Quality assurance of radiation therapy after breast-conserving surgery among patients in the BOOG 2013-08 trial

BACKGROUND AND PURPOSE

In the BOOG 2013-08 trial (NCT02271828), cT1-2N0 breast cancer patients were randomized between breast conserving surgery with or without sentinel lymph node biopsy (SLNB) followed by whole breast radiotherapy (WBRT). While awaiting primary endpoint results (axillary recurrence rate), this study aims to perform a quality assurance analysis on protocol adherence and (incidental) axillary radiation therapy (RT) dose.

MATERIALS AND METHODS

Patients were enrolled between 2015 and 2022. Data on prescribed RT and (in 25% of included patients) planning target volumes (PTV) parameters were recorded for axillary levels I-IV and compared between treatment arms. Multivariable linear regression analysis was performed to determine prognostic variables for incidental axillary RT dose.

RESULTS

1,439/1,461 included patients (98.5%) were treated according to protocol and 87 patients (5.9%) received regional RT (SLNB 10.9%, no-SLNB 1.5 %). In 326 patients included in the subgroup analysis, the mean incidental PTV dose at axilla level I was 59.5% of the prescribed breast RT dose. In 5 patients (1.5%) the mean PTV dose at level I was ≥95% of the prescribed breast dose. No statistically or clinically significant differences regarding incidental axillary RT dose were found between treatment arms. Tumour bed boost (yes/no) was associated with a higher incidental mean dose in level I (R2 = 0.035, F(6, 263) = 1.532, p 0.168).

CONCLUSION

The results indicate that RT-protocol adherence was high, and that incidental axillary RT dose was low in the BOOG 2013-08 trial. Potential differences between treatmentarms regarding the primary endpoint can thus not be attributed to different axillary radiation doses.

Gene expression profiles in clinically T1-2N0 ER+HER2- breast cancer patients treated with breast-conserving therapy: their added value in case sentinel lymph node biopsy is not performed

PURPOSE

Omitting sentinel lymph node biopsy (SLNB) in breast cancer treatment results in patients with unknown positive nodal status and potential risk for systemic undertreatment. This study aimed to investigate whether gene expression profiles (GEPs) can lower this risk in cT1-2N0 ER+ HER2- breast cancer patients treated with BCT.

METHODS

Patients were included if diagnosed between 2011 and 2017 with cT1-2N0 ER+ HER2- breast cancer, treated with BCT and SLNB, and in whom GEP was applied. Adjuvant chemotherapy recommendations based on clinical risk status (Dutch breast cancer guideline of 2020 versus PREDICT v2.1) with and without knowledge on SLNB outcome were compared to GEP outcome. We examined missing adjuvant chemotherapy indications, and the number of GEPs needed to identify one patient at risk for systemic undertreatment.

RESULTS

Of 3585 patients, 2863 (79.9%) had pN0 and 722 (20.1%) pN + disease. Chemotherapy was recommended in 1354 (37.8% guideline-2020) and 1888 patients (52.7% PREDICT). Eliminating SLNB outcome (n = 722) resulted in omission of chemotherapy recommendation in 475 (35.1% guideline-2020) and 412 patients (21.8% PREDICT). GEP revealed genomic high risk in 126 (26.5% guideline-2020) and 82 patients (19.9% PREDICT) in case of omitted chemotherapy recommendation in the absence of SLNB. Extrapolated to the whole group, this concerns 3.5% and 2.3%, respectively, resulting in the need for 28-44 GEPs to identify one patient at risk for systemic undertreatment.

CONCLUSION

If no SLNB is performed, clinical risk status according to the guideline of 2020 and PREDICT predicts a very low risk for systemic undertreatment. The number of GEPs needed to identify one patient at risk for undertreatment does not justify its standard use.

Axillary lymph node response to neoadjuvant systemic therapy with dedicated axillary hybrid 18F-FDG PET/MRI in clinically node-positive breast cancer patients: a pilot study

AIM

To investigate the diagnostic performance of dedicated axillary hybrid ¹⁸F-2-[¹⁸F]-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET)/magnetic resonance imaging (MRI) in detecting axillary pathological complete response (pCR) following neoadjuvant systemic therapy (NST) in clinically node-positive breast cancer patients.

MATERIALS AND METHODS

Ten prospectively included clinically node-positive breast cancer patients underwent dedicated axillary hybrid ¹⁸F-FDG PET/MRI after completing NST followed by axillary surgery. PET images were reviewed by a nuclear medicine physician and coronal T1-weighted and T2-weighted MRI images by a radiologist. All axillary lymph nodes visible on PET/MRI were matched with those removed during axillary surgery. Diagnostic performance parameters were calculated based on patient-by-patient and node-by-node validation with histopathology of the axillary surgical specimen as the reference standard.

RESULTS

Six patients achieved axillary pCR at final histopathology. A total of 84 surgically harvested axillary lymph nodes were matched with axillary lymph nodes depicted on PET/MRI. Histopathological examination of the matched axillary lymph nodes resulted in 10 lymph nodes with residual axillary disease of which eight contained macrometastases and two micrometastases. The patient-by-patient analysis yielded a sensitivity, specificity, positive predictive value, and negative predictive value of 25%, 100%, 100%, and 67%, respectively. The diagnostic performance parameters of the node-by-node analysis were 0%, 96%, 0%, and 88%, respectively. Excluding micrometastases from the node-by-node analysis increased the negative predictive value to 90%.

CONCLUSION

This pilot study suggests that the negative predictive value and sensitivity of dedicated axillary ¹⁸F-FDG PET/MRI are insufficiently accurate to detect axillary pCR or exclude residual axillary disease following NST in clinically node-positive breast cancer patients.

Test-Retest Data for the Assessment of Breast MRI Radiomic Feature Repeatability

Background

Radiomic features extracted from breast MRI have potential for diagnostic, prognostic, and predictive purposes. However, before they can be used as biomarkers in clinical decision support systems, features need to be repeatable and reproducible.

Objective

Identify repeatable radiomics features within breast tissue on prospectively collected MRI exams through multiple test–retest measurements.

Study Type

Prospective.

Population

11 healthy female volunteers.

Field Strength/Sequence

1.5 T; MRI exams, comprising T2‐weighted turbo spin‐echo (T2W) sequence, native T1‐weighted turbo gradient‐echo (T1W) sequence, diffusion‐weighted imaging (DWI) sequence using b‐values 0/150/800, and corresponding derived ADC maps.

Assessment

18 MRI exams (three test–retest settings, repeated on 2 days) per healthy volunteer were examined on an identical scanner using a fixed clinical breast protocol. For each scan, 91 features were extracted from the 3D manually segmented right breast using Pyradiomics, before and after image preprocessing. Image preprocessing consisted of 1) bias field correction (BFC); 2) z‐score normalization with and without BFC; 3) grayscale discretization using 32 and 64 bins with and without BFC; and 4) z‐score normalization + grayscale discretization using 32 and 64 bins with and without BFC.

Statistical Tests

Features' repeatability was assessed using concordance correlation coefficient(CCC) for each pair, i.e. each MRI was compared to each of the remaining 17 MRI with a cut‐off value of CCC > 0.90.

Results

Images without preprocessing produced the highest number of repeatable features for both T1W sequence and ADC maps with 15 of 91 (16.5%) and 8 of 91 (8.8%) repeatable features, respectively. Preprocessed images produced between 4 of 91 (4.4%) and 14 of 91 (15.4%), and 6 of 91 (6.6%) and 7 of 91 (7.7%) repeatable features, respectively for T1W and ADC maps. Z‐score normalization produced highest number of repeatable features, 26 of 91 (28.6%) in T2W sequences, in these images, no preprocessing produced 11 of 91 (12.1%) repeatable features.

Data Conclusion

Radiomic features extracted from T1W, T2W sequences and ADC maps from breast MRI exams showed a varying number of repeatable features, depending on the sequence. Effects of different preprocessing procedures on repeatability of features were different for each sequence.

Level of Evidence

2

Technical Efficacy Stage

1

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.

