Patterns of Occurrence and Outcomes of Contralateral Breast Cancer: Analysis of SEER Data

Second primary cancer risks according to race and ethnicity among U.S. breast cancer survivors

Breast cancer survivors have an increased risk of developing second primary cancers, yet risks by race and ethnicity have not been comprehensively described. We evaluated second primary cancer risks among 717,335 women diagnosed with first primary breast cancer (aged 20-84 years and survived ≥1-year) in the SEER registries using standardized incidence ratios (SIRs; observed/expected). SIRs were estimated by race and ethnicity compared with the racial- and ethnic-matched general population, and further stratified by clinical characteristics of the index breast cancer. Poisson regression was used to test for heterogeneity by race and ethnicity. SIRs for second primary cancer differed by race and ethnicity with the highest risks observed among non-Hispanic/Latina Asian American, Native Hawaiian, or other Pacific Islander (AANHPI), non-Hispanic/Latina Black (Black), and Hispanic/Latina (Latina) survivors and attenuated risk among non-Hispanic/Latina White (White) survivors (SIRAANHPI = 1.49, 95% CI = 1.44-1.54; SIRBlack = 1.41, 95% CI = 1.37-1.45; SIRLatina = 1.45, 95% CI = 1.41-1.49; SIRWhite = 1.09, 95% CI = 1.08-1.10; p-heterogeneity<.001). SIRs were particularly elevated among AANHPI, Black, and Latina survivors diagnosed with an index breast cancer before age 50 (SIRs range = 1.88-2.19) or with estrogen receptor-negative tumors (SIRs range = 1.60-1.94). Heterogeneity by race and ethnicity was observed for 16/27 site-specific second cancers (all p-heterogeneity's < .05) with markedly elevated risks among AANHPI, Black, and Latina survivors for acute myeloid and acute non-lymphocytic leukemia (SIRs range = 2.68-3.15) and cancers of the contralateral breast (SIRs range = 2.60-3.01) and salivary gland (SIRs range = 2.03-3.96). We observed striking racial and ethnic differences in second cancer risk among breast cancer survivors. Additional research is needed to inform targeted approaches for early detection strategies and treatment to reduce these racial and ethnic disparities.

Imaging for local recurrence of breast cancer

PURPOSE

Isolated locoregional recurrence of breast cancer (ILRR) and contralateral breast cancer (CBC) affect up to 20% of all breast cancer (BC) patients in the first 20 years after primary diagnosis. Treatment options comprise surgical interventions and further systemic therapies depending on the histological subtype. Patients with hereditary breast or ovarian cancer (HBOC) undergo MRI, mammography, and ultrasound in the aftercare of BC, while non-HBOC (nHBOC) patients do not regularly receive MRI. Since early detection is crucial for morbidity and mortality, the evaluation and constant improvement of imaging methods of the breast is necessary.

METHODS

We retrospectively analyzed the data of 1499 former BC patients that received imaging of the breast at a tertiary-care university hospital between 2015 and 2020. The analysis comprised various patient characteristics, such as breast density, age, tumor size and subtype, and their influence on BC detection rates by the different imaging methods.

RESULTS

Within the patient sample, 176 individuals (11.7% of former BC patients) were diagnosed with either ILRR or CBC. CBC was observed in 32.4% of patients, while both ILRR and secondary breast cancer occurred in 20.5% and 23.9% of all patients. Sensitivity of MRI, mammography, and ultrasound for recurrent malignancy was 97.9%, 66.3%, and 67.8%, respectively. ILRR and CBC detection rates were similar for patients with and without HBOC history. Lower breast density and larger tumor size increased the detection rates of all imaging modalities.

CONCLUSION

In breast cancer survivors, MRI might improve the early detection of ILRR and CBC in both HBOC and nHBOC patients.

Contralateral prophylactic mastectomy in a rural population: A single-institution experience

Background

The incidence of contralateral prophylactic mastectomy (CPM) for unilateral breast cancer (UBC) has continued to increase, despite an absent survival benefit except in populations at highest risk for developing contralateral breast cancer (CBC). CPM rates may be higher in rural populations but causes remain unclear. A study performed at our institution previously found that 21.8 % of patients with UBC underwent CPM from 2000 to 2009. This study aimed to evaluate the CPM trend at a single institution serving a rural population and identify the CPM rate in average-risk patients.

Methods

Retrospective review of patients who underwent mastectomies for UBC at our institution from 2017 to 2021 was performed. Analysis utilized frequencies and percentages, descriptive statistics, chi-square, and independent sample t-tests.

Results

A total of 438 patients were included, of whom 64.4 % underwent bilateral mastectomy for UBC (CPM). Patients who underwent CPM were significantly younger, underwent genetic testing, had germline pathogenic variants, had a family history of breast cancer, had smaller tumors, underwent reconstruction, and had more wound infections. Of CPM patients, 50.4 % had no identifiable factors for increased risk of developing CBC.

Conclusions

The rate of CPM in a rural population at a single institution increased from 21.8 % to 64.4 % over two decades, with an average-risk CPM rate of 50.4 %. Those that undergo CPM are more likely to undergo reconstruction and have more wound infections. Identifying characteristics of patients undergoing CPM in a rural population and the increased associated risks allows for a better understanding of this trend to guide conversations with patients.

