Prediction of outcome after diagnosis of metachronous contralateral breast cancer

Determining the Need for Metastatic Staging in Patients with Bilateral Breast Cancers

Introduction: Bilateral breast cancers (BBC) diagnosed at an interval apart are uncommon. While metastatic staging guidelines are established in patients with unilateral breast cancer, its role in BBC diagnosed at an interval apart is unclear. We aim to identify the subgroup who would benefit from metastatic staging at contralateral cancer diagnosis. Methods: Eligible patients were divided into three categories: (A) ipsilateral invasive cancer and contralateral ductal carcinoma in situ (DCIS), (B) bilateral invasive cancers and (C) ipsilateral DCIS and contralateral invasive cancer and reviewed retrospectively. We excluded patients with bilateral DCIS, synchronous BBC diagnosed within 6 months from first cancer, patients who were stage IV at first cancer diagnosis and patients with recurrence prior to contralateral cancer. Results: Of 4516 newly diagnosed breast cancer patients, 79 patients were included. Systemic metastasis occurred in 15.6% of patients in Group B. Having nodal positivity of either cancer which were diagnosed ≤30 months apart and nodal positivity of only the contralateral cancer when diagnosed >30 months apart was significantly associated with systemic metastasis (p = 0.0322). Conclusions: Both the nodal status and a 30 months cut-off time interval between the two cancers can be used to identify patients who will benefit from metastatic staging. This finding requires validation in larger studies.

Risk factors of developing contralateral breast cancer after first primary breast cancer treatment

BACKGROUND

Breast cancer (BC) is the most common cancer among women worldwide. Increased survival of primary BC (PBC) has increased contralateral breast cancer (CBC) and become a health problem.

AIMS

This study aimed to determine the effect of disease-free interval (DFI), risk factors and PBC characteristics on the progression of CBC within primary BC survivors.

METHODS AND RESULTS

This retrospective study identified 5003 women diagnosed with breast cancer between 2000 and 2020 in the cancer research center. The study included 145 CBC and 4858 PBC survivors, with CBC diagnosed at least 6 months after the detection of primary BC. ER+, PR+, and HER2+ were reported in 72.13%, 66.67%, and 30% of CBC patients. Invasive ductal carcinoma (IDC) BC was reported in 69.57% of patients, and 81.90% and 83.64% of the patients were treated with adjuvant chemotherapy and external radiotherapy. The Kaplan-Meier method indicated that the median time interval between PBC and CBC was 3.92 years, and the 5-year DFI was 97%. The Cox proportional hazard regression model indicated that although more than half of the participants had no family history of BC (69.57%), women 60 years and older were negatively associated with CBC.

CONCLUSION

This study provides the first investigation of CBC and DFI risk factors among PBC survivors in Iran. Age was found to be negatively associated with CBC development particularly after the age of 60, indicating the necessity of tracking CBC survivors carefully in this age group.

Survival After Development of Contralateral Breast Cancer in Korean Patients With Breast Cancer

Importance

Contralateral breast cancer (CBC) is the most frequently diagnosed primary cancer in patients with breast cancer. Although many studies have reported survival after the development of CBC, results have been inconsistent.

Objective

To investigate whether the development of CBC is associated with survival among patients with breast cancer.

Design, Setting, and Participants

This cohort study was conducted at the Asan Medical Center, Korea, among patients who were diagnosed with primary unilateral, nonmetastatic, stage 0 to III breast cancer between 1999 and 2013 and followed up through 2018. The median (IQR) follow-up was 107 (75-143) months. Patients were categorized into CBC and no-CBC groups by whether they developed CBC during the follow-up period. Data were analyzed from November 2021 to March 2023.

Exposure

Development of CBC.

Main outcomes and measures

Survival rates of CBC and no-CBC groups were compared using a time-dependent Cox proportional hazard model in the entire study population and in subgroup analyses by interval of CBC development and subtype of the primary breast cancer.

Results

Among 16 251 patients with breast cancer (all Asian, specifically Korean; mean [SD] age, 48.61 [10.06] years), 418 patients developed CBC. There was no significant difference in overall survival between CBC and no-CBC groups (hazard ratio, 1.166; 95% CI, 0.820-1.657). Patients who developed CBC within 1.5 years after the surgery of the primary breast cancer had a higher risk for overall death during the study period (hazard ratio, 2.014; 95% CI, 1.044-3.886), and those who developed CBC after 1.5 years showed no significant difference in survival compared with the no-CBC group. Patients with hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (ERBB2, formerly HER2)-negative breast cancer had a higher risk for overall death in the CBC group (hazard ratio, 1.882; 95% CI, 1.143-3.098) compared with the no-CBC group.

Conclusions and Relevance

This study found that development of CBC in patients with breast cancer was not associated with survival but that early development of CBC after diagnosis of the primary breast cancer or development of CBC in patients with HR-positive/ERBB2-negative breast cancer was associated with survival. These results may provide valuable information for patients seeking advice on opting for contralateral prophylactic mastectomy.

