Chemotherapy may eradicate ductal carcinoma in situ (DCIS) but not the associated microcalcifications

Does the Presence of Ductal Carcinoma in situ Affect Prognostic Outcomes After Neoadjuvant Therapy in Invasive Ductal Carcinoma of the Breast?

AIMS

The presence of ductal carcinoma in situ (DCIS) alongside invasive ductal carcinoma (IDC) of the breast is common in clinical practice and affects clinical outcomes and treatment strategies. This study aimed to compare the clinicopathological characteristics and prognosis of patients with IDC coexisting with DCIS versus pure IDC after neoadjuvant therapy (NAT) and to explore the risk factors for residual DCIS following NAT.

MATERIAL AND METHODS

Patients with Stage II-III IDC who underwent NAT followed by radical surgery between January 2015 and December 2022 were included. Baseline data, clinical characteristics, preoperative treatment, surgical approach, pathological outcomes, and prognostic information were collected and analysed.

RESULTS

A total of 852 patients were enrolled in this study, with 279 and 573 patients in the IDC + DCIS and IDC groups, respectively. Compared with patients in the IDC group, those in the IDC + DCIS group had a lower proportion of triple-negative molecular type (15.1% vs. 33.9%, P < 0.001), better histological grade (52.0% vs. 37.7%, P < 0.001), and higher residual rate of DCIS (71.3% vs. 38.7%, P < 0.001). The 5-year disease-free survival (DFS) (85.2% vs. 82.4%, P = 0.188) and overall survival (OS) (93.2% vs. 93.0%, P = 0.810) rates of patients in the IDC + DCIS group were similar to those in the IDC group. However, in the triple-negative breast cancer population, the DFS (88.6% vs. 75.8%, P = 0.032) of patients with IDC + DCIS was significantly better than that of patients with IDC. For patients with IDC + DCIS, age ≥40 years (odds ratio [OR] = 0.421; 95% confidence interval [CI], 0.163-0.889, P = 0.035) and HR+/HER2-molecular subtype (OR=3.347; 95% CI, 1.237-6.577, P = 0.047) were independent preoperative predictors for residual DCIS after NAT.

CONCLUSION

The presence of DCIS in IDC demonstrated less tumour aggressiveness than pure IDC. However, a survival benefit was only observed in patients with triple-negative IDC combined with DCIS after NAT. Furthermore, patients with IDC + DCIS have a higher risk of residual DCIS after NAT, and age <40 years and the luminal subtype are risk factors for residual DCIS after NAT in patients with IDC + DCIS.

Does concomitant ductal carcinoma in situ influence the prognostic outcome after neoadjuvant therapy in triple-negative invasive ductal carcinoma?

PURPOSE

Ductal carcinoma in situ (DCIS) is considered a precursor to invasive ductal carcinoma (IDC), and the coexistence of DCIS with IDC is often observed during the diagnosis of breast cancer. The aim of study is to investigated the clinicopathological features and prognosis of triple-negative IDC with DCIS following neoadjuvant therapy (NAT). Additionally, we explored the risk factors for residual DCIS in these patients post-NAT.

METHODS

This study included patients with stages II-III triple-negative breast cancer with histologically confirmed IDC who underwent radical surgery after NAT between January 2011 and December 2021. Baseline data, clinical features, pathological outcomes, and prognostic information were collected and analyzed.