Conditional local recurrence risk: the effect of event-free years in different subtypes of breast cancer

Background

After breast cancer treatment, follow-up consists of physical examination and mammography for at least 5 years, to detect local and regional recurrence. The risk of recurrence may decrease after event-free time. This study aims to determine the risk of local recurrence (LR) as a first event until 5 years after diagnosis, conditional on being event-free for 1, 2, 3 and 4 years.

Methods

From the Netherlands Cancer Registry, all M0 breast cancers diagnosed between 2005 and 2008 were included. LR risk was calculated with Kaplan–Meier analysis, overall and for different subtypes. Conditional LR (assuming x event-free years) was determined by selecting event-free patients at x years, and calculating their LR risk within 5 years after diagnosis.

Results

Five-year follow-up was available for 34,453 patients. Overall, five-year LR as a first event occurred in 3.0%. This risk varied for different subtypes and was highest for triple negative (6.8%) and lowest for ER+PR+Her2− (2.2%) tumors. After 1, 2, 3 and 4 event-free years, the average risk of LR before 5 years after diagnosis decreased from 3.0 to 2.4, 1.6, 1.0, and 0.6%. The risk decreased in all subtypes, the effect was most pronounced in subtypes with the highest baseline risk (ER−Her2+ and triple negative breast cancer). After three event-free years, LR risk in the next 2 years was 1% or less in all subtypes except triple negative (1.6%).

Conclusion

The risk of 5-year LR as a first event was low and decreased with the number of event-free years. After three event-free years, the overall risk was 1%. This is reassuring to patients and also suggests that follow-up beyond 3 years may produce low yield of LR, both for individual patients and studies using LR as primary outcome. This can be used as a starting point to tailor follow-up to individual needs.

Elicitation of preferences in the second half of the shared decision making process needs attention; a qualitative study

BACKGROUND

It is known that the use of a Patient Decision Aid (PtDA), combined with advice for professionals on how and when to use it, can enhance the involvement of patients in the treatment decision. However, we need more knowledge with respect to the intention-behaviour gap. This study aims to analyse patients' experiences with the Shared Decision Making (SDM) process to find clues to close this gap.

METHODS

This qualitative study was part of a pilot study aiming to implement SDM in early adopter breast cancer teams. Patients were given access to a personalised PtDA. Breast cancer teams were instructed on how and when to deliver the PtDA. We interviewed 20 patients about their experience with the PtDA and SDM in general.

RESULTS

Most patients experienced SDM, though to a certain extent. Choice talk and option talk were commonly experienced, however the elicitation of preferences and decision talk was rare. The PtDA was used by the majority of patients (N = 13), all indicating that it was useful, especially to recall all the information given. Patients appreciated the contribution of breast cancer nurses in the SDM process. They considered them as true case managers, easy to approach and supportive.

CONCLUSION

Although patients felt well-informed and satisfied about risk-communication, the elicitation of preferences appeared very limited to non-existent. We recommend that breast cancer teams divide tasks in the SDM process and reallocate the elicitation of preferences to the nurses in a well-defined clinical pathway.

Diagnostic performance of axillary ultrasound and standard breast MRI for differentiation between limited and advanced axillary nodal disease in clinically node-positive breast cancer patients

Preoperative differentiation between limited (pN1; 1–3 axillary metastases) and advanced (pN2–3; ≥4 axillary metastases) nodal disease can provide relevant information regarding surgical planning and guiding adjuvant radiation therapy. The aim was to evaluate the diagnostic performance of preoperative axillary ultrasound (US) and breast MRI for differentiation between pN1 and pN2–3 in clinically node-positive breast cancer. A total of 49 patients were included with axillary metastasis confirmed by US-guided tissue sampling. All had undergone breast MRI between 2008–2014 and subsequent axillary lymph node dissection. Unenhanced T2-weighted MRI exams were reviewed by two radiologists independently. Each lymph node on the MRI exams was scored using a confidence scale (0–4) and compared with histopathology. Diagnostic performance parameters were calculated for differentiation between pN1 and pN2–3. Interobserver agreement was determined using Cohen’s kappa coefficient. At final histopathology, 67.3% (33/49) and 32.7% (16/49) of patients were pN1 and pN2–3, respectively. Breast MRI was comparable to US in terms of accuracy (MRI reader 1 vs US, 71.4% vs 69.4%, p = 0.99; MRI reader 2 vs US, 73.5% vs 69.4%, p = 0.77). In the case of 1–3 suspicious lymph nodes, pN2–3 was observed in 30.4% on US (positive predictive value (PPV) 69.6%) and in 22.2–24.3% on MRI (PPV 75.7–77.8%). In the case of ≥4 suspicious lymph nodes, pN1 was observed in 33.3% on US (negative predictive value (NPV) 66.7%) and in 38.5–41.7% on MRI (NPV 58.3–61.5%). Interobserver agreement was considered good (k = 0.73). In clinically node-positive patients, the diagnostic performance of axillary US and breast MRI is comparable and limited for accurate differentiation between pN1 and pN2–3. Therefore, there seems no added clinical value of preoperative breast MRI regarding nodal staging in patients with positive axillary US.

Excision of both pretreatment marked positive nodes and sentinel nodes improves axillary staging after neoadjuvant systemic therapy in breast cancer

BACKGROUND

Marking the axilla with radioactive iodine seed and sentinel lymph node (SLN) biopsy have been proposed for axillary staging after neoadjuvant systemic therapy in clinically node-positive breast cancer. This study evaluated the identification rate and detection of residual disease with combined excision of pretreatment-positive marked lymph nodes (MLNs) together with SLNs.

METHODS

This was a multicentre retrospective analysis of patients with clinically node-positive breast cancer undergoing neoadjuvant systemic therapy and the combination procedure (with or without axillary lymph node dissection). The identification rate and detection of axillary residual disease were calculated for the combination procedure, and for MLNs and SLNs separately.

RESULTS

At least one MLN and/or SLN(s) were identified by the combination procedure in 138 of 139 patients (identification rate 99·3 per cent). The identification rate was 92·8 per cent for MLNs alone and 87·8 per cent for SLNs alone. In 88 of 139 patients (63·3 per cent) residual axillary disease was detected by the combination procedure. Residual disease was shown only in the MLN in 20 of 88 patients (23 per cent) and only in the SLN in ten of 88 (11 per cent), whereas both the MLN and SLN contained residual disease in the remainder (58 of 88, 66 per cent).

CONCLUSION

Excision of the pretreatment-positive MLN together with SLNs after neoadjuvant systemic therapy in patients with clinically node-positive disease resulted in a higher identification rate and improved detection of residual axillary disease.

Contrast-enhanced spectral mammography in the evaluation of breast suspicious calcifications: diagnostic accuracy and impact on surgical management

Background

Detecting pathological breast calcifications remains challenging. Based on recent studies, contrast-enhanced spectral mammography (CESM) was shown to be superior compared to full-field digital mammography (FFDM).

Purpose

To evaluate the diagnostic accuracy of CESM in suspicious breast calcifications and its impact on surgical decision-making.

Material and Methods

All screening recalled patients with suspicious calcifications that underwent CESM in the period October 2012 until September 2015 were included. One experienced radiologist provided a BI-RADS classification for the FFDM images only. The evaluation was repeated for the CESM exam. In a simulated tumor board meeting, two breast surgeons decided on the preferred surgical treatment (breast conservation therapy [BCT] versus mastectomy) for all malignant cases. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated defining BI-RADS ≥4 as being malignant. In addition, differences in surgical decision-making were analyzed and compared using McNemar’s test.

Results

In total, 147 women were included in this study (mean age = 61 years; age range = 49–75 years). Pathology showed 82 benign and 65 malignant lesions, of which 33 were ductal carcinomas in situ and 32 were invasive lesions. Diagnostic performances of CESM (differences compared to FFDM in brackets) were: sensitivity 93.8% (+3%), specificity 36.6% (−2.5%), PPV 54% (0%), and NPV 88.2% (+4%). Based on low-energy images, surgeons suggested BCT in 89% of the cases. Based on the CESM exam, no statistical changes in decisions were observed (86% BCT, P = 0.453).

