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

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.

The effect of neoadjuvant chemotherapy on ductal carcinoma in situ in triple-negative breast cancer patients: A nationwide analysis

PURPOSE

Recent studies show that ductal carcinoma in situ (DCIS) accompanying HER2+ breast cancer can be completely eradicated following neoadjuvant systemic therapy in up to 52 %. We aimed to determine the complete response rate of DCIS in triple-negative breast cancer (TNBC) patients in a nationwide cohort and to assess clinicopathological variables associated with response. Furthermore, the impact on surgical treatment after neoadjuvant chemotherapy (NACT) was investigated.

METHODS

Women diagnosed with TNBC, treated with NACT followed by surgery, between 2010 and 2020, were selected from the Netherlands Cancer Registry (NCR). Pre-NACT and postoperative pathology reports were obtained from Palga, the Dutch nationwide pathology databank, to determine presence of DCIS. Clinicopathological factors associated with DCIS response were investigated using uni- and multivariable logistic regression analysis.

RESULTS

In total, 4494 patients were included. A DCIS component was present in the pre-NACT biopsy of 442 (9.8 %) patients. Pathologic complete response of the DCIS component was achieved in 53.6 % of these patients. The presence of calcifications in the pre-NACT biopsy was associated with a lower chance of DCIS response in univariable logistic regression analysis (OR 0.52, CI 95 % 0.27-0.98, p = 0.04). In multivariable analysis, no statistically significant associations were found between DCIS response and clinicopathological variables. Mastectomy rates were higher in case of IBC + DCIS compared to IBC (53.4 % vs 40.1 %, p < 0.001).

CONCLUSION

Pathologic complete response of DCIS to NACT occurred in 53.6 % of TNBC patients. Future studies are required to be able to predict DCIS response based on clinicopathological variables and imaging.

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.

Surgical treatment after neoadjuvant systemic therapy for HER2-positive invasive breast cancer in the Netherlands: 10-Year trends and the influence an accompanying DCIS component

BACKGROUND

The presence of a DCIS component accompanying invasive breast cancer (IBC) is associated with a higher rate of primary mastectomy compared to IBC without DCIS. After neoadjuvant systemic therapy (NST), HER2+ IBC patients show high response rates, allowing for increasing breast-conserving surgery rates. The aim of this study was to examine surgical trends after NST in a Dutch nationwide HER2+ cohort, and the influence of a DCIS component on mastectomy rate.

METHODS

Women with HER2+ IBC, diagnosed between 2010 and 2019 and treated with NST and surgery were included from the Netherlands Cancer Registry. Mastectomy rate was examined over the years, and compared between patients with and without a DCIS component in the pre-NST biopsy. Multivariable logistic regression analysis was used to investigate the association of the DCIS component with mastectomy rate and likelihood of achieving ypT0.

RESULTS

In total, 5289 patients were included. Over 10 years, mastectomy rate significantly decreased from 62.6 % in 2010 to 35.1 % in 2019. Patients with IBC+DCIS more often underwent mastectomy, with a rate of 48.4 % in 2019, compared to 30.0 % in IBC only (p < 0.001). Percentage of ypT0 was significantly lower in patients with IBC+DCIS (38.7 %), compared to IBC only (47.3 %, p < 0.001) Multivariable logistic regression analyses showed presence of DCIS (OR 1.69, 95%CI 1.47-1.95, p < 0.001) to be independently associated with mastectomy.

CONCLUSION

Rate of mastectomy decreased significantly in HER2+ IBC treated with NST between 2010 and 2019. Presence of DCIS in the biopsy remained associated with higher mastectomy rate, yet 38.7 % of these patients do achieve ypT0.

Comparing core needle biopsy and surgical excision in breast cancer diagnosis: implications for clinical practice from a retrospective cohort study

BACKGROUND

Preoperative ultrasound-guided core needle biopsy (CNB) is currently the standard procedure for managing breast illnesses. However, the differences in outcomes between CNB and surgical excision (SE) have not been thoroughly assessed. This study aimed to explore the disparities in pathological outcomes between these two procedures, using a large sample dataset.

METHODS

This retrospective study consecutively included patients who underwent CNB and SE at Shenzhen People's Hospital from May 2016 to June 2023. Immunohistochemistry (IHC) was utilized to determine the status of estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor-2 (HER2), and Ki-67. Patients presenting with HER2 IHC 2+ underwent additional fluorescence in situ hybridization (FISH) examination. The cutoff value for high Ki-67 expression was established at 14%. Molecular subtypes were classified into four groups (Luminal A, Luminal B, Triple-negative, and HER2-positive) and five groups [Luminal A, Luminal B+ (HER2-positive), Luminal B- (HER2-negative), Triple-negative, and HER2-positive], based on different criteria.