RESULTS

A total of 315 patients were enrolled and categorized into the IDC + DCIS (n = 67) and IDC groups (n = 248) according to the composition of the pre-NAT biopsy. The proportion of patients with histological grade G3 (78.2% vs. 61.2%, p = 0.004) and a Ki-67 index > 20% (98.4% vs. 86.6%, p < 0.001) was significantly higher in the IDC group than in the IDC + DCIS group. Although no significant difference was observed in the 5-year overall survival (OS) (93.4% vs. 90.8%, p = 0.298) between the two groups, the 5-year disease-free survival (DFS) (90.6% vs. 83.5%, p = 0.041) of the IDC + DCIS group was significantly better than that in the IDC group. Multivariate analysis demonstrated that IDC + DCIS (HR: 0.502; 95% CI, 0.284-0.952; p = 0.048) was an independent prognostic factor for DFS. In addition, the clinical T3-T4 stage (OR = 3.891; 95% CI, 1.320-15.219, p = 0.040) and clinical N1-N3 (OR = 4.500; 95% CI, 1.495-13.564, p = 0.012) were independent preoperative predictors of residual DCIS after NAT in patients with IDC and DCIS components.

CONCLUSION

The presence of DCIS component in patients with triple-negative IDC is associated with lower tumor aggressiveness and improved DFS after NAT compared to patients without DCIS. Additionally, clinical T and N stages are risk factors for residual DCIS after NAT in patients with triple-negative IDC and a DCIS component.

Pathologic Complete Response After Neoadjuvant Chemotherapy in Breast Cancer Patients Treated With Mastectomy: Indications for Treatment and Oncological Outcomes

Objective

The aim of this study was to evaluate the clinical outcomes of breast cancer (BC) patients treated with neoadjuvant chemotherapy (NAC) followed by mastectomy, focusing on cases achieving pathologic complete response (pCR). The implications of residual ductal carcinoma in situ (DCIS) on prognosis and survival were examined.

Materials and Methods

A retrospective cohort study included BC patients treated with NAC followed by mastectomy at the breast unit of IRCCS Humanitas Research Hospital between March 2010 and October 2021. Patients were sub-grouped into two: Those with residual DCIS (ypTis) and those with complete response without residual tumor (ypT0). Key variables such as demographics, tumor characteristics, treatment regimens, and survival outcomes were analyzed.

Results

Of 681 patients treated with NAC, 175 achieved pCR, with 60 undergoing mastectomy. Among these 60 patients, 24 had residual DCIS (ypTis) while 36 had no residual invasive or in situ disease (ypT0). Patients with ypTis had higher rates of multifocal disease (62.5% vs. 27.8%, p = 0.006) and stage III disease (37.5% vs. 11.1%, p = 0.046). Triple-negative breast cancer was more prevalent in the ypT0 group (55.6% vs. 20.8%, p = 0.005). During a mean follow-up of 47 months, 11 patients experienced recurrence, with no significant differences in disease-free survival (DFS) and overall survival (OS) between the groups (p = 0.781, p = 0.963, respectively).

Conclusion

Residual DCIS after NAC did not significantly impact DFS or OS compared to complete pathologic response without residual DCIS. This study underscores the need for further research to refine pCR definitions and improve NAC's prognostic and therapeutic roles in BC management.

Case report: An ultrasound-based approach as an easy tool to evaluate hormone receptor-positive HER-2-negative breast cancer in advanced/metastatic settings: preliminary data of the Plus-ENDO study

Background

Hormone receptor-positive tumors are unlikely to exhibit a complete pathological tumor response. The association of CDK 4/6 inhibitor plus hormone therapy has changed this perspective.

Case presentation

In this study, we retrospectively reviewed the charts of patients with a diagnosis of luminal A/B advanced/metastatic tumors treated with a CDK 4/6 inhibitor-based therapy. In this part of the study, we present clinical and ultrasound evaluation. Eight female patients were considered eligible for the study aims. Three complete and five partial responses were reported, including a clinical tumor response of 50% or more in five out of nine assessed lesions (55%). All patients showed a response on ultrasound. The mean lesion size measured by ultrasound was 27.1 ± 15.02 mm (range, 6-47 mm) at the baseline; 16.08 ± 14.6 mm (range, 0-40 mm) after 4 months (T1); and 11.7 ± 12.9 mm (range, 0-30 mm) at the 6 months follow-up (T2). Two patients underwent surgery. The radiological complete response found confirmation in a pathological complete response, while the partial response matched a moderate residual disease.