Conclusion

CESM only slightly improves the diagnostic accuracy of the evaluation of breast calcifications. It is not of added value compared to FFDM in guiding surgical decision-making.

Risk of Positive Sentinel Lymph Node After Neoadjuvant Systemic Therapy in Clinically Node-Negative Breast Cancer: Implications for Postmastectomy Radiation Therapy and Immediate Breast Reconstruction

Background

Residual axillary lymph node involvement after neoadjuvant systemic therapy (NST) is the determining factor for postmastectomy radiation therapy (PMRT). Preoperative identification of patients needing PMRT is essential to enable shared decision-making when choosing the optimal timing of breast reconstruction. We determined the risk of positive sentinel lymph node (SLN) after NST in clinically node-negative (cN0) breast cancer.

Methods

All cT1-3N0 patients treated with NST followed by mastectomy and SLNB between 2010 and 2016 were identified from the Netherlands Cancer Registry. Rate of positive SLN for different breast cancer subtypes was determined. Logistic regression analysis was performed to determine correlated clinicopathological variables with positive SLN.

Results

In total 788 patients were included, of whom 25.0% (197/788) had positive SLN. cT1-3N0 ER+HER2+, cT1-3N0 ER−HER2+ , and cT1-2N0 triple-negative patients had the lowest rate of positive SLN: 7.2–11.5%, 0–6.3%, and 2.9–6.2%, respectively. cT1-3N0 ER+HER2− and cT3N0 triple-negative patients had the highest rate of positive SLN: 23.8–41.7% and 30.4%, respectively. Multivariable regression analysis showed that cT2 (odds ratio [OR] 1.93; 95% confidence interval [CI] 1.01–3.96), cT3 (OR 2.56; 95% CI 1.30–5.38), grade 3 (OR 0.44; 95% CI 0.21–0.91), and ER+HER2− subtype (OR 3.94; 95% CI 1.77–8.74) were correlated with positive SLN.

Conclusions

In cT1-3N0 ER+HER2+, cT1-3N0 ER−HER2+, and cT1-2N0 triple-negative patients treated with NST, immediate reconstruction can be considered an acceptable option due to low risk of positive SLN. In cT1-3N0 ER+HER2− and cT3N0 triple-negative patients treated with NST, risks and benefits of immediate reconstruction should be discussed with patients due to the relatively high risk of positive SLN.

Abstract P1-08-19: 10-year conditional recurrence risks, overall and relative survival for breast cancer patients in the Netherlands: Taking account of event-free years

Background

Survival estimates valid at the time of diagnosis are of limited value for (ex-)breast cancer patients who survived several years, as it includes information on already deceased patients. This study analyzed the 10-year conditional risk of recurrent breast cancer in specific prognostic subgroups according to T and N stage and breast cancer subtypes. Secondly, we investigated 10-year conditional overall (OS) and relative survival (RS), adjusted for confounding.

Patients and methods

We selected all women diagnosed in 2005 with operated T1-2N0-1 breast cancer from the Netherlands Cancer Registry. Patients were classified into T1N0, T1N1, T2N0 and T2N1 stage. Ten-year conditional recurrence rates were calculated for every year from diagnosis for patients without an event (local (LR), regional recurrence (RR), distant metastasis (DM) or death). Ten-year conditional OS was calculated using multivariable Cox regression. RS was estimated by dividing patient survival rates by those of the general Dutch population.

Results

We included 7,969 patients: 52.3% had T1N0, 15.3% T1N1, 19.9% T2N0 and 12.5% T2N1 stage. For T1N0, 10-year LR rates changed from 4.6% at diagnosis to 0.5% in year 10. RR rates decreased from 2.3% to 0.2% and DM rates decreased from 7.8% to 0.6%. For T2N1 stage, the LR, RR and DM rates decreased from 6.2% to 0.8%, 5.2% to 0.4% and 19.6% to 1.5%, respectively. Of all patients, 1,702 patients (21.4%) had an unknown breast cancer subtype and were consequently excluded from the analyses according to subtype. Of the remaining 6,267 patients, 3,774 (60.2%) had luminal A, 1,465 (23.4%) had luminal B, 314 (5.0%) had HER2 positive and 714 (11.4%) had triple negative disease For the luminal A subtype, LR, RR and DM rates ranged from 3.9% to 0.4%, 1.7% to 0.5% and 7.3% to 1.1%, while for triple negative these rates ranged between 5.6% to 0.7%, 4.9% to 0.2% and 16.7% to 0%, respectively. Differences between subgroups attenuated over time and all recurrence rates became ≤1.5% in year 10. Ten-year OS and RS, adjusted for confounding, showed diminishing risk differences between subgroups over time.

Conclusion

Differences in recurrence rates, OS and RS between prognostic subgroups decreased as years passed by. These results highlight the importance of taking into account disease-free years to more accurately predict (ex-)breast cancer patients' prognosis over time.

Citation Format: van Maaren MC, Strobbe LJ, Smidt ML, Moossdorff M, Poortmans PM, Siesling S. 10-year conditional recurrence risks, overall and relative survival for breast cancer patients in the Netherlands: Taking account of event-free years [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-08-19.

Can high school students help to improve breast radiologists in detecting missed breast cancer lesions on full-field digital mammography?

Aim: To investigate whether full-field digital mammography (FFDM) and contrast-enhanced mammography (CEM), evaluated by non-experienced high school students, improves detection of missed breast cancer lesions on FFDM, in the same cohort of patients. Methods: Non-experienced first- and second year high school students examined fourteen cases of patients diagnosed with breast cancer. These cases consisted of missed breast cancer lesions on FFDM by a breast radiologist. Sensitivity of assessment of the students on FFDM and CEM was analysed and compared with the initial results of the breast radiologists. Results: A total of 134 high school students participated in this study. Mean age was 12.8 years (range 10-14). Based on FFDM, mean overall sensitivity of the students was 29.2% (18.9 - 39.6%). When recombined CEM images were used, mean overall sensitivity of students improved to 82.6% (74.0 - 91.2%) (p=0.001). Mean overall sensitivity of FFDM exams evaluated by radiologists was 75.7% (64.2 - 87.3%), which was lower when compared to student's evaluations on recombined CEM exams, yet not statistically significant (p=0.098). Conclusions: Contrast-enhanced mammography evaluated by non-experienced high school students might improve detection rate of breast cancer when compared to evaluations of only full-field digital mammography by radiologists.

Added value of dedicated axillary hybrid 18F-FDG PET/MRI for improved axillary nodal staging in clinically node-positive breast cancer patients: a feasibility study

Purpose

To investigate the feasibility and potential added value of dedicated axillary 18F-FDG hybrid PET/MRI, compared to standard imaging modalities (i.e. ultrasound [US], MRI and PET/CT), for axillary nodal staging in clinically node-positive breast cancer.

Methods

Twelve patients with clinically node-positive breast cancer underwent axillary US and dedicated axillary hybrid 18F-FDG PET/MRI. Nine of the 12 patients also underwent whole-body PET/CT. Maximum standardized uptake values (SUVmax) were measured for the primary breast tumor and the most FDG-avid axillary lymph node. A positive axillary lymph node on dedicated axillary hybrid PET/MRI was defined as a moderate to very intense FDG-avid lymph node. The diagnostic performance of dedicated axillary hybrid PET/MRI was calculated by comparing quantitative and its qualitative measurements to results of axillary US, MRI and PET/CT. The number of suspicious axillary lymph nodes was subdivided as follows: N0 (0 nodes), N1 (1–3 nodes), N2 (4–9 nodes) and N3 (≥ 10 nodes).

Results

According to dedicated axillary hybrid PET/MRI findings, seven patients were diagnosed with N1, four with N2 and one with N3. With regard to mean SUVmax, there was no significant difference in the primary tumor (9.0 [±5.0] vs. 8.6 [±5.7], p = 0.678) or the most FDG-avid axillary lymph node (7.8 [±5.3] vs. 7.7 [±4.3], p = 0.767) between dedicated axillary PET/MRI and PET/CT. Compared to standard imaging modalities, dedicated axillary hybrid PET/MRI resulted in changes in nodal status as follows: 40% compared to US, 75% compared to T2-weighted MRI, 40% compared to contrast-enhanced MRI, and 22% compared to PET/CT.