Clinical application of artificial neural network (ANN) modeling to predict BRCA1/2 germline deleterious variants in Chinese bilateral primary breast cancer patients

BACKGROUND

Bilateral breast cancer (BBC), as well as ovarian cancer, are significantly associated with germline deleterious variants in BRCA1/2, while BRCA1/2 germline deleterious variants carriers can exquisitely benefit from poly (ADP-ribose) polymerase (PARP) inhibitors. However, formal genetic testing could not be carried out for all patients due to extensive use of healthcare resources, which in turn results in high medical costs. To date, existing BRCA1/2 deleterious variants prediction models have been developed in women of European or other descent who are quite genetically different from Asian population. Therefore, there is an urgent clinical need for tools to predict the frequency of BRCA1/2 deleterious variants in Asian BBC patients balancing the increased demand for and cost of cancer genetics services.

METHODS

The entire coding region of BRCA1/2 was screened for the presence of germline deleterious variants by the next generation sequencing in 123 Chinese BBC patients. Chi-square test, univariate and multivariate logistic regression were used to assess the relationship between BRCA1/2 germline deleterious variants and clinicopathological characteristics. The R software was utilized to develop artificial neural network (ANN) and nomogram modeling for BRCA1/2 germline deleterious variants prediction.

RESULTS

Among 123 BBC patients, we identified a total of 20 deleterious variants in BRCA1 (8; 6.5%) and BRCA2 (12; 9.8%). c.5485del in BRCA1 is novel frameshift deleterious variant. Deleterious variants carriers were younger at first diagnosis (P = 0.0003), with longer interval between two tumors (P = 0.015), at least one medullary carcinoma (P = 0.001), and more likely to be hormone receptor negative (P = 0.006) and HER2 negative (P = 0.001). Area under the receiver operating characteristic curve was 0.903 in ANN and 0.828 in nomogram modeling individually (P = 0.02).

CONCLUSION

This study shows the spectrum of the BRCA1/2 germline deleterious variants in Chinese BBC patients and indicates that the ANN can accurately predict BRCA deleterious variants than conventional statistical linear approach, which confirms the BRCA1/2 deleterious variants carriers at the lowest costs without adding any additional examinations.

Effect of breast-conserving surgery plus radiotherapy versus mastectomy on breast cancer-specific survival for early-stage contralateral breast cancer

Background

Breast-conserving surgery followed by radiotherapy is recommended in most women with early-stage unilateral breast cancer. However, its role in contralateral breast cancer (CBC) patients remains unclear. This retrospective study aimed to evaluate the breast cancer-specific survival (BCSS) outcomes after breast-conserving surgery plus radiotherapy compared with mastectomy in women with early-stage (T1-2N0-1M0) CBC.

Methods

Data were extracted from the Surveillance, Epidemiology, and End Results database. BCSS was analyzed using the log-rank method, competing risks regression model, and propensity score matching method.

Results

A total of 9,336 early-stage CBC patients were included. After multivariable adjustment, no significant difference in BCSS was found between early-stage CBC patients undergoing breast-conserving surgery plus radiotherapy and those undergoing mastectomy [hazard ratio (HR) 1.11, 95% confidence interval (CI): 0.90-1.37, P=0.329]. BCSS was similar in both treatment groups and in the subgroups stratified by age at first primary breast cancer or CBC diagnosis (≤50, 51-60, and >60 years), time interval between cancers (<0.25, 0.25-4, 5-9, and ≤10 years), stage of first primary breast cancer, T classification of CBC, histology and hormone receptors status of both cancers (all P>0.05). Among patients with N1 disease at CBC diagnosis, breast-conserving surgery plus radiotherapy was associated with a boundary significantly improved BCSS (HR 1.45, 95% CI: 1.00-2.12, P=0.050). Among patients who underwent breast-conserving surgery for first primary cancer, bilateral mastectomy for contralateral cancer did not improve BCSS compared with breast-conserving surgery plus radiotherapy (P>0.05). There was no significant difference in BCSS between breast-conserving surgery plus radiotherapy and mastectomy plus radiotherapy (P>0.05). Stable results were obtained after propensity score matching.

Conclusions

Breast-conserving surgery plus radiotherapy did not significantly influence BCSS outcomes of patients with early-stage CBC. Bilateral mastectomy and mastectomy plus radiotherapy did not confer a survival advantage over breast-conserving surgery plus radiotherapy in these patients. Future prospective studies are necessary to expand on these results.

Plasma membrane expression of G protein-coupled estrogen receptor (GPER)/G protein-coupled receptor 30 (GPR30) is associated with worse outcome in metachronous contralateral breast cancer

Background

G protein-coupled estrogen receptor (GPER), or G protein-coupled receptor 30 (GPR30), is reported to mediate non-genomic estrogen signaling. GPR30 associates with breast cancer (BC) outcome and may contribute to tamoxifen resistance. We investigated the expression and prognostic significance of GPR30 in metachronous contralateral breast cancer (CBC) as a model of tamoxifen resistance.

Methods

Total GPR30 expression (GPR30_TOT) and plasma membrane-localized GPR30 expression (GPR30_PM) were analyzed by immunohistochemistry in primary (BC1; n_BC1 = 559) and contralateral BC (BC2; n_BC2 = 595), and in lymph node metastases (LGL; n_LGL1 = 213; n_LGL2 = 196). Death from BC (BCD), including BC death or death after documented distant metastasis, was used as primary end-point.