Key message

This study demonstrates that the rate of contralateral prophylactic mastectomy for unilateral breast cancers performed at a single institution serving a largely rural population has nearly tripled over the last two decades, with half of these patients having no factors that increase the risk for developing contralateral breast cancers. Contralateral prophylactic mastectomy was significantly associated with smaller tumors, younger age, genetic testing, germline pathogenic variants, family history of breast cancer, breast reconstruction, and increased wound infections.

Breast Cancer in the Tissue of the Contralateral Breast Reduction

Breast cancer is the most prevalent malignancy among women worldwide, and the increasing number of survivors is due to advances in early diagnosis and treatment efficacy. Consequently, the risk of developing contralateral breast cancer (CBC) among these survivors has become a concern. While surgical intervention with lumpectomy is a widely used primary approach for breast cancer, post-operative breast asymmetry is a potential concern. Many women opt for symmetrizing reduction procedures to improve aesthetic outcomes and quality of life. However, despite careful radiological screening, there is a chance of accidentally finding CBC. To address this, tissue excised during symmetrizing surgery is examined pathologically. In some cases, CBC or in situ lesions have been incidentally discovered in these specimens, prompting a need for a more thorough examination. Resection in pieces and the absence of surgical marking and pathological inking of the margin have made it challenging to precisely identify tumor location and assess tumor size and margin status, hampering adjuvant treatment decisions. A new protocol introduced in July 2022 aims to enhance the precision of CBC diagnosis, allowing for tailored treatment plans, including re-excision, systemic adjuvant therapy, or radiation therapy.

Historical trends in breast cancer presentation among women in Pakistan from join-point regression analysis

Objective

Breast cancer prevalence in Pakistan is among the highest in Asian countries. Recent changes in the temporal trends of breast cancer are largely unknown and examination of these trends can provide a direction in national planning for future health programs. The aim of this study was to examine recent changes in breast cancer incidence in Pakistan.

Methods

A total of 9,771 diagnosed breast cancer women were registered from 2004 to 2015 in three hospitals of Karachi. Join-point regression analysis was applied to assessing the age-standardized breast cancer presentation trends for each five-year age group. Age-specific average annual percentage changes were also calculated to assess the proportion of women with increased or decreased incidence of breast cancer.

Results

Age-standardized rates of breast cancer steadily increased from 24.7 per 100,000 in 2004, to 45.4 per 100,000 in 2015. The analytical trend based on the join-point model showed an average percentage increase breast cancer prevalence of 5.4 (95% CI = 3.1, 7.8). Significantly higher prevalence rates were identified among women aged 40-44 years and 65-69 years with an average percentage change of 18.5 (95% CI = 2.3, 37.2) and 14.3 (95% CI = 2.2, 27.9) respectively in the four years from 2011 to 2015.

Conclusion

The findings indicate the trend in age-standardized prevalence increased significantly in all age groups with noticeably larger increases observed among older and post-menopausal women from 2011 to 2015. The results warrant the need for more targeted interventions to high-risk groups and a sound foundation for cancer control program planning and policy development in Pakistan to reduce the increasing incidence of breast cancer.

Racial and Ethnic Disparities in Synchronous and Metachronous Bilateral Breast Cancer

INTRODUCTION

Significant racial and ethnic disparities exist in breast cancer treatment and survival. However, studies characterizing these disparities among patients developing bilateral breast cancers (BBC) are lacking. The purpose of this study is to understand the association between race and ethnicity, sociodemographic factors, clinical variables, treatment, and mortality in patients with BBC--synchronous bilateral breast cancer (sBBC) or metachronous bilateral breast cancer (mBBC).

METHODS

Patients diagnosed with mBBC or sBBC in the Surveillance, Epidemiology, and End Results program between 2010 and 2016 were examined. sBBC was defined as contralateral breast cancer <1 year after the initial cancer diagnosis, and mBBC was contralateral cancer ≥1 year. Univariable analysis examined sociodemographic, clinical, and treatment variables. Kaplan-Meier curves and Cox regression models evaluated disease-specific mortality.

RESULTS

Of the 11,493 patients that met inclusion criteria, 9575 (83.3%) had sBBC, and 1918 (16.7%) had mBBC. There were significant racial and ethnic differences in stage, tumor subtype, surgical management, and chemotherapy within sBBC and mBBC groups. On adjusted multivariate analysis of all BBC patients, Black race (HR 1.42; 95%CI 1.11-1.80; p<0.005; Ref White) was associated with a higher disease-specific mortality. Conversely, patients with mBBC had a 25% relative risk reduction in disease-specific mortality (HR 0.75; 95%CI 0.61-0.92; p<0.01) compared to sBBC. Subset analysis suggested Black Race modified the effect of sBBC on mortality (p<0.0001).

CONCLUSIONS

Among patients with BBC, there are racial and ethnic disparities in clinical characteristics, treatment, and mortality. Future studies should focus on strategies to reduce these disparities.

