Is sentinel lymph node biopsy indicated in patients with a diagnosis of ductal carcinoma in situ? A systematic literature review and meta-analysis

Sentinel Lymph Node Biopsy in Early-Stage Breast Cancer: ASCO Guideline Update

PURPOSE

To update the ASCO evidence-based recommendations on the use of sentinel lymph node biopsy (SLNB) in patients with early-stage breast cancer treated with initial surgery.

METHODS

ASCO convened an Expert Panel to develop updated recommendations based on a systematic literature review (January 2016-May 2024).

RESULTS

Eleven randomized clinical trials (14 publications), eight meta-analyses and/or systematic reviews, and one prospective cohort study met the inclusion criteria for this systematic review. Expert Panel members used available evidence and informal consensus to develop practice recommendations.

RECOMMENDATIONS

Clinicians should not recommend routine SLNB in select patients who are postmenopausal and ≥50 years of age and with negative findings on preoperative axillary ultrasound for grade 1-2, small (≤2 cm), hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer and who undergo breast-conserving therapy. Clinicians may offer postmastectomy radiation (RT) with regional nodal irradiation (RNI) and omit axillary lymph node dissection (ALND) in patients with clinically node-negative invasive breast cancer ≤5 cm who receive mastectomy and have one to two positive sentinel nodes. Clinicians may offer SLNB in patients who have cT3-T4c or multicentric tumors (clinically node-negative) or ductal carcinoma in situ treated with mastectomy, and in patients who are obese, male, or pregnant, or who have had prior breast or axillary surgery. Clinicians should not recommend ALND for patients with early-stage breast cancer who do not have nodal metastases, and clinicians should not recommend ALND for patients with early-stage breast cancer who have one or two sentinel lymph node metastases and will receive breast-conserving surgery and whole-breast RT with or without RNI.Additional information is available at www.asco.org/breast-cancer-guidelines.This guideline has been endorsed by the American Society for Radiation Oncology (ASTRO).

De-Escalating the Extent of Sentinel Lymph Node Biopsy in Patients With Ductal Carcinoma in Situ Undergoing Mastectomy

BACKGROUND

Sentinel lymph node biopsy (SLNB) for axillary staging in patients with ductal carcinoma in situ (DCIS) undergoing mastectomy is debated due to low nodal positivity rate and risk of morbidity. Standard SLNB entails removing all lymph nodes (LN) that have a radioactive count > 10% of the most radioactive node, contain blue dye or are palpably suspicious. In this study, we hypothesize that judicious SLNB with attempt to remove only the node with the highest radioactive count provides sufficient pathologic information while minimizing morbidity.

METHOD

A single institution prospective database was retrospectively reviewed to identify women with DCIS who underwent mastectomy and SLNB between 2010 and 2022. Patient characteristics, number of SLNs retrieved, pathologic results and long-term upper extremity complications were analyzed.

RESULTS

A total of 743 LNs were removed in 324 pts. Median (IQR) age was 62 (51-70) years. Dual tracer technique, with technetium-99m labeled radiocolloid and blue dye, was used in 311 (96%) pts, whereas single agent (radioisotope or blue dye alone) was utilized in 9 (2.8%) and 4 (1.2%) patients, respectively. Median (IQR) number of SLN removed was 2 (1-3) (range 1-9). In 99% of cases, the SLN with the highest radioactive count was identified among the first 3 dissected LNs. Final pathology revealed upstaging to invasive cancer in 27.5% (n = 89) of the breasts and nodal positivity in 1.9% (n = 6) of the patients. In all 6 cases, metastatic disease was identified in the LN with highest radioactive count among the LNs retrieved. No additional metastatic nodes were identified after > 3 SLN had been removed. At median follow-up of 57 (range 28-87) months, 8.3% (n = 27) of pts complained of long-term upper extremity symptoms. 7.1% (23 pts) were referred to physical therapy for symptoms such as swelling, fullness, heaviness, stiffness, or sensory discomfort in the upper extremity and/or axillary cording. Long-term upper extremity complications were higher when > 3 SLNs compared to ≤ 3 SLNs were removed (10.4% vs. 6.5%, P = .005).

CONCLUSION

In this cohort of patients with DCIS undergoing mastectomy who were upstaged on final pathology to node positive invasive cancers, the SLN with the highest radioactive count provided sufficient information for axillary staging. Acknowledging that the "hottest" LN is not always the first 1 removed, these data support an increased likelihood of developing long-term complications when more than 3 SLNs are removed. Rather than comprehensive removal of all SLNs meeting the standard "10% rule," prioritizing the sequence of removal to the highest count provides the same prognostic information with reduced morbidity.

How much do we know about the metastatic process?

Cancer cells can leave their primary sites and travel through the circulation to distant sites, where they lodge as disseminated cancer cells (DCCs), even during the early and asymptomatic stages of tumor progression. In experimental models and clinical samples, DCCs can be detected in a non-proliferative state, defined as cellular dormancy. This state can persist for extended periods until DCCs reawaken, usually in response to niche-derived reactivation signals. Therefore, their clinical detection in sites like lymph nodes and bone marrow is linked to poor survival. Current cancer therapy designs are based on the biology of the primary tumor and do not target the biology of the dormant DCC population and thus fail to eradicate the initial or subsequent waves of metastasis. In this brief review, we discuss the current methods for detecting DCCs and highlight new strategies that aim to target DCCs that constitute minimal residual disease to reduce or prevent metastasis formation. Furthermore, we present current evidence on the relevance of DCCs derived from early stages of tumor progression in metastatic disease and describe the animal models available for their study. We also discuss our current understanding of the dissemination mechanisms utilized by genetically less- and more-advanced cancer cells, which include the functional analysis of intermediate or hybrid states of epithelial-mesenchymal transition (EMT). Finally, we raise some intriguing questions regarding the clinical impact of studying the crosstalk between evolutionary waves of DCCs and the initiation of metastatic disease.

Ductal Carcinoma In Situ

In breast cancer (BC) pathogenesis models, normal cells acquire somatic mutations and there is a stepwise progression from high-risk lesions and ductal carcinoma in situ to invasive cancer. The precancer biology of mammary tissue warrants better characterization to understand how different BC subtypes emerge. Primary methods for BC prevention or risk reduction include lifestyle changes, surgery, and chemoprevention. Surgical intervention for BC prevention involves risk-reducing prophylactic mastectomy, typically performed either synchronously with the treatment of a primary tumor or as a bilateral procedure in high-risk women. Chemoprevention with endocrine therapy carries adherence-limiting toxicity.