RESULTS

A total of 4,209 patients were included in this study. Post-surgical confirmation revealed 2,410 cases as benign and 1,799 as malignant. Among the malignant cases, 334 were excluded due to either not having undergone direct surgery or having incomplete IHC results. The remaining 1,465 cases underwent IHC testing. CNB demonstrated a 97% concordance rate (CR) in diagnosing benign cases. The CRs for diagnosing invasive breast cancer (IBC) and carcinoma in situ (CIS) were 92% and 54%, respectively. ER, PgR, HER2, and Ki-67 exhibited CRs of 94%, 91%, 98%, and 84%, respectively. In the four-group classification, the overall diagnostic CR was 82%, with CRs for Luminal A, Luminal B, HER2-positive, and triple-negative breast cancer (TNBC) being 84%, 82%, 78%, and 85%, respectively. Under the five-group classification, the overall diagnostic CR was also 82%, with CRs for Luminal A, Luminal B+, Luminal B-, HER2-positive, and TNBC being 86%, 85%, 94%, 88%, and 92%, respectively.

CONCLUSIONS

This study demonstrates that CNB is highly accurate in differentiating benign from malignant breast lesions, particularly showing significant consistency in the diagnosis of molecular subtypes, providing a reliable reference for clinical diagnosis.

Initial MRI findings predictive of a pathological complete response to neoadjuvant treatments in HER2-positive breast cancers

PURPOSE

This study aimed to determine if initial MRI findings could predict a pathological complete response (pCR) following neoadjuvant systemic therapy (NST) in HER2-positive breast cancers.

METHODS

The study retrospectively included 111 patients (Center 1, training set) and 71 patients (Center 2, validation set) with HER2-positive cancer who underwent NST. Initial clinicopathological data and MRI findings were recorded. Continuous variables were analyzed using the Mann-Whitney and Student's t-tests, while categorical variables were analyzed using the χ2 or Fisher's exact test. Univariate analysis was conducted to determine the associations between these variables and pathological complete response (pCR), defined as the absence of invasive malignant cells in the breast and lymph nodes. Interobserver reproducibility was assessed for associated non-mass enhancement (NME) parameter by analyzing 50 MR studies (intraclass correlation coefficient).

RESULTS

pCR was achieved in 67 patients, 51 (46 %) from Center 1 and 16 (23%) from Center 2 (p = 0.003), with significant differences between Centers 1 and 2 in tumor-infiltrating lymphocyte levels and lymphovascular invasion (p < 0.001). The initial presence of suspicious associated NME was the only significant parameter predictive of pCR (p < 0.001 for Center 1 and 0.04 for Center 2). The inter-observer reproducibility for this MRI feature was good, with an intraclass correlation coefficient of 0.872 (95 % CI: 0.73-1.00).

CONCLUSION

The presence of suspicious associated NME in HER2-positive cancers on the initial MRI study was predictive of achieving pCR after NST. This significant preliminary finding warrants confirmation through prospective multicenter studies.

Surgical outcomes and prognosis of HER2+ invasive breast cancer patients with a DCIS component treated with breast-conserving surgery after neoadjuvant systemic therapy

INTRODUCTION

In up to 72 % of HER2+ invasive breast cancer (IBC), a ductal carcinoma in situ (DCIS) component is present. The presence of DCIS is associated with increased positive surgical margins after breast-conserving surgery (BCS). The aim of this study was to assess surgical margins, recurrence and survival in a nationwide cohort of HER2+ IBC with versus without a DCIS component, treated with neoadjuvant systemic therapy (NST) and BCS.

MATERIALS AND METHODS

Women diagnosed with HER2+ IBC treated with NST and BCS, between 2010 and 2019, were selected from the Netherlands Cancer Registry and linked to the Dutch Nationwide Pathology Databank. Kaplan-Meier and Cox regression analyses were performed to determine locoregional recurrence rate (LRR) and overall survival (OS) and associated clinicopathological variables. Surgical outcomes and prognosis were compared between IBC only and IBC+DCIS.

RESULTS

A total of 3056 patients were included: 1832 with IBC and 1224 with IBC+DCIS. Patients with IBC+DCIS had significantly more often positive surgical margins compared to IBC (12.8 % versus 4.9 %, p < 0.001). Five-year LRR was significantly higher in patients with IBC+DCIS compared to IBC (6.8 % versus 3.6 %, p < 0.001), but the presence of DCIS itself was not significantly associated with LRR after adjusting for confounders in multivariable analysis. Five-year OS did not differ between IBC+DCIS and IBC (94.9 % versus 95.7 %, p = 0.293).

CONCLUSION

The presence of DCIS is associated with higher rates of positive surgical margins, but not with LRR and lower OS when adjusted for confounders. Further research is necessary to adequately select IBC+DCIS patients for BCS after NST.

A model combining BI-RADS® descriptors from pre-treatment B-mode breast ultrasound with clinicopathological tumor features shows promise in the prediction of residual disease after neoadjuvant chemotherapy

PURPOSE

To create a simple model using standard BI-RADS® descriptors from pre-treatment B-mode ultrasound (US) combined with clinicopathological tumor features, and to assess the potential of the model to predict the presence of residual tumor after neoadjuvant chemotherapy (NAC) in breast cancer (BC) patients.