Conclusion

The evaluation of breast cancer by ultrasound is basically informative of response and may be an easy and practical tool to monitor advanced tumors, especially in advanced/unfit patients who are reluctant to invasive exams.

Other malignancies in the history of CLL: an international multicenter study conducted by ERIC, the European Research Initiative on CLL, in HARMONY

Background

Patients with chronic lymphocytic leukemia (CLL) have a higher risk of developing other malignancies (OMs) compared to the general population. However, the impact of CLL-related risk factors and CLL-directed treatment is still unclear and represents the focus of this work.

Methods

We conducted a retrospective international multicenter study to assess the incidence of OMs and detect potential risk factors in 19,705 patients with CLL, small lymphocytic lymphoma, or high-count CLL-like monoclonal B-cell lymphocytosis, diagnosed between 2000 and 2016. Data collection took place between October 2020 and March 2022.

Findings

In 129,254 years of follow-up after CLL diagnosis, 3513 OMs were diagnosed (27.2 OMs/1000 person-years). The most common hematological OMs were Richter transformation, myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Non-melanoma skin (NMSC) and prostate cancers were the most common solid tumors (STs).The only predictor for MDS and AML development was treatment with fludarabine and cyclophosphamide with/without rituximab (FC ± R) (OR = 3.7; 95% CI = 2.79-4.91; p < 0.001). STs were more frequent in males and patients with unmutated immunoglobulin heavy variable genes (OR = 1.77; 95% CI = 1.49-2.11; p < 0.001/OR = 1.89; 95% CI = 1.6-2.24; p < 0.001).CLL-directed treatment was associated with non-melanoma skin and prostate cancers (OR = 1.8; 95% CI = 1.36-2.41; p < 0.001/OR = 2.11; 95% CI = 1.12-3.97; p = 0.021). In contrast, breast cancers were more frequent in untreated patients (OR = 0.17; 95% CI = 0.08-0.33; p < 0.001).Patients with CLL and an OM had inferior overall survival (OS) than those without. AML and MDS conferred the worst OS (p < 0.001).

Interpretation

OMs in CLL impact on OS. Treatment for CLL increased the risk for AML/MDS, prostate cancer, and NMSC. FCR was associated with increased risk for AML/MDS.

Funding

AbbVie, and EU/EFPIAInnovative Medicines Initiative Joint Undertaking HARMONY grant n° 116026.

Imaging findings for response evaluation of ductal carcinoma in situ in breast cancer patients treated with neoadjuvant systemic therapy: a systematic review and meta-analysis

OBJECTIVES

In approximately 45% of invasive breast cancer (IBC) patients treated with neoadjuvant systemic therapy (NST), ductal carcinoma in situ (DCIS) is present. Recent studies suggest response of DCIS to NST. The aim of this systematic review and meta-analysis was to summarise and examine the current literature on imaging findings for different imaging modalities evaluating DCIS response to NST. More specifically, imaging findings of DCIS pre- and post-NST, and the effect of different pathological complete response (pCR) definitions, will be evaluated on mammography, breast MRI, and contrast-enhanced mammography (CEM).

METHODS

PubMed and Embase databases were searched for studies investigating NST response of IBC, including information on DCIS. Imaging findings and response evaluation of DCIS were assessed for mammography, breast MRI, and CEM. A meta-analysis was conducted per imaging modality to calculate pooled sensitivity and specificity for detecting residual disease between pCR definition no residual invasive disease (ypT0/is) and no residual invasive or in situ disease (ypT0).

RESULTS

Thirty-one studies were included. Calcifications on mammography are related to DCIS, but can persist despite complete response of DCIS. In 20 breast MRI studies, an average of 57% of residual DCIS showed enhancement. A meta-analysis of 17 breast MRI studies confirmed higher pooled sensitivity (0.86 versus 0.82) and lower pooled specificity (0.61 versus 0.68) for detection of residual disease when DCIS is considered pCR (ypT0/is). Three CEM studies suggest the potential benefit of simultaneous evaluation of calcifications and enhancement.