Personalizing Locoregional Therapy in Patients With Breast Cancer in 2024: Tailoring Axillary Surgery, Escalating Lymphatic Surgery, and Implementing Evidence-Based Hypofractionated Radiotherapy

The management of axillary lymph nodes in breast cancer is continually evolving. Recent data now support omitting axillary lymph node dissection (ALND) in most patients with metastases in up to two sentinel lymph nodes (SLNs) during upfront surgery and those with residual isolated tumor cells after neoadjuvant chemotherapy (NACT). In the upfront surgery setting, ALND is still indicated, however, in patients with clinically node-positive breast cancer or more than two positive SLNs and, after NACT, in case of residual micrometastases and macrometastases. Omission of the sentinel lymph node biopsy (SLNB) can be considered in many postmenopausal patients with small luminal breast cancer, particularly when axillary ultrasound is negative. Several randomized controlled trials (RCTs) are currently aiming at eliminating the remaining indications for ALND and also establishing omission of SLNB in a broader patient population. The movement to deescalate axillary staging is in part because of the association between ALND and lymphedema, which is swelling of an extremity because of lymphatic damage and obstructed lymphatic drainage. To reduce the risk of developing this condition, patients undergoing ALND can undergo reverse mapping of the axilla and immediate reconstruction or bypass of the lymphatics from the involved extremity. Decongestion and compression are the foundation of conservative treatment for established lymphedema, while lymphovenous bypass and lymph node transfer are surgical procedures to address the physiologic dysfunction. Radiotherapy is an essential component of breast locoregional therapy: more than three decades of radiation research has optimized treatment according to patient's risk of local recurrence while substantially reducing the number of treatment visits. High-quality RCTs have shown the efficacy and safety of hypofractionation-more than 2Gy radiation dose per treatment (fraction)-significantly reducing the burden of radiotherapy treatment for many patients with breast cancer. In 2024, guidelines recommend no more than 15-16 fractions for whole-breast and nodal radiotherapy, with some recommending five fractions for whole-breast radiotherapy. In addition, simultaneous integrated boost (SIB) has been shown to be noninferior to sequential boost with regards to ipsilateral breast tumor recurrence with similar or reduced long-term side effects, also reducing overall treatment length. Further RCTs are underway investigating other indications for five fractions, including SIB and regional node irradiation, such that, in future, it may be possible for the majority of breast radiotherapy patients to be treated with a 1-week course. This manuscript serves to outline the latest updates on axillary surgical staging, lymphatic surgery, and evidence-based radiotherapy in the treatment of breast cancer.

Evolving Treatment Paradigms for Low-Risk Ductal Carcinoma In Situ: Imaging Needs

Ductal carcinoma in situ (DCIS) is a nonobligate precursor to invasive cancer that classically presents as asymptomatic calcifications on screening mammography. The increase in DCIS diagnoses with organized screening programs has raised concerns about overdiagnosis, while a patientcentric push for more personalized care has increased awareness about DCIS overtreatment. The standard of care for most new DCIS diagnoses is surgical excision, but nonsurgical management via active monitoring is gaining attention, and multiple clinical trials are ongoing. Imaging, along with demographic and pathologic information, is a critical component of active monitoring efforts. Commonly used imaging modalities including mammography, ultrasound, and MRI, as well as newer modalities such as contrast-enhanced mammography and dedicated breast PET, can provide prognostic information to risk stratify patients for DCIS active monitoring eligibility. Furthermore, radiologists will be responsible for closely surveilling patients on active monitoring and identifying if invasive progression occurs. Active monitoring is a paradigm shift for DCIS care, but the success or failure will rely heavily on the interpretations and guidance of radiologists.

Survival Outcomes Based on Axillary Surgery in Ductal Carcinoma In Situ: A Nationwide Study From the Korean Breast Cancer Society

PURPOSE

In total mastectomy (TM), sentinel lymph node biopsy (SLNB) is recommended but can be omitted for breast-conserving surgery (BCS) in patients with ductal carcinoma in situ (DCIS). However, concerns regarding SLNB-related complications and their impact on quality of life exist. Consequently, further research is required to evaluate the role of axillary surgeries, including SLNB, in the treatment of TM. We aimed to explore the clinicopathological factors and outcomes associated with axillary surgery in patients with a final diagnosis of pure DCIS who underwent BCS or TM.

METHODS

We retrospectively analyzed large-scale data from the Korean Breast Cancer Society registration database, highlighting on patients diagnosed with pure DCIS who underwent surgery and were categorized into two groups: BCS and TM. Patients were further categorized into surgery and non-surgery groups according to their axillary surgery status. The analysis compared clinicopathological factors and outcomes according to axillary surgery status between the BCS and TM groups.

RESULTS

Among 18,196 patients who underwent surgery for DCIS between 1981 and 2022, 11,872 underwent BCS and 6,324 underwent TM. Both groups leaned towards axillary surgery more frequently for large tumors. In the BCS group, clinical lymph node status was associated with axillary surgery (odds ratio, 11.101; p = 0.003). However, in the TM group, no significant differences in these factors were observed. Survival rates did not vary between groups according to axillary surgery performance.

CONCLUSION

The decision to perform axillary surgery in patients with a final diagnosis of pure DCIS does not affect the prognosis, regardless of the breast surgical method. Furthermore, regardless of the breast surgical method, axillary surgery, including SLNB, should be considered for high-risk patients, such as those with large tumors. This may reduce unnecessary axillary surgery and enhance the patients' quality of life.

Ultrafast MRI and T1 and T2 Radiomics for Predicting Invasive Components in Ductal Carcinoma in Situ Diagnosed With Percutaneous Needle Biopsy

OBJECTIVE

This study aimed to investigate the feasibility of ultrafast magnetic resonance imaging (MRI) and radiomic features derived from breast MRI for predicting the upstaging of ductal carcinoma in situ (DCIS) diagnosed using percutaneous needle biopsy.

MATERIALS AND METHODS

Between August 2018 and June 2020, 95 patients with 98 DCIS lesions who underwent preoperative breast MRI, including an ultrafast sequence, and subsequent surgery were included. Four ultrafast MRI parameters were analyzed: time-to-enhancement, maximum slope (MS), area under the curve for 60 s after enhancement, and time-to-peak enhancement. One hundred and seven radiomic features were extracted for the whole tumor on the first post-contrast T1WI and T2WI using PyRadiomics. Clinicopathological characteristics, ultrafast MRI findings, and radiomic features were compared between the pure DCIS and DCIS with invasion groups. Prediction models, incorporating clinicopathological, ultrafast MRI, and radiomic features, were developed. Receiver operating characteristic curve analysis and area under the curve (AUC) were used to evaluate model performance in distinguishing between the two groups using leave-one-out cross-validation.

RESULTS

Thirty-six of the 98 lesions (36.7%) were confirmed to have invasive components after surgery. Compared to the pure DCIS group, the DCIS with invasion group had a higher nuclear grade (P < 0.001), larger mean lesion size (P = 0.038), larger mean MS (P = 0.002), and different radiomic-related characteristics, including a more extensive tumor volume; higher maximum gray-level intensity; coarser, more complex, and heterogeneous texture; and a greater concentration of high gray-level intensity. No significant differences in AUCs were found between the model incorporating nuclear grade and lesion size (0.687) and the models integrating additional ultrafast MRI and radiomic features (0.680-0.732).