Conclusions

Adding dedicated axillary 18F-FDG hybrid PET/MRI to diagnostic work-up may improve the diagnostic performance of axillary nodal staging in clinically node-positive breast cancer patients.

TNM classification and the need for revision of pN3a breast cancer

BACKGROUND

According to the seventh edition of tumour-node-metastasis (TNM) classification, pN3a status in breast cancer patients consists of presence of an infraclavicular lymph node metastasis (LNM) and/or presence of ≥10 axillary LNMs. The aim of this study was to determine whether prognosis of pN3a based on at least an infraclavicular LNM differs from ≥10 axillary LNMs.

METHODS

Data were obtained from the Netherlands Cancer Registry. All patients were diagnosed between 2005 and 2008 with primary invasive epithelial breast cancer and pN2a or pN3a status as pathologic result. Patients with pN3a were subdivided in pN3a based on at least an infraclavicular LNM or ≥10 axillary LNMs. Disease-free survival (DFS) included any local, regional or contralateral recurrence, distant metastasis or death within 5 years. Kaplan-Meier curves provided information on 5-year DFS and 8-year overall survival (OS). In addition, Cox proportional hazards model was used to measure the effect of relevant clinicopathological variables on DFS and OS.

RESULTS

A total of 3400 patients with pN2a and 1788 patients with pN3a were included. In 83 patients, pN3a was based on at least an infraclavicular LNM (4.6%) and in 1705 patients because of ≥10 axillary LNMs (95.4%). After multivariable analyses, DFS and OS were inferior in patients with pN3a based on ≥10 axillary LNMs compared to infraclavicular LNM (DFS 48.8% versus 63.8%, hazard ratio [HR] 1.59, p = 0.036; OS 46.6% versus 63.9%, HR 1.46, p = 0.042). Furthermore, pN2a and pN3a based on infraclavicular LNM had comparable DFS and OS.

CONCLUSION

PN3a status based on an at least an infraclavicular LNM is rare, yet its prognosis is superior to ≥10 axillary LNMs. Reclassification of infraclavicular LNM in the next TNM should therefore be considered into pN2a.

Developing a patient decision aid for the treatment of women with early stage breast cancer: the struggle between simplicity and complexity

Background

A patient decision aid (PtDA) can support shared decision making (SDM) in preference-sensitive care, with more than one clinically applicable treatment option. The development of a PtDA is a complex process, involving several steps, such as designing, developing and testing the draft with all the stakeholders, known as alpha testing. This is followed by testing in ‘real life’ situations, known as beta testing, and then finalising the definite version.

Our aim was developing and alpha testing a PtDA for primary treatment of early stage breast cancer, ensuring that the tool is considered relevant, valid and feasible by patients and professionals.

Methods

Our qualitative descriptive study applied various methods including face-to-face think-aloud interviews, a focus group and semi-structured telephone interviews. The study population consisted of breast cancer patients facing the choice between breast-conserving therapy with or without preceding neo-adjuvant chemotherapy and mastectomy, and professionals involved in breast cancer care in dedicated multidisciplinary breast cancer teams.

Results

A PtDA was developed in four iterative test rounds, taking nearly 2 years, involving 26 patients and 26 professionals. While the research group initially opted for simplicity for the sake of implementation, the clinicians objected that the complexity of the decision could not be ignored. Other topics of concern were the conflicting views of professionals and patients regarding side effects, the amount of information and how to present it.

Conclusion

The development was an extensive process, because the professionals rejected the simplifications proposed by the research group. This resulted in the development of a completely new draft PtDA, which took double the expected time and resources. The final version of the PtDA appeared to be well-appreciated by professionals and patients, although its acceptability will only be proven in actual practice (beta testing).

Trial registration

NTR TC 5721.

Electronic supplementary material

The online version of this article (doi:10.1186/s12911-017-0505-6) contains supplementary material, which is available to authorized users.

Clinically node negative breast cancer patients undergoing breast conserving therapy, sentinel lymph node procedure versus follow-up: a Dutch randomized controlled multicentre trial (BOOG 2013-08)

BACKGROUND

Studies showed that axillary lymph node dissection can be safely omitted in presence of positive sentinel lymph node(s) in breast cancer patients treated with breast conserving therapy. Since the outcome of the sentinel lymph node biopsy has no clinical consequence, the value of the procedure itself is being questioned. The aim of the BOOG 2013-08 trial is to investigate whether the sentinel lymph node biopsy can be safely omitted in clinically node negative breast cancer patients treated with breast conserving therapy.

METHODS

The BOOG 2013-08 is a Dutch prospective non-inferiority randomized multicentre trial. Women with pathologically confirmed clinically node negative T1-2 invasive breast cancer undergoing breast conserving therapy will be randomized for sentinel lymph node biopsy versus no sentinel lymph node biopsy. Endpoints include regional recurrence after 5 (primary endpoint) and 10 years of follow-up, distant-disease free and overall survival, quality of life, morbidity and cost-effectiveness. Previous data indicate a 5-year regional recurrence free survival rate of 99% for the control arm and 96% for the study arm. In combination with a non-inferiority limit of 5% and probability of 0.8, this result in a sample size of 1.644 patients including a lost to follow-up rate of 10%. Primary and secondary endpoints will be reported after 5 and 10 years of follow-up.

DISCUSSION

If the sentinel lymph node biopsy can be safely omitted in clinically node negative breast cancer patients undergoing breast conserving therapy, this study will cost-effectively lead to a decreased axillary morbidity rate and thereby improved quality of life with non-inferior regional control, distant-disease free survival and overall survival.

TRIAL REGISTRATION

The BOOG 2013-08 study is registered in ClinicalTrials.gov since October 20, 2014, Identifier: NCT02271828. https://clinicaltrials.gov/ct2/show/NCT02271828.

Does the TNM classification of solitary internal mammary lymph node metastases in breast cancer still apply?

PURPOSE

TNM classification of solitary internal mammary lymph node metastases (IMLNMs) in breast cancer varies depending on their method of detection: sentinel lymph node biopsy (pN1b) or clinical examination including radiological and/or physical examination (pN2b). This study aimed to evaluate whether there is a difference in prognosis between both groups.

METHODS

Data of all patients diagnosed with primary invasive epithelial breast cancer between 2005 and 2008 were obtained from the Netherlands Cancer Registry. Patients with IMLNMs were divided in groups according to their pN1b and pN2b status. The main outcome measures disease-free survival (DFS) after 5 years and overall survival (OS) after 8 years were analyzed using Kaplan-Meier survival analysis. Cox regression analysis was used to determine independent predictors for DFS and OS.

RESULTS

A total of 73 patients with pN1b status and 28 patients with pN2b status were included. DFS rate was 74.1% in the pN1b group compared to 85.0% in the pN2b group (p = 0.211). Regarding OS, 20.5% (pN1b) and 25.0% (pN2b) of the patients deceased within 8 years of follow-up (p = 0.589). In multivariable cox regression analysis, nodal status was not statistically significant for DFS (HR 0.29 [95% CI 0.04-2.33], p = 0.244) or OS (HR 1.04 [95% CI 0.37-2.89], p = 0.947).

CONCLUSIONS

Although the TNM classification considers pN1b and pN2b to be distinct prognostic entities, we did not observe any prognostic differences between these groups. Therefore, solitary IMLNMs may be regarded as a single category in the future and revision of TNM classification should be considered.