EBCC-13 manifesto: Balancing pros and cons for contralateral prophylactic mastectomy

After a diagnosis of unilateral breast cancer, increasing numbers of patients are requesting contralateral prophylactic mastectomy (CPM), the surgical removal of the healthy breast after diagnosis of unilateral breast cancer. It is important for the community of breast cancer specialists to provide meaningful guidance to women considering CPM. This manifesto discusses the issues and challenges of CPM and provides recommendations to improve oncological, surgical, physical and psychological outcomes for women presenting with unilateral breast cancer: (1) Communicate best available risks in manageable timeframes to prioritise actions; better risk stratification and implementation of risk-assessment tools combining family history, genetic and genomic information, and treatment and prognosis of the first breast cancer are required; (2) Reserve CPM for specific situations; in women not at high risk of contralateral breast cancer (CBC), ipsilateral breast-conserving surgery is the recommended option; (3) Encourage patients at low or intermediate risk of CBC to delay decisions on CPM until treatment for the primary cancer is complete, to focus on treating the existing disease first; (4) Provide patients with personalised information about the risk:benefit balance of CPM in manageable timeframes; (5) Ensure patients have an informed understanding of the competing risks for CBC and that there is a realistic plan for the patient; (6) Ensure patients understand the short- and long-term physical effects of CPM; (7) In patients considering CPM, offer psychological and surgical counselling before surgery; anxiety alone is not an indication for CPM; (8) Eliminate inequality between countries in reimbursement strategies; CPM should be reimbursed if it is considered a reasonable option resulting from multidisciplinary tumour board assessment; (9) Treat breast cancer patients at specialist breast units providing the entire patient-centred pathway.

Guidelines for breast cancer management in Bosnia and Herzegovina

Breast cancer is the most common cancer among women. In Bosnia and Herzegovina, accurate data on the status of breast cancer are lacking due to the absence of a central registry. Multiple international guidelines imply that institutions that monitor breast cancer patients should have optimal therapeutic options for treatment. In addition, there have been several international consensus guidelines written on the management of breast cancer. Application of consensus guidelines has previously been demonstrated to have a positive influence on breast cancer care. The importance of specialty breast centers has previously been reported. As part of the 2021 Bosnian-Herzegovinian American Academy of Arts and Sciences (BHAAAS) conference in Mostar, a round table of multidisciplinary specialists from Bosnia and Herzegovina and the diaspora was held. All were either members of BHAAAS or regularly participate in collaborative projects. The focus of the consortium was to write the first multidisciplinary guidelines for the general management of breast cancer in Bosnia and Herzegovina. Guidelines were developed for each area of breast cancer treatment and management. These guidelines will serve as a resource for practitioners managing breast cancer in the Bosnia and Herzegovina region. This might also be of benefit to the ministry of health and any future investors interested in developing breast cancer care policies in this region of the world.

Relapse-free survival in Sudanese women with non-metastatic breast cancer

Background

Breast cancer (BC) is the most frequently diagnosed cancer and a major cause of cancer mortality in Sudan. However, there is lack of data related to BC relapse. Therefore, this study was undertaken to estimate the 5-year relapse free survival (RFS) rate and factors related to BC relapse in Sudanese women with non-metastatic BC.

Methods

Data of BC women with BC diagnosed and treated at the National Cancer Institute-University of Gezira during 2012 were retrieved from medical records. The cases were followed-up through hospital records and telephone contact. Survival functions were calculated using Kaplan-Meier method and compared by log-rank test. The prognostic factors were tested using univariate and multivariable Cox regression analyses.

Results

We included 168 women with median age of 45 years (range, 22-83 years). 53.5%of women had stage III at time of diagnosis, whereas 4.2% and 42.3% of women presented with stage I and stage II, respectively. At the end of 5 years follow-up, with median follow-up period of 64 months, 94 (56.0%) women were alive in remission, 11 (6.5%) were alive with BC relapse, 49 (29.2%) were dead, and survival status was unknown in 14 (8.3%) women. Most of the occurred relapses were distant relapses. The 5-year RFS was 59%. The independent predictors of relapse were: larger primary tumor size (HR:1.84, 95% CI: 1.54-5.48, p=0.018); involved axillary lymph nodes with tumour (HR:  2.91, 95% CI:  1.53-7.91, p=0.001); not receiving adjuvant radiotherapy (HR: 2.2, 95% CI: 1.22-3.95, p=0.009); and not receiving hormone therapy (HR: 1.67, 95% CI: 1.01-2.76, p= 0.046).

Conclusion

We found a high risk of BC relapse in our resource-constrained settings. Advanced stages, not receiving adjuvant radiotherapy, and not receiving adjuvant hormone therapy were independent predictors associated with worse 5-year RFS. Therefore, enhancing the early diagnosis of BC and improving timely access to appropriate treatments represent key approaches to achieving better treatment outcomes.

A single centre study from western India to evaluate the frequency of developing second and subsequent multiple primary malignancies among cancer survivors

Aim

This study was designed to evaluate the frequency of developing second and subsequent primary cancers among cancer survivors.

Methods

We have retrospectively analyzed 121 multiple primary cancer patients treated at Bhagwan Mahavir Cancer Hospital and Research Centre, Jaipur, Rajasthan, India from the last 20 years. The survival analysis was performed by Kaplan-Meier methodology.

Results

The prevalence of multiple primary malignant tumors (MPMTs) was 1.51% (121/8000), with a male to female ratio of 1:1.42. In males most of the reported MPMTs were synchronous and most common first primary cancer cases were head & neck and lung whereas, in females most of the reported MPMTs were metachronous and most common first primary cancer cases were breast and gynaecological malignancies. Family history was reported in 15 cases. Maximum 33.05% patients received combined treatment of chemotherapy, radiotherapy and 91.73% (111/121) of patients with MPMTs were effectively followed up, 35 (28.92%) patients died and 5-year survival rate of the remaining 86 patients was 68.46%.