CONCLUSION

High nuclear grade, larger lesion size, larger MS, and multiple radiomic features were associated with DCIS upstaging. However, the addition of MS and radiomic features to the prediction model did not significantly improve the prediction performance.

Human Ductal Carcinoma In Situ: Advances and Future Perspectives

Due to widespread adoption of screening mammography, there has been a significant increase in new diagnoses of ductal carcinoma in situ (DCIS). However, DCIS outcomes remain unclear. A large fraction of human DCIS (>50%) may not need the multimodality treatment options currently offered to all DCIS patients. More importantly, while we may be overtreating many, we cannot identify those most at risk of invasion or metastasis following a DCIS diagnosis. This review summarizes the studies that have furthered our understanding of DCIS pathology and mechanisms of invasive progression by using advanced technologies including spatial genomics, transcriptomics, and multiplex proteomics. This review also highlights a need for rethinking DCIS with a more focused view on epithelial states and programs and their cross talk with the microenvironment.

An MRI-Based Radiomics Nomogram to Distinguish Ductal Carcinoma In Situ with Microinvasion From Ductal Carcinoma In Situ of Breast Cancer

RATIONALE AND OBJECTIVES

Accurate preoperative differentiation between ductal carcinoma in situ with microinvasion (DCISM) and ductal carcinoma in situ (DCIS) could facilitate treatment optimization and individualized risk assessment. The present study aims to build and validate a radiomics nomogram based on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) that could distinguish DCISM from pure DCIS breast cancer.

MATERIALS AND METHODS

MR images of 140 patients obtained between March 2019 and November 2022 at our institution were included. Patients were randomly divided into a training (n = 97) and a test set (n = 43). Patients in both sets were further split into DCIS and DCISM subgroups. The independent clinical risk factors were selected by multivariate logistic regression to establish the clinical model. The optimal radiomics features were chosen by the least absolute shrinkage and selection operator, and a radiomics signature was built. The nomogram model was constructed by integrating the radiomics signature and independent risk factors. The discrimination efficacy of our nomogram was assessed by using calibration and decision curves.

RESULTS

Six features were selected to construct the radiomics signature for distinguishing DCISM from DCIS. The radiomics signature and nomogram model exhibited better calibration and validation performance in the training (AUC 0.815, 0.911, 95% confidence interval [CI], 0.703-0.926, 0.848-0.974) and test (AUC 0.830, 0.882, 95% CI, 0.672-0.989, 0.764-0.999) sets than in the clinical factor model (AUC 0.672, 0.717, 95% CI, 0.544-0.801, 0.527-0.907). The decision curve also demonstrated that the nomogram model exhibited good clinical utility.

CONCLUSION

The proposed noninvasive MRI-based radiomics nomogram model showed good performance in distinguishing DCISM from DCIS.

Delayed Sentinel Lymph Node Dissection in Patients with a Preoperative Diagnosis of Ductal Cancer In Situ by Preoperative Injection with Superparamagnetic Iron Oxide (SPIO) Nanoparticles: The SentiNot Study

BACKGROUND

Difficulty in preoperatively assessing the risk for occult invasion or surgery that precludes future accurate axillary mapping in patients with ductal cancer in situ (DCIS) account for overutilization of SLND.

METHODS

Prospective, multicenter, cohort study, including women with any DCIS planned for mastectomy or DCIS grade 2 and > 20 mm, any DCIS grade 3, any mass-forming DCIS and any planned surgery. Patients received an interstitial SPIO injection during breast surgery, but no upfront SLND was performed. If invasion was identified on final pathology, delayed SLND (d-SLND) was performed separately with the coadministration of isotope ± blue dye (BD). Study outcomes were proportion of upfront SLNDs that were avoided, detection rates during d-SLND, and impact on healthcare costs.

RESULTS

In total, 78.7% of study participants (N = 254, mean age 60 years, mean DCIS size 37.8 mm) avoided upfront SLND. On d-SLND (median 28 days, range 9-46), SPIO outperformed Tc99 with (98.2% vs. 63.6%, p < 0.001) or without BD (92.7% vs. 50.9%, p < 0.001) and had higher nodal detection rate (86.9% vs. 32.3%, p < 0.001) and with BD (93.9% vs. 41.4%, p < 0.001). Only 27.9% of all SLNs retrieved were concordant for Tc99 and SPIO. Type of breast procedure (WLE vs. oncoplastic BCT vs. mastectomy) affected these outcomes and accounted for the low performance of Tc99 (p < 0.001). d-SLND resulted in a 28.1% total cost containment for women with pure DCIS on final pathology (4190 vs. 5828 USD, p < 0.001).

CONCLUSIONS

Marking the SLN with SPIO may avoid overtreatment and allow for accurate d-SLND in patients with DCIS.

The Landmark Series-Ductal Carcinoma in Situ: The Evolution of Treatment

The evolution of ductal carcinoma in situ (DCIS) management has been driven by a parallel evolution in our understanding of its natural history. Early trials established the benefit of adjuvant therapies in all patients with DCIS. In contrast, subsequent studies have stratified patients to determine their eligibility for progressively less invasive and less intensive therapies. Large, randomized trials and meta-analyses have supported this shift away from treating DCIS as an homogenous disease treated with similar intensity to invasive breast cancer. This review describes the landmark studies on which current DCIS management is based.

Upgrade Rate of Ductal Carcinoma In Situ to Invasive Carcinoma and the Clinicopathological Factors Predicting the Upgrade Following a Mastectomy: A Retrospective Study

Background The rate of upgrading ductal carcinoma in situ (DCIS) to invasive cancer varies widely in the literature with no consensus regarding sentinel lymph node biopsy (SLNB) for DCIS; however, some guidelines do recommend it in the event of a mastectomy. The primary aim of this study was to determine the upgrade rate of DCIS to invasive carcinoma (IC) in patients undergoing mastectomy for DCIS and identify the clinicopathological predicting factors for the upgrade. The secondary aim was to determine the SLNB positivity rate. Methodology We retrospectively analysed consecutive patients with DCIS diagnosed through a biopsy who then underwent mastectomy over a 10-year period (2010 to 2020). Clinical, radiological, and histological variables were collected from medical records. Results We studied 143 women (mean age = 57.4 years, range = 26-85 years) who underwent mastectomy for DCIS identified on biopsy. Almost two-thirds (62.9%, 90/143) of the patients were detected on screening mammography, while 35.6% (51/143) were diagnosed following presentation with either an area of palpable concern or nipple discharge. The most common mammographic presentation of DCIS was calcification (83.9%, 120/143), and, in 85.9% of the patients, the mammographic lesion was more than 20 mm. High-grade DCIS was noted in 76.9% of preoperative biopsy results, while the rest was either low or intermediate-grade DCIS. Overall, 24.5% (35/143) were upgraded to IC (upgraded group) on postoperative histology, whereas 108/143 remained DCIS postoperatively (pure DCIS group). The positivity rate of SLNB was 4.8%. Multifocality was the only significant predictor of IC on multivariate analyses of clinicopathological predictors (odds ratio = 3.0, 95% confidence interval = 1.0-8.7). The presence of comedonecrosis was higher in the upgraded group compared to the pure DCIS group (42.9% vs. 27.8%), but this was not statistically significant. Conclusions In our study cohort, nearly one in four (24.5%) patients were upgraded from DCIS to IC on postoperative histology, with an SLNB positivity rate of 4.8%. This is important when counselling patients regarding the risk of coincident occult IC and the importance of SLNB at the time of mastectomy. Multifocality on preoperative imaging was the only significant predictive factor. Based on this result, we recommend that SLNB should also be considered if patients have multifocal DCIS and planned for oncoplastic breast-conserving surgery. However, further studies are required to investigate the association between multifocal DCIS and the risk of upgrading to IC.