Results

GPR30_PM in BC2 and LGL2 were associated with increased risk of BCD (HR_BC2 = 1.7, p = 0.03; HR_LGL2 = 2.0; p = 0.02). In BC1 and BC2, GPR30_PM associated with estrogen receptor (ER)-negativity (p_BC1<0.0001; p_BC2<0.0001) and progesterone receptor (PR)-negativity (p_BC1 = 0.0007; p_BC2<0.0001). The highest GPR30_TOT and GPR30_PM were observed in triple-negative BC. GPR30_PM associated with high Ki67 staining in BC1 (p<0.0001) and BC2 (p<0.0001). GPR30_TOT in BC2 did not associate with tamoxifen treatment for BC1. However, BC2 that were diagnosed during tamoxifen treatment were more likely to express GPR30_PM than BC2 diagnosed after treatment completion (p = 0.01). Furthermore, a trend was observed that patients with GPR30_PM in an ER-positive BC2 had greater benefit from tamoxifen treatment.

Conclusion

PM-localized GPR30 staining is associated with increased risk of BC death when expressed in BC2 and LGL2. Additionally, PM-localized GPR30 correlates with prognostic markers of worse outcome, such as high Ki67 and a triple-negative subtype. Therefore, PM-localized GPR30 may be an interesting new target for therapeutic exploitation. We found no clear evidence that total GPR30 expression is affected by tamoxifen exposure during development of metachronous CBC, or that GPR30 contributes to tamoxifen resistance.

Clinicopathological Characteristics, Treatment and Outcome of 123 Patients with Synchronous or Metachronous Bilateral Breast Cancer in a Swiss Institutional Retrospective Series

Objective

To evaluate the prognosis, the patient and tumor characteristics, and the treatment of bilateral breast cancer (BBC) and to compare synchronous (sBBC) and metachronous BBC (mBBC).

Materials and Methods

For this retrospective study, data from 123 consecutive BBC patients (56 sBBC and 67 mBBC) that were presented at the Sion Hospital tumor board between 2007 and 2018 were collected retrospectively.

Results

Mean follow-up was 85 months. 2^nd tumors in both groups were more often diagnosed radiologically. Mean time interval between mBBC was 115 months. A shorter interval was positively correlated with a negative hormonal receptor (HR) status and higher grade for the 2^nd tumor. There was no difference in overall survival (OS) and relapse-free survival (RFS) between sBBC and mBBC. OS was longer if both tumors were hormonal receptor (HR) positive. mBBC exhibited a higher local recurrence rate than sBBC (p=0.03).

Conclusion

sBBC and mBBC patients did not show any difference in OS or RFS, although mBBC patients were more prone to local relapses.

Expression of HIF-1α is related to a poor prognosis and tamoxifen resistance in contralateral breast cancer

Background

Adjuvant endocrine treatment improves survival after estrogen receptor (ER) positive breast cancer. Recurrences occur, and most patients with metastatic breast cancer develop treatment resistance and incurable disease. An influential factor in relation to endocrine treatment resistance is tumor hypoxia and the hypoxia inducible transcription factors (HIFs). Poor perfusion makes tumors hypoxic and induces the HIFs, which promote cell survival. We previously showed that hypoxic breast cancer cells are tamoxifen-resistant, and that HIF-inhibition restored tamoxifen-sensitivity. We found that HIF-induced tamoxifen-resistance involve cross-talk with epithelial growth factor receptor (EGFR), which itself is linked to tamoxifen resistance. Contralateral breast cancer (CBC), i.e. development of a second breast cancer in the contralateral breast despite adjuvant tamoxifen treatment is in essence a human in vivo-model for tamoxifen-resistance that we explore here to find molecular pathways of tamoxifen-resistance.

Methods

We constructed a tissue-microarray including tumor-tissue from a large well-defined cohort of CBC-patients, a proportion of which got their second breast cancer despite ongoing adjuvant therapy. Using immunohistochemistry >500 patients were evaluable for HIF-1α and EGFR in both tumors, and correlations to treatment, patient outcome, prognostic and predictive factors were analyzed.

Results

We found an increased proportion of HIF-1α-positive tumors in tamoxifen-resistant (CBC during adjuvant tamoxifen) compared to naïve tumors (CBC without prior tamoxifen). Tumor HIF-1α-positivity correlated to increased breast cancer mortality, and negative prognostic factors including low age at diagnosis and ER-negativity. There was a covariance of HIF-1α- and EGFR-expression and also EGFR-expression correlated to poor prognosis.

Conclusions

The increased percentage of HIF-1α-positive tumors formed during adjuvant tamoxifen suggests a role for HIF-1α in escaping tamoxifen’s restraining effects on breast cancer. Implicating a potential benefit of HIF-inhibitors in targeting breast cancers resistant to endocrine therapy.

Long-term survival outcomes in invasive lobular carcinoma patients with and without preoperative MR imaging: a matched cohort study

OBJECTIVE

To investigate and compare the effect of preoperative breast magnetic resonance (MR) imaging on recurrence-free survival (RFS) and overall survival (OS) outcomes among patients with invasive lobular carcinoma (ILC).