Conclusions

In the present observational study the most frequent sites of MPMTs in men were head & neck and lung whereas, in women breast and gynaecological sites were common. Therefore, careful monitoring and follow up are required for these patients.

Genetic Risk of Second Primary Cancer in Breast Cancer Survivors: The Multiethnic Cohort Study

Women who have had breast cancer in the past are at increased risk of developing a second primary cancer (SPC), including second primary breast cancer (SPBC) or a second primary non-breast cancer (SPNBC). In the Multiethnic Cohort (MEC) Study, we conducted a prospective cohort analysis in 3,223 female breast cancer survivors from five racial/ethnic populations (White, African American, Japanese American, Latino, and Native Hawaiian) to assess the association of rare pathogenic variants (PV) in 37 known cancer predisposition genes with risk of SPC. A total of 719 (22.3%) women developed SPC, of which, 323 (10.0%) were SPBC. Germline PVs in BRCA1 (HR, 2.28; 95% CI, 1.11-4.65) and ERCC2 (HR, 3.51; 95% CI, 1.29-9.54) were significantly enriched in women with SPC. In the subtype analysis for SPBC, a significant association of ERCC2 PVs (HR, 5.09; 95% CI, 1.58-16.4) and a suggestive association of BRCA2 PVs (HR, 2.24; 95% CI, 0.91-5.55) were observed. There was also a higher risk of SPNBC in carriers of BRCA1 PVs (HR, 2.98; 95% CI, 1.21-7.36). These results provide evidence that germline PVs in BRCA1, BRCA2, and ERCC2 contribute to the development of SPC in breast cancer survivors. These findings also suggest that compromised DNA repair mechanisms could be a predisposition factor for SPC in patients with breast cancer, supporting the need for closer monitoring of SPC in women carrying PVs in these genes.

SIGNIFICANCE

This multiethnic study links germline pathogenic variants in BRCA1, BRCA2, and ERCC2 to the development of second primary cancer in breast cancer survivors, providing biological insights and biomarkers to guide patient monitoring.

Timely cancer genetic counseling and testing for young women with breast cancer: impact on surgical decision-making for contralateral risk-reducing mastectomy

PURPOSE

Genetic testing (GT) can identify individuals with pathogenic/likely pathogenic variants (PV/LPVs) in breast cancer (BC) predisposition genes, who may consider contralateral risk-reducing mastectomy (CRRM). We report on CRRM rates in young women newly diagnosed with BC who received GT through a multidisciplinary clinic.

METHODS

Clinical data were reviewed for patients seen between November 2014 and June 2019. Patients with non-metastatic, unilateral BC diagnosed at age ≤ 45 and completed GT prior to surgery were included. Associations between surgical intervention and age, BC stage, family history, and GT results were evaluated.

RESULTS

Of the 194 patients, 30 (15.5%) had a PV/LPV in a BC predisposition gene (ATM, BRCA1, BRCA2, CHEK2, NBN, NF1), with 66.7% in BRCA1 or BRCA2. Of 164 (84.5%) uninformative results, 132 (68%) were negative and 32 (16.5%) were variants of uncertain significance (VUS). Overall, 67 (34.5%) had CRRM, including 25/30 (83.3%) PV/LPV carriers and 42/164 (25.6%) non-carriers. A positive test result (p < 0.01) and significant family history were associated with CRRM (p = 0.02). For the 164 with uninformative results, multivariate analysis showed that CRRM was not associated with age (p = 0.23), a VUS, (p = 0.08), family history (p = 0.10), or BC stage (p = 0.11).

CONCLUSION

In this cohort of young women with BC, the identification of a PV/LPV in a BC predisposition gene and a significant family history were associated with the decision to pursue CRRM. Thus, incorporation of genetic services in the initial evaluation of young patients with a new BC could contribute to the surgical decision-making process.

CBCRisk-Black: a personalized contralateral breast cancer risk prediction model for black women

PURPOSE

Black breast cancer (BC) survivors have a higher risk of developing contralateral breast cancer (CBC) than Whites. Existing CBC risk prediction tools are developed based on mostly White women. To address this racial disparity, it is crucial to develop tools tailored for Black women to help them inform about their actual risk of CBC.

METHODS

We propose an absolute risk prediction model, CBCRisk-Black, specifically for Black BC patients. It uses data on Black women from two sources: Breast Cancer Surveillance Consortium (BCSC) and Surveillance, Epidemiology, and End Results (SEER). First, a matched lasso logistic regression model for estimating relative risks (RR) is developed. Then, it is combined with relevant hazard rates and attributable risks to obtain absolute risks. Six-fold cross-validation is used to internally validate CBCRisk-Black. We also compare CBCRisk-Black with CBCRisk, an existing CBC risk prediction model.

RESULTS

The RR model uses data from BCSC on 744 Black women (186 cases). CBCRisk-Black has four risk factors (RR compared to baseline): breast density (2.13 for heterogeneous/extremely dense), family history of BC (2.28 for yes), first BC tumor size (2.14 for T3/T4, 1.56 for TIS), and age at first diagnosis of BC (1.41 for < 40). The area under the receiver operating characteristic curve (AUC) for 3- and 5-year predictions are 0.72 and 0.65 for CBCRisk-Black while those are 0.65 and 0.60 for CBCRisk.

