasive carcinoma, papillary carcinoma, Paget\'s disease, more lobular carcinoma in situ (LCIS) than DCIS present, initial mastectomy, no DCIS present, routine shave margins (of all vectors), and ≥ 2 mm margins of all six vectors were excluded. Selective intraoperative margin re-excisions were included.
RESULTS: A total of 208 patients who met inclusion criteria were retrospectively reviewed. 122 (25%) had one close/positive (< 2 mm) margin and 86 (18%) had two or more close/positive margins. Of the patients with one close/positive margin, 7% (9/122) eventually underwent mastectomy. Of the patients with two or more close/positive margins, 20% (17/86) eventually underwent mastectomy. Overall, no patients with opposing margins underwent mastectomy.
CONCLUSIONS: Patients undergoing PM for DCIS have a mastectomy rate that is increased threefold, with two or more close/positive margins at initial PM, when compared with those with only one close/positive margin. The presence of opposing close/positive margins at initial PM did not increase the mastectomy rate and most were cleared with re-excision.

Preoperatively predicting extensive intraductal component in invasive breast cancer through imaging is crucial for informed decision-making, guiding surgical planning to mitigate risks of incomplete resection or re-operation for positive margins in breast-conserving surgery. This study aimed to characterize intra- and peri-tumor heterogeneity using high-spatial resolution ultrafast DCE-MRI to predict the extensive intraductal component in invasive breast cancer (IBC-EIC) preoperatively. A retrospective analysis included invasive breast cancer patients who underwent preoperative high-spatial resolution ultrafast DCE-MRI, categorized based on intraductal component status (IBC-EIC vs. IBC without EIC). Propensity score matching (PSM) was employed to balance clinicopathological covariates between the groups. Personalized kinetic intra-tumor heterogeneity (ITHkinetic) and peri-tumor heterogeneity (PTHkinetic) scores were quantified using clustered voxels with similar enhancement patterns. An image combined model, incorporating MRI features, ITHkinetic, and PTHkinetic scores, was developed and assessed. Of 368 patients, 26.4% (97/368) had IBC-EIC. PSM yielded well-matched pairs of 97 patients each. After PSM, ITHkinetic and PTHkinetic scores were significantly higher in the IBC-EIC group (ITHkinetic: 0.68 ± 0.23; PTHkinetic: 0.58 ± 0.19) compared to IBC without EIC (ITHkinetic: 0.32 ± 0.25; PTHkinetic: 0.42 ± 0.18; p < 0.001). Before PSM, ITHkinetic (0.71 ± 0.20 vs. 0.49 ± 0.28, p < 0.001) and PTHkinetic (0.61 ± 0.18 vs. 0.50 ± 0.20, p < 0.001) scores remained higher in the IBC-EIC group. The Image Combined Model demonstrated good predictive performance for IBC-EIC, with an AUC of 0.91 (95% CI 0.86-0.95) after PSM and 0.85 (95% CI 0.81-0.90) before PSM. Inclusion of ITHkinetic and PTHkinetic scores significantly improved prediction capability. ITHkinetic and PTHkinetic characterization from high-spatial resolution ultrafast DCE-MRI kinetic curves enhances preoperative prediction of IBC-EIC, offering valuable insights for personalized breast cancer management.

