Outcome without any adjuvant systemic treatment in stage I ER+/HER2- breast cancer patients included in the MINDACT trial.

BACKGROUND: Adjuvant systemic treatments (AST) reduce mortality, but have associated short- and long-term toxicities. Careful selection of patients likely to benefit from AST is needed. We evaluated outcome of low-risk breast cancer patients of the EORTC 10041/BIG 3-04 MINDACT trial who received no AST. PATIENTS AND METHODS: Patients with estrogen receptor-positive, HER2-negative, lymph node-negative tumors ≤2 cm who received no AST were matched 1 : 1 to patients with similar tumor characteristics treated with adjuvant endocrine therapy (ET), using propensity score matching and exact matching on age, genomic risk (70-gene signature) and grade. In a post hoc analysis, distant metastasis-free interval (DMFI) and overall survival (OS) were assessed by Kaplan-Meier analysis and hazard ratios (HR) by Cox regression. Cumulative incidences of locoregional recurrence (LRR) and contralateral breast cancer (CBC) were assessed with competing risk analyses. RESULTS: At 8 years, DMFI rates were 94.8% [95% confidence interval (CI) 92.7% to 96.9%] in 509 patients receiving no AST, and 97.3% (95% CI 95.8% to 98.8%) in 509 matched patients who received only ET [absolute difference: 2.5%, HR 0.56 (95% CI 0.30-1.03)]. No statistically significant difference was seen in 8-year OS rates, 95.4% (95% CI 93.5% to 97.4%) in patients receiving no AST and 95.6% (95% CI 93.8% to 97.5%) in patients receiving only ET [absolute difference: 0.2%, HR 0.86 (95% CI 0.53-1.41)]. Cumulative incidence rates of LRR and CBC were 4.7% (95% CI 3.0% to 7.0%) and 4.6% (95% CI 2.9% to 6.9%) in patients receiving no AST versus 1.4% (95% CI 0.6% to 2.9%) and 1.5% (95% CI 0.6% to 3.1%) in patients receiving only ET. CONCLUSIONS: In patients with stage I low-risk breast cancer, the effect of ET on DMFI was limited, but overall significantly fewer breast cancer events were observed in patients who received ET, after the relatively short follow-up of 8 years. These benefits and side-effects of ET should be discussed with all patients, even those at a very low risk of distant metastasis.

Omitting SLNB in Breast Cancer: Is a Nomogram the Answer?

BACKGROUNDS: Sentinel lymph node biopsy (SLNB) is standard care as a staging procedure in patients with invasive breast cancer. The axillary recurrence rate, even after positive SLNB, is low. This raises serious doubts regarding the clinical value of SLNB in early breast cancer. The purpose of this study is to select patients with low suspected axillary burden in whom SLNB might be omitted. PATIENTS AND METHODS: We retrospectively analyzed 2015 primary breast cancer patients between 2007 and 2015, with 982 patients allocated to the training and 961 to the validation cohort. Variables associated with nodal disease were analyzed and used to build a nomogram for predicting nodal disease. RESULTS: A total of 32.8% of patients had macrometastatic disease. A predictive model was constructed based on age, cN0, morphology, grade, multifocality, and tumor size with an area under the receiver operating characteristic curve (AUC) of 0.83. Considering a false-negative rate of 5%, 32.8% of patients could be spared axillary surgery. In a subanalysis of patients with relatively favorable characteristics, 26.8% had less than 5% chance of macrometastases. CONCLUSIONS: We present a model with excellent predictive value that can select one-third of patients in whom SLNB is deemed not necessary because of less than 5% chance of nodal involvement. Whether missing 1 in 20 patients with macrometastatic disease is worthwhile balanced against preventing side-effects of the SLN procedure remains to be established. A number of ongoing large prospective trials evaluating the outcome of omitting SLNB are awaited. Meanwhile, this nomogram may be used for individual decision-making.

Combining method of detection and 70-gene signature for enhanced prognostication of breast cancer.