In vitro Sequential Selection and Characterization of Human Immunodeficiency Virus Type 1 Variants with Reduced Sensitivity to Hydroxyethylurea Protease Inhibitors

In vitro resistance to the human immunodeficiency virus (HIV) protease inhibitors SC-52151 and SC-55389A was evaluated in an in vitro sequential selection scheme. HIVRF variants were selected for reduced sensitivity to SC-52151 and subsequently passaged in both SC-52151 and a structurally different hydroxyethylurea protease inhibitor, SC-55389A, to select for dual-resistant virus. SC-52151 selection alone resulted in a 23-fold reduction in virus sensitivity whereas selection in both inhibitors resulted in 34- and eightfold reductions in virus sensitivity to SC-52151 and SC-55389A, respectively. Sequence analysis of the protease gene revealed that SC-52151 -resistant virus had a Gly to Val substitution at residue 48 (G48V) and, in 58% of subclones, an accompanying Val to Ala substitution at residue 82 (V82A). Dual-resistant virus had both G48V and V82A substitutions present and, in the majority of subclones, an lle to Thr and/or Leu to Pro substitution at residues 54 and 63, respectively. Drug susceptibility assays with limiting dilution-cloned HIVRFR (G48V/V82A) and HIVRFRR (G48V/154T/L63P/V82A) viruses demonstrated moderate to high-level cross-resistance to additional structurally non-related protease inhibitors. Recombinant HIVHXB2 proviral clones with G48V, L63P and V82A substitutions showed that one active site mutation was permissible, but the presence of both G48V and V82A substitutions together significantly reduced infectious virus production. Insight into the contributions of the observed substitutions to drug resistance is presented in molecular modelling studies.

Sentinel lymph node biopsy can be omitted in DCIS patients treated with breast conserving therapy

Breast cancer guidelines advise sentinel lymph node biopsy (SLNB) in patients with ductal carcinoma in situ (DCIS) on core biopsy at high risk of invasive cancer or in case of mastectomy. This study investigates the incidence of SLNB and SLN metastases and the relevance of indications in guidelines and literature to perform SLNB in order to validate whether SLNB is justified in patients with DCIS on core biopsy in current era. Clinically node negative patients diagnosed from 2004 to 2013 with only DCIS on core needle biopsy were selected from a national database. Incidence of SLN biopsy and metastases was calculated. With Fisher exact tests correlation between SLNB indications and actual presence of SLN metastases was studied. Further, underestimation rate for invasive cancer and correlation with SLN metastases was analysed. 910 patients were included. SLNB was performed in 471 patients (51.8 %): 94.5 % had pN0, 3.0 % pN1mi and 2.5 % pN1. Patients undergoing mastectomy had 7 % SLN metastases versus 3.5 % for breast conserving surgery (BCS) (p = 0.107). The only factors correlating to SLN metastases were smaller core needle size (p = 0.01) and invasive cancer (p < 0.001). Invasive cancer was detected in 16.7 % by histopathology with 15.6 % SLN metastases versus only 2 % in pure DCIS. SLNB showed metastases in 5.5 % of patients; 3.5 % in case of BCS (any histopathology) and 2 % when pure DCIS was found at definitive histopathology (BCS and mastectomy). Consequently, SLNB should no longer be performed in patients diagnosed with DCIS on core biopsy undergoing BCS. If definitive histopathology shows invasive cancer, SLNB can still be considered after initial surgery.

Abstract P4-02-01: Only in lobular breast cancer MRI use is associated with a lower risk of positive surgical margins and a reduced number of mastectomies. A real-world analysis in The Netherlands

Background

The value of magnetic resonance imaging (MRI) for patients with breast cancer remains under debate. Breast MRI may contribute to the planning of local therapy, but also bears the risk of overtreatment. We analyzed the use of MRI and its impact on surgical treatment and risk of detecting contralateral breast cancer in the Netherlands.

Patients and methods

All patients who underwent primary surgery for stage I-III invasive breast cancer in the years 2011-2013 were identified through the Netherlands Cancer Registry. The following data were documented: year of diagnosis, hospital type and volume, age at diagnosis, clinical T and N stage, histological type and grade, presence of multifocality in resection specimen, hormone receptor status, HER2 status and use of MRI. We analyzed whether MRI use was related to type of surgery (primary or secondary mastectomy or breast conserving surgery), surgical margin involvement, and diagnosis of synchronous contralateral breast cancer.

Results

MRI was performed in 10,819 (29,8%) out of 36,333 patients newly diagnosed with invasive breast cancer and treated with primary surgery in the years 2011-2013 in the Netherlands. Use of MRI did not clearly increase in this period.

In the multivariate analysis, patients younger than 50 years of age compared to patients aged 70 years or older (OR 6.34, 95% CI 5.86-6.87), patients with lobular breast cancer compared to those with ductal carcinoma (OR 3.46; 95% CI 3.23-3.70) and patients with multifocal tumors compared to those without multifocality (OR 2.30, 95% CI 2.15-2.45) were more likely to undergo MRI. Hospital volume (&lt;150 versus &gt;150) was only marginally related to MRI use (OR 0.93; 95% CI 0.87-0.99).

Patients with invasive breast cancer undergoing MRI were more likely to undergo primary mastectomy than those without MRI (OR 1.21; 95% CI 1.15-1.28), but the subgroup with invasive lobular cancer undergoing MRI were less likely to undergo primary mastectomy (OR 0.85; 95% CI 0.75-0.98). A significantly lower risk of positive surgical margins was seen in patients with lobular breast cancer and breast conserving surgery who had undergone MRI as compared to those without MRI (OR 0.58, 95% CI 0.44-0.78) and, consequently, also a lower risk of secondary mastectomy (OR 0.60, 95% CI 0.41-0.87). Risk of positive surgical margins was not reduced by MRI use in patients with invasive ductal carcinoma (OR 0.91; 95% CI 0.77-1.07). Patients who underwent MRI were almost four times more frequently diagnosed with contralateral breast cancer, compared to those in whom MRI was not performed (OR 3.60, 95% CI 3.06-4.24).

Conclusion

Breast MRI was significantly more often used in younger patients, patients with lobular and/or multifocal breast cancer. Interestingly, MRI use was associated with less primary and secundary mastectomies in lobular invasive breast cancer, in contrast to an increased number of primary mastectomies in patients with invasive ductal cancer. MRI was further associated with an almost fourfold higher incidence of contralateral breast cancer.

Citation Format: Tjan-Heijnen VC, Lobbes MB, Vriens IJ, van Bommel AC, Nieuwenhuijzen GA, Smidt ML, Boersma LJ, van Dalen T, Smorenburg CH, Siesling S, Voogd AC. Only in lobular breast cancer MRI use is associated with a lower risk of positive surgical margins and a reduced number of mastectomies. A real-world analysis in The Netherlands. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-02-01.

The value of completion axillary treatment in sentinel node positive breast cancer patients undergoing a mastectomy: a Dutch randomized controlled multicentre trial (BOOG 2013-07)

Background

Trials failed to demonstrate additional value of completion axillary lymph node dissection in case of limited sentinel lymph node metastases in breast cancer patients undergoing breast conserving therapy. It has been suggested that the low regional recurrence rates in these trials might partially be ascribed to accidental irradiation of part of the axilla by whole breast radiation therapy, which precludes extrapolation of results to mastectomy patients. The aim of the randomized controlled BOOG 2013–07 trial is therefore to investigate whether completion axillary treatment can be safely omitted in sentinel lymph node positive breast cancer patients treated with mastectomy.

Design

This study is designed as a non-inferiority randomized controlled multicentre trial. Women aged 18 years or older diagnosed with unilateral invasive clinically T1-2 N0 breast cancer who are treated with mastectomy, and who have a maximum of three axillary sentinel lymph nodes containing micro- and/or macrometastases, will be randomized for completion axillary treatment versus no completion axillary treatment. Completion axillary treatment can consist of completion axillary lymph node dissection or axillary radiation therapy. Primary endpoint is regional recurrence rate at 5 years. Based on a 5-year regional recurrence free survival rate of 98 % among controls and 96 % for study subjects, the sample size amounts 439 per arm (including 10 % lost to follow-up), to be able to reject the null hypothesis that the rate for study and control subjects is inferior by at least 5 % with a probability of 0.8. Results will be reported after 5 and 10 years of follow-up.

Discussion

We hypothesize that completion axillary treatment can be safely omitted in sentinel node positive breast cancer patients undergoing mastectomy. If confirmed, this study will significantly decrease the number of breast cancer patients receiving extensive treatment of the axilla, thereby diminishing the risk of morbidity and improving quality of life, while maintaining excellent regional control and without affecting survival.

