The combined endocrine receptor in breast cancer, a novel approach to traditional hormone receptor interpretation and a better discriminator of outcome than ER and PR alone

Estrogen/HER2 receptor crosstalk in breast cancer: combination therapies to improve outcomes for patients with hormone receptor-positive/HER2-positive breast cancer

The human epidermal growth factor receptor 2 (HER2) is overexpressed in 13-22% of breast cancers (BC). Approximately 60-70% of HER2+ BC co-express hormone receptors (HRs). HR/HER2 co-expression modulates response to both anti-HER2-directed and endocrine therapy due to "crosstalk" between the estrogen receptor (ER) and HER2 pathways. Combined HER2/ER blockade may be an effective treatment strategy for patients with HR+/HER2+ BC in the appropriate clinical setting(s). In this review, we provide an overview of crosstalk between the ER and HER2 pathways, summarize data from recently published and ongoing clinical trials, and discuss clinical implications for targeted treatment of HR+/HER2+ BC.

Prediction of Oncotype DX Recurrence Score Using Clinicopathological Variables in Estrogen Receptor-Positive/Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer

PURPOSE

Oncotype DX (ODX) is a well-validated multigene assay that is increasingly used in Korean clinical practice. This study aimed to develop a clinicopathological prediction (CPP) model for the ODX recurrence scores (RSs).

METHODS

A total of 297 patients (study group, n = 175; external validation group, n = 122) with estrogen receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative, T1-3N0-1M0 breast cancer, and available ODX test results were included in the study. Risk categorization as determined by ODX RSs concurred with the TAILORx study (low-risk, RS ≤ 25; high-risk, RS > 25). Univariate and multivariate logistic regression analyses were used to assess the relationships between clinicopathological variables and risk stratified by the ODX RSs. A CPP model was constructed based on regression coefficients (β values) for clinicopathological variables significant by multivariate regression analysis.

RESULTS

Progesterone receptor (PR) negativity, high Ki-67 index, and nuclear grade (NG) 3 independently predicted high-risk RS, and these variables were used to construct the CPP model. The C-index, which represented the discriminatory ability of our CPP model for predicting a high-risk RS, was 0.915 (95% confidence interval [CI], 0.859-0.971). When the CPP model was applied to the external validation group, the C-index was 0.926 (95% CI, 0.873-0.978).

CONCLUSION

Our CPP model based on PR, Ki-67 index, and NG could aid in the selection of patients with breast cancer requiring an ODX test.

Morphological Features and Immunohistochemical Profiling of Male Breast Gynaecomastia; A Large Tissue Microarray Study

Introduction

Gynaecomastia is the commonest male breast condition accounting for approximately 85% of male breast lesions. There is minimal information on the immunohistochemical profile of gynaecomastia. We aimed to comprehensively profile a large series of gynaecomastia samples for putative mammary diagnostic, predictive and prognostic markers.

Methods

A total of 156 samples, were histologically reviewed, assembled onto tissue microarrays, and stained for oestrogen receptors (ERα, ERβ1, ERß2), progesterone receptors (total PR, PRα), androgen receptor (AR), basal & luminal cytokeratins (CK5/6, CK14, CK8/18) and the proliferation marker Ki67. Relevant cut offs for marker positivity were defined based on existing literature: AR (10%), ERα and PR (Allred score >3/8), ERß (10% and 20%), cytokeratins (10%) and Ki67 (10% and 20%).

Results

108 samples from 86 patients aged 13-75 years were available for immunohistochemical assessment. 73.1% of the lesions were AR positive, compared to 99% for ERα and 100% for both ERß1 and ERß2. 98% of samples were positive for total PR and 97.1% for PRα. 69.8% expressed CK5/6 whilst 57% were CK14 positive. A tri-layered pattern of cytokeratin expression was also observed. Ki67 positivity was low with 17.1% and 6.7% classified as Ki67 positive using 10% and 20% cut off values respectively. A significant negative correlation was found between ERα expression and patient age (rs = -0.221, p=0.023). Bivariate correlations were produced, and comparisons made with previously published data regarding the immunohistochemical status in normal female breast tissue, proliferative and neoplastic breast diseases of the female and male breast.