PURPOSE: Studies have shown that screen detection by national screening programs is independently associated with better prognosis of breast cancer. The aim of this study is to evaluate the association between tumor biology according to the 70-gene signature (70-GS) and survival of patients with screen-detected and interval breast cancers. METHODS: All Dutch breast cancer patients enrolled in the MINDACT trial (EORTC-10041/BIG3-04) accrued 2007-2011, who participated in the national screening program (biennial screening, ages 50-75) were included (n = 1102). Distant Metastasis-Free Interval (DMFI) was evaluated according to the 70-GS for patients with screen-detected (n = 754) and interval cancers (n = 348). RESULTS: Patients with screen-detected cancers had 8-year DMFI rates of 98.2% for 70-GS ultralow-, 94.6% for low-, and 93.8% for high-risk tumors (p = 0.4). For interval cancers, there was a significantly lower 8-year DMFI rate for patients with 70-GS high-risk tumors (85.2%) compared to low- (92.2%) and ultralow-risk tumors (97.4%, p = 0.0023). Among patients with 70-GS high-risk tumors, a significant difference in 8-year DMFI rate was observed between interval (85.2%, n = 166) versus screen-detected cancers (93.8%, n = 238; p = 0.002) with a HR of 2.3 (95%CI 1.2-4.4, p = 0.010) adjusted for clinical-pathological characteristics and adjuvant systemic treatment. CONCLUSION: Among patients with 70-GS high-risk tumors, a significant difference in DMFI was observed between screen-detected and interval cancers, suggesting that method of detection is an additional prognostic factor in this subgroup and should be taken into account when deciding on adjuvant treatment strategies.

Incidence, clinical features, and outcomes of special types in breast cancer in a single institution population.

The low incidence of special types of breast cancer hinders adequate clinical research efforts. As such, collecting sufficient data to develop well-established therapy strategies are difficult. The aim of our study was to obtain more data on these special types in order to better understand the different characteristics and optimize therapy strategies. A single-institution retrospective cohort study from January 2007 until September 2015. One hundred and five patients remained after excluding the patients with invasive ductal and lobular carcinoma. The percentage of these so called special types in this population was 4%. Tubular carcinoma, cribriform carcinoma, carcinoma with medullary features, carcinoma with apocrine differentiation, secretory carcinoma, mucinous carcinoma, and invasive papillary carcinoma had a good or excellent prognosis, while invasive micropapillary carcinoma, adenoid cystic carcinoma, metaplastic carcinoma, and carcinoma with neuroendocrine features had a worse prognosis. Special types of breast cancer form a heterogeneous group. Submitting them all to the same treatment modality may lead to both over- and under-treatment. We need to combine our data to optimize treatment strategies for the different special types.

Immunohistochemical versus molecular (BluePrint and MammaPrint) subtyping of breast carcinoma. Outcome results from the EORTC 10041/BIG 3-04 MINDACT trial.

PURPOSE: This study compares immunohistochemical (IHC) versus molecular subtyping (BluePrint and MammaPrint) in the population of patients enrolled in MINDACT and outcome based on molecular subtyping (MS) versus surrogate pathological subtyping (PS) as defined by the 2013 St. Gallen guidelines. METHODS: MS classified patients in the following subtypes: Luminal A, Luminal B, HER-2-, and Basal-type. IHC/FISH for pathological subtyping (ER, PgR, HER-2, and Ki67) was centrally assessed in the European Institute of Oncology (n = 5806). Hazard ratios for distant-metastasis-free survival (DMFS) by subtype were adjusted for chemotherapy and endocrine therapy administration and thus independent of adjuvant treatment allocation. RESULTS: PS Luminal cancers classified as HER-2+ or Basal-type by MS did not have a significantly lower DMFS than the Luminal-type cancers by MS (95.9%): HR = 1.40, 95% CI 0.75-2.60 (p = 0.294). More patients were identified with Luminal A disease by MS (63%) as compared with PS (47%) with comparable 5-year DMFS (≥96.0%). Among the 500 patients with PS TN cancers, MS identified 24 (5%) patients as Luminal-type with 5-year DMFS estimated at 100% versus 71.4% for MS HER-2+ or 90.1% for MS Basal-type. CONCLUSIONS: MS was able to re-stratify 54% of patients with a Luminal-B PS subtype to a low-risk Luminal A-type group with comparable outcome. Among TN EBC, 5% were classified as Luminal by MS with Luminal-like outcome. Molecular classification can help to identify a larger group of patients with low risk of recurrence compared with the more contemporarily used classification methodology including high-quality assessed Ki67.