METHODS

A total of 287 ILC patients between January 2005 and December 2012 were included. One hundred twenty (41.8%) had undergone preoperative breast MR imaging (MR group) and 167 (58.2%) had not (no MR group). Two groups were matched for 21 covariates in terms of patient demographics, tumor characteristics, and clinical features. We compared unmatched variables between the patients with and without breast MR imaging using the chi-square or Student's t test. Comparisons of matched data were performed with McNemar's test or test of symmetry for categorical variables and paired t test for continuous variables. The RFS and OS outcomes were compared using the Kaplan-Meier estimates. MR effects were estimated after adjusting for significant potential confounders of specific outcomes in the multivariable modeling.

RESULTS

In the matched cohort, no statistically significant association was observed between MR imaging and total recurrence (hazard ratio [HR], 1.096; p = 0.821), loco-regional recurrence (HR, 1.204; p = 0.796), contralateral breast recurrence (HR, 0.945; p = 0.952), or distant recurrence (HR, 1.020; p = 0.973). MR imaging was associated with improved OS with 51% reduction, but not significantly (HR, 0.485; p = 0.231). Analysis with multivariable Cox regression model indicated that MR imaging was not significant independent factor for better RFS (HR, 0.823; p = 0.586) or improved OS (HR, 0.478; p = 0.168).

CONCLUSION

Preoperative MR imaging is not significant prognostic factor and produces no apparent recurrence or survival outcome benefits in ILC patients.

KEY POINTS

• Preoperative breast MR imaging in invasive lobular carcinoma was associated with a better overall survival with 51% reduction, but not statistically significant. • Preoperative breast MR imaging does not show significant prognostic value in invasive lobular carcinoma as there is no apparent benefit in terms of recurrence or survival outcomes.

Stability of oestrogen and progesterone receptor antigenicity in formalin-fixed paraffin-embedded breast cancer tissue over time

Use of archived formalin-fixed paraffin-embedded (FFPE) tissue is a standard method for evaluation of proposed prognostic and predictive tumour markers. However, little is known of the preservation of biomarker expression in old FFPE tumour blocks. We investigate the quality of immunohistochemical (IHC) oestrogen (ER) and progesterone receptor (PR) evaluation in FFPE tissue over time (1978-2000) using a large breast cancer tissue microarray (N = 573) with access to receptor analyses in cytosol (CYT) at diagnosis, coexpression of other biomarkers and follow-up data. We found a good correlation between ER analysed with CYT at diagnosis and ER analysed with IHC in archived FFPE tissue from the same tumour. ER evaluation did not seem to be affected by tissue storage time. Nor was there any time-dependent difference in ER_IHC correlation with other biomarkers (HER2, Ki67) or survival. Discordant cases were more often classified as ER-positive with IHC than with CYT. For PR, however, we found an increased correlation between methods in more recent time periods. This may possibly be explained by more reliable PR_IHC results in newer samples, although other explanations may also contribute. Our results indicate stable ER expression in FFPE tissue archived for up to 40 years.

Mortality after contralateral breast cancer in Denmark

PURPOSE

How a second breast cancer diagnosis affects survival in comparison with unilateral breast cancer (UBC) is unclear. Prognostic factors for contralateral breast cancer (CBC) are also not well established. We aimed to investigate the survival pattern after CBC with particular focus on time between first and second breast cancer diagnosis and age at CBC diagnosis.

METHODS

Within the nationwide Danish Breast Cancer Cooperative Group database, we identified 68,466 breast cancer patients diagnosed during 1978-2012. Patients who subsequently developed CBC were identified in a previously established database (N = 3004). Patients were followed for breast cancer-specific death in the Danish Register of Causes of Death until 2015. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazard regression models. Cumulative breast cancer mortality from date of CBC was estimated using the Aalen-Johansen method.

RESULTS

Compared with UBC patients, the rate of dying from breast cancer was more than twofold higher following a CBC diagnosis, after adjustment for age, period, tumor characteristics, and treatment of the first breast cancer (HR 2.48; 95% CI 2.31-2.66). Short time interval (< 5 years) was associated with higher breast cancer-specific mortality after CBC among patients < 70 years at CBC diagnosis compared with longer time intervals, but not among patients ≥ 70 years at CBC diagnosis.

CONCLUSION

Breast cancer-specific mortality rates were markedly higher after compared with before a CBC diagnosis. We found higher breast cancer-specific mortality after CBC associated with a short interval between diagnoses among patients diagnosed with CBC before age 70 years.

Utility of Regular Radiological Follow-up on Early Detection of Contralateral Malignancy and Long-term Outcomes in Metachronous Bilateral Breast Cancer Patients

Objectives We investigated the utility of regular radiological follow-up on the early detection of contralateral breast cancer(CBC) and prognosis in patients with metachronous bilateral breast cancer. Methods Between 1983 and 2010, 49(2.1%) metachronous bilateral breast cancer patients were identified among a total of 2,343 cases of invasive or in situ breast carcinomas. We reviewed the patients' medical records including age, stage, duration between the first and second breast cancer diagnosis, operation method, recurrence, and breast cancer-specific survival. Results The mean ages at the first and second breast cancer diagnosis were 43.8 and 49.2 years, respectively. The mean duration between the first and second breast cancer diagnosis was 68.9 months (range, 7–266 months). Regular radiological follow-up with annual mammography(MMG) with or without ultrasonography was conducted in 28 patients (63.6%, Group 1), and no regular follow-up was performed in 12 patients (27.3%, Group 2). The median follow-up duration was 150 months. In a comparative analysis, Group 1 patients exhibited more stage 0 and stage 1 malignancies (82.1% vs. 25%, P =0.006) as second cancer and the same or an improved stage (71.4% vs. 33.3%, P =0.042) of second cancer compared to Group 2 patients. Breast cancer-specific survival rates between the two groups after the first cancer occurrence were higher in Group 1 patients compared to Group 2 patients, although this did not reach statistical significance. Conclusion Screening for CBC with regular radiological follow-up could result in early detection of CBC, less invasive surgical procedures, and enhanced breast cancer-specific survival outcomes.

