Prognostic impact of HER2 biomarker levels in trastuzumab-treated early HER2-positive breast cancer.

BACKGROUND: Overexpression of human epidermal growth factor receptor 2 (HER2) caused by HER2 gene amplification is a driver in breast cancer tumorigenesis. We aimed to investigate the prognostic significance of manual scoring and digital image analysis (DIA) algorithm assessment of HER2 copy numbers and HER2/CEP17 ratios, along with ERBB2 mRNA levels among early-stage HER2-positive breast cancer patients treated with trastuzumab. METHODS: This retrospective study comprised 371 early HER2-positive breast cancer patients treated with adjuvant trastuzumab, with HER2 re-testing performed on whole tumor sections. Digitized tumor tissue slides were manually scored and assessed with uPath HER2 Dual ISH image analysis, breast algorithm. Targeted ERBB2 mRNA levels were assessed by the Xpert® Breast Cancer STRAT4 Assay. HER2 copy number and HER2/CEP17 ratio from in situ hybridization assessment, along with ERBB2 mRNA levels, were explored in relation to recurrence-free survival (RFS). RESULTS: The analysis showed that patients with tumors with the highest and lowest manually counted HER2 copy number levels had worse RFS than those with intermediate levels (HR = 2.7, CI 1.4-5.3, p = 0.003 and HR = 2.1, CI 1.1-3.9, p = 0.03, respectively). A similar trend was observed for HER2/CEP17 ratio, and the DIA algorithm confirmed the results. Moreover, patients with tumors with the highest and the lowest values of ERBB2 mRNA had a significantly worse prognosis (HR = 2.7, CI 1.4-5.1, p = 0.003 and HR = 2.8, CI 1.4-5.5, p = 0.004, respectively) compared to those with intermediate levels. CONCLUSIONS: Our findings suggest that the association between any of the three HER2 biomarkers and RFS was nonlinear. Patients with tumors with the highest levels of HER2 gene amplification or ERBB2 mRNA were associated with a worse prognosis than those with intermediate levels, which is of importance to investigate in future clinical trials studying HER2-targeted therapy.

Impact of Primary Breast Surgery on Overall Survival of Patients With De Novo Metastatic Breast Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND: Breast surgery in cases of de novo metastatic breast cancer (MBC) is associated with improved outcomes in retrospective studies, although the results of randomized controlled trials (RCTs) are conflicting. We aimed to investigate whether surgery in this context prolongs patient survival. METHODS: We performed a systematic review of the literature to identify RCTs comparing surgery of primary breast cancer to no surgery in patients with de novo MBC. Cochrane Library, Embase, Medline (OVID), and Web of Science were searched with latest update in July 2023, while conference proceedings were manually searched. Data concerning patient and tumor characteristics, as well as outcomes, were extracted. A meta-analysis with random effects models was performed considering heterogeneity between trials. RESULTS: Overall, 3255 entries were identified and 5 RCTs fulfilled all inclusion criteria, which had enrolled 1381 patients. The overall estimation in the intention-to-treat population showed no benefit for patients who had surgical excision of the primary breast tumor (HR = 0.93; 95% CI, 0.76-1.14). No subgroups in terms of receptor status or patterns of metastasis seemed to benefit from surgery, except for younger/premenopausal patients (HR = 0.74, 95% CI, 0.58-0.94). Breast surgery was associated with improved local progression-free survival (HR = 0.37, 95% CI, 0.19-0.74). CONCLUSION: Surgery of the primary tumor in patients with de novo MBC does not prolong survival, except possibly in younger/premenopausal patients. Breast surgery should be offered within the context of well-designed clinical trials examining the issue.

Treatment utilization and effectiveness of neoadjuvant chemotherapy comparing men and women diagnosed with breast cancer: a Swedish retrospective cohort study.