Trial registration

The BOOG 2013–07 study is registered in the register of ClinicalTrials.gov since April 10, 2014, Identifier: NCT02112682.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1613-2) contains supplementary material, which is available to authorized users.

The diagnostic performance of sentinel lymph node biopsy in pathologically confirmed node positive breast cancer patients after neoadjuvant systemic therapy: A systematic review and meta-analysis

PURPOSE

To provide a systematic review and meta-analysis of studies investigating sentinel lymph node biopsy after neoadjuvant systemic therapy in pathologically confirmed node positive breast cancer patients.

METHODS

Pubmed and Embase databases were searched until June 19th, 2015. All abstracts were read and data extraction was performed by two independent readers. A random-effects model was used to pool the proportion for identification rate, false-negative rate (FNR) and axillary pCR with 95% confidence intervals. Subgroup analyses affirmed potential confounders for identification rate and FNR.

RESULTS

A total of 997 abstracts were identified and eventually eight studies were included. Pooled estimates were 92.3% (90.8-93.7%) for identification rate, 15.1% (12.7-17.6%) for FNR and 36.8% (34.2-39.5%) for axillary pCR. After subgroup analysis, FNR is significantly worse if one sentinel node was removed compared to two or more sentinel nodes (23.9% versus 10.4%, p = 0.026) and if studies contained clinically nodal stage 1-3, compared to studies with clinically nodal stage 1-2 patients (21.4 versus 13.1%, p = 0.049). Other factors, including single tracer mapping and the definition of axillary pCR, were not significantly different.

CONCLUSION

Based on current evidence it seems not justified to omit further axillary treatment in every clinically node positive breast cancer patients with a negative sentinel lymph node biopsy after neoadjuvant systemic therapy.

The role of MRI in axillary lymph node imaging in breast cancer patients: a systematic review

Objectives

To assess whether MRI can exclude axillary lymph node metastasis, potentially replacing sentinel lymph node biopsy (SLNB), and consequently eliminating the risk of SLNB-associated morbidity.

Methods

PubMed, Cochrane, Medline and Embase databases were searched for relevant publications up to July 2014. Studies were selected based on predefined inclusion and exclusion criteria and independently assessed by two reviewers using a standardised extraction form.

Results

Sixteen eligible studies were selected from 1,372 publications identified by the search. A dedicated axillary protocol [sensitivity 84.7 %, negative predictive value (NPV) 95.0 %] was superior to a standard protocol covering both the breast and axilla simultaneously (sensitivity 82.0 %, NPV 82.6 %). Dynamic, contrast-enhanced MRI had a lower median sensitivity (60.0 %) and NPV (80.0 %) compared to non-enhanced T1w/T2w sequences (88.4, 94.7 %), diffusion-weighted imaging (84.2, 90.6 %) and ultrasmall superparamagnetic iron oxide (USPIO)- enhanced T2*w sequences (83.0, 95.9 %). The most promising results seem to be achievable when using non-enhanced T1w/T2w and USPIO-enhanced T2*w sequences in combination with a dedicated axillary protocol (sensitivity 84.7 % and NPV 95.0 %).

Conclusions

The diagnostic performance of some MRI protocols for excluding axillary lymph node metastases approaches the NPV needed to replace SLNB. However, current observations are based on studies with heterogeneous study designs and limited populations.

Main Messages

• Some axillary MRI protocols approach the NPV of an SLNB procedure.

• Dedicated axillary MRI is more accurate than protocols also covering the breast.

• T1w/T2w protocols combined with USPIO-enhanced sequences are the most promising sequences.

Inconsistent selection and definition of local and regional endpoints in breast cancer research

BACKGROUND

Results in breast cancer research are reported using study endpoints. Most are composite endpoints (such as locoregional recurrence), consisting of several components (for example local recurrence) that are in turn composed of specific events (such as skin recurrence). Inconsistent endpoint selection and definition might lead to unjustified conclusions when comparing study outcomes. This study aimed to determine which locoregional endpoints are used in breast cancer studies, and how these endpoints and their components are defined.

METHODS

PubMed was searched for breast cancer studies published in nine leading journals in 2011. Articles using endpoints with a local or regional component were included and definitions were compared.

RESULTS

Twenty-three different endpoints with a local or regional component were extracted from 44 articles. Most frequently used were disease-free survival (25 articles), recurrence-free survival (7), local control (4), locoregional recurrence-free survival (3) and event-free survival (3). Different endpoints were used for similar outcomes. Of 23 endpoints, five were not defined and 18 were defined only partially. Of these, 16 contained a local and 13 a regional component. Included events were not specified in 33 of 57 (local) and 27 of 50 (regional) cases. Definitions of local components inconsistently included carcinoma in situ and skin and chest wall recurrences. Regional components inconsistently included specific nodal sites and skin and chest wall recurrences.

CONCLUSION

Breast cancer studies use many different endpoints with a locoregional component. Definitions of endpoints and events are either not provided or vary between trials. To improve transparency, facilitate trial comparison and avoid unjustified conclusions, authors should report detailed definitions of all endpoints.

The impact of the pathological lymph node status on adjuvant systemic treatment recommendations in clinically node negative breast cancer patients

Several independent randomized controlled trials are initiated to investigate whether sentinel lymph node biopsy can be safely omitted in clinically node negative breast cancer patients with negative axillary ultrasound findings, who are treated with breast conserving therapy. A consequence of omitting sentinel lymph node biopsy is absence of pathological lymph node status information. We aimed to investigate the impact of omitting sentinel lymph node biopsy on adjuvant systemic treatment recommendations. Data from all consecutive patients with invasive breast cancer and negative axillary ultrasound findings treated with breast conserving therapy and sentinel lymph node biopsy between 2008 and 2012 were collected from a prospective database. Two methods, Adjuvant! Online and the Dutch breast cancer guideline 2012, were used to determine the adjuvant systemic treatment recommendations of every patient. At first, each patient was considered to be lymph node negative, and secondly the patients' true pathological lymph node status was used. A total of 303 patients were consecutively included. Pathological lymph node status was pN0 in 72.3 %, pN0(i+) in 12.9 %, pN1mi+ in 5.6 %, pN1 in 7.3 %, and pN2 in 2.0 % of the patients. The decision to recommend adjuvant systemic treatment changed due to the pathological lymph node status in 1.0 % of the patients (3/303) when using Adjuvant! Online and in 3.6 % (11/303) when using the 2012 Dutch breast cancer guideline. The impact of the pathological lymph node status on adjuvant systemic treatment recommendations in clinically node negative breast cancer patients with negative axillary ultrasound findings treated with breast conserving therapy is limited. The safety of omitting the sentinel lymph node biopsy should be confirmed by the initiated randomized controlled trials.

No increase of local recurrence rate in breast cancer patients treated with skin-sparing mastectomy followed by immediate breast reconstruction

BACKGROUND

The aim of this study was to evaluate the incidence of local recurrence after SSM with IBR and to determine whether complications lead to postponement of adjuvant therapy.

METHOD

Patients that underwent IBR after SSM between 2004 and 2011 were included.

RESULTS

A total of 157 reconstruction procedures were performed in 147 patients for invasive breast cancer (n = 117) and ductal carcinoma in situ (n = 40). The median follow-up was 39 months [range 6-97]. Estimated 5-year local recurrence rate was 2.9% (95% CI 0.1-5.7). The median time to start adjuvant therapy was 27.5 days [range 19-92] in 18 patients with complications, and 23.5 days [range 8-54] in 46 patients without complications (p = 0.025).

CONCLUSION

In our single-institution cohort, IBR after SSM carried an acceptable local recurrence rate. Complications caused a delay of adjuvant treatment but this was within guidelines and therefore not clinically relevant.

The role of magnetic resonance imaging in assessing residual disease and pathologic complete response in breast cancer patients receiving neoadjuvant chemotherapy: a systematic review

OBJECTIVES

This systematic review aimed to assess the role of magnetic resonance imaging (MRI) in evaluating residual disease extent and the ability to detect pathologic complete response (pCR) after neoadjuvant chemotherapy for invasive breast cancer.