Natural History of Invasive Papillary Breast Carcinoma Followed for 10 Years: A Case Report and Literature Review

Diachronic research on untreated breast cancer completely depends on past medical records when no more recent, advanced methods are available. Herein, we report a case of invasive papillary breast carcinoma followed for 10 years in a 59-year-old woman who refused any treatment. The diagnosis was based on core needle biopsies. At the patient's first visit in July 2006, the tumor measured 10.4 × 7.2 × 3.5 cm. It was staged as IIIB (T4bN1). In May 2016, the tumor was staged as IIIC (T4bN3a). In the past 10 years, the tumor has increased to 12.1 × 9.0 × 4.2 cm. However, a whole-body bone scan and ¹⁸F-FDG PET/CT showed no evidence of distant metastasis. Immunohistochemistry results, corresponding to biopsies taken at subsequent examinations, have remained unaltered since 2006. The tumor was estrogen/progesterone receptor-positive and C-erbB2 expression was not detected. The Ki-67 labeling index was around 10%.

Prior Adjuvant Tamoxifen Treatment in Breast Cancer Is Linked to Increased AIB1 and HER2 Expression in Metachronous Contralateral Breast Cancer

Aim

The estrogen receptor coactivator Amplified in Breast Cancer 1 (AIB1) has been associated with an improved response to adjuvant tamoxifen in breast cancer, but also with endocrine treatment resistance. We hereby use metachronous contralateral breast cancer (CBC) developed despite prior adjuvant tamoxifen for the first tumor as an “in vivo”-model for tamoxifen resistance. AIB1-expression in the presumable resistant (CBC after prior tamoxifen) and naïve setting (CBC without prior tamoxifen) is compared and correlated to prognosis after CBC.

Methods

From a well-defined population-based cohort of CBC-patients we have constructed a unique tissue-microarray including >700 patients.

Results

CBC developed after adjuvant tamoxifen more often had a HER2-positive/triple negative-subtype and a high AIB1-expression (37% vs. 23%, p = 0.009), than if no prior endocrine treatment had been administered. In patients with an estrogen receptor (ER) positive CBC, a high AIB1-expression correlated to an inferior prognosis. However, these patients seemed to respond to tamoxifen, but only if endocrine therapy had not been administered for BC1.

Conclusions

Metachronous CBC developed after prior endocrine treatment has a decreased ER-expression and an increased HER2-expression. This is consistent with endocrine treatment escape mechanisms previously suggested, and indicates metachronous CBC to be a putative model for studies of treatment resistance “in vivo”. The increased AIB1-expression in CBC developed after prior tamoxifen suggests a role of AIB1 in endocrine treatment resistance. In addition, we found indications that the response to tamoxifen in CBC with a high AIB1-expression seem to differ depending on previous exposure to this drug. A different function for AIB1 in the tamoxifen treatment naïve vs. resistant setting is suggested, and may explain previously conflicting results where a high AIB1-expression has been correlated to both a good response to adjuvant tamoxifen and tamoxifen resistance.

Incidence of metachronous contralateral breast cancer in the Canton of Zurich: a population-based study of the cancer registry

PURPOSE

To examine the incidence and characteristics of metachronous contralateral breast cancer (CBC) among women in the Canton of Zurich, Switzerland.

METHODS

For 1980-2006, patients with unilateral invasive breast cancer (UBC) were analysed for metachronous CBC. Poisson's regression was used to estimate incidence rates of metachronous CBC according to age, year of diagnosis, follow-up period since first breast cancer and morphology.

RESULTS

Of 16,323 patients with UBC, 700 (4.3%) developed a second malignant tumour of the opposite breast. Median age at first breast cancer was lower in the CBC group than in the full cohort. Median interval time between first and second breast cancer was 5.5 (interquartile range 2.6-10.1) years. Incidence rate at age 20-29 was 1006 (95% confidence interval, CI, 452-2238) cases per 100,000 person-years and decreased to 299 (199-450) at 80-84. Age-adjusted incidence rates according to period of diagnosis decreased from 618 (530-721) for 1980-1984 to 329 (217-500) cases per 100,000 person-years for 2005-2006. Incidence rate ratio of CBC for lobular carcinoma was 1.28 (95% CI 0.99-1.67) adjusted by age group and period of diagnosis compared to ductal carcinoma.

CONCLUSIONS

In our study, incidence rates for CBC are comparable with findings from the literature. A reduction in the incidence of metachronous CBC, thought to be due to adjuvant therapies, is seen in our data. In our cohort, younger age and lobular carcinoma were associated with an increased risk of CBC.