Conclusions

Hormone receptors, including oestrogen receptor α and ß isoforms as well as androgen receptors were abundantly expressed within the intraductal luminal hyperplastic epithelium in gynaecomastia supporting the hormonal role in the pathogenesis and treatment. ERα, ERβ1 and ERβ2 were expressed in a higher proportion of cells compared with their expression in the female breast benign lesions which further characterises gynaecomastia biology. The identification of a low Ki67 proliferative index and the mixed cytokeratin profile in gynaecomastia differentiates this benign condition from male breast cancer. Therefore, Ki67 and cytokeratins can help in the differential diagnosis from histological mimics in the routine diagnostic work up.

Type 1 Nuclear Receptor Activity in Breast Cancer: Translating Preclinical Insights to the Clinic

The nuclear receptor (NR) family of transcription factors is intimately associated with the development, progression and treatment of breast cancer. They are used diagnostically and prognostically, and crosstalk between nuclear receptor pathways and growth factor signalling has been demonstrated in all major subtypes of breast cancer. The majority of breast cancers are driven by estrogen receptor α (ER), and anti-estrogenic therapies remain the backbone of treatment, leading to clinically impactful improvements in patient outcomes. This serves as a blueprint for the development of therapies targeting other nuclear receptors. More recently, pivotal findings into modulating the progesterone (PR) and androgen receptors (AR), with accompanying mechanistic insights into NR crosstalk and interactions with other proliferative pathways, have led to clinical trials in all of the major breast cancer subtypes. A growing body of evidence now supports targeting other Type 1 nuclear receptors such as the glucocorticoid receptor (GR), as well as Type 2 NRs such as the vitamin D receptor (VDR). Here, we reviewed the existing preclinical insights into nuclear receptor activity in breast cancer, with a focus on Type 1 NRs. We also discussed the potential to translate these findings into improving patient outcomes.

Prediction of Late Recurrence and Distant Metastasis in Early-stage Breast Cancer: Overview of Current and Emerging Biomarkers

Recently, a significant number of breast cancer (BC) patients have been diagnosed at an early stage. It is therefore critical to accurately predict the risk of recurrence and distant metastasis for better management of BC in this setting. Clinicopathologic patterns, particularly lymph node status, tumor size, and hormonal receptor status are routinely used to identify women at increased risk of recurrence. However, these factors have limitations regarding their predictive ability for late metastasis risk in patients with early BC. Emerging molecular signatures using gene expression-based approaches have improved the prognostic and predictive accuracy for this indication. However, the use of their based-scores for risk assessment has provided contradictory findings. Therefore, developing and using newly emerged alternative predictive and prognostic biomarkers for identifying patients at high- and low-risk is of great importance. The present review discusses some serum biomarkers and multigene profiling scores for predicting late recurrence and distant metastasis in early-stage BC based on recently published studies and clinical trials.

Hormone Receptor Expression on Endocrine Therapy in Patients with Breast Cancer: A Meta-Analysis

OBJECTIVE

To evaluate the role of hormone receptor expression on endocrine therapy in patients with breast cancer.

METHODS

The databases were used to collect the effect of high expression and low expression of hormone receptors on the efficacy of endocrine therapy in breast cancer. Two evaluators independently screened the literature based on preset inclusion and exclusion criteria. The quality of the article was evaluated using a modified Newcastle-Ottawa Scale (NOS) system. The survival data included in the literature were extracted and the ln(hazard ratio (HR)) and se[ln(HR)] of the overall survival (OS), disease-free survival (DFS), and recurrence-free survival (RFS) rates were calculated according to different level of hormone receptors. The RevMan 5.3 software was used to evaluate the meta-analysis.

RESULTS

A total of 13 relevant literature were included in the study. There were 8318 estrogen receptor (ER)-positive and 7926 progesterone receptor (PR)-positive patients. Overall survival, DFS, and RFS rates in high expression of ER(+) patients were significantly higher in low expression of ER(+) patients (OS HR = .59, 95% confidence interval (CI): .46-.76, P < .0001; DFS HR = .62, 95%CI: .50-.76, P < .00001; RFS HR = .44, 95% CI: .33-.58, P < .00001). In patients with high expression of PR(+), OS, DFS, and RFS rates were significantly higher than those with low expression of PR(+) (OS HR = .66, 95% CI: .57-.78, P < .00001; DFS HR = .52, 95% CI: .42-.65, P < .00001; RFS HR = .24, 95% CI: .11-.53, P = .0004).

CONCLUSION

The expression of ER and PR are powerful predictors of adjuvant endocrine therapy response. Breast cancer patients with high expression of hormone receptors benefit more from endocrine therapy and have better prognosis.