De-escalating and escalating treatments for early-stage breast cancer: the St. Gallen International Expert Consensus Conference on the Primary Therapy of Early Breast Cancer 2017.

The 15th St. Gallen International Breast Cancer Conference 2017 in Vienna, Austria reviewed substantial new evidence on loco-regional and systemic therapies for early breast cancer. Treatments were assessed in light of their intensity, duration and side-effects, seeking where appropriate to escalate or de-escalate therapies based on likely benefits as predicted by tumor stage and tumor biology. The Panel favored several interventions that may reduce surgical morbidity, including acceptance of 2 mm margins for DCIS, the resection of residual cancer (but not baseline extent of cancer) in women undergoing neoadjuvant therapy, acceptance of sentinel node biopsy following neoadjuvant treatment of many patients, and the preference for neoadjuvant therapy in HER2 positive and triple-negative, stage II and III breast cancer. The Panel favored escalating radiation therapy with regional nodal irradiation in high-risk patients, while encouraging omission of boost in low-risk patients. The Panel endorsed gene expression signatures that permit avoidance of chemotherapy in many patients with ER positive breast cancer. For women with higher risk tumors, the Panel escalated recommendations for adjuvant endocrine treatment to include ovarian suppression in premenopausal women, and extended therapy for postmenopausal women. However, low-risk patients can avoid these treatments. Finally, the Panel recommended bisphosphonate use in postmenopausal women to prevent breast cancer recurrence. The Panel recognized that recommendations are not intended for all patients, but rather to address the clinical needs of the majority of common presentations. Individualization of adjuvant therapy means adjusting to the tumor characteristics, patient comorbidities and preferences, and managing constraints of treatment cost and access that may affect care in both the developed and developing world.

Combined PET-CT and axillary lymph node marking with radioactive iodine seeds (MARI procedure) for tailored axillary treatment in node-positive breast cancer after neoadjuvant therapy.

BACKGROUND: The treatment of axillary lymph node metastases after neoadjuvant systemic therapy (NST) remains debatable and axillary lymph node dissection (ALND) is still the standard of care. Marking axillary lymph nodes with radioactive iodine seeds (MARI procedure) is accurate in restaging the axilla after NST (false-negative rate 7 per cent). Here, the potential of tailored axillary treatment, determined by combining the results of PET-CT before NST with those of the MARI procedure after NST, was analysed. METHODS: A cohort of axillary node-positive patients was used to construct a hypothetical treatment algorithm based on a combination of PET-CT and the MARI procedure. In the algorithm, the number of fluorodeoxyglucose (FDG)-avid axillary lymph nodes (1-3 versus 4 or more) before NST and the tumour status of the MARI node (positive versus negative) after NST were used to tailor axillary treatment. All patients in the cohort underwent ALND, allowing estimation of potential overtreatment and undertreatment. RESULTS: A total of 93 patients were included in the study. Between one and three FDG-avid axillary lymph nodes were observed in 59 patients, and four or more in 34 patients. The MARI node was tumour-negative in 32 patients and showed residual disease in 61. Treatment according to the constructed algorithm would have resulted in 74 per cent of patients avoiding an ALND, with potential undertreatment in three patients (3 per cent) and overtreatment in 16 (17 per cent). CONCLUSION: Tailored axillary treatment after NST in node-positive patients, by combining PET-CT before NST and the MARI procedure after NST, has the potential for ALND to be avoided in 74 per cent of patients.

Changes over time in the impact of gene-expression profiles on the administration of adjuvant chemotherapy in estrogen receptor positive early stage breast cancer patients: A nationwide study.