Diffusion-weighted Breast MRI in Prediction of Upstaging in Women with Biopsy-proven Ductal Carcinoma in Situ

Background Accurate preoperative prediction of upstaging in women with biopsy-proven ductal carcinoma in situ (DCIS) is important for surgical planning, but published models using predictive MRI features remain lacking. Purpose To develop and validate a predictive model based on preoperative breast MRI to predict upstaging in women with biopsy-proven DCIS and to select high-risk women who may benefit from sentinel lymph node biopsy at initial surgery. Materials and methods Consecutive women with biopsy-proven DCIS who underwent preoperative 3.0-T breast MRI including dynamic contrast-enhanced (DCE) MRI and diffusion-weighted imaging (DWI) and who underwent surgery between June 2019 and March 2020 were retrospectively identified (development set) from an academic medical center. The apparent diffusion coefficients of lesions from DWI, lesion size and morphologic features on DCE MRI scans, mammographic findings, age, symptoms, biopsy method, and DCIS grade at biopsy were collected. The presence of invasive cancer and axillary metastases was determined with surgical pathology. A predictive model for upstaging was developed by using multivariable logistic regression and validated in a subsequent prospective internal validation set recruited between July 2020 and April 2021. Results Fifty-seven (41%) of 140 women (mean age, 53 years ± 11 [SD]) in the development set and 43 (41%) of 105 women (mean age, 53 years ± 10) in the validation set were upstaged after surgery. The predictive model combining DWI and clinical-pathologic factors showed the areas under the receiver operating characteristic curve at 0.87 (95% CI: 0.80, 0.92) in the development set and 0.76 (95% CI: 0.67, 0.84) in the validation set. The predicted probability of invasive cancer showed good interobserver agreement (intraclass correlation coefficient, 0.79); the positive predictive value was 85% (28 of 33), and the negative predictive value was 92% (22 of 24). Conclusion A predictive model based on diffusion-weighted breast MRI identified women at high risk of upstaging. © RSNA, 2022 Online supplemental material is available for this article See also the editorial by Baltzer in this issue.

Addressing the problem of overtreatment in breast cancer

INTRODUCTION

As breast cancer treatment options have multiplied and biologic diversity within breast cancer has been recognized, the use of the same treatment strategies for patients with early-stage and favorable disease, and for those with biologically aggressive disease, has been questioned. In addition, as patient-reported outcome measures have called attention to the morbidity of many common treatments, and as the cost of breast cancer care has continued to increase, reduction in the overtreatment of breast cancer has assumed increasing importance.

AREAS COVERED

Here we review selected aspects of surgery, radiation oncology, and medical oncology for which scientific evidence supports de-escalation for invasive carcinoma and ductal carcinoma in situ, and assess strategies to address overtreatment.

EXPERT OPINION

The problems of breast cancer overtreatment we face today are based on improved understanding of the biology of breast cancer and abandonment of the 'one-size-fits-all' approach. As breast cancer care becomes increasingly complex, and as our knowledge base continues to increase exponentially, these problems will only be magnified in the future. To continue progress, the move must be made from advocating the maximum-tolerated treatment to advocating the minimum-effective one.

Multiple Metastases of the Liver and Lung After Breast-Conserving Surgery for Ductal Carcinoma In Situ Without Microinvasion of the Breast: A Case Report and Literature Review

Background

Ductal carcinoma in situ (DCIS) is a non-invasive disease that rarely causes distant metastasis. It is extremely rare for patients diagnosed with DCIS without microinvasion to develop distant metastasis in the absence of ipsilateral or contralateral breast recurrence. This is the first case report of multiple liver and lung metastases from DCIS after breast-conserving surgery and radiotherapy.

Case Presentation

A 45-year-old woman who was diagnosed with DCIS and received breast-conserving surgery, radiotherapy, and sequential endocrine therapy developed multiple metastases in the liver and lung despite not having bilateral breast recurrence at the 62-month follow-up. Comprehensive advanced breast cancer therapy was administered but did not prevent the progression of metastatic foci in the liver.

Conclusions

This case shows the poor potential outcome in DCIS. Further research should be conducted on metastasis in DCIS; reexamination and monitoring are indispensable for patients diagnosed with DCIS.

OUP accepted manuscript

Background

Axillary lymph node status remains the most powerful prognostic indicator in invasive breast cancer. Ductal carcinoma in situ (DCIS) is a non-invasive disease and does not spread to axillary lymph nodes. The presence of an invasive component to DCIS mandates nodal evaluation through sentinel lymph node biopsy (SLNB). Quantification of the necessity of upfront SLNB for DCIS requires investigation. The aim was to establish the likelihood of having a positive SLNB (SLNB+) for DCIS and to establish parameters predictive of SLNB+.

Methods

A systematic review was performed as per the PRISMA guidelines. Prospective studies only were included. Characteristics predictive of SLNB+ were expressed as dichotomous variables and pooled as odds ratios (o.r.) and associated 95 per cent confidence intervals (c.i.) using the Mantel–Haenszel method.

Results

Overall, 16 studies including 4388 patients were included (mean patient age 54.8 (range 24 to 92) years). Of these, 72.5 per cent of patients underwent SLNB (3156 of 4356 patients) and 4.9 per cent had SLNB+ (153 of 3153 patients). The likelihood of having SLNB+ for DCIS was less than 1 per cent (o.r. <0.01, 95 per cent c.i. 0.00 to 0.01; P < 0.001, I² = 93 per cent). Palpable DCIS (o.r. 2.01, 95 per cent c.i. 0.64 to 6.24; P = 0.230, I² = 0 per cent), tumour necrosis (o.r. 3.84, 95 per cent c.i. 0.85 to 17.44; P = 0.080, I² = 83 per cent), and grade 3 DCIS (o.r. 1.34, 95 per cent c.i. 0.80 to 2.23; P = 0.270, I² = 0 per cent) all trended towards significance in predicting SLNB+.