Contralateral breast cancer can represent a metastatic spread of the first primary tumor: determination of clonal relationship between contralateral breast cancers using next-generation whole genome sequencing

INTRODUCTION

By convention, a contralateral breast cancer (CBC) is treated as a new primary tumor, independent of the first cancer (BC1). Although there have been indications that the second tumor (BC2) sometimes may represent a metastatic spread of BC1, this has never been conclusively shown. We sought to apply next-generation sequencing to determine a "genetic barcode" for each tumor and reveal the clonal relationship of CBCs.

METHODS

Ten CBC patients with detailed clinical information and available fresh frozen tumor tissue were studied. Using low-coverage whole genome DNA-sequencing data for each tumor, chromosomal rearrangements were enumerated and copy number profiles were generated. Comparisons between tumors provided an estimate of clonal relatedness for tumor pairs within individual patients.

RESULTS

Between 15-256 rearrangements were detected in each tumor (median 87). For one patient, 76 % (68 out of 90) of the rearrangements were shared between BC1 and BC2, highly consistent with what has been seen for true primary-metastasis pairs (>50 %) and thus confirming a common clonal origin of the two tumors. For most of the remaining cases, BC1 and BC2 had similarly low overlap as unmatched randomized pairs of tumors from different individuals, suggesting the CBC to represent a new independent primary tumor.

CONCLUSION

Using rearrangement fingerprinting, we show for the first time with certainty that a contralateral BC2 can represent a metastatic spread of BC1. Given the poor prognosis of a generalized disease compared to a new primary tumor, these women need to be identified at diagnosis of CBC for appropriate determination of treatment. Our approach generates a promising new method to assess clonal relationship between tumors. Additional studies are required to confirm the frequency of CBCs representing metastatic events.

Clinicopathologic features and time interval analysis of contralateral breast cancers

INTRODUCTION

We hypothesized that most contralateral breast cancers (CBCs) develop ≥5 years after the primary breast cancer (PBC) and that CBCs have more favorable tumor characteristics.

METHODS

This is a single-institution retrospective review of 323 patients who were diagnosed with CBC from 1990 to 2014. CBCs were diagnosed at least 1 year after the diagnosis of PBC. Χ(2) tests and one-way analysis of variance were used to examine the time interval and pathologic features between the PBC and CBC.

RESULTS

The median time interval between the PBC and CBC was 6.2 years (average: 7.1, range: 1.01-23.0), and 189 (58.5%) patients had a time interval ≥5 years. Patients ≥70 years old developed a CBC sooner than patients <50 years (median: 4.3 vs 6.6 years, P < .001). Patients with infiltrating lobular carcinoma developed their CBC in 9.0 years versus 6.2 years for infiltrating ductal carcinoma histology (P = .028). In comparison with the PBC, a greater proportion of CBCs were stage I (50.8%), T1 (72.1%), node negative (67.5%), and estrogen receptor positive (68.7%). Of the 252 patients with available tumor size information for both cancers, only 54 (21.4%) patients developed a CBC that was >1 cm larger than their PBC, and only 25 (9.9%) patients developed a CBC that was >2 cm larger than their PBC. Only 28 of 201 (13.9%) node-negative PBCs developed a node-positive CBC.

CONCLUSION

A majority of CBCs develop ≥5 years after the diagnosis of the PBC. CBCs have more favorable tumor characteristics than the PBC and tend to be smaller and node negative.

The Sweden Cancerome Analysis Network - Breast (SCAN-B) Initiative: a large-scale multicenter infrastructure towards implementation of breast cancer genomic analyses in the clinical routine

BACKGROUND

Breast cancer exhibits significant molecular, pathological, and clinical heterogeneity. Current clinicopathological evaluation is imperfect for predicting outcome, which results in overtreatment for many patients, and for others, leads to death from recurrent disease. Therefore, additional criteria are needed to better personalize care and maximize treatment effectiveness and survival.

METHODS

To address these challenges, the Sweden Cancerome Analysis Network - Breast (SCAN-B) consortium was initiated in 2010 as a multicenter prospective study with longsighted aims to analyze breast cancers with next-generation genomic technologies for translational research in a population-based manner and integrated with healthcare; decipher fundamental tumor biology from these analyses; utilize genomic data to develop and validate new clinically-actionable biomarker assays; and establish real-time clinical implementation of molecular diagnostic, prognostic, and predictive tests. In the first phase, we focus on molecular profiling by next-generation RNA-sequencing on the Illumina platform.

RESULTS

In the first 3 years from 30 August 2010 through 31 August 2013, we have consented and enrolled 3,979 patients with primary breast cancer at the seven hospital sites in South Sweden, representing approximately 85% of eligible patients in the catchment area. Preoperative blood samples have been collected for 3,942 (99%) patients and primary tumor specimens collected for 2,929 (74%) patients. Herein we describe the study infrastructure and protocols and present initial proof of concept results from prospective RNA sequencing including tumor molecular subtyping and detection of driver gene mutations. Prospective patient enrollment is ongoing.

CONCLUSIONS

We demonstrate that large-scale population-based collection and RNA-sequencing analysis of breast cancer is feasible. The SCAN-B Initiative should significantly reduce the time to discovery, validation, and clinical implementation of novel molecular diagnostic and predictive tests. We welcome the participation of additional comprehensive cancer treatment centers.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02306096.