Ten years ago gene-expression profiles were introduced to aid adjuvant chemotherapy decision making in breast cancer. Since then subsequent national guidelines gradually expanded the indication area for adjuvant chemotherapy. In this nation-wide study the evolution of the proportion of patients with estrogen-receptor positive (ER+) tumors receiving adjuvant chemotherapy in relation to gene-expression profile use in patient groups that became newly eligible for chemotherapy according to national guideline changes over time is assessed. Data on all surgically treated early breast cancer patients diagnosed between 2004-2006 and 2012-2014 were obtained from the Netherlands Cancer Registry. ER+/Her2- patients with tumor-characteristics making them eligible for gene-expression testing in both cohorts and a discordant chemotherapy recommendation over time (2004 guideline not recommending and 2012 guideline recommending chemotherapy) were identified. We identified 3,864 patients eligible for gene-expression profile use during both periods. Gene-expression profiles were deployed in 5% and 35% of the patients in the respective periods. In both periods the majority of patients was assigned to a low genomic risk-profile (67% and 69%, respectively) and high adherence rates to the test result were observed (86% and 91%, respectively). Without deploying a gene-expression profile 8% and 52% (p <0.001) of the respective cohorts received chemotherapy while 21% and 28% of these patients received chemotherapy when a gene-expression profile was used (p 0.191). In conclusion, in ER+/Her2- early stage breast cancer patients gene-expression profile use was associated with a consistent proportion of patients receiving chemotherapy despite an adjusted guideline-based recommendation to administer chemotherapy.

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.

Very low local recurrence rates after breast-conserving therapy: analysis of 8485 patients treated over a 28-year period.

The purpose of this study was to study the impact of changes in clinical practice on outcome in patients treated with breast-conserving therapy (BCT) over a period of 28 years. Patients with early invasive breast cancer, who were treated with BCT at the Netherlands Cancer Institute between 1980 and 2008, were studied. Clinical characteristics, treatment and outcome were compared between groups (1980-1987; 1988-1998; 1999-2008). The main endpoint analyzed was ipsilateral breast tumor recurrence (IBTR). 8485 patients with a median follow-up of 9 years (IQR 6-14 years) were analyzed. The cumulative 5- and 10-year IBTR incidences were, respectively, 2 and 5 % for the whole cohort and 4 and 9 % in patients ≤40 years. Young age was a significant risk factor for IBTR in multivariable analysis. IBTR-free interval was better for patients who received a RT boost (HR 0.65) or systemic therapy (HR 0.52). In later years, patients less often received a boost and more often underwent adjuvant systemic treatment. 761 patients (9.0 %) underwent a re-excision; the tumor resection margins were tumor free for 85 %. In later years (1999-2008), 89 % of patients had a tumor-free margin. The margin status of invasive carcinoma did not influence IBTR, DM rate, or OS. Between 1980 and 2008, locoregional control after BCT remained stable with low IBTR rates, even in young patients. These good results were achieved under the policy of accepting close or focally positive margins, indicating this is a safe approach. The results of this study may help in lowering the re-excision rates, which are high in many centers.

Using a gene expression signature when controversy exists regarding the indication for adjuvant systemic treatment reduces the proportion of patients receiving adjuvant chemotherapy: a nationwide study.

PURPOSE: The Dutch national guideline advises use of gene-expression signatures, such as the 70-gene signature (70-GS), in case of ambivalence regarding the benefit of adjuvant chemotherapy (CT). In this nationwide study, the impact of 70-GS use on the administration of CT in early breast cancer patients with a dubious indication for CT is assessed. METHODS: Patients within a national guideline directed indication area for 70-GS use who were surgically treated between November 2011 and April 2013 were selected from the Netherlands Cancer Registry database. The effect of 70-GS use on the administration of CT was evaluated in guideline- and age-delineated subgroups addressing potential effect of bias by linear mixed-effect modeling and instrumental variable (IV) analyses. RESULTS: A total of 2,043 patients within the indicated area for 70-GS use were included, of whom 298 received a 70-GS. Without use of the 70-GS, 45% of patients received CT. The 70-GS use was associated with a 9.5% decrease in CT administration (95% confidence interval (CI): -15.7 to -3.3%) in linear mixed-effect model analyses and IV analyses showed similar results (-9.9%; 95% CI: -19.3 to -0.4). CONCLUSION: In patients in whom the Dutch national guidelines suggest the use of a gene-expression profile, 70-GS use is associated with a 10% decrease in the administration of adjuvant CT.Genet Med 18 7, 720-726.Genetics in Medicine (2016); 18 7, 720-726. doi:10.1038/gim.2015.152.