Sequential Colocalization of ERa, PR, and AR Hormone Receptors Using Confocal Microscopy Enables New Insights into Normal Breast and Prostate Tissue and Cancers

Simple Summary

At present, platforms for multiplex immunohistochemistry (e.g., Opal) identify markers in distinct cell populations within a tissue section using multispectral fluorescence and optic microscopy. However, the optic resolution is not enough to colocalize markers at the subcellular level in the main epithelial or cancer population. We use confocal microscopy in multiplex detection of nuclear hormone receptors since they are an important part of the diagnosis and treatment of breast and prostate cancer. Moreover, we increased the quantitative dynamic range and resolution through increasing the signal/noise ration through reducing autofluorescence and increased longer antibody incubations. ColNu mIHCF identified distinct patterns of nuclear receptor colocalization in breast cancers. Furthermore, in prostate cancer all cancer epithelium was positive for ERa at the plasma membrane; and in normal prostate a small ERa+/p63+/AR− basal population suggest stem cell commitment to differentiation. ColNu mIHCF could be used for improving diagnosis and treatment in cancer.

Abstract

Multiplex immunohistochemistry (mIHC) use markers staining different cell populations applying widefield optical microscopy. Resolution is low not resolving subcellular co-localization. We sought to colocalize markers at subcellular level with antibodies validated for clinical diagnosis, including the single secondary antibody (combination of anti-rabbit/mouse-antibodies) used for diagnostic IHC with any primary antibody, and confocal microscopy. We explore colocalization in the nucleus (ColNu) of nuclear hormone receptors (ERa, PR, and AR) along with the baseline marker p63 in paired samples of breast and prostate tissues. We established ColNu mIHCF as a reliable technique easily implemented in a hospital setting. In ERa+ breast cancer, we identified different colocalization patterns (nuclear or cytoplasmatic) with PR and AR on the luminal epithelium. A triple-negative breast-cancer case expressed membrane-only ERa. A PR-only case was double positive PR/p63. In normal prostate, we identified an ERa+/p63+/AR-negative distinct population. All prostate cancer cases characteristically expressed ERa on the apical membrane of the AR+ epithelium. We confirmed this using ERa IHC and needle-core biopsies. ColNu mIHCF is feasible and already revealed a new marker for prostate cancer and identified sub-patterns in breast cancer. It could be useful for pathology as well as for functional studies in normal prostate and breast tissues.

Evaluating the Age-Based Recommendations for Long-Term Follow-Up in Breast Cancer

BACKGROUND

After 5 years of annual follow-up following breast cancer, Dutch guidelines are age based: annual follow-up for women <60 years, 60-75 years biennial, and none for >75 years. We determined how the risk of recurrence corresponds to these consensus-based recommendations and to the risk of primary breast cancer in the general screening population.

SUBJECTS, MATERIALS, AND METHODS

Women with early-stage breast cancer in 2003/2005 were selected from the Netherlands Cancer Registry (n = 18,568). Cumulative incidence functions were estimated for follow-up years 5-10 for locoregional recurrences (LRRs) and second primary tumors (SPs). Risks were compared with the screening population without history of breast cancer. Alternative cutoffs for age were determined by log-rank tests.

RESULTS

The cumulative risk for LRR/SP was lower in women <60 years (5.9%, 95% confidence interval [CI] 5.3-6.6) who are under annual follow-up than for women 60-75 (6.3%, 95% CI 5.6-7.1) receiving biennial visits. All risks were higher than the 5-year risk of a primary tumor in the screening population (ranging from 1.4% to 1.9%). Age cutoffs <50, 50-69, and > 69 revealed better risk differentiation and would provide more risk-based schedules. Still, other factors, including systemic treatments, had an even greater impact on recurrence risks.

CONCLUSION

The current consensus-based recommendations use suboptimal age cutoffs. The proposed alternative cutoffs will lead to a more balanced risk-based follow-up and thereby more efficient allocation of resources. However, more factors should be taken into account for truly individualizing follow-up based on risk for recurrence.

IMPLICATIONS FOR PRACTICE

The current age-based recommendations for breast cancer follow-up after 5 years are suboptimal and do not reflect the actual risk of recurrent disease. This results in situations in which women with higher risks actually receive less follow-up than those with a lower risk of recurrence. Alternative cutoffs could be a start toward risk-based follow-up and thereby more efficient allocation of resources. However, age, or any single risk factor, is not able to capture the risk differences and therefore is not sufficient for determining follow-up. More risk factors should be taken into account for truly individualizing follow-up based on the risk for recurrence.