Conclusion

While aggressive clinicopathological parameters may guide SLNB for patients with DCIS, the absolute and relative risk of SLNB+ for DCIS is less than 5 per cent and 1 per cent, respectively. Well-designed randomized controlled trials are required to establish fully the necessity of SLNB for patients diagnosed with DCIS.

Registration number

CRD42021284194 (https://www.crd.york.ac.uk/prospero/)

Underestimation of invasive breast carcinoma in patients with initial diagnosis of ductal carcinoma in situ: Size matters

BACKGROUND

The aim of our study was to identify those patients with preoperative diagnosis of ductal carcinoma in situ (DCIS) and high risk of upstaging to invasive breast carcinoma (IBC), in whom sentinel lymph node biopsy (SLNB) should be considered.

MATERIALS AND METHODS

One-hundred and five DCIS patients treated with breast-conserving surgery (BCS) or mastectomy were studied. Preoperative features of the tumours were analyzed to investigate its association with underestimation of IBC on final pathology.

RESULTS

Overall, the underestimation rate of IBC was 16.2%. The underestimation rate was highest in lesions with initial size >2 cm compared with those with size ≤2 cm (26.8% vs. 4.1%, respectively; p < 0.003). Eighty-eight patients (83.8%) underwent concurrent SLNB and only one case had lymph node involvement (1.1%).

CONCLUSIONS

SLNB should be considered in DCIS patients receiving BCS with lesions greater than 2 cm since approximately one in four will harbour an IBC.

When is Sentinel Lymph Node Biopsy Useful in Ductal Carcinoma In Situ? The Experience at a Latin American Cancer Center

Introduction

Ductal carcinoma in situ (DCIS) accounts for 15% of breast cancers. Surgery is the main treatment, and the use of sentinel node biopsy (SLNB) is restricted to patients at risk of infiltration, which is estimated to be around 26%.

Materials and methods

Aimed at evaluating the benefit of SLNB in patients with DCIS at the Breast and Soft Tissue Functional Unit of the National Cancer Institute (INC for its initials in Spanish), a descriptive observational study of a retrospective cases series was conducted between August 1, 2013, and September 30, 2018.

Results

A total of 40 patients with a median age of 57 years were included in the study; 62.5% of them underwent mastectomy with SLNB, and the remaining 37.5% underwent conservative surgery with SLNB. 100% of sentinel nodes were identified, by using lymphoscintigraphy in 95%. Sentinel node was positive in four patients (10%), three of whom had infiltration in the surgical specimen reported. With a follow-up of 49 months, only one patient had a local relapse. None of the patients had axillary or distant recurrence.

Conclusions

SLNB in DCIS should be limited to patients with risk factors for infiltration (tumor size greater than 3 cm, comedo-type histology, and high-grade DCIS), and patients with an indication for mastectomy. Its percentage of complications is low, and a high identification percentage in surgical groups with adequate training.

Ductal Carcinoma in situ: Underestimation of Percutaneous Biopsy and Positivity of Sentinel Lymph Node Biopsy in a Brazilian Public Hospital

Background

Mammography screening has become widely spread and provided a marked increase in ductal carcinoma in situ (DCIS) diagnosis. In DCIS, the ductal epithelium proliferates without invasion through the basal cell membrane. However, histologic underestimation can happen in some cases.

Objective

To analyze the rate of histologic underestimation (histopathologic results upgraded to invasive carcinoma after surgery) and the rate of positive results of sentinel lymph node biopsy (SLNB) in patients diagnosed with DCIS in a Brazilian public hospital.

Methods

We reviewed medical records of all consecutive patients admitted between 2009 and 2013 whose initial diagnosis was DCIS through core needle biopsy. DCIS cases with a high risk of invasion underwent SLNB. We excluded cases with invasion or micro-invasion components in the first biopsy.

Results

A total of 86 women were included, most with microcalcifications as the primary radiological lesion (73.2%), and underwent preoperative biopsy, with an invasive component in 21 (24.4%) in the final pathology report. Most had invasive carcinoma of no special type (NST): 52.3% (n = 11) and microinvasive tumors (7 cases, 33.3%). The main factors associated with histologic underestimation were nodular lesion (61.9%, p<0.001) and an ultra-sonography-guided biopsy (71.4%, p=0.0005). The positivity rate of SLNB was 4.3%. All these patients underwent mastectomy, and the initial histologic pattern was solid DCIS.

Conclusion

The “histologic underestimation” rate among patients with DCIS was not low, and less than 5% of patients who underwent SLNB had axillary positivity. This result suggests that patients who have DCIS and a high risk of invasion and undergoing mastectomy should have SLNB. As to the patients who will undergo lumpectomy, SLNB could be omitted and could be performed if patients have upgraded to invasive breast cancer.

Axillary evaluation in ductal cancer in situ of the breast: challenging the diagnostic accuracy of clinical practice guidelines

BACKGROUND

Staging of the axilla is not routine in ductal cancer in situ (DCIS) although invasive cancer is observed in 20-25 per cent of patients at final pathology. Upfront sentinel lymph node dissection (SLND) is advocated in clinical practice guidelines in certain situations. These include expected challenges in subsequent SLN detection and when the risk for invasion is high. Clinical practice guidelines are, however, inconsistent and lead to considerable practice variability.

METHODS

Clinical practice guidelines for upfront SLND in DCIS were identified and applied to patients included in the prospective SentiNot study. These patients were evaluated by six independent, blinded raters. Agreement statistics were performed to assess agreement and concordance. Receiver operating characteristic curves were constructed, to assess guideline accuracy in identifying patients with underlying invasion.

RESULTS

Eight guidelines with relevant recommendations were identified. Interobserver agreement varied greatly (kappa: 0.23-0.9) and the interpretation as to whether SLND should be performed ranged from 40-90 per cent and with varying concordance (32-88 per cent). The diagnostic accuracy was low with area under the curve ranging from 0.45 to 0.55. Fifty to 90 per cent of patients with pure DCIS would undergo unnecessary SLNB, whereas 10-50 per cent of patients with invasion were not identified as 'high risk'. Agreement across guidelines was low (kappa = 0.24), meaning that different patients had a similar risk of being treated inaccurately.

CONCLUSION

Available guidelines are inaccurate in identifying patients with DCIS who would benefit from upfront SLNB. Guideline refinement with detailed preoperative work-up and novel techniques for SLND identification could address this challenge and avoid overtreatment.

Breast ductal carcinoma in situ with micro-invasion versus ductal carcinoma in situ: a comparative analysis of clinicopathological and mammographic findings

AIM

To determine the differences in clinicopathological and mammographic findings between ductal carcinoma in situ (DCIS) and ductal carcinoma in situ with micro-invasion (DCIS-MI) and explore clinicopathological and mammographic factors associated with DCIS-MI.