Synchronous and metachronous breast malignancies: a cross-sectional retrospective study and review of the literature

Objective. There is increasing interest in patients with metachronous (MBC) and synchronous breast cancer (SBC). The objective of this study was to evaluate the occurrence and outcome of MBCs and SBCs. Methods. A retrospective study on women operated in our department for breast cancer between 2002 and 2005 was carried out. Patients were divided into three groups: women with MBC, SBC, and unilateral breast cancer (UBC). Moreover, we performed a meta-analysis of the English literature about multiple breast cancers between 2000 and 2011 taking into consideration their prevalence and overall survival (OS). Results. We identified 584 breast cancer patients: 16 women (3%) presented SBC and 40 MBC (7%, second cancer after 72-month follow-up IQR 40–145). Although the meta-analysis showed significant OS differences between MBC or SBC and UBC, we did not observe any significant OS difference among the three groups of our population. Anyway, we found a significant worse disease-free survival in MBC than UBC and a significant higher prevalence of radical surgery in MBC and SBC than UBC. Conclusions. Despite the low prevalence of MBC and SBC, the presence of a long time risk of MBC confirms the crucial role of ipsi- and contralateral mammographies in the postoperative follow-up.

Effectiveness of routine follow-up in the detection of contralateral breast cancer in young women with early breast cancer

BACKGROUND

The purpose of the study was to determine the effectiveness of routine follow-up to detect contralateral breast cancer (CBC) in young women.

METHODS

We used the data of the population-based Eindhoven Cancer Registry, which covers the southern part of the Netherlands. Between 1988 and 2005, 1451 women aged ≤ 40 years were treated for early-stage breast cancer with breast-conserving treatment or mastectomy.

RESULTS

Of the 94 patients who developed CBC 17 had an in situ carcinoma. Fifty-seven CBCs (61%) were diagnosed more than 5 years after the primary tumour. Forty-two CBCs (45%) were detected during routine follow-up visits, while 52 (55%) presented between two visits. Of the CBC diagnosed between two visits, only 27 (60%) were visible on mammography. Of the invasive CBCs more than 25% was larger than 2 cm in diameter and in 34% positive axillary lymph nodes were found.

CONCLUSIONS

These figures indicate that routine follow-up does not guarantee early detection of CBC in young women with breast cancer.

Contralateral mastectomy improves survival in women with BRCA1/2-associated breast cancer

BRCA1/2 mutation carriers with breast cancer are at high risk of contralateral disease. Such women often elect to have contralateral risk-reducing mastectomy (CRRM) to reduce the likelihood of recurrence. This study considers whether CRRM improves overall survival. 105 female BRCA1/2 mutation carriers with unilateral breast cancer who underwent CRRM were compared to controls (593 mutation carriers and 105 specifically matched) not undergoing CRRM and diagnosed between 1985 and 2010. Survival was assessed by proportional hazards models, and extended to a matched analysis using stratification by risk-reducing bilateral salpingo-oophorectomy (RRBSO), gene, grade and stage. Median time to CRRM was 1.1 years after the primary diagnosis (range 0.0-13.3). Median follow-up was 9.7 years in the CRRM group and 8.6 in the non-CRRM group. The 10-year overall survival was 89 % in women electing for CRRM (n = 105) compared to 71 % in the non-CRRM group (n = 593); p < 0.001. The survival advantage remained after matching for oophorectomy, gene, grade and stage: HR 0.37 (0.17-0.80, p = 0.008)-CRRM appeared to act independently of RRBSO. CRRM appears to confer a survival advantage. If this finding is confirmed in a larger series it should form part of the counselling procedure at diagnosis of the primary tumour. The indication for CRRM in women who have had RRBSO also requires further research.

Inferior survival for young patients with contralateral compared to unilateral breast cancer: a nationwide population-based study in the Netherlands

To compare overall survival between women with unilateral breast cancer (UBC) and contralateral breast cancer (CBC). Women with UBC (N = 182,562; 95 %) and CBC (N = 8,912; 5 %) recorded in the Netherlands Cancer Registry between 1989 and 2008 were included and followed until 2010. We incorporated CBC as a time-dependent covariate to compute the overall mortality rate ratio between women with CBC and UBC. Prognostic factors for overall death were examined according to age at first breast cancer. Women with CBC exhibited a 30 % increase in overall mortality (Hazard Ratio (HR), 95 % Confidence Interval: 1.3, 1.3-1.4) compared with UBC, decreasing with rising age at diagnosis of first breast cancer (<50 years: 2.3, 2.2-2.5 vs. ≥70 years: 1.1, 1.0-1.1). Women older than 50 years at CBC diagnosis and diagnosed 2-5 years after their first breast cancer exhibited a 20 % higher death risk (1.2, 1.0-1.3) compared to those diagnosed within the first 2 years. In women younger than 50 years, the HR was significantly lower if the CBC was diagnosed >5 years after the first breast cancer (0.7, 0.5-0.9). The prognosis for women with CBC significantly improved over time (2004-2008: 0.6, 0.5-0.7 vs. 1989-1993). Women with CBC had a lower survival compared to women with UBC, especially those younger than 50 years at first breast cancer diagnosis. A tailored follow-up strategy beyond current recommendations is needed for these patients who, because of their age and absence of known familial risk, are currently not invited for population-based screening.