The Mitotic Activity Index in combination with Her2neu: a strong prognosticator in breast cancer

PURPOSE

The aim of this study is to evaluate the prognostic value of the Mitotic Activity Index (MAI) in combination with the human epidermal growth factor receptor (Her2) for distant metastases-free survival (DMFS) and disease-specific survival (DSS) in breast cancer and compare it with the immunohistochemically (IHC) profile types.

METHODS

Analyses were based on 2.923 breast-conserving breast cancer specimens with known MAI, Her2 status, and hormone receptor status, resulting in 2.678 Her2MAI combinations, MAI ≤ 12/Her2negative, MAI > 12/Her2negative, MAI > 12/Her2positive, and MAI ≤ 12/Her2positive, and 2.560 IHC profile types, luminal A, luminal B, triple negative, and non-luminal Her2positive.

RESULTS

For DMFS, the MAI > 12/Her2negative combination showed a significantly worse outcome in multivariate analyses compared to the MAI ≤ 12/Her2negative combination. None of the IHC profile types showed significantly different outcomes for DMFS and DSS as compared to luminal A. We performed a separate analysis on age and lymph node status. The significance of MAI > 12/Her2negative seems to be limited to women ≤ 55 years for both DMFS and DSS. However, with respect to DSS, this seems to be limited to node negative cases. The IHC profile types for DSS, luminal B showed a significantly worse outcome for women > 55 years compared to that for luminal A, although it showed rather wide confidence interval.

CONCLUSION

The MAI > 12/Her2negative combination seems to be a strong prognosticator for DMFS and DSS, particularly for women ≤ 55 years. However, none of the IHC profile types seems to be a prognosticator in breast cancer.

Meta-analysis of the impact of progesterone receptor status on oncological outcomes in oestrogen receptor-positive breast cancer

BACKGROUND

Assessment of the oestrogen receptor (ER) provides important prognostic information in breast cancer. The impact of progesterone receptor (PgR) status is less clear. Standardization of immunohistochemical analysis of these receptors has reduced interstudy heterogeneity. The aim of this meta-analysis was to evaluate the impact of PgR negativity on outcomes in ER-positive (ER+) breast cancer.

METHODS

This study was performed according to PRISMA and MOOSE guidelines. PubMed, Embase and the Cochrane Library were searched systematically to identify studies comparing disease-free survival as the primary outcome and overall survival as secondary outcome between PgR-positive (PgR+) and PgR-negative (PgR-) status in ER+ breast cancer. A meta-analysis of time-to-effect measures from included studies was undertaken.

RESULTS

Eight studies including 13 667 patients, 11 838 in the ER+PgR+ group and 1829 in the ER+PgR- group, met the inclusion criteria. Treatment characteristics did not differ significantly between the two groups. Patients in the ER+PgR- group had a higher risk of disease recurrence than those who had ER+PgR+ disease (hazard ratio (HR) 1·57, 95 per cent c.i. 1·38 to 1·79; P < 0·001). This hazard was increased in patients with human epidermal growth factor receptor 2-negative tumours (HR 1·62, 1·37 to 1·93; P < 0·001). A similar result was observed for overall survival (HR 1·69, 1·33 to 2·14; P < 0·001).

CONCLUSION

PgR negativity is associated with significant reductions in disease-free and overall survival in ER+ breast cancer. Treatment and surveillance strategies in these patients should be tailored accordingly.

Reirradiation of recurrent breast cancer with proton beam therapy: A case report and literature review

BACKGROUND

Locoregional recurrence of breast cancer is challenging for clinicians, due to the various former treatments patients have undergone. However, treatment of the recurrence with systemic therapy and subsequent reirradiation of chest wall is accompanied by increased toxicities, particularly radiation-induced cardiovascular disease. Reirradiation by proton beam therapy (PBT) enables superior preservation of adjacent organs at risk as well as concurrent dose escalation for delivery to the gross tumor. This technology is expected to improve the overall outcome of recurrent breast cancer.