MATERIALS AND METHODS

All DCIS patients with or without micro-invasion who underwent preoperative mammography at The Affiliated Hospital of Qingdao University from January 2016 through June 2020 were identified retrospectively. The correlations of clinicopathological findings with DCIS-MI were evaluated using univariate and multivariate binary logistic regression analyses. Imaging findings were compared between the groups by using the Pearson chi-square test.

RESULTS

A total of 445 DCIS lesions and 151 DCIS-MI lesions were included in the final analysis. Large extent (≥2.7 cm), high nuclear grade, comedo-type, negative progesterone receptor (PR), negative oestrogen receptor (ER), high Ki-67 and axillary lymph node metastasis were more frequently found in DCIS-MI than in DCIS (all p<0.05), and the first four of these were found to be independent predictors of DCIS-MI in the multivariate analysis (all p<0.05). Regarding imaging findings, compared to DCIS, DCIS-MI showed fewer occult lesions and more lesions with calcifications in mass, asymmetry, and architectural distortion (p=0.004). Grouped calcifications were usually associated with DCIS, while regional calcifications were commonly found in DCIS-MI (p<0.05).

CONCLUSION

Large extent, high nuclear grade, comedo-type and negative PR were found to be independent predictors of DCIS-MI. Lesions with calcifications and regional calcifications were more likely associated with DCIS-MI on mammography.

Underestimation of invasive breast carcinoma in patients with initial diagnosis of ductal carcinoma in situ: Size matters

INTRODUCTION

The aim of our study was to identify those patients with preoperative diagnosis of ductal carcinoma in situ (DCIS) and high risk of upstaging to invasive breast carcinoma (IBC), in whom sentinel lymph node biopsy (SLNB) should be considered.

METHODS

One-hundred and five DCIS patients treated with breast-conserving surgery (BCS) or mastectomy were studied. Preoperative features of the tumors were analyzed to investigate its association with underestimation of IBC on final pathology.

RESULTS

Overall, the underestimation rate of IBC was 16.2%. The underestimation rate was highest in lesions with initial size >2 cm compared with those with size ≤2 cm (26.8% vs. 4.1%, respectively; p < 0.003). Eighty-eight patients (83.8%) underwent concurrent SLNB and only one case had lymph node involvement (1.1%).

CONCLUSIONS

SLNB should be considered in DCIS patients receiving BCS with lesions greater than 2 cm since approximately one in four will harbor an IBC.

A Network Meta-Analysis of Surgical Treatment in Patients With Early Breast Cancer

BACKGROUND

In early breast cancer treatment, the preferred surgical regimen remains a topic of controversy, and conventional pairwise meta-analysis cannot provide a hierarchy based on clinical trial evidence. Therefore, a network meta-analysis was performed both for direct and indirect comparisons and to assess the survival outcomes of surgical regimens.

METHODS

Randomized clinical trials comparing different surgical regimens for the treatment of early breast cancer were identified. Overall survival (OS) and disease-free-survival (DFS) were analyzed using random-effects network meta-analysis on the hazard ratio (HR) scale and calculated as combined HRs and 95% confidence intervals (CIs). All statistical tests were two-sided.

RESULTS

The network meta-analysis compared 11 different surgical regimens that consisted of 13 and 17 direct comparisons between strategies for OS (34 trials; n = 23 587 patients) and DFS (32 trials; n = 22 552 patients), respectively. The values of surface under the cumulative ranking for OS and DFS after mastectomy (M)+radiotherapy (RT) were observed to be the largest. Breast-conserving surgery (BCS)+axillary node sampling+RT almost achieved the threshold for inferiority compared with the other surgical treatment arms and was statistically significantly associated with worse OS (HR = 0.51, 95% CI = 0.24 to 0.94; HR = 0.48, 95% CI = 0.22 to 0.92; HR = 0.51, 95% CI = 0.23 to 0.96). No statistically significant difference between BCS+sentinel lymph node biopsy (SLNB)+RT vs BCS+SLNB+intraoperative RT was observed in carrying out network meta-analysis (HR = 0.95, 95% CI = 0.64 to 1.36).

CONCLUSIONS

M+RT has the most favorable survival outcomes among the various surgical regimens for the treatment of early breast cancer patients. For patients who receive BCS, SNLB has more favorable outcomes than axillary node sampling. Intraoperative RT and postoperative RT have similar outcomes in patients who receive SLNB.

Evidence map of ductal carcinoma in situ management options

OBJECTIVE

Ductal carcinoma in situ (DCIS) has the potential to progress to invasive carcinoma. The optimal management of DCIS and methods for individualizing treatment of DCIS are still being determined. This evidence map depicts the robustness and topical span of research on DCIS management choice on patient-centered and clinical outcomes.

METHODS

We searched PubMed, EMBASE, PsycINFO, PubMed Health, PROSPERO, and clinical practice guideline sites to identify systematic reviews of DCIS management options and consulted with topic experts. A bubble plot visualizes the literature volume and research content for patient-centered outcomes. An online decision tree facilitates discussions with patients and guides through the available evidence.

RESULTS

In total, 40 systematic reviews met inclusion criteria. The research syntheses addressed DCIS management options, including the role of magnetic resonance imaging, axillary surgery/sentinel lymph node biopsy, and excisional biopsy. The map shows existing evidence for mutually exclusive treatment options including active surveillance, breast-conserving surgery, nipple sparing mastectomy, and simple mastectomy. Research findings for intraoperative radiation, adjuvant radiation therapy, adjuvant hormone therapy, hypofractionation radiotherapy, accelerated partial breast irradiation, radiation therapy plus boost, and combined radiation and hormone therapy, as well as for breast reconstruction after mastectomy and surveillance mammography postsurgery are also displayed. The evidence map highlights a scarcity of robust evidence on patient-centered outcomes.

CONCLUSIONS

The evidence map provides an overview of DCIS research showing the range of management options and remaining decisional dilemmas that follow a diagnosis of DCIS. It maps the evidence in accessible tools to guide practice and future research. : Video Summary:http://links.lww.com/MENO/A448.

Predictive factors of axillary positive sentinel lymph node biopsy in extended ductal carcinoma in situ treated by simple mastectomy at once

BACKGROUND

The incidence of positive sentinel lymph node biopsy (SLNB) in ductal carcinoma in situ (DCIS) ranged from 0 to 14%. The main hypothesis would be the presence of an invasive contingent on the final histology. The objective was to identify predictive factors of sentinel lymph node positivity in the management of extended ductal carcinoma in situ treated by simple mastectomy.

METHODS

This was a retrospective study carried out at the Lorraine Cancer Institute from January 2003 to December 2017. Women with DCIS on core-needle biopsy whose management consisted of simple mastectomy and SLNB procedure were included.