CONCLUSION

CBCRisk-Black may serve as a useful tool to clinicians in counseling Black BC patients by providing a more accurate and personalized CBC risk estimate.

The association between physical health-related quality of life, physical functioning, and risk of contralateral breast cancer among older women

BACKGROUND

Physical limitations prior to cancer diagnosis may lead to suboptimal health outcomes. Our objective was to evaluate the impacts of poor physical health-related quality of life (HRQOL) and physical functioning (PF) on the risk of contralateral breast cancer (CBC).

METHODS

We performed a nested case-control study of women with invasive unilateral breast cancer (UBC) who did not receive prophylactic contralateral mastectomy using the Surveillance, Epidemiology and End Results Medicare Health Outcomes Survey data resource. Among 2938 women aged ≥ 65 years diagnosed with first stage I-III UBC between 1997 and 2011, we identified 100 subsequent CBC cases and 915 matched controls without CBC using incidence density sampling without replacement. Pre-diagnosis physical HRQOL and PF were determined using Medical Outcomes Trust Short Form-36 (SF-36)/Veterans Rand 12-Item Health Survey (VR-12) responses within 2 years prior to first UBC diagnosis. We estimated adjusted odds ratios (OR) and 95% confidence intervals (CI) using conditional logistic regression models.

RESULTS

Cases and controls were similar with respect to comorbidities, stage, surgery, and radiation treatments, but differed by hormone receptor status (ER/PR-negative, 23% and 11%, respectively) of first UBC. Cases had modestly lower mean pre-diagnosis physical HRQOL (- 1.8) and PF (- 2.2) scores. In multivariable models, we observed an increased CBC risk associated with low physical HRQOL (lowest vs. highest quartile, OR = 1.8; 95% CI 0.8-4.3), but CIs included 1.0. Low PF was associated with a 2.7-fold (95% CI 1.1-6.7) increased CBC risk.

CONCLUSIONS

Findings indicate that low physical HRQOL, specifically poor PF, is associated with CBC risk. Efforts to understand and minimize declines in PF post-breast cancer are well motivated.

Race, ethnicity and risk of second primary contralateral breast cancer in the United States

Breast cancer survivors have a high risk of a second primary contralateral breast cancer (CBC), but there are few studies of CBC risk in racial/ethnic minority populations. We examined whether the incidence and risk factors for CBC differed by race/ethnicity in the United States. Women with a first invasive Stage I-IIB breast cancer diagnosis at ages 20-74 years between 2000 and 2015 in the Surveillance, Epidemiology, and End Results Program (SEER) 18 registries were followed through 2016 for a diagnosis of invasive CBC ≥1 year after the first breast cancer diagnosis. We used cause-specific Cox proportional hazards models to test the association between race/ethnicity and CBC, adjusting for age, hormone receptor status, radiation therapy, chemotherapy and stage at first diagnosis, and evaluated the impact of contralateral prophylactic mastectomy, socioeconomic status, and insurance status on the association. After a median follow-up of 5.9 years, 9247 women (2.0%) were diagnosed with CBC. Relative to non-Hispanic (NH) White women, CBC risk was increased in NH Black women (hazard ratio = 1.44, 95% CI 1.35-1.54) and Hispanic women (1.11, 95% CI 1.02-1.20), with the largest differences among women diagnosed at younger ages. Adjustment for contralateral prophylactic mastectomy, socioeconomic status and health insurance did not explain the associations. Therefore, non-Hispanic Black and Hispanic women have an increased risk of CBC that is not explained by clinical or socioeconomic factors collected in SEER. Large studies of diverse breast cancer survivors with detailed data on treatment delivery and adherence are needed to inform interventions to reduce this disparity.

Breast Cancer in Adolescent and Young Adult Women Under the Age of 40 Years

In the United States, one in 196 women is diagnosed with breast cancer under the age of 40 years. Adolescents and young adults (AYAs), of age 15-39 years at diagnosis, experience a number of unique challenges when confronting breast cancer. The incidence of invasive breast cancer has increased among AYA women in the United States since 2004, and most of this change is due to an increase in young women diagnosed with distant disease. AYAs are more likely than older women to present with aggressive subtypes and advanced disease, and they often require systemic staging at diagnosis. Clinical trials should be considered whenever possible, particularly in AYAs with locally advanced or metastatic disease at diagnosis and those with disease progression or recurrence. A significant proportion of AYAs carry germline cancer predisposition mutations, which necessitates prompt genetic testing for all AYAs at diagnosis and may influence choice of local therapy. Suppression of ovarian function, as an adjunct to chemotherapy, may improve breast cancer survival in AYAs. To provide optimal care for AYAs with breast cancer, clinicians should engage multidisciplinary teams that offer fertility preservation, genetic counseling, physical and occupational therapy, nutrition, and psychosocial support, along with medical expertise in tailoring cancer-directed therapy and symptom management toward young women.