UNASSIGNED: Ductal carcinoma in situ (DCIS), characterized by a proliferation of neoplastic cells confined within the mammary ducts, is distinctly isolated from the surrounding stroma by an almost uninterrupted layer of myoepithelial cells (MECs) and by the basement membrane. Heightened interactions within the adipose microenvironment, particularly in obese patients, may play a key role in the transition from DCIS to invasive ductal carcinoma (IDC), which is attracting growing interest in scientific research. Adipose tissue undergoes metabolic changes in obesity, impacting adipokine secretion and promoting chronic inflammation. This study aimed to assess the interactions between DCIS, including in situ cancer cells and MECs, and the various components of its inflammatory adipose microenvironment (adipocytes and macrophages).
UNASSIGNED: To this end, a 3D co-culture model was developed using bicellular bi-fluorescent DCIS-like tumoroids, adipose cells, and macrophages to investigate the influence of the inflammatory adipose microenvironment on DCIS progression.
UNASSIGNED: The 3D co-culture model demonstrated an inhibition of the expression of genes involved in apoptosis (BAX, BAG1, BCL2, CASP3, CASP8, and CASP9), and an increase in genes related to cell survival (TP53, JUN, and TGFB1), inflammation (TNF-α, PTGS2, IL-6R), invasion and metastasis (TIMP1 and MMP-9) in cancer cells of the tumoroids under inflammatory conditions versus a non-inflammatory microenvironment. On the contrary, it confirmed the compromised functionality of MECs, resulting in the loss of their protective effects against cancer cells. Adipocytes from obese women showed a significant increase in the expression of all studied myofibroblast-associated genes (myoCAFs), such as FAP and α-SMA. In contrast, adipocytes from normal-weight women expressed markers of inflammatory fibroblast phenotypes (iCAF) characterized by a significant increase in the expression of LIF and inflammatory cytokines such as TNF-α, IL-1β, IL-8, and CXCL-10. These changes also influenced macrophage polarization, leading to a pro-inflammatory M1 phenotype. In contrast, myoCAF-associated adipocytes, and the cancer-promoting microenvironment polarized macrophages towards an M2 phenotype, characterized by high CD163 receptor expression and IL-10 and TGF-β secretion.
UNASSIGNED: Reciprocal interactions between the tumoroid and its microenvironment, particularly in obesity, led to transcriptomic changes in adipocytes and macrophages, may participate in breast cancer progression while disrupting the integrity of the MEC layer. These results underlined the importance of adipose tissue in cancer progression.

UNASSIGNED: To develop a clinical-radiomics model using a multimodal machine learning method for distinguishing ductal carcinoma in situ (DCIS) from breast fibromatosis.
UNASSIGNED: The clinical factors, ultrasound features, and related ultrasound images of 306 patients (198 DCIS patients) were retrospectively collected. Patients in the development and validation cohort were 184 and 122, respectively. The independent clinical and ultrasound factors identified by the multivariable logistic regression analysis were used for the clinical-ultrasound model construction. Then, the region of interest of breast lesions was delineated and radiomics features were extracted. Six machine learning algorithms were trained to develop a radiomics model. The algorithm with higher and more stable prediction ability was chosen to convert the output of the results into the Radscore. Further, the independent clinical predictors and Radscore were enrolled into the logistic regression analysis to generate a combined clinical-radiomics model. The receiver operating characteristic curve analysis, DeLong test, and decision curve analysis were adopted to compare the prediction ability and clinical efficacy of three different models.
UNASSIGNED: Among the six classifiers, logistic regression model was selected as the final radiomics model. Besides, the combined clinical-radiomics model exhibited a superior ability in distinguishing DCIS from breast fibromatosis to the clinical-ultrasound model and the radiomics model.
UNASSIGNED: The combined model by integrating clinical-ultrasound factors and radiomics features performed well in predicting DCIS, which might promote prompt interventions to improve the early diagnosis and prognosis of the patients.

Background: This retrospective study aimed to investigate the outcomes and adverse events (AEs) associated with adjuvant radiotherapy with helical tomotherapy (hT) after breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS). Methods: Twenty-eight patients with DCIS underwent postoperative hT between 2011 and 2020. hT was chosen since it provided optimal target coverage and tolerable organ-at-risk doses to the lungs and heart when tangential 3-dimensional conformal radiotherapy (3D-CRT) was presumed to provide unfavorable dosimetry. The median total (single) dose was 50.4 Gy (1.8 Gy). The median time between BCS and the start of hT was 5 weeks (range, 4-38 weeks). Statistical analysis included local recurrence-free survival, overall survival (OS), and secondary cancer-free survival. AEs were classified according to the Common Toxicity Criteria for Adverse Events, version 5. Results: The patients\' median age was 58 years. The median follow-up period was 61 months (range, 3-123 months). The 1-, 3-, and 5-year OS rates were 100% each. None of the patients developed secondary cancer, local recurrence, or invasive breast cancer during follow-up. The most common acute AEs were dermatitis (n = 27), fatigue (n = 4), hyperpigmentation (n = 3), and thrombocytopenia (n = 4). The late AE primarily included surgical scars (n = 7) and hyperpigmentation (n = 5). None of the patients experienced acute or late AEs > grade 3. The mean conformity and homogeneity indices were 0.9 (range, 0.86-0.96) and 0.056 (range, 0.05-0.06), respectively. Conclusion: hT after BCS for DCIS is a feasible and safe form of adjuvant radiotherapy for patients in whom 3D-CRT is contraindicated due to unfavorable dosimetry. During follow-up, there were no recurrences, invasive breast cancer diagnoses, or secondary cancers, while the adverse effects were mild.