METHODS

PubMed, the Cochrane Library, MEDLINE, and Embase databases were searched for relevant studies published until 1 July 2012. After primary selection, two reviewers independently assessed the content of each eligible study using a standardised extraction form and pre-defined inclusion and exclusion criteria.

RESULTS

A total of 35 eligible studies were selected. Correlation coefficients of residual tumour size assessed by MRI and pathology were good, with a median value of 0.698. Reported sensitivity, specificity, positive predictive value and negative predictive value for predicting pCR with MRI ranged from 25 to 100 %, 50-97 %, 47-73 % and 71-100 %, respectively. Both overestimation and underestimation were observed. MRI proved more accurate in determining residual disease than physical examination, mammography and ultrasound. Diagnostic accuracy of MRI after neoadjuvant chemotherapy could be influenced by treatment regimen and breast cancer subtype.

CONCLUSIONS

Breast MRI accuracy for assessing residual disease after neoadjuvant chemotherapy is good and surpasses other diagnostic means. However, both overestimation and underestimation of residual disease extent could be observed.

MAIN MESSAGES

• Breast MRI accuracy for assessing residual disease is good and surpasses other diagnostic means. • Correlation coefficients of residual tumour size assessed by MRI and pathology were considered good. • However, both overestimation and underestimation of residual disease were observed. • Diagnostic accuracy of MRI seems to be affected by treatment regimen and breast cancer subtype.

Abstract OT2-1-03: The Z11 design for breast cancer patients undergoing a mastectomy

Background: The diagnostic work-up and treatment of axillary lymph nodes in breast cancer patients is an ongoing topic of research. The ACOSOG-Z0011 study demonstrated no additional value of complementary axillary lymph node dissection (cALND) in case of limited axillary sentinel lymph node (SLN) metastases in breast cancer patients undergoing breast conserving therapy1. It is questionable whether these results can be applied to patients undergoing a mastectomy2.

Trial design: A prospective non-inferiority randomized multicenter trial was designed.

Breast cancer patients with cT1-2N0 disease treated with mastectomy and limited axillary SLN metastases will be randomized for follow-up versus complementary axillary treatment. To assess the Quality of Life and morbidity benefits of this experimental treatment, 3 validated questionnaires will be used: QLQ-C30, QLQ-BR 23 and Lymph-ICF3-5.

Eligibility criteria: – Women with histological confirmed cT1-2 invasive unilateral breast carcinoma– Clinical node negative: no palpable nodes in physical examination and the axillary ultrasound without signs of lymph node metastases (cyto-/histology if indicated)– Sentinel lymph node biopsy must contain at least one and a maximum of 3 (micro)metastases– Neoadjuvant systemic therapy is allowed

Specific aims: Primary endpoint is the axillary recurrence rate. The number of delayed axillary dissections will be registered. Secondary endpoints are distant-disease free survival, overall survival, local recurrence, morbidity and Quality of Life.

Statistical methods: Based on 5-year axillary recurrence free survival rate, a failure rate of 0.98 among controls and a true failure rate of 0.96 for study subjects are considered acceptable. Overall, 1114 patients will be included to be able to reject the null hypothesis that the failure rate for experimental and control subjects is inferior by at least 5% (D = −5%) with probability of 0.8 and alpha of 5%.

Present accrual and target accrual: This study is expected to start in late 2012 after approval by the Ethical Medical Committee.

References

1. Giuliano, A.E., et al., Axillary dissection vs no axillary dissection in women with invasive breast cancer and sentinel node metastasis: a randomized clinical trial. JAMA, 2011. 305(6): p. 569–75. 2. Morrow, M. and A.E. Giuliano, To cut is to cure: can we really apply Z11 in practice? Ann Surg Oncol, 2011. 18(9): p. 2413–5. 3. Aaronson, N.K., et al., The European Organization for Research and Treatment of Cancer QLQ-C30: a quality-of-life instrument for use in international clinical trials in oncology. J Natl Cancer Inst, 1993. 85(5): p. 365–76. 4. Sprangers, M.A., et al., The European Organization for Research and Treatment of Cancer breast cancer-specific quality-of-life questionnaire module: first results from a three-country field study. J Clin Oncol, 1996. 14(10): p. 2756–68. 5. Devoogdt, N., et al., Lymphoedema Functioning, Disability and Health questionnaire (Lymph-ICF): reliability and validity. Phys Ther, 2011. 91(6): p. 944–57.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr OT2-1-03.

Abstract P5-01-13: Flat Epithelial Atypia: Management and outcome in three Dutch teaching hospitals

Background: Flat Epithelial Atypia (FEA) is a presumably neoplastic alteration of terminal duct-lobular units, characterized by the replacement of native luminal epithelium by ductal cells demonstrating low-grade cytologic atypia. The architecture shows stratification of epithelial cells. FEA is often accompanied by microcalcifications and therefore discovered in biopsies following screening mammography. FEA is frequently seen in association with ADH (atypical ductal hyperplasia), DCIS (ductal carcinoma in situ), lobular neoplasia and invasive tubular carcinomas. There is emerging evidence suggesting FEA may represent a precursor to DCIS. The risk of subsequent breast carcinoma remains to be defined. The aim of this study is therefore to inventorise the management and outcome of solitary FEA in histological biopsies in three Dutch teaching hospitals.

Materials and Methods: Data of this retrospective multicentre study were collected in a database. Local pathology databases were screened with the terms: ‘FEA’, ‘Flat Epithelial Atypia’, ‘columnar atypia’ and Dutch equivalents. Results were manually screened, only including solitary FEA.

Patient files were viewed for information on presentation, mammography, ultrasound and management: surgery vs follow-up. In case of excision, definitive pathology was added.

Results: We included 103 patients showing only solitary FEA in the primary biopsy. Management of these patients consisted of follow-up for 60 patients (58,3%) and surgery for 43 patients (41,7%, 49 excisions): lumpectomy (42) or mastectomy (7). Reason for choosing mastectomy was preventive in case of contralateral breast cancer or increased familial or genetic risk.

Definitive pathology of lumpectomy or mastectomy showed no abnormalities or solitary FEA in 31 patients; other findings were ADH in 7, LCIS in 4 and DCIS in 7 patients. Some patients showed more than one finding. Invasive breast cancer (IBC) was detected in 3 patients. Only one mastectomy showed invasive disease, located in a different lobe, however.

No incidents occurred in the follow-up group.

Conclusions: No consistent management exists concerning solitary FEA in these three hospitals. Also, one hospital used the diagnosis of FEA inconsistently and interchangingly with other terms. Lack of this study is the retrospective gathering of data, making it difficult to detect the reasons for the chosen management. DCIS or IBC was discovered in 20,4% of all surgical specimens. It was concluded that FEA should be seen as a red flag, indicating the possible presence of a more malignant lesion. Additional research is warranted concerning long term follow-up for this patient group.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-01-13.

Abstract P3-02-08: Is repetition of the contralateral mammogram of patients referred from breast cancer screening for unilateral findings necessary?

Introduction - The Netherlands started a nationwide breast cancer screening program in 1989, including women from the age of 50 until 75. Screening mammograms are performed two yearly in a mobile unit and consist of a bilateral two-view mammogram of the breast (mediolateral oblique and craniocaudal views).

If indicated, patients are referred to a breast clinic for diagnostic analysis. This work-up consist of among others repeating the bilateral two-view mammogram. Since the screening is digitalized, repeating of at least the mammogram of the non suspicious side might be unnecessary.

The aim of this study is to determine the additional value of repeating the contralateral mammogram in patients referred for a suspicious unilateral lesion.

Material and methods – 395 patients were referred from breast screening program to our institution for unilateral findings between October 2009 and August 2011. In all patients a bilateral mammogram was repeated and analyzed by an experienced breast radiologist. In the case of breast cancer a breast magnetic resonance imaging (MRI) was performed for preoperative staging. Anonymised data concerning the date of registration of the screening mammogram, the referred side (left/right or bilateral), age, screening's BI-RADS classification, breast density, biopsy results and breast MRI results were collected.