Breast Cancer Polygenic Risk Score and Contralateral Breast Cancer Risk

Previous research has shown that polygenic risk scores (PRSs) can be used to stratify women according to their risk of developing primary invasive breast cancer. This study aimed to evaluate the association between a recently validated PRS of 313 germline variants (PRS313) and contralateral breast cancer (CBC) risk. We included 56,068 women of European ancestry diagnosed with first invasive breast cancer from 1990 onward with follow-up from the Breast Cancer Association Consortium. Metachronous CBC risk (N = 1,027) according to the distribution of PRS313 was quantified using Cox regression analyses. We assessed PRS313 interaction with age at first diagnosis, family history, morphology, ER status, PR status, and HER2 status, and (neo)adjuvant therapy. In studies of Asian women, with limited follow-up, CBC risk associated with PRS313 was assessed using logistic regression for 340 women with CBC compared with 12,133 women with unilateral breast cancer. Higher PRS313 was associated with increased CBC risk: hazard ratio per standard deviation (SD) = 1.25 (95%CI = 1.18-1.33) for Europeans, and an OR per SD = 1.15 (95%CI = 1.02-1.29) for Asians. The absolute lifetime risks of CBC, accounting for death as competing risk, were 12.4% for European women at the 10th percentile and 20.5% at the 90th percentile of PRS313. We found no evidence of confounding by or interaction with individual characteristics, characteristics of the primary tumor, or treatment. The C-index for the PRS313 alone was 0.563 (95%CI = 0.547-0.586). In conclusion, PRS313 is an independent factor associated with CBC risk and can be incorporated into CBC risk prediction models to help improve stratification and optimize surveillance and treatment strategies.

Prediction of contralateral breast cancer: external validation of risk calculators in 20 international cohorts

BACKGROUND

Three tools are currently available to predict the risk of contralateral breast cancer (CBC). We aimed to compare the performance of the Manchester formula, CBCrisk, and PredictCBC in patients with invasive breast cancer (BC).

METHODS

We analyzed data of 132,756 patients (4682 CBC) from 20 international studies with a median follow-up of 8.8 years. Prediction performance included discrimination, quantified as a time-dependent Area-Under-the-Curve (AUC) at 5 and 10 years after diagnosis of primary BC, and calibration, quantified as the expected-observed (E/O) ratio at 5 and 10 years and the calibration slope.

RESULTS

The AUC at 10 years was: 0.58 (95% confidence intervals [CI] 0.57-0.59) for CBCrisk; 0.60 (95% CI 0.59-0.61) for the Manchester formula; 0.63 (95% CI 0.59-0.66) and 0.59 (95% CI 0.56-0.62) for PredictCBC-1A (for settings where BRCA1/2 mutation status is available) and PredictCBC-1B (for the general population), respectively. The E/O at 10 years: 0.82 (95% CI 0.51-1.32) for CBCrisk; 1.53 (95% CI 0.63-3.73) for the Manchester formula; 1.28 (95% CI 0.63-2.58) for PredictCBC-1A and 1.35 (95% CI 0.65-2.77) for PredictCBC-1B. The calibration slope was 1.26 (95% CI 1.01-1.50) for CBCrisk; 0.90 (95% CI 0.79-1.02) for PredictCBC-1A; 0.81 (95% CI 0.63-0.99) for PredictCBC-1B, and 0.39 (95% CI 0.34-0.43) for the Manchester formula.

CONCLUSIONS

Current CBC risk prediction tools provide only moderate discrimination and the Manchester formula was poorly calibrated. Better predictors and re-calibration are needed to improve CBC prediction and to identify low- and high-CBC risk patients for clinical decision-making.

The impact of lifestyle and reproductive factors on the risk of a second new primary cancer in the contralateral breast: a systematic review and meta-analysis

PURPOSE

The risk of being diagnosed with contralateral breast cancer (CBC) is an important health issue among breast cancer survivors. There is an increasing interest in the effect of lifestyle and reproductive factors on CBC risk, since these factors may partly be modifiable. We performed a systematic review and meta-analysis and aimed to evaluate the impact of lifestyle and reproductive factors on CBC risk in population-based breast cancer studies.

METHODS

The PubMed electronic database was searched up to 2nd November 2019, for relevant publications. Of the included studies, a meta-analysis per lifestyle or reproductive factor was performed.

RESULTS

Thirteen out of 784 publications were used for the meta-analysis. Body mass index (≥ 25 vs. < 25 kg/m²; RR = 1.22; 95% CI 1.01-1.47) was associated with increased CBC risk. The estimates for alcohol use (ever vs. never; RR = 1.15; 95% CI 1.02-1.31) and age at primiparity (≥ 25 vs. < 25 years; RR = 1.06; 95% CI 1.02-1.10) also showed an association with increased CBC risk. For parity (≥ 4 vs. nulliparous; RR = 0.56; 95% CI 0.42-0.76) and age at menopause (< 45 vs ≥ 45 years; RR = 0.79; 95% CI 0.67-0.93), results from two studies suggested a decreased CBC risk. We observed no association between CBC and smoking, age at menarche, oral contraceptive use, gravidity, breastfeeding, or menopausal status. Overall, the number of studies per risk factor was limited (n = 2-5).

CONCLUSIONS

BMI is a modifiable risk factor for CBC. Data on the effect of other modifiable lifestyle and reproductive factors are limited. For better counseling of patients on lifestyle effects, more studies are urgently needed.