CASE SUMMARY

A 47-year-old female presented with an extensive locoregional recurrence at 10 yr after primary treatment of a luminal A breast cancer. Because of tumor progression despite having undergone bilateral ovarectomy and systemic therapy, the patient was treated with PBT BE total dose of 64.40 Gy to each gross tumor and 56.00 Gy to the upper mediastinal and retrosternal lymphatics including the entire sternum in 28 fractions. Follow-up computed tomography showed a partial remission, without evidence of newly emerging metastasis. At 19 mo after the PBT, the patient developed a radiation-induced pericardial disease and pleural effusions with clinical burden of dyspnea, which were successfully treated by drainage and corticosteroid. Cytological analysis of the puncture fluid showed no malignancy, and the subsequent computed tomography scan indicated stable disease as well as significantly decreased pericardial and pleural effusions. The patient remains free of progression to date.

CONCLUSION

PBT was a safe and effective method of reirradiation for locoregionally recurrent breast cancer in our patient.

Higher ER load is not associated with better outcome in stage 1-3 breast cancer: a descriptive overview of quantitative HR analysis in operable breast cancer

PURPOSE

In breast cancer, hormone receptor (HR) status is generally a qualitative measure; positive or negative. Quantitatively measured oestrogen and progesterone receptors (ER and PR) are frequently proposed prognostic and predictive markers, some guidelines even provide different treatment options for patients with strong versus weak expression.

AIM

To evaluate quantitative HR load assessed by immunohistochemistry as a prognostic and predictive measure in stage 1-3 breast cancer.

METHODS

We reviewed all the available literature on quantitatively measured HRs using immunohistochemistry.

RESULTS

All included studies (n = 19) comprised a cohort of 30,754 patients. Only 2 out of 17 studies found a clear correlation between higher quantitative ER and better disease outcome. Only one trial examined quantitative ER both as prognostic and predictive marker and found no association between ER% and survival. Ten studies examined quantitative PR load, only two of those found a significant correlation between higher PR load and better disease outcome. Two trials examined quantitative PR both as prognostic and predictive marker, neither found any association between PR% and disease outcome.

CONCLUSIONS

There is no clear evidence for using quantitatively assessed ER and PR as prognostic nor predictive marker in patients with stage 1-3 breast cancer. We recommend only using a qualitative HR status in future guidelines and treatment considerations.

Dasatinib inhibition of cSRC prevents the migration and metastasis of canine mammary cancer cells with enhanced Wnt and HER signalling

Human epidermal growth factor 2 (HER2) overexpression leads to aggressive mammary tumour growth. Although the prognosis of HER2⁺ tumours in humans is greatly improved using biologicals, therapy resistance, which may be caused by increased phosphatidyl-3-kinase (PI3K), rous sarcoma proto-oncogene (cSRC) or wingless-type MMTV integration site family (Wnt) activity, is a major concern. A recent analysis of 12 canine mammary cell lines showed an association between HER2/3 overexpression and phosphatase and tensin homologue (PTEN) deletion with elevated Wnt-signalling. Wnt-activity appeared to be insensitive to phosphatidyl-3-kinase (PI3K) inhibitors but sensitive to Src-I1. We hypothesized that Wnt activation, was caused by HER2/3-activated cSRC activation. The role of HER2/3 on Wnt signalling was investigated by silencing HER2/3 expression using specific small interfering RNA (siRNAs). Next, the effect of an epidermal growth factor receptor (EGFR)/HER2 tyrosine kinase inhibitor on Wnt activity and migration was investigated and compared to other tyrosine kinase inhibitors (TKIs) of related signalling pathways. Finally, two TKIs, a cSRC and a PI3K inhibitor, were investigated in a zebrafish xenograft model. Silencing of HER1-3 did not inhibit the intrinsic high Wnt activity, whereas the HER kinase inhibitor afatinib showed enhanced Wnt activity. The strongest inhibition of Wnt activity and cell viability and migration was shown by cSRC inhibitors, which also showed strong inhibition of cell viability and metastasis in a zebrafish xenograft model. HER2/3 overexpression or HER2/3-induced cSRC activation is not the cause of enhanced Wnt activity. However, inhibition of cSRC resulted in a strong inhibition of Wnt activity and cell migration and metastasis. Further studies are needed to unravel the mechanism of cSRC activation and cSRC inhibition to restore sensitivity to HER-inhibitors in HER2/3-positive breast cancer.