METHOD

245 female BC patients receiving NAC between January 2017 and December 2019 were included in this retrospective study. Two breast imaging fellows independently evaluated representative B-mode tumor images from baseline US. Additional clinicopathological tumor features were retrieved. The dataset was split into 170 training and 83 validation cases. Logistic regression was used in the training set to identify independent predictors of residual disease post NAC and to create a model, whose performance was evaluated by ROC curve analysis in the validation set. The reference standard was postoperative histology to determine the absence (pathological complete response, pCR) or presence (non-pCR) of residual invasive tumor in the breast or axillary lymph nodes.

RESULTS

100 patients (40.8%) achieved pCR. Logistic regression demonstrated that tumor size, microlobulated margin, spiculated margin, the presence of calcifications, the presence of edema, HER2-positive molecular subtype, and triple-negative molecular subtype were independent predictors of residual disease. A model using these parameters demonstrated an area under the ROC curve of 0.873 in the training and 0.720 in the validation set for the prediction of residual tumor post NAC.

CONCLUSIONS

A simple model combining standard BI-RADS® descriptors from pre-treatment B-mode breast US with clinicopathological tumor features predicts the presence of residual disease after NAC.

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.

Pathologic complete response of ductal carcinoma in situ to neoadjuvant systemic therapy in HER2-positive invasive breast cancer patients: a nationwide analysis

PURPOSE

Ductal carcinoma in situ (DCIS) is present in more than half of HER2-positive invasive breast cancer (IBC). Recent studies show that DCIS accompanying HER2-positive IBC can be completely eradicated by neoadjuvant systemic therapy (NST). Our aim was to determine the percentage of pathologic complete response of the DCIS component in a nationwide cohort and to assess associated clinicopathologic variables. Furthermore, the impact on surgical treatment after NST was investigated.

METHODS

Women diagnosed with HER2-positive IBC, treated with NST and surgery, between 2010 and 2020, were selected from the Netherlands Cancer Registry. Pre-NST biopsy and postoperative pathology reports were obtained from the Dutch Nationwide Pathology Databank and assessed for the presence of DCIS. Clinicopathologic factors associated with DCIS response were assessed using logistic regression analyses.

RESULTS

A DCIS component was present in the pre-NST biopsy in 1403 (25.1%) of 5598 included patients. Pathologic complete response of the DCIS component was achieved in 730 patients (52.0%). Complete response of DCIS occurred more frequently in case of complete response of IBC (63.4% versus 33.8%, p < 0.001). ER-negative IBC (OR 1.79; 95%CI 1.33-2.42) and more recent years of diagnosis (2014-2016 OR 1.60; 95%CI 1.17-2.19, 2017-2019 OR 1.76; 95%CI 1.34-2.34) were associated with DCIS response. Mastectomy rates were higher in IBC+DCIS compared to IBC (53.6% versus 41.0%, p < 0.001).

CONCLUSION

Pathologic complete response of DCIS occurred in 52.0% of HER2-positive IBC patients and was associated with ER-negative IBC and more recent years of diagnosis. Future studies should investigate imaging evaluation of DCIS response to improve surgical decision making.

Initial Results of 68Ga-FAPI-46 PET/MRI to Assess Response to Neoadjuvant Chemotherapy in Breast Cancer

Improving imaging-based response after neoadjuvant chemotherapy (NAC) in breast cancer assessment could obviate histologic confirmation of pathologic complete response (pCR) and facilitate deescalation of chemotherapy or surgery. Fibroblast activation protein inhibitor (FAPI) PET/MRI is a promising novel molecular imaging agent for the tumor microenvironment with intense uptake in breast cancer. We assessed the diagnostic performance of follow-up breast 68Ga-FAPI-46 (68Ga-FAPI) PET/MRI in classifying the response status of local breast cancer and lymph node metastases after completion of NAC and validated this approach immunohistochemically. Methods: In women who completed NAC for invasive breast cancer, follow-up 68Ga-FAPI PET/MRI and corresponding fibroblast activation protein (FAP) immunostainings were retrospectively analyzed. Metrics of 68Ga-FAPI uptake and FAP immunoreactivity in women with or without pCR were compared using the Mann-Whitney U test. Diagnostic performance to detect remnant invasive cancer was calculated for tracer uptake metrics using receiver-operating-characteristic curves and for masked readers' visual assessment categories of PET/MRI and MRI alone. Results: Thirteen women (mean age ± SD, 47 ± 9 y) were evaluated. Seven of the 13 achieved pCR in the breast and 6 in the axilla. FAP immunoreactivity was significantly associated with response status. The 68Ga-FAPI PET/MRI mean breast tumor-to-background ratio was 0.9 (range, 0.6-1.2) for pCR and 2.1 (range, 1.4-3.1) for no pCR (P = 0.001). Integrated PET/MRI could classify breast response correctly in all 13 women based on readers' visual assessment or tumor-to-background ratio. Evaluation of MRI alone resulted in at least 2 false-positives. For lymph nodes, PET/MRI readers had at least 2 false-negative classifications, whereas MRI alone resulted in 2 false-negatives and 1 false-positive. Conclusion: To our knowledge, this was the first analysis of 68Ga-FAPI PET/MRI for response assessment after NAC for breast cancer. The diagnostic performance of PET/MRI in a small study sample trended toward a gain over MRI alone, clearly supporting future prospective studies.

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).