Systemic investigations into the molecular features of bilateral breast cancer for diagnostic purposes

Introduction: Many breast cancer (BC) patients develop the disease bilaterally. The emergence of two tumors in the same host is unlikely to be a random co-incidence: bilateral BC (biBC) patients are enriched by women who are susceptible to this disease due to genetic or non-genetic factors.Areas covered: Data on molecular pathogenesis and translational aspects of biBC research are summarized.Expert opinion: Studies on concordant and discordant molecular events occurring in paired tumors resemble twin studies, as they help to reveal core components of BC pathogenesis and to analyze interactions between host factors and tumor phenotype. Mutation profiling of biBC pairs suggested that most biBCs are clonally independent malignancies, although some instances of presumably contralateral metastatic spread were shown as well. Many biBCs, especially synchronous ones, demonstrate the similarity of essential tumor characteristics, which can be explained by sharing of genetic background, hormonal milieu, metabolic environment, and external exposures. biBC is strongly associated with BC-predisposing germline mutations; therefore, clinical management of biBC patients must include comprehensive genetic testing. Some contralateral metachronous BCs demonstrate high-level microsatellite instability (MSI-H). MSI-H is sometimes observed in radiation- and chemotherapy-induced tumors; therefore, it is possible that some second BCs are causally related to the therapy applied for the first cancer. MSI-H tumors are responsive to immune checkpoint blockade; hence, MSI-H analysis is advisable for biBC molecular testing. Systematic cataloging of biBC molecular portraits is likely to provide valuable information on fundamental aspects of cancer pathogenesis.

Prediction and clinical utility of a contralateral breast cancer risk model

BACKGROUND

Breast cancer survivors are at risk for contralateral breast cancer (CBC), with the consequent burden of further treatment and potentially less favorable prognosis. We aimed to develop and validate a CBC risk prediction model and evaluate its applicability for clinical decision-making.

METHODS

We included data of 132,756 invasive non-metastatic breast cancer patients from 20 studies with 4682 CBC events and a median follow-up of 8.8 years. We developed a multivariable Fine and Gray prediction model (PredictCBC-1A) including patient, primary tumor, and treatment characteristics and BRCA1/2 germline mutation status, accounting for the competing risks of death and distant metastasis. We also developed a model without BRCA1/2 mutation status (PredictCBC-1B) since this information was available for only 6% of patients and is routinely unavailable in the general breast cancer population. Prediction performance was evaluated using calibration and discrimination, calculated by a time-dependent area under the curve (AUC) at 5 and 10 years after diagnosis of primary breast cancer, and an internal-external cross-validation procedure. Decision curve analysis was performed to evaluate the net benefit of the model to quantify clinical utility.

RESULTS

In the multivariable model, BRCA1/2 germline mutation status, family history, and systemic adjuvant treatment showed the strongest associations with CBC risk. The AUC of PredictCBC-1A was 0.63 (95% prediction interval (PI) at 5 years, 0.52-0.74; at 10 years, 0.53-0.72). Calibration-in-the-large was -0.13 (95% PI: -1.62-1.37), and the calibration slope was 0.90 (95% PI: 0.73-1.08). The AUC of Predict-1B at 10 years was 0.59 (95% PI: 0.52-0.66); calibration was slightly lower. Decision curve analysis for preventive contralateral mastectomy showed potential clinical utility of PredictCBC-1A between thresholds of 4-10% 10-year CBC risk for BRCA1/2 mutation carriers and non-carriers.

CONCLUSIONS

We developed a reasonably calibrated model to predict the risk of CBC in women of European-descent; however, prediction accuracy was moderate. Our model shows potential for improved risk counseling, but decision-making regarding contralateral preventive mastectomy, especially in the general breast cancer population where limited information of the mutation status in BRCA1/2 is available, remains challenging.

Metachronous Second Primary Malignancies in Known Breast Cancer Patients on 18F-Fluoro-2-Deoxyglucose Positron Emission Tomography-Computerized Tomography in a Tertiary Care Center

Introduction:

Breast cancer is the most common malignancy among women all over the world, which accounts to 25% of all cancers. In known cases of breast cancer, the risk of developing another denovo malignancy is more when compared to low risk groups, which might be due to common environmental risk factors, treatment induced risk factors, Genetic susceptibility for mutations, presence of cancer syndromes or better detection due to close surveillance.

Objective:

To study the profile of Metachronous 2^nd primary malignancies suspected on 18F-FDG PET CT in known Breast cancer patients. In this Retrospective study from January 2014 to April 2018, all the consecutive patients with known Breast cancer, who were referred to Nuclear Medicine department for 18F- FDG PET CT for follow up evaluation were included. Suspected 2^nd primary malignancies were correlated with Histopathological examination (HPE).

Results:

During the study period, a total of 233 Breast cancer patients (all are females), with a mean age of 54.2+13.4 years were studied. On 18F-FDG PET CT scan, suspicion for 2^nd primary malignancy was observed in 37 patients. HPE was done in 28/37 patients at the site of suspected lesions. 15/28 were positive for second malignancy, and remaining 13/28 were either a benign pathology or a part of metastatic disease from the primary breast cancer. The sites of 2^nd primary malignancies included Contralateral breast in 8/15 (53.3%), Ovary in 2/15 (13.3%), Endometrium in 2/15 (13.3%), Lung in 1/15 (6.6%), Stomach in 1/15 (6.6%) and Urinary bladder in 1/15 (6.6%) patients respectively. The incidence of metachronous 2^nd primaries in breast cancer is 67.3 per 1000 breast cancer patients.

Conclusion:

Metachronous second primary cancers in breast cancer patients are not very rare. A high imaging suspicion on 18F-FDG PET CT helps in early detection of 2^nd primary cancer, thereby facilitating early and appropriate management.