Results - Of the 395 patients referred for a suspicious unilateral finding, a malignancy on the referred side was observed in 144 patients (36.5%). In five patients bilateral breast cancer was detected. In one patient no malignancy was detected on the referred side, though on the contralateral side. Three of these six contralateral malignancies were directly mammographically detected. All six malignancies were detected with preoperative breast MRI.

Conclusion - Repetition of the two-view mammogram of the contralateral side in patients referred with a unilateral suspicious finding seems unnecessary, since all contralateral malignancies were depicted on the preoperative staging breast MRI recommended according to the EUSOBI-guidelines. Omission of the contralateral mammogram could lead to reduction of associated health care costs, radiation exposure, and patient discomfort caused by the exam.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-02-08.

Pre-treatment differences and early response monitoring of neoadjuvant chemotherapy in breast cancer patients using magnetic resonance imaging: a systematic review

OBJECTIVES

To assess whether magnetic resonance imaging (MRI) can identify pre-treatment differences or monitor early response in breast cancer patients receiving neoadjuvant chemotherapy.

METHODS

PubMed, Cochrane library, Medline and Embase databases were searched for publications until January 1, 2012. After primary selection, studies were selected based on predefined inclusion/exclusion criteria. Two reviewers assessed study contents using an extraction form.

RESULTS

In 15 studies, which were mainly underpowered and of heterogeneous study design, 31 different parameters were studied. Most frequently studied parameters were tumour diameter or volume, K(trans), K(ep), V(e), and apparent diffusion coefficient (ADC). Other parameters were analysed in only two or less studies. Tumour diameter, volume, and kinetic parameters did not show any pre-treatment differences between responders and non-responders. In two studies, pre-treatment differences in ADC were observed between study groups. At early response monitoring significant and non-significant changes for all parameters were observed for most of the imaging parameters.

CONCLUSIONS

Evidence on distinguishing responders and non-responders to neoadjuvant chemotherapy using pre-treatment MRI, as well as using MRI for early response monitoring, is weak and based on underpowered study results and heterogeneous study design. Thus, the value of breast MRI for response evaluation has not yet been established.

KEY POINTS

Few well-validated pre-treatment MR parameters exist that identify responders and non-responders. Eligible studies showed heterogeneous study designs which hampered pooling of data. Confounders and technical variations of MRI accuracy are not studied adequately. Value of MRI for response evaluation needs to be established further.

P5-14-18: Today's Estrogen Receptor Positive/Her-2-neu Receptor Negative Breast Cancer Patients Do Significantly Better Than Yesterday's Estrogen Receptor Positive Breast Cancer Patients

Background: Her-2-neu receptor (Her2) positive and triple negative breast cancer patients have a poor prognosis. The majority of cancers are characterized as estrogen receptor (ER)+/Her2- and these patients may now have a better prognosis compared to before the introduction of the Her-2-neu receptor.

Material and methods: Since 1997 3424 patients were treated for cT1-2N0 breast cancer in three hospitals. Determination of Her2-neu status was introduced between 1999 and 2004. Trastuzumab treatment has been given routinely since 2005. Survival was evaluated for the different groups; ER+/Her2-, ER+/Her2+, ER+/Her2 unknown (status not determined).

Results: 2284 patients had ER+/Her2- tumors, 259 had ER+/Her2+ tumors and 262 had ER+/Her2 unknown tumors. Systemic treatment was given to 48.4%, 71.0% and 43.9% respectively. Estimated 5-and 10-year overall survival was 92.0% and 82.2% for ER+/Her2-, 91.6% and 70.8% ER+/Her2+ and 83.4% and 72.2% for ER+/Her2 unknown (p &lt; 0.001). The outcome differences between ER+/Her-2- and ER+/Her-2 unknown tumors remained following adjustment for tumor malignancy grade, nodal status and adjuvant systemic treatment (OR 0.8: CI 0.72 — 0.88; p&lt;0.001). For patients with ER+/Her2+ tumors 5 year overall survival was comparable with ER+/Her2- tumors but 10 year overall survival was comparable with ER+/Her2 unknown tumors.

Discussion: Patients with ER+/Her2- tumors have a significantly better outcome than patients who were classified as ER+ before the assessment of Her-2-neu over-expression. Current prognostic models do not take this effect into account.

The branching off of the survival curve for patients with ER+/Her2+ tumors can be explained by the standard use of trastuzumab during the last five years.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-14-18.

Axillary Recurrence after Negative Sentinel Lymphnode Biopsy; a Multicentre Cohort Study

IntroductionSentinel Lymphnode Biopsy (SLNB) is generally excepted as a minimal invasive technique to stage the axilla in clinically node negative breast cancer patients. Though the reported clinically overt axillary recurrences after negative SLNB is low (0-2,8%), these false negative results after SLNB remain a concern in the treatment of pN0(slnb) breast cancer patients. In this respect many have investigated factors that may influence the risk of developing an axillary recurrence, either to explain the unexpected low incidence or to try to identify subgroups of patients with higher risk of developing an axillary recurrence. Downside to many of these studies is the single-centre study design, mostly presenting small numbers of patients with relatively short follow-up making it difficult to extrapolate the results to the every-day practice.We conducted this multicentre cohort study to identify prognostic factors for developing axillary recurrences after negative SLNB.Patients and MethodsProspectively collected data from seven large volume hospitals in the Netherlands were analyzed. Patients underwent surgery including SLNB between January 2000 and December 2002. Pathological work-up of the sentinel node, local and systemic treatment, and follow-up were performed according to Dutch National guidelines. Statistical analysis was performed to test homogeneity between the institutes. Multivariate analysis was performed to identify prognostic factors. A p-value of &lt;0,05 was considered significant.ResultsA total of 1597 patients were identified; 569 (35,6%) had positive SLNB (including micrometastasis &lt;2mm and &gt;0,2mm) and underwent Axillary Lymphnode Dissection (ALND). In the remaining 1028 patients, 986 (61,7%) were SLN negative and 42 (2,6%) patients were found to have isolated tumor cells (i.e. metastases &lt;0,2mm). In 81 of these 1028 pN0 staged patients ALND was however performed, i.e. a total of 947 SLN negative patients did not receive further axillary treatment.After a median follow-up of 77 months, eighteen patients were identified that developed clinically overt axillary recurrence (recurrence rate 1,9%). The median interval between SLNB and detection of the axillary recurrence was 37 months. Median follow-up post-recurrence was 33 months. One patient developed contra lateral breast recurrence and 9 patients developed distant metastasis (including 4 visceral metastasis). Three patients died during follow-up.Multivariate analysis showed that younger age increases (p=0,0004) and external beam radiation therapy to the breast reduces (p= 0,0012) the risk of developing an axillary recurrence. T-stage, receptor-status and number of nodes removed were not statistically significant. Adjuvant systemic therapy did not significantly influence the risk of developing an axillary recurrence in multivariate analysis.ConclusionYoung age and the absence of external beam radiation therapy to the breast both increase the risk of developing an axillary recurrence after negative SLNB.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1006.

False-negative sentinel lymph node biopsy

BACKGROUND

The clinical significance of false-negative axillary sentinel lymph node (SLN) biopsy has yet to be established. The aim of this study was to assess the axillary recurrence rate and false-negative rate, to identify prognostic factors and to monitor survival.

METHODS

A prospective registry of sentinel lymph node biopsy (SLNB) procedures performed between 1998 and 2004 was analysed. All nodes retrieved were examined by haematoxylin and eosin and immunohistochemical staining. Further surgical treatment was performed only for positive SLNs. Adjuvant treatment was given according to Dutch guidelines.

RESULTS

Of 592 patients, 392 had a negative SLNB. After a median follow-up of 65 months, 11 patients developed axillary recurrence (2.8 per cent). Ten of these patients were primarily treated by simple mastectomy and therefore had no external-beam radiation therapy; no further prognostic factors could be identified. The false-negative rate was 6.9 per cent. The median time from SLNB to detection of the axillary recurrence was 27 months. The median follow-up after recurrence was 35 months, and one patient developed systemic disease. Pathology revision revealed two previously undetected micrometastases.

CONCLUSION

Axillary recurrence and false-negative rates after SLNB increase with longer follow-up.