Radioactive seed localization in breast cancer treatment.

BACKGROUND: Breast cancer screening, improved imaging and neoadjuvant systemic therapy (NST) have led to increased numbers of non-palpable tumours suitable for breast-conserving surgery (BCS). Accurate tumour localization is essential to achieve a complete resection in these patients. This study evaluated the role of radioactive seed localization (RSL) in improving breast- and axilla-conserving surgery in patients with breast cancer with or without NST. METHODS: Patients who underwent RSL between 2007 and 2014 were included. Learning curves were analysed by the rates of minimally involved (in situ/invasive tumour cells on a length of 0-4 mm on ink) and positive resection margins (over 4 mm on ink) after BCS, and the median resection volume over time. RESULTS: A total of 367 patients with in situ carcinomas and 199 with non-palpable invasive breast cancer underwent RSL before primary surgery. A further 697 patients had RSL before NST, of whom 206 also underwent RSL of a histologically verified axillary lymph node metastasis. BCS was performed in 93·2 and 87·9 per cent of patients undergoing primary surgery for in situ and invasive tumours respectively, and 57·5 per cent of those in the NST group. The rate of BCS with positive resection margins was low and stable over time in the three groups (9·1, 9·7 and 11·2 per cent respectively). The median resection volume decreased significantly with time in the invasive cancer and NST groups. CONCLUSION: In the present study of more than 1200 patients and 7 years of experience, RSL was shown to facilitate breast- and axilla-conserving surgery in a diverse patient population. There was a significant reduction in resection volume while maintaining low positive resection margin rates after BCS.

Repeat sentinel node biopsy should be considered in patients with locally recurrent breast cancer.

Most patients with locally recurrent breast cancer undergo axillary lymph node dissection (ALND). However, repeat sentinel node biopsy (SNB) could provide regional nodal staging and obviate the need for standard ALND. The Sentinel Node and Recurrent Breast Cancer (SNARB) study is a Dutch nationwide registration study conducted to determine feasibility, aberrant drainage rates, and clinical consequences of repeat SNB. A total of 536 patients with locally recurrent non-metastatic breast cancer underwent lymphatic mapping and repeat SNB in 29 Dutch hospitals. A repeat sentinel node (SN) was identified in 333 of 536 patients (62.1 %) and surgically harvested in 287 patients (53.5 %). Aberrant lymph drainage was observed in 180 (54.1 %) of the 333 patients, more often after previous ALND (81.9 %) than SNB (28.4 %; P < 0.001). In 230 patients (80.1 %), the retrieved SN was tumor negative; 17 SNs (5.9 %) contained a micrometastasis and 29 (10.1 %) a macrometastasis. Confirmation ALND in 31 repeat SN-negative patients revealed a macrometastasis in two patients (6.5 %). The negative predictive value (NPV) of repeat SNB was 93.6 %, and ALND was omitted in 109 of the 248 patients (44.0 %) with a negative repeat SN. In 29 of the 44 patients (63.0 %) with a positive SN, adjuvant treatment plans were altered based on the repeat SNB. Repeat SNB is a feasible procedure with a high NPV, leading to a change in management in a substantial proportion of patients. Therefore, repeat SNB should replace routine ALND and serve as the standard of care in recurrent breast cancer.

The Value of Ipsilateral Breast Tumor Recurrence as a Quality Indicator: Hospital Variation in the Netherlands.