Association of a Pathway-Specific Genetic Risk Score With Risk of Radiation-Associated Contralateral Breast Cancer

IMPORTANCE

Radiation therapy for breast cancer is associated with increased risk of a second primary contralateral breast cancer, but the genetic factors modifying this association are not well understood.

OBJECTIVE

To determine whether a genetic risk score comprising single nucleotide polymorphisms in the nonhomologous end-joining DNA repair pathway is associated with radiation-associated contralateral breast cancer.

DESIGN, SETTING, AND PARTICIPANTS

This case-control study included a case group of women with contralateral breast cancer that was diagnosed at least 1 year after a first primary breast cancer who were individually matched to a control group of women with unilateral breast cancer. Inclusion criteria were receiving a first invasive breast cancer diagnosis prior to age 55 years between 1985 and 2008. Women were recruited through 8 population-based cancer registries in the United States, Canada, and Denmark as part of the Women's Environment, Cancer, and Radiation Epidemiology Studies I (November 2000 to August 2004) and II (March 2010 to December 2012). Data analysis was conducted from July 2017 to August 2019.

EXPOSURES

Stray radiation dose to the contralateral breast during radiation therapy for the first breast cancer. A novel genetic risk score comprised of genetic variants in the nonhomologous end-joining DNA repair pathway was considered the potential effect modifier, dichotomized as high risk if the score was above the median of 74 and low risk if the score was at or below the median.

MAIN OUTCOMES AND MEASURES

The main outcome was risk of contralateral breast cancer associated with stray radiation dose stratified by genetic risk score, age, and latency.

RESULTS

A total of 5953 women were approached for study participation, and 3732 women (62.7%) agreed to participate. The median (range) age at first diagnosis was 46 (23-54) years. After 5 years of latency or more, among women who received the first diagnosis when they were younger than 40 years, exposure to 1.0 Gy (to convert to rad, multiply by 100) or more of stray radiation was associated with a 2-fold increased risk of contralateral breast cancer compared with women who were not exposed (rate ratio, 2.0 [95% CI, 1.1-3.6]). The risk was higher among women with a genetic risk score above the median (rate ratio, 3.0 [95% CI, 1.1-8.1]), and there was no association among women with a genetic risk score below the median (rate ratio, 1.3 [95% CI, 0.5-3.7]). Among younger women with a high genetic risk score, the attributable increased risk for contralateral breast cancer associated with stray radiation dose was 28%.

CONCLUSIONS AND RELEVANCE

This study found an increased risk of contralateral breast cancer that was attributable to stray radiation exposure among women with a high genetic risk score and who received a first breast cancer diagnosis when they were younger than 40 years after 5 years or more of latency. This genetic risk score may help guide treatment and surveillance for women with breast cancer.

Identification of a 4-mRNA metastasis-related prognostic signature for patients with breast cancer

Metastasis‐related mRNAs have showed great promise as prognostic biomarkers in various types of cancers. Therefore, we attempted to develop a metastasis‐associated gene signature to enhance prognostic prediction of breast cancer (BC) based on gene expression profiling. We firstly screened and identified 56 differentially expressed mRNAs by analysing BC tumour tissues with and without metastasis in the discovery cohort (GSE102484, n = 683). We then found 26 of these differentially expressed genes were associated with metastasis‐free survival (MFS) in the training set (GSE20685, n = 319). A metastasis‐associated gene signature built using a LASSO Cox regression model, which consisted of four mRNAs, can classify patients into high‐ and low‐risk groups in the training cohort. Patients with high‐risk scores in the training cohort had shorter MFS (hazard ratio [HR] 3.89, 95% CI 2.53‐5.98; P < 0.001), disease‐free survival (DFS) (HR 4.69, 2.93‐7.50; P < 0.001) and overall survival (HR 4.06, 2.56‐6.45; P < 0.001) than patients with low‐risk scores. The prognostic accuracy of mRNAs signature was validated in the two independent validation cohorts (GSE21653, n = 248; GSE31448, n = 246). We then developed a nomogram based on the mRNAs signature and clinical‐related risk factors (T stage and N stage) that predicted an individual's risk of disease, which can be assessed by calibration curves. Our study demonstrated that this 4‐mRNA signature might be a reliable and useful prognostic tool for DFS evaluation and will facilitate tailored therapy for BC patients at different risk of disease.

Breast Cancer Estimate Modeling via PDE Thermal Analysis Algorithms

The significance of this study lies in the importance of (1) nondestructive testing in defect studies and (2) securing the reliability of breast cancer prediction through thermal analysis in nondestructive testing. Most nondestructive tests have negative effects on the human body. Moreover, the precision and accuracy of such tests are poor. This study analyzes these drawbacks and increases the reliability of such methods. A theoretical model was constructed, by which simulated inner breast tissue was observed in a nondestructive way through thermal analysis, and the presence and extent of simulated breast cancer were estimated based on the thermal observations. Herein, we studied the medical diagnosis of breast cancer by creating a theoretical environment that simulated breast cancer in a real-world setting; the model used two-dimensional modeling and partial differential equation (PDE) thermal analysis. Our theoretical analysis, based on partial differential equations, allowed us to demonstrate that non-wounding defect detection is possible and, in many ways, preferable. The main contribution of this paper lies in studying long-term estimates. In addition, the model in this study can be extended to predict breast cancer through pure heat and can also be used for various other cancer and tumor analyses in the human body.