RESULTS

188 patients were analyzed. Preoperatively, 18 patients (9.6%) had DCIS with microinvasion, while the others had pure DCIS. Eight patients (4.2%) had positive sentinel lymph node biopsy, the majority of which were single micrometastases. Predictive factor of node invasion was microinvasion on biopsy (p<0.01). Only in cases of pure DCIS, the percentage of positive SLNB was reduced to 2.9%. Invasive carcinoma was found in the majority of patients with positive axillary SLNB procedure (75%, n=6), compared to 16.7% (n=30) without SLNB involvement (p<0.01).

CONCLUSIONS

The low rate of positive sentinel node biopsy in pure ductal carcinoma in situ suggests that in the absence of microinvasion, the sentinel procedure would seem less appropriate. New techniques for identifying sentinel lymph node biopsy could report axillary staging after definitive histologic results.

Preoperative Delays in the Treatment of DCIS and the Associated Incidence of Invasive Breast Cancer

Background

Although treatment delays have been associated with survival impairment for invasive breast cancer, this has not been thoroughly investigated for ductal carcinoma in situ (DCIS). With trials underway to assess whether DCIS can remain unresected, this study was performed to determine whether longer times to surgery are associated with survival impairment or increased invasion.

Methods

A population-based study of prospectively collected national data derived from women with a clinical diagnosis of DCIS between 2004 and 2014 was conducted using the National Cancer Database. Overall survival (OS) and presence of invasion were assessed as functions of time by evaluating five intervals (≤ 30, 31–60, 61–90, 91–120, 121–365 days) between diagnosis and surgery. Subset analyses assessed those having pathologic DCIS versus invasive cancer on final pathology.

Results

Among 140,615 clinical DCIS patients, 123,947 had pathologic diagnosis of DCIS and 16,668 had invasive ductal carcinoma. For all patients, 5-year OS was 95.8% and unadjusted median delay from diagnosis to surgery was 38 days. With each delay interval increase, added relative risk of death was 7.4% (HR 1.07; 95% CI 1.05–1.10; P < 0.001). On final pathology, 5-year OS for noninvasive patients was 96.0% (95% CI 95.9–96.1%) versus 94.9% (95% CI 94.6–95.3%) for invasive patients. Increasing delay to surgery was an independent predictor of invasion (OR 1.13; 95% CI 1.11–1.15; P < 0.001).

Conclusions

Despite excellent OS for invasive and noninvasive cohorts, invasion was seen more frequently as delay increased. This suggests that DCIS trials evaluating nonoperative management, which represents infinite delay, require long term follow up to ensure outcomes are not compromised.

Electronic supplementary material

The online version of this article (10.1245/s10434-019-07844-4) contains supplementary material, which is available to authorized users.

Ductal Carcinoma in situ after Core Needle Biopsy: In Which Cases Is a Sentinel Node Biopsy Necessary?

Introduction

In some hospitals it is still common practice to carry out a sentinel node biopsy (SNB) if ductal carcinoma in situ (DCIS) is determined in preoperative staging, although this is against international guidelines. The reason for this is because an infiltrative component can be demonstrated frequently in the final pathohistological examination. In this study, we wanted to investigate possible predictors for infiltrative growth, to select patients to do an SNB or to omit it.

Material and Methods

All patients with DCIS in the core needle biopsy (CNB), who were treated with surgery including an SNB, were included in a prospective data registry. Patient characteristics were collected through physical examination, mammography and ultrasonography. All characteristics of the DCIS were noted. After surgery, the pathological results were collected.

Results

From the 287 patients, 39 (13.6%) had an infiltrative component in the definitive pathological examination despite only DCIS in preoperative CNB. In total, there were only 14 (4.9%) positive SNBs, of which 11 patients had infiltrative growth in the breast tumor and 3 (1.2% of patients with DCIS alone in the final pathology) did not. In addition, characteristics of the CNB, including microcalcifications and comedonecrosis, did not show a statistically significant higher risk for infiltration.

Discussion

Considering the low rates of positive SNBs in our population, we think that an SNB should not be performed in advance when DCIS is diagnosed, because if infiltrative growth is found in the final biopsy, an SNB could always be performed afterwards. Only if an SNB cannot be performed afterwards is an SNB indicated.

Effect of preoperative injection of superparamagnetic iron oxide particles on rates of sentinel lymph node dissection in women undergoing surgery for ductal carcinoma in situ (SentiNot study)

Background

One-fifth of patients with a preoperative diagnosis of ductal carcinoma in situ (DCIS) have invasive breast cancer (IBC) on definitive histology. Sentinel lymph node dissection (SLND) is performed in almost half of women having surgery for DCIS in Sweden. The aim of the present study was to try to minimize unnecessary SLND by injecting superparamagnetic iron oxide (SPIO) nanoparticles at the time of primary breast surgery, enabling SLND to be performed later, if IBC is found in the primary specimen.

Methods

Women with DCIS at high risk for the presence of invasion undergoing breast conservation, and patients with DCIS undergoing mastectomy were included. The primary outcome was whether this technique could reduce SLND. Secondary outcomes were number of SLNDs avoided, detection rate and procedure-related costs.

Results

This was a preplanned interim analysis of 189 procedures. IBC was found in 47 and a secondary SLND was performed in 41 women. Thus, 78·3 per cent of patients avoided SLND (P &lt; 0·001). At reoperation, SPIO plus blue dye outperformed isotope and blue dye in detection of the sentinel node (40 of 40 versus 26 of 40 women; P &lt; 0·001). Costs were reduced by a mean of 24·5 per cent in women without IBC (€3990 versus 5286; P &lt; 0·001).

Conclusion

Marking the sentinel node with SPIO in women having surgery for DCIS was effective at avoiding unnecessary SLND in this study. Registration number: ISRCTN18430240 (http://www.isrctn.com).

Prognostic impact and possible pathogenesis of lymph node metastasis in ductal carcinoma in situ of the breast

PURPOSE

Ductal carcinoma in situ (DCIS)-preinvasive breast cancer-with lymph node metastasis can clinically be treated as different stages: occult invasive cancer with true metastasis (T1N1) or pure DCIS with iatrogenic dissemination (TisN0). In this retrospective cohort study, we aimed to elucidate the prognostic impact and possible pathogenesis of nodal metastasis in DCIS to improve clinical management.

METHODS

Subjects were comprised of 427 patients with routine postoperative diagnosis of DCIS who underwent sentinel node (SN) biopsy using molecular whole-lymph-node analysis. Clinicopathological characteristics and prognosis were compared between SN-positive and -negative patients. Primary tumour tissues of SN-positive patients were exhaustively step-sectioned to detect occult invasions, and predictive factors for occult invasion were investigated. Median follow-up time was 73.6 months.