Impact of combining the progesterone receptor and preoperative endocrine prognostic index (PEPI) as a prognostic factor after neoadjuvant endocrine therapy using aromatase inhibitors in postmenopausal ER positive and HER2 negative breast cancer

The preoperative endocrine prognostic index (PEPI) predicts survival after neoadjuvant endocrine therapy (NAE) using aromatase inhibitors (AIs) for women with postmenopausal estrogen receptor (ER)-positive breast cancer irrespective of the human epidermal growth factor receptor 2 (HER2) status. Although the progesterone receptor (PgR) is also a prognostic factor for ER-positive breast cancer, the PgR status was not considered a prognostic factor in the original PEPI scoring system. In this study, we investigated the utility of a modified PEPI including the PgR status (PEPI-P) as a prognostic factor after NAE for postmenopausal patients with ER-positive and HER2-negative breast cancer. We enrolled 107 patients with invasive ER-positive and HER2-negative breast cancer treated with exemestane for ≥4 months as NAE. We initially assessed PEPI and compared survival between the groups. Additionally, we obtained an effective cutoff for PgR through survival analysis. Then, we assessed the survival significance of PEPI-P. A PgR staining rate of 50% was the most significant cutoff for predicting recurrence-free survival (RFS) and cancer-specific survival (CSS). PEPI was a significant prognostic factor; moreover, PEPI-P was the most significant prognostic indicator for RFS and CSS. PEPI-P is a potent prognostic indicator of survival after NAE using AIs for postmenopausal patients with ER-positive and HER2-negative breast cancer. This modified PEPI may be useful for therapeutic decision-making regarding postmenopausal ER-positive and HER2-negative breast cancer after NAE.

Estrogen and progesterone signalling in the normal breast and its implications for cancer development

The ovarian hormones estrogen and progesterone are master regulators of the development and function of a broad spectrum of human tissues, including the breast, reproductive and cardiovascular systems, brain and bone. Acting through the nuclear estrogen (ER) and progesterone receptors (PR), both play complex and essential coordinated roles in the extensive development of the lobular alveolar epithelial structures of the normal breast during puberty, the normal menstrual cycle and pregnancy. The past decade has seen major advances in understanding the mechanisms of action of estrogen and progesterone in the normal breast and in the delineation of the complex hierarchy of cell types regulated by ovarian hormones in this tissue. There is evidence for a role for both ER and PR in driving breast cancer, and both are favourable prognostic markers with respect to outcome. In this review, we summarize current knowledge of the mechanisms of action of ER and PR in the normal breast, and implications for the development and management of breast cancer.

Steroid metabolism in breast cancer: Where are we and what are we missing?

It is well-known that breast cancer is hormone-dependent and that steroid hormones exert their mitogenic effects by binding to estrogen, progesterone and androgen receptors. Vital to our understanding and treatment of this malignancy, is the local metabolism of steroid hormones in breast cancer tissue. This review summarises our current knowledge on steroid producing pathways in the adrenal, ovary and breast, while focussing on the availability of specific circulating hormone precursors and steroidogenic enzymes involved in the local synthesis and metabolism of steroid hormones in the breast. Consequently, we highlight alternate pathways that may be instrumental in the etiology of breast cancer.

Patterns and predictors of first and subsequent recurrence in women with early breast cancer

Purpose

Little is known about the occurrence, timing and prognostic factors for first and also subsequent local (LR), regional (RR) or distant (DM) breast cancer recurrence. As current follow-up is still consensus-based, more information on the patterns and predictors of subsequent recurrences can inform more personalized follow-up decisions.

Methods

Women diagnosed with stage I-III invasive breast cancer who were treated with curative intent were selected from the Netherlands Cancer Registry (N = 9342). Extended Cox regression was used to model the hazard of recurrence over ten years of follow-up for not only site-specific first, but also subsequent recurrences after LR or RR.

Results

In total, 362 patients had LR, 148 RR and 1343 DM as first recurrence. The risk of first recurrence was highest during the second year post-diagnosis (3.9%; 95% CI 3.5–4.3) with similar patterns for LR, RR and DM. Young age (<40), tumour size >2 cm, tumour grade II/III, positive lymph nodes, multifocality and no chemotherapy were prognostic factors for first recurrence. The risk of developing a second recurrence after LR or RR (N = 176) was significantly higher after RR than after LR (50 vs 29%; p < 0.001). After a second LR or RR, more than half of the women were diagnosed with a third recurrence.

Conclusions

Although the risk of subsequent recurrence is high, absolute incidence remains low. Also, almost half the second recurrences are detected in the first year after previous recurrence and more than 80% are DM. This suggests that more intensive follow-up for early detection subsequent recurrence is not likely to be (cost-)effective.

Electronic supplementary material

The online version of this article (doi:10.1007/s10549-017-4340-3) contains supplementary material, which is available to authorized users.