CONCLUSIONS AND CLINICAL RELEVANCE

Calcifications on mammography can remain despite complete response of DCIS, and residual DCIS does not always show enhancement on breast MRI and CEM. Moreover, pCR definition effects diagnostic performance of breast MRI. Given the lack of evidence on imaging findings of response of the DCIS component to NST, further research is demanded.

KEY POINTS

• Ductal carcinoma in situ has shown to be responsive to neoadjuvant systemic therapy, but imaging studies mainly focus on response of the invasive tumour. • The 31 included studies demonstrate that after neoadjuvant systemic therapy, calcifications on mammography can remain despite complete response of DCIS and residual DCIS does not always show enhancement on MRI and contrast-enhanced mammography. • The definition of pCR has impact on the diagnostic performance of MRI in detecting residual disease, and when DCIS is considered pCR, pooled sensitivity was slightly higher and pooled specificity slightly lower.

New insights into breast microcalcification for poor prognosis: NACT cohort and bone metastasis evaluation cohort

OBJECTIVES

The study aimed to analyze the poor prognosis of microcalcification in breast cancer (BC), including the pathological complete response (pCR) to neoadjuvant chemotherapy (NACT) and the risk of bone metastases.

MATERIALS AND METHODS

313 breast cancer patients received NACT to evaluate pCR and 1182 patients from a multicenter database to assess bone metastases were retrospectively included. Two groups were divided according to the presence or absence of mammography microcalcification. Clinical data, image characteristics, neoadjuvant treatment response, bone involvement, and follow-up information were recorded. The pCR and bone metastases were compared between subgroups using the Mann-Whitney and χ2 tests and logistic regression, respectively.

RESULTS

Mammographic microcalcification was associated with a lower pCR than uncalcified BC in the NACT cohort (20.6% vs 31.6%, P = 0.029). Univariate and multivariate analysis suggested that calcification was a risk factor for poor NACT response [OR = 1.780, 95%CI (1.065-2.974), P = 0.028], [OR = 2.352, 95%CI (1.186-4.667), P = 0.014]. Microcalcification was more likely to be necrosis on MRI than those without microcalcification (53.0% vs 31.7%, P < 0.001), multivariate analysis indicated that tumor necrosis was also a risk factor for poor NACT response [OR = 2.325, 95%CI (1.100-4.911), P = 0.027]. Age, menopausal status, breast density, mass, molecular, and pathology type were not significantly associated with non-pCR risk assessment. In a multicenter cohort of 1182 patients with pathologically confirmed BC, those with microcalcifications had a higher proportion of bone metastases compared to non-calcified BC (11.6% vs 4.9%, P < 0.001). Univariate and multivariate analysis showed that microcalcification was an independent risk factor for bone metastasis [OR = 2.550, 95%CI (1.620-4.012), P < 0.001], [OR = 2.268(1.263-4.071), P = 0.006)]. Osteolytic bone metastases predominated but there was no statistical difference between the two groups (78.9% vs 60.7%, P = 0.099). Calcified BC was mainly involved in axial bone, but was more likely to involve the whole-body bone than non-calcified BC (33.8% vs 10.7%, P = 0.021).

CONCLUSION

This study provides important insights into the poor prognosis of microcalcification, not only in terms of poor response to NACT but also the risk factor of bone metastases.

ACR Appropriateness Criteria® Monitoring Response to Neoadjuvant Systemic Therapy for Breast Cancer: 2022 Update

Imaging plays a vital role in managing patients undergoing neoadjuvant chemotherapy, as treatment decisions rely heavily on accurate assessment of response to therapy. This document provides evidence-based guidelines for imaging breast cancer before, during, and after initiation of neoadjuvant chemotherapy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Correlation of Mammographic Microcalcifications with Final Surgical Pathology After Neoadjuvant Chemotherapy for Breast Cancer

INTRODUCTION

Imaging guidelines for post-neoadjuvant chemotherapy (NAC) breast cancer patients lack specificity on appropriateness and utility of individual modalities for surgical planning. Microcalcifications confound mammographic interpretation. We examined the correlation between the mammographic extent of microcalcifications present post-NAC, corresponding magnetic resonance imaging (MRI) lesions, and definitive surgical pathology.