PURPOSE: All Dutch hospitals are obliged to report their 5-year ipsilateral breast tumor recurrence (IBTR) rate after breast cancer surgery. Experts decided that these rates should not exceed 5 %. This study determined the value of IBTR as an indicator to compare quality of care between hospitals. METHODS: All patients with breast cancer (pT1-3, any N, M0) who underwent surgery in 1 of 92 Dutch hospitals from 2003 to 2006 were identified in the Netherlands Cancer Registry. Data of recurrence was retrieved from hospital records. Five-year IBTR rates for breast-conserving surgery (BCS) and mastectomy were calculated by using the Kaplan-Meier method. Hospital variation was presented in funnel plots. Multivariate analysis was used to assess hospital characteristics associated with IBTR rates. RESULTS: A total of 40,892 breast cancer patients were included. The overall 5-year IBTR rate was 2.85 % (95 % confidence interval 2.68-3.03) and was significantly lower for BCS than for mastectomy (2.38 vs. 3.45 %, p < 0.001). IBTR rates decreased over time in both groups. Rates varied between 0.77 and 5.70 % between hospitals. When random variation is taken into account, only extremely high IBTR rates can be detected as deviant from the target value of 5 %. Adjusting for tumor and patient characteristics, analyses showed that a higher volume of mastectomies is associated with lower IBTR rates. CONCLUSIONS: Our population-based findings show that IBTR rates in the Netherlands are low and have improved over time. The 5-year IBTR rate as an indicator for quality of care of individual hospitals is of limited value.

Improving the Success Rate of Repeat Sentinel Node Biopsy in Recurrent Breast Cancer.

PURPOSE: Repeat sentinel node biopsy (SNB) is an alternative to axillary lymph node dissection (ALND) for axillary staging in recurrent breast cancer. This study was conducted to determine factors associated with technical success of repeat SNB. METHODS: A total of 536 patients with locally recurrent nonmetastatic breast cancer underwent lymphatic mapping (LM) and repeat SNB in 29 Dutch hospitals. RESULTS: A total of 179 patients previously underwent breast-conserving surgery (BCS) with SNB, 262 patients BCS with ALND and 61 patients mastectomy, 35 with SNB and 26 with ALND. Another 34 patients underwent breast surgery without axillary interventions. A repeat sentinel node (SN) was identified in 333 patients (62.1 %) and was successfully removed in 235 (53.5 %). The overall repeat SN identification rate was 62.1 %, varying from 35 to 100 % in the participating hospitals. Previous radiotherapy of the breast [odds ratio (OR) 0.16; 95 % confidence interval (CI) 0.03-0.84], subareolar tracer injection (OR 0.34; 95 % CI 0.16-0.73), and a 2-day LM protocol (OR 0.57; 95 % CI 0.33-0.97) after previous BCS were independently associated with failure of SN identification. Injection of a larger amount of tracer (>180 MBq) led to a higher identification rate (OR 4.40; 95 % CI 1.45-13.32). CONCLUSIONS: Repeat SNB is a technically feasible procedure for axillary staging in recurrent breast cancer patients. Previous radiotherapy appears to be associated with failure of SN identification. Injection with a larger amount of tracer (>180 MBq) leads to a higher identification rate; subareolar injection and a 2-day LM protocol after previous BCS appear to be less adequate.

Impact of rapid genetic counselling and testing on the decision to undergo immediate or delayed prophylactic mastectomy in newly diagnosed breast cancer patients: findings from a randomised controlled trial.