BACKGROUND: As the benefits of intensive locoregional therapy for ductal carcinoma in situ (DCIS) are realized over time in older adults, life expectancy may help to guide treatment decisions. We examined whether life expectancy was associated with extent of locoregional therapy in this population.
METHODS: Women ≥ 70 years old with < 5 cm of DCIS diagnosed 2010-2015 were identified in the Surveillance, Epidemiology, and End Results (SEER)-Medicare dataset and categorized by a life expectancy ≤ 5 or > 5 years, defined by a validated claims-based measure. Differences in locoregional therapy (mastectomy + axillary surgery, mastectomy-only, lumpectomy + radiation therapy (RT) + axillary surgery, lumpectomy + RT, lumpectomy-only, and no treatment) by life expectancy were assessed using Pearson chi-squared tests. Generalized linear mixed models were used to identify factors associated with receipt of lumpectomy-only.
RESULTS: Of 5346 women (median age of 75 years, range 70-97 years), 927 (17.3%) had a life expectancy ≤ 5 years. Of the 4041 patients who underwent lumpectomy, 710 (13.3%) underwent axillary surgery. More patients with life expectancy ≤ 5 years underwent lumpectomy-only (39.4% versus 27%), mastectomy-only (8.1% versus 5.3%), or no treatment (5.8% versus 3.2%; p < 0.001). On multivariable analysis, women with life expectancy ≤ 5 years had a significantly greater likelihood of undergoing lumpectomy-only [OR 1.90, 95% CI (1.63-2.22)].
CONCLUSIONS: Life expectancy is associated with lower-intensity locoregional therapy for older women with DCIS, yet a large proportion of patients with a life expectancy ≤ 5 years received RT and axillary surgery, highlighting potential overtreatment and opportunities to de-escalate locoregional therapy in older adults.

OBJECTIVE: Ductal carcinoma in situ (DCIS) is recognised by the World Health Organisation (WHO) Classification of Tumours (WCT) as a non-invasive neoplastic epithelial proliferation confined to the mammary ducts and lobules. This report categorises the references cited in the DCIS chapter of the 5th edition of the WCT (Breast Tumours) according to prevailing evidence levels for evidence-based medicine and the Hierarchy of Evidence for Tumour Pathology (HETP), identifying potential gaps that can inform subsequent editions of the WCT for this tumour.
RESULTS: We included all citations from the DCIS chapter of the WCT (Breast Tumours, 5th edition). Each citation was appraised according to its study design and evidence level. We developed our map of cited evidence, which is a graphical matrix of tumour type (column) and tumour descriptors (rows). Spheres were used to represent the evidence, with size and colour corresponding to their number and evidence level respectively. Thirty-six publications were retrieved. The cited literature in the DCIS chapter comprised mainly case series and were regarded as low-level. We found an unequal distribution of citations among tumour descriptors. \'Pathogenesis\' and \'prognosis and prediction\' contained the most references, while \'clinical features\', \'aetiology\' and \'diagnostic molecular pathology\' had only a single citation each. \'Prognosis and prediction\' had the greatest proportion of moderate- and high-levels of evidence.
CONCLUSIONS: Our findings align with the disposition for observational studies inherent in the field of pathology. Our map is a springboard for future efforts in mapping all available evidence on DCIS, potentially augmenting the editorial process and future editions of WCTs.

Ductal carcinoma in situ (DCIS) accounts for approximately 30% of new breast cancer diagnoses. However, our understanding of how normal breast tissue evolves into DCIS and invasive cancers remains insufficient. Further, conclusions regarding the mechanisms of disease progression in terms of histopathology, genetics, and radiology are often conflicting and have implications for treatment planning. Moreover, the increase in DCIS diagnoses since the adoption of organized breast cancer screening programs has raised concerns about overdiagnosis and subsequent overtreatment. Active monitoring, a nonsurgical management strategy for DCIS, avoids surgery in favor of close imaging follow-up to de-escalate therapy and provides more treatment options. However, the two major challenges in active monitoring are identifying occult invasive cancer and patients at risk of invasive cancer progression. Subsequently, four prospective active monitoring trials are ongoing to determine the feasibility of active monitoring and refine the patient eligibility criteria and follow-up intervals. Radiologists play a major role in determining eligibility for active monitoring and reviewing surveillance images for disease progression. Trial results published over the next few years would support a new era of multidisciplinary DCIS care.