Influence of radiotherapy for the first tumor on aggressiveness of contralateral breast cancer

We aimed to investigate if characteristics of contralateral breast cancer (CBC) are influenced by adjuvant radiotherapy for the first breast cancer. Using information from population-based registers and medical records, we analyzed two cohorts comprising all women with CBC diagnosed >3 months after their first cancer (809 patients in Stockholm 1976-2005 and 750 patients in South Sweden 1977-2005). We used Poisson regression to calculate risk of distant metastasis after CBC, comparing patients treated and not treated with radiotherapy for the first cancer. Logistic regression was used to estimate odds ratio (OR) of more aggressive tumor characteristics in the second cancer, compared to the first. For patients with CBC in Stockholm with <5 years between the cancers radiotherapy for the first cancer conferred a nearly doubled risk of distant metastasis [incidence rate ratio (IRR) = 1.91; 95% confidence interval (CI): 1.27-2.88], compared to those not treated with radiotherapy. This was replicated in the South Swedish cohort [IRR = 2.12 (95% CI: 1.40-3.23)]. In Stockholm, we found an increased odds that, following radiotherapy, a second cancer was of more advanced TNM-stage [OR 2.16 (95% CI 1.13-4.11)] and higher histological grade [OR = 2.00 (95% CI 1.08-3.72)] compared to the first, for patients with CBC with <5 years between the cancers. No effect on any of the investigated outcomes was seen for patients diagnosed with CBC >5 years from the first cancer. In conclusion, patients diagnosed with CBC within 5 years had worse prognosis and more aggressive tumor characteristics of the second cancer, if they had received radiotherapy for their first cancer, compared to no radiotherapy.

A population perspective to mitigating risk for second primary breast cancer

SUMMARY There are more than 2 million breast cancer survivors in the USA. Approximately 5–10% of survivors will develop a second, metachronous breast cancer within 10 years’ time; a risk two- to six-times higher than that in the general population. Women who develop metachronous cancer are more likely to die from the disease compared with women with unilateral cancer. Risk factors for metachronous cancer include BRCA mutation status, young age, family history and tumor phenotype, while adjuvant chemotherapy and endocrine therapy may attenuate the risk. Surveillance guidelines recommend annual mammography, but MRI is not currently indicated for most women. An increasing number of women are choosing prophylactic contralateral mastectomy, although it is not likely to be beneficial for most women. Improved strategies are needed for identifying survivors at an increased risk in order to help guide clinical decisions regarding follow-up care. This review presents an overview of the burden and risk factors for metachronous breast cancer and discusses challenges and opportunities for a population approach to mitigating risk and adverse outcomes from these cancers.

The molecular and clinicopathologic characteristics of bilateral breast cancer

In this study, we compared the clinicopathologic characteristics between the bilateral breast cancer (BiBC) and unilateral breast cancer (UBC) and investigated the role of CXC chemokine receptor type 4 (CXCR4) in BiBC. 48 BiBC and 1650 UBC were studied. We found BiBC patients were associated with family history of cancer, invasive lobular histology in the first tumor and an advanced nodal status as compared with UBC patients with. Survival analysis indicated that BiBC was not associated with impaired survival. The time interval between the development of first breast cancer and the contralateral cancer did not correlate with the prognosis. Patients with BiBC were more likely to have bone metastasis (P = 0.011) and visceral metastasis (P < 0.001) than those with UBC. However, CXCR4 was not found in any association with poor clinical outcome and increasing visceral metastasis in BiBC patients.

Tumor Stage Affects Risk and Prognosis of Contralateral Breast Cancer: Results From a Large Swedish-Population–Based Study

Purpose

The number of breast cancer survivors at risk of developing contralateral breast cancer (CBC) is increasing. However, ambiguity remains regarding risk factors and prognosis for women with CBC.

Patients and Methods

In a cohort of 42,670 women with breast cancer in the Uppsala/Örebro and Stockholm regions in Sweden in 1992 to 2008, we assessed risk factors for and prognosis of metachronous CBC by using survival analysis. Breast cancer–specific survival for women with CBC was evaluated and compared with results for women with unilateral breast cancer (UBC) by using time-dependent Cox-regression modeling.

Results

An increased risk for CBC was observed among women who had primary breast cancer with ≥ 10 involved lymph nodes compared with node-negative women (adjusted hazard ratio [HR], 1.8; 95% CI, 1.2 to 2.7). The prognosis was poorer in women with CBC than with UBC. The hazard of dying from breast cancer was especially high for women with a short interval time to CBC (adjusted HR, 2.3; 95% CI, 1.8 to 2.8 for CBC diagnosed ≤ 5 years v UBC) and gradually decreased with longer follow-up time but remained higher than the hazard originating from the primary tumor for ≥ 10 years.

Conclusion

Women with advanced-stage primary breast cancer had an increased risk of developing CBC. CBC is associated with an increased risk of dying from breast cancer throughout a long period of follow-up after the primary tumor. Our findings suggest that the event of CBC marks a new clinical situation in terms of investigations for metastases, treatment considerations, and follow-up strategy.