BACKGROUND: Female breast cancer patients with a BRCA1/2 mutation have an increased risk of contralateral breast cancer. We investigated the effect of rapid genetic counselling and testing (RGCT) on choice of surgery. METHODS: Newly diagnosed breast cancer patients with at least a 10% risk of a BRCA1/2 mutation were randomised to an intervention group (offer of RGCT) or a control group (usual care; ratio 2 : 1). Primary study outcomes were uptake of direct bilateral mastectomy (BLM) and delayed contralateral prophylactic mastectomy (CPM). RESULTS: Between 2008 and 2010, we recruited 265 women. On the basis of intention-to-treat analyses, no significant group differences were observed in percentage of patients opting for a direct BLM (14.6% for the RGCT group vs 9.2% for the control group; odds ratio (OR) 2.31; confidence interval (CI) 0.92-5.81; P=0.08) or for a delayed CPM (4.5% for the RGCT group vs 5.7% for the control group; OR 0.89; CI 0.27-2.90; P=0.84). Per-protocol analysis indicated that patients who received DNA test results before surgery (59 out of 178 women in the RGCT group) opted for direct BLM significantly more often than patients who received usual care (22% vs 9.2%; OR 3.09, CI 1.15-8.31, P=0.03). INTERPRETATION: Although the large majority of patients in the intervention group underwent rapid genetic counselling, only a minority received DNA test results before surgery. This may explain why offering RGCT yielded only marginally significant differences in uptake of BLM. As patients who received DNA test results before surgery were more likely to undergo BLM, we hypothesise that when DNA test results are made routinely available pre-surgery, they will have a more significant role in surgical treatment decisions.

Long-term impact of the 70-gene signature on breast cancer outcome.

Several studies have validated the prognostic value of the 70-gene prognosis signature (MammaPrint(R)), but long-term outcome prediction of these patients has not been previously reported. The follow-up of the consecutively treated cohort of 295 patients (<53 years) with invasive breast cancer (T1-2N0-1M0; n = 151 N0, n = 144 N1) diagnosed between 1984 and 1995, in which the 70-gene signature was previously validated, was updated. The median follow-up for this series is now extended to 18.5 years. A significant difference is seen in long-term distant metastasis-free survival (DMFS) for the patients with a low- and a high-risk 70-gene signature (DMFS p < 0.0001), as well as separately for node-negative (DMFS p < 0.0001) and node-positive patients (DMFS p = 0.0004). The 25-year hazard ratios (HRs) for all patients for DMFS and OS were 3.1 (95 % CI 2.02-4.86) and 2.9 (95 % CI 1.90-4.28), respectively. The HRs for DMFS and OS were largest in the first 5 years after diagnosis: 9.6 (95 % CI 4.2-22.1) and 11.3 (95 % CI 3.5-36.4), respectively. The 25-year HRs in the subgroup of node-negative patients for DMFS and OS were 4.57 (95 % CI 2.31-9.04) and 4.73 (95 % CI 2.46-9.07), respectively, and for node-positive patients for DMFS and OS were 2.24 (95 % CI 1.25-4.00) and 1.83 (95 % CI 1.07-3.11), respectively. The 70-gene signature remains prognostic at longer follow-up in patients <53 years of age with stage I and II breast cancer. The 70-gene signature's strongest prognostic power is seen in the first 5 years after diagnosis.

Gene expression profiling to predict the risk of locoregional recurrence in breast cancer: a pooled analysis.

The 70-gene signature (MammaPrint) has been developed to predict the risk of distant metastases in breast cancer and select those patients who may benefit from adjuvant treatment. Given the strong association between locoregional and distant recurrence, we hypothesize that the 70-gene signature will also be able to predict the risk of locoregional recurrence (LRR). 1,053 breast cancer patients primarily treated with breast-conserving treatment or mastectomy at the Netherlands Cancer Institute between 1984 and 2006 were included. Adjuvant treatment consisted of radiotherapy, chemotherapy, and/or endocrine therapy as indicated by guidelines used at the time. All patients were included in various 70-gene signature validation studies. After a median follow-up of 8.96 years with 87 LRRs, patients with a high-risk 70-gene signature (n = 492) had an LRR risk of 12.6% (95% CI 9.7-15.8) at 10 years, compared to 6.1% (95% CI 4.1-8.5) for low-risk patients (n = 561; P < 0.001). Adjusting the 70-gene signature in a competing risk model for the clinicopathological factors such as age, tumour size, grade, hormone receptor status, LVI, axillary lymph node involvement, surgical treatment, endocrine treatment, and chemotherapy resulted in a multivariable HR of 1.73 (95% CI 1.02-2.93; P = 0.042). Adding the signature to the model based on clinicopathological factors improved the discrimination, albeit non-significantly [C-index through 10 years changed from 0.731 (95% CI 0.682-0.782) to 0.741 (95% CI 0.693-0.790)]. Calibration of the prognostic models was excellent. The 70-gene signature is an independent prognostic factor for LRR. A significantly lower local recurrence risk was seen in patients with a low-risk 70-gene signature compared to those with high-risk 70-gene signature.