RESULTS

Of the 427 patients, 19 (4.4%) were SN-positive and 408 (95.6%) were SN-negative. More SN-positive patients received adjuvant systemic therapy than SN-negative patients (84.2% vs. 5.4%). Seven-year distant disease-free survivals were favourable for both cohorts (SN-positive, 100%; SN-negative, 99.7%). By examining 1421 slides, occult invasion was identified in 9 (47.4%) of the 19 SN-positive patients. Tumour burdens in SN and incidence of non-SN metastasis were similar between patients with and without occult invasion, and no predictive factor for occult invasion was found.

CONCLUSIONS

Node-positive DCIS has favourable prognosis with adjuvant systemic therapy. Half of the cases may be occult invasive cancer with true metastasis. In practical settings, clinicians may have to treat these tumours as node-positive small invasive cancers because it is difficult to predict the pathogenesis without exhaustive primary tumour sectioning.

Risk factors of sentinel and non-sentinel lymph node metastases in patients with ductal carcinoma in situ of the breast: A nationwide study

OBJECTIVES

Unexplained axillary metastases have been detected in some patients with ductal carcinoma in situ (DCIS), possibly because of occult invasion or iatrogenic tumor cell displacement. The significance of these metastases is unknown and brings into questions the need for upstaging and axillary surgery. What are the risk factors for sentinel lymph node (SN) and non-SN metastases, including the risk of iatrogenic displacement of tumor cells in relation to an excisional biopsy, in patients diagnosed with DCIS?

METHODS

Nationwide data on 1787 women diagnosed with DCIS between 2001 and 2015 were retrieved from the Danish Breast Cancer Group database. The association of clinicopathological variables with a positive SN (isolated tumor cells (ITCs), micro- or macrometastases) was evaluated using univariate and multivariate analyses.

RESULTS

Of the 1787 patients, 71 (4.0%) had a positive SN: 15 (0.8%) had macrometastases, 42 (2.4%) had micrometastases, and 14 (0.8%) had ITCs. Five patients with a positive SN also had a positive non-SN. In adjusted analysis, a positive SN was associated with younger age (P = 0.036), increased size (P = 0.002), palpability (P = 0.0004) and surgical excisional biopsy (P < 0.001).

CONCLUSIONS

The overall risk of a positive SN in patients with DCIS on final pathology is low and less than 9% of these patients had positive non-SNs. This argues against using axillary lymph node dissection in this group. The odds of positive SN after surgical excisional biopsies showed more than a four-fold increase, indicating iatrogenic tumor cell displacement. It is questioned whether these patients should be upstaged and classified as having invasive carcinoma.

Reducing harms from treatment. Sixteen years of surgery of the axilla for screen-detected breast cancers in Italy

OBJECTIVES

Available evidence on axillary surgery has accumulated dramatically in the last two decades in favor of less invasive care. The aim of this paper is to study 16-years trends in the surgical management of the axilla in a large population-based data set of screen-detected breast cancers in Italy and to document at what extent recommendations have been adopted in actual clinical care.

MATERIAL AND METHODS

This is a retrospective cohort study documenting the surgical management of the axilla in primary breast cancer patients over time. We retrieved from the Italian database of screen-detected cancers 41213 cases diagnosed in women aged 50-69 between years 2000 and 2015 in twelve Italian Regions.

RESULTS

In pN0 cases, an increasing trend (p < 0.001) in the number of patients who received sentinel lymph node biopsy (SLNB) as the only axillary staging procedure was observed. In pN + cases SLNB was the only staging procedure in an increasing number of patients (p < 0.001) especially since the publication of the ACOSOG-Z0011 paper. In ductal carcinoma in situ (DCIS) SLNB was more frequent in mastectomies and in high grade and large lesions. However, 45% of low grade, small DCIS over the whole time period had some form of axillary surgery.

CONCLUSION

This large series of screen-detected cases documents a strong time trend in the direction of reducing axillary surgery and hence potential harms from treatment. The continuing practice of SLNB in low risk DCIS is of concern in an era of increasing awareness towards overdiagnosis and overtreatment.

Is invasion a necessary step for metastases in breast cancer?

PURPOSE

To review the empirical evidence to support the conventional (sequential) model of breast cancer progression, which is based on the paradigm that cancer passes through several stages, including an in situ stage prior to an invasive stage, and thereafter (in some cases) disseminates to the lymph nodes and distant organs.

METHODS

We review the cancer literature of the last 50 years which relates to the prevention of invasive breast cancer (through radiotherapy or surgery) and reductions in the mortality for breast cancer.

RESULTS

For both invasive cancers and DCIS, the literature indicates that prevention of in-breast invasive recurrences does not prevent death from breast cancer. Moreover, the presence of residual cancer cells in the breast after breast-conserving surgery does not compromise the cure rate.

CONCLUSION

We propose an alternate (parallel) model of breast cancer wherein there is a small pool of cancer stem cells which have metastatic potential from their inception and which disseminate synchronously through several routes-to the breast stroma, to the lymph nodes and to distant organs. Cancer cells which disseminate to the breast give rise to cells which make up the bulk of the tumour mass but these are not the source of the distant metastases.

Impact of microinvasion on breast cancer mortality in women with ductal carcinoma in situ

BACKGROUND

Ductal carcinoma in situ (DCIS) is a neoplastic proliferation of epithelial cells which is confined within the basement membrane of the mammary ductal-lobular system. It is of interest to determine to what extent the potential to metastasize increases for DCIS patients when the basement membrane is breached (i.e. microinvasion is present).

METHODS

We retrieved the records of 525,395 women who had either first primary DCIS or small (≤ 2.0 cm) node-negative invasive breast cancer in the Surveillance, Epidemiology and End Results (SEER) registries database (1990-2013). For each patient, we extracted information on year of diagnosis, age at diagnosis, tumour size, tumour grade, oestrogen receptor status, use of radiotherapy, type of surgery, cause of death and follow-up time. We classified patients into four groups, according to the size of the invasive component of the primary tumour. We estimated the actuarial rate of breast cancer-specific mortality at ten and 20 years for women in each size category.

RESULTS

We identified 161,394 women with pure DCIS, 13,489 women with microinvasive carcinoma (≤ 0.1 cm of invasion), 153,856 women with invasive cancer 0.2-1.0 cm in size and 196,656 women with invasive cancer 1.1-2.0 cm in size. The 20-year actuarial breast cancer-specific mortality rate was 3.8% for women with pure DCIS, was 6.9% for women with microinvasive carcinoma, was 6.8% for women with invasive cancer 0.2-1.0 cm in size and was 12.1% for women with invasive cancer 1.1-2.0 cm in size. The adjusted hazard ratio for death associated with microinvasive carcinoma (vs. pure DCIS) was 2.00 (95% CI 1.76-2.26; p < 0.0001).

CONCLUSIONS

In terms of prognosis, microinvasive cancer more closely resembles small invasive cancer 0.2-1.0 cm) than pure DCIS. For invasive cancers under 1.0 cm, size has little impact on mortality.