METHODS

In this retrospective cohort study, patients with calcifications on mammography were collected from a database of consecutive breast cancer patients receiving NAC. The primary objective was to determine the correlation between maximum dimension of post-NAC calcifications with surgical pathology (invasive disease, tumor bed, and ductal carcinoma in situ [DCIS]), stratified by tumor receptor subgroup. Secondarily, we examined the correlation of residual disease with MRI mass enhancement (ME) and non-ME (NME). Pearson's correlation coefficient was used to evaluate statistical significance (strong: R² ≥70%; moderate: R²=25-70%; weak: R² ≤25%).

RESULTS

Overall, 186 patients met the inclusion criteria. Mammographic calcifications correlated poorly with invasive disease (R² = 10.8%), overestimating by 57%. In patients with calcifications on mammography, MRI ME and NME correlated weakly with the maximum dimension of invasive disease and DCIS. In triple-negative breast cancer (TNBC) patients, invasive disease correlated strongly with the maximum dimension of calcifications (R² = 83%) and moderately with ME (R² = 37.7%) and NME (R² = 28.4%).

CONCLUSION

Overall, current imaging techniques correlate poorly and overestimate final surgical pathology. This poor correlation may lead to uncertainty in the extent of required surgical excision and the exclusion of potential candidates for non-surgical management in ongoing trials. TNBCs would be good candidates for these trials given the stronger observed correlations between pathology and imaging.

Lymph node microcalcifications after neoadjuvant chemotherapy: A therapeutic response marker

Lymph node microcalcifications are rare events, and when they are accompanied by neoplasia, they usually seem to be associated with a metastatic condition. We present a case of a patient with breast cancer and lymph node microcalcifications undergoing neoadjuvant chemotherapy (NCT). A change in the calcification pattern towards becoming coarse was observed. Calcification represented a marker of axillary disease, and it was resected after NCT. This is the first report of a patient with lymph node microcalcification undergoing NCT. We observed a change in the calcification format, which facilitated lymph node sentinel identification. Pathological evaluation indicated metastatic disease.

Pathologic Response of Associated Ductal Carcinoma In Situ to Neoadjuvant Systemic Therapy: A Systematic Review

Contrary to traditional assumptions, recent evidence suggests that neoadjuvant systemic therapy (NST) given for invasive breast cancer may eradicate co-existent ductal carcinoma in-situ (DCIS), which may facilitate de-escalation of breast resections. The aim of this systematic review was to assess the eradication rate of DCIS by NST given for invasive breast cancer. Searches were performed in MEDLINE using appropriate search terms. Six studies (N = 659) in which pathological data were available regarding the presence of DCIS prior to neoadjuvant chemotherapy (NACT) were identified. Only one study investigating the impact of neoadjuvant endocrine therapy (NET) met the search criteria. After pooled analysis, post-NACT pathology showed no residual DCIS in 40.5% of patients (267/659; 95% CI: 36.8-44.3). There was no significant difference in DCIS eradication rate between triple negative breast cancer (TNBC) and HER2-positive disease (45% vs. 46% respectively). NET achieved eradication of DCIS in 15% of patients (9/59). Importantly, residual widespread micro-calcifications after NST did not necessarily indicate residual disease. In view of the results of the pooled analysis, the presence of extensive DCIS prior to NST should not mandate mastectomy and de-escalation to breast conserving surgery (BCS) should be considered in patients identified by contrast enhanced magnetic resonance imaging (CE-MRI).