Mammographic screening detects low-risk tumor biology breast cancers.

Overdiagnosis of breast cancer, i.e. the detection of slow-growing tumors that would never have caused symptoms or death, became more prevalent with the implementation of population-based screening. Only rough estimates have been made of the proportion of patients that are overdiagnosed and identification of those patients is difficult. Therefore, the aim of this study is to evaluate whether tumor biology can help identify patients with screen-detected tumors at such a low risk of recurrence that they are likely to be overdiagnosed. Furthermore, we wish to evaluate the impact of the transition from film-screen mammography (FSM) to the more sensitive full-field digital mammography (FFDM) on the biology of the tumors detected by each screening-modality. All Dutch breast cancer patients enrolled in the MINDACT trial (EORTC-10041) accrued 2007-2011, who participated in the national screening program (biennial screening ages 50-75) were included (n = 1,165). We calculated the proportions of high-, low- and among those the ultralow-risk tumors according to the 70-gene signature for patients with screen-detected (n = 775) and interval (n = 390) cancers for FSM and FFDM. Screen-detected cancers had significantly more often a low-risk tumor biology (68 %) of which 54 % even an ultralow-risk compared to interval cancers (53 % low-, of which 45 % ultralow-risk (p = 0.001) with an OR of 2.33 (p < 0.0001; 95 % CI 1.73-3.15). FFDM detected significantly more high-risk tumors (35 %) compared to FSM (27 %) (p = 0.011). Aside from favorable clinico-pathological factors, screen-detected cancers were also more likely to have a biologically low-risk or even ultralow-risk tumor. Especially for patients with screen-detected cancers the use of tools, such as the 70-gene signature, to differentiate breast cancers by risk of recurrence may minimize overtreatment. The recent transition in screening-modalities led to an increase in the detection of biologically high-risk cancers using FFDM.

Optimized outcome prediction in breast cancer by combining the 70-gene signature with clinical risk prediction algorithms.

Clinical guidelines for breast cancer treatment differ in their selection of patients at a high risk of recurrence who are eligible to receive adjuvant systemic treatment (AST). The 70-gene signature is a molecular tool to better guide AST decisions. The aim of this study was to evaluate whether adding the 70-gene signature to clinical risk prediction algorithms can optimize outcome prediction and consequently treatment decisions in early stage, node-negative breast cancer patients. A 70-gene signature was available for 427 patients participating in the RASTER study (cT1-3N0M0). Median follow-up was 61.6 months. Based on 5-year distant-recurrence free interval (DRFI) probabilities survival areas under the curve (AUC) were calculated and compared for risk estimations based on the six clinical risk prediction algorithms: Adjuvant! Online (AOL), Nottingham Prognostic Index (NPI), St. Gallen (2003), the Dutch National guidelines (CBO 2004 and NABON 2012), and PREDICT plus. Also, survival AUC were calculated after adding the 70-gene signature to these clinical risk estimations. Systemically untreated patients with a high clinical risk estimation but a low risk 70-gene signature had an excellent 5-year DRFI varying between 97.1 and 100 %, depending on the clinical risk prediction algorithms used in the comparison. The best risk estimation was obtained in this cohort by adding the 70-gene signature to CBO 2012 (AUC: 0.644) and PREDICT (AUC: 0.662). Clinical risk estimations by all clinical algorithms improved by adding the 70-gene signature. Patients with a low risk 70-gene signature have an excellent survival, independent of their clinical risk estimation. Adding the 70-gene signature to clinical risk prediction algorithms improves risk estimations and therefore might improve the identification of early stage node-negative breast cancer patients for whom AST has limited value. In this cohort, the PREDICT plus tool in combination with the 70-gene signature provided the best risk prediction.