The effectiveness and safety of neoadjuvant pertuzumab and trastuzumab in women with locally advanced, inflammatory, or early-stage human epidermal growth factor receptor 2-positive breast cancer: Turkish Oncology Group study

In our study, we aimed to evaluate the pathological response rates and side effect profile of adding pertuzumab to the treatment of HER2+ locally advanced, inflammatory, or early-stage breast cancer. This study was conducted by the Turkish Oncology Group (TOG) with data collected from 32 centers. Our study was multicentric, and a total of 364 patients were included. The median age of the patients was 49 years (18-85 years). Two hundred fifteen (60%) of the cases were hormone receptor/HER2+ positive(ER+ or PR+, or both), and 149 (40%) of them were HER2-rich (ER and PR negative). The number of complete responses was 124 (54%) in the docetaxel+trastuzumab+pertuzumab arm and 102 (45%) in the paclitaxel+trastuzumab+pertuzumab arm, and there was no difference between the groups in terms of complete response. In 226 (62%) patients with complete response, a significant correlation was found with DCIS, tumor focality, removed lymph node, and ER status P < 0.05. Anemia, nausea, vomiting, myalgia, alopecia, and mucosal inflammation were significantly higher in the docetaxel arm, P < 0.05. In our study, no statistical difference was found between the before-after echocardiography values. DCIS positivity in biopsy before neoadjuvant chemotherapy, tumor focality; the number of lymph nodes removed and ER status were found to be associated with pCR. In conclusion, we think that studies evaluating pCR-related clinicopathological variables and radiological imaging features will play a critical role in the development of nonsurgical treatment approaches.

The percentage of residual DCIS in patients diagnosed with primary invasive breast cancer treated with neoadjuvant systemic therapy: A nationwide retrospective study

INTRODUCTION

Neoadjuvant systemic therapy (NST) is increasingly applied in breast cancer to improve surgical and oncological outcome. Approximately 21% of patients receiving NST achieve pathological complete response (pCR) of the breast. There is disagreement on the definition of pCR with respect to residual DCIS (ypT0 versus ypT0/is). The aim of this retrospective study was to determine the percentage of breast pCR (ypT0) and residual DCIS (ypTis), and its association with clinicopathological variables, in patients treated with NST and surgery.

MATERIALS AND METHODS

Patients with invasive breast cancer treated with neoadjuvant chemotherapy, with or without targeted therapy, in the period of 2010-2019 were selected from the Netherlands Cancer Registry (NCR). Descriptive statistics and multivariable logistic regression analyses were used to analyse the percentage of ypT0 and ypTis and its association with clinicopathological variables.

RESULTS

From the NCR database, 20495 patients were included, of whom 5847 (28.5%) achieved breast pCR (ypT0) and 881 (4.3%) showed residual DCIS (ypTis). The percentage of ypTis was highest in HER2+ tumour subtypes (ER+HER2+ 7.9%, ER-HER2+ 9.8%, ER+HER2- 2.1%, triple negative 3.3%, p < 0.001). Multivariable logistic regression analyses demonstrated high tumour grade (OR 2.00, p = 0.003) and HER2+ tumour subtype (ER+HER2+ OR 3.58, ER-HER2+ OR 4.37, p < 0.001) as independent predictors for ypTis.

CONCLUSION

pCR (ypT0) was achieved in 5847 (28.5%) patients receiving NST and residual DCIS (ypTis) was found in 881 (4.3%) patients. Consequently, the rate of pCR may be affected by ypTis when not excluded from the definition. The percentage of ypTis is highest in HER2+ subtypes.

Pathologic response of ductal carcinoma in situ to neoadjuvant systemic treatment in HER2-positive breast cancer

Purpose

The presence of extensive ductal carcinoma in situ (DCIS) adjacent to HER2-positive invasive breast cancer (IBC) is often a contra-indication for breast-conserving surgery, even in case of excellent treatment response of the invasive component. Data on the response of DCIS to neoadjuvant systemic treatment (NST) are limited. Therefore, we estimated the response of adjacent DCIS to NST-containing HER2-blockade in HER2-positive breast cancer patients and assessed the association of clinicopathological and radiological factors with response.

Methods

Pre-NST biopsies were examined to determine presence of DCIS in all women with HER2-positive IBC treated with trastuzumab-containing NST ± pertuzumab between 2004 and 2017 in a comprehensive cancer center. When present, multiple DCIS factors, including grade, calcifications, necrosis, hormone receptor, and Ki-67 expression, were scored. Associations of clinicopathological and radiological factors with complete response were assessed using logistic regression models.

Results

Adjacent DCIS, observed in 138/316 patients with HER2-positive IBC, was eradicated after NST in 46% of patients. Absence of calcifications suspicious for malignancy on pre-NST mammography (odds ratio (OR) 3.75; 95% confidence interval (95% CI) 1.72–8.17), treatment with dual HER2-blockade (OR 2.36; 95% CI 1.17–4.75), a (near) complete response on MRI (OR 3.55; 95% CI 1.31–9.64), and absence of calcifications (OR 3.19; 95% CI 1.34–7.60) and Ki-67 > 20% in DCIS (OR 2.74; 95% CI 1.09–6.89) on pre-NST biopsy were significantly associated with DCIS response.

Conclusions

As DCIS can respond to NST containing HER2-blockade, the presence of extensive DCIS in HER2-positive breast cancer before NST should not always indicate a mastectomy. The predictive factors we found could be helpful when considering breast-conserving surgery in these patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-021-06235-2.

The Presence of an In Situ Component on Pre-Treatment Biopsy Is Not Associated with Response to Neoadjuvant Chemotherapy for Breast Cancer

Simple Summary

Identifying markers predictive of response and resistance to neoadjuvant chemotherapy (NAC) has become a major research objective. Ductal carcinoma in situ (DCIS) is associated with invasive disease in more than half of invasive breast cancer cases. It is generally assumed that DCIS does not respond to NAC, but the effect of chemotherapy on in situ components has been little studied. We assessed the predictive value of the presence of an in situ component on pre-NAC biopsy on pathological complete response (pCR) in a real-life cohort of patients treated by NAC. We included 1148 patients; 44% of tumors were luminal (n = 508), 31% triple negative breast cancer (TNBC) (n = 359) and 24% HER2-positive (n = 281). DCIS was found in 225 samples (19.6%) before NAC. The presence of a DCIS component on pre-NAC biopsy was not associated with pCR and did not seem to be a critical factor for the prediction of response to NAC.

Abstract

A ductal in situ (DCIS) component is often associated with invasive breast carcinoma (BC), and its effect on response to treatment is unknown. We assessed the predictive value of the DCIS component for pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC). We analyzed a cohort of 1148 T1–3NxM0 breast cancer (BC) patients treated by NAC at Institut Curie between 2002 and 2012. The presence of a DCIS component was retrospectively recorded from both the pre-NAC biopsy pathological report and surgical specimens. We included 1148 BC patients treated by NAC for whom pre- and post-NAC data concerning the in situ component were available. DCIS was present before NAC in 19.6% of the population. Overall, 283 patients (19.4%) achieved pCR after NAC. There was no significant association between the presence of DCIS on pre-NAC biopsy and pCR. In a multivariate analysis including subtype, tumor size, grade, mitotic index, and Ki67 index, only BC subtype (luminal/TNBC/HER2-positive) and Ki67 were significantly associated with pCR. The presence of a DCIS component on pre-NAC biopsy is not associated with pCR and does not seem to be a critical factor for predicting response to NAC.

Surgical Management of Breast Cancer Treated with Neoadjuvant Therapy

Neoadjuvant therapy (NAT) allows downstaging in some cases of breast cancer. By consequence, it may enable a more conservative surgical approach or make surgery possible in cases ineligible for surgery before NAT. In this article, we review the evidence and management recommendations for optimal surgical treatment in this setting.