PURPOSE: Evidence supporting the use of neoadjuvant chemotherapy (NAC) in early breast cancer is based on studies mainly including women, whereas the utilization and effectiveness of NAC in men is less studied. The present study aimed to investigate the utilization and effectiveness of NAC in men and women with early breast cancer. METHODS: Eligible patients were identified through the Swedish National Breast Cancer Quality Register, that includes all newly diagnosed breast cancer cases in Sweden from 2008 and onwards. For the treatment utilization analysis, all patients with stage I-III between 2008 and 2020 were included (n = 82,888), whereas for the effectiveness analysis the cohort was restricted to patients receiving NAC (n = 6487). For both analyses, multivariate logistic regression models were applied to investigate potential sex disparities in NAC utilization and effectiveness, adjusted for patient- and tumor characteristics. RESULTS: In the NAC utilization analysis, 487 men and 82,401 women with stage I-III were included. No statistically significant difference between sexes in terms of NAC utilization was observed (adjusted Odds Ratio (adjOR): 1.135; 95% Confidence Interval (CI) 0.606-2.128) with an overall utilization rate of 4.9% in men compared to 7.8% in women. Among the 24 men and 6463 women who received NAC, the pathologic complete response (pCR) rates were 16.7% and 21.2%, respectively (adjOR: 1.141; 95% CI 0.141-9.238). CONCLUSION: The present study did not find any sex disparities in NAC utilization or effectiveness in terms of pCR. This supports the current recommendations of treating men with breast cancer with the same indications for NAC as women.

Use of beta-blockers in patients with ductal carcinoma in situ and risk of invasive breast cancer recurrence: a Swedish retrospective cohort study.

BACKGROUND: Retrospective observational studies suggest a potential role of beta-blockers as a protective strategy against progression and metastasis in invasive breast cancer. In this context, we investigated the impact of beta-blocker exposure on risk for progression to invasive breast cancer after diagnosis of ductal cancer in situ (DCIS). METHODS: The retrospective study population included 2535 women diagnosed with pure DCIS between 2006 and2012 in three healthcare regions in SwedenExposure to beta-blocker was quantified using a time-varying percentage of days with medication available. The absolute risk was quantified using cumulative incidence functions and cox models were applied to quantify the association between beta-blocker exposure and time from DCIS diagnosis to invasive breast cancer, accounting for delayed effects, competing risks and pre-specified confounders. RESULTS: The median follow-up was 8.7 years. One third of the patients in our cohort were exposed to beta-blockers post DCIS diagnosis. During the study period, 48 patients experienced an invasive recurrence, giving a cumulative incidence of invasive breast cancer progression of 1.8% at five years. The cumulative exposure to beta-blocker was associated with a reduced risk in a dose-dependent manner, though the effect was not statistically significant. CONCLUSION: Our observational study is suggestive of a protective effect of beta-blockers against invasive breast cancer after primary DCIS diagnosis. These results provide rationales for experimental and clinical follow-up studies in carefully selected DCIS groups.

Immune cell infiltrate in ductal carcinoma in situ and the risk of dying from breast cancer: case-control study.

BACKGROUND: Studies identifying risk factors for death from breast cancer after ductal carcinoma in situ (DCIS) are rare. In this retrospective nested case-control study, clinicopathological factors in women treated for DCIS and who died from breast cancer were compared with those of patients with DCIS who were free from metastatic disease. METHODS: The study included patients registered with DCIS without invasive carcinoma in Sweden between 1992 and 2012. This cohort was linked to the National Cause of Death Registry. Of 6964 women with DCIS, 96 were registered with breast cancer as cause of death (cases). For each case, up to four controls (318; women with DCIS, alive and without metastatic breast cancer at the time of death of the corresponding case) were selected randomly by incidence density sampling. Whole slides of tumour tissue were evaluated for DCIS grade, comedo necrosis, and intensity of periductal lymphocytic infiltrate. Composition of the immune cell infiltrate, expression of oestrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, and proliferation marker Ki-67 were scored on tissue microarrays. Clinical information was obtained from medical records. Information on date, site, and histological characteristics of local and distant recurrences was obtained from medical records for both cases and controls. RESULTS: Tumour tissue was analysed from 65 cases and 195 controls. Intense periductal lymphocytic infiltrate around DCIS was associated with an increased risk of later dying from breast cancer (OR 2.21. 95% c.i. 1.01 to 4.84). Tumours with more intense lymphocytic infiltrate had a lower T cell/B cell ratio. None of the other biomarkers correlated with increased risk of breast cancer death. CONCLUSION: The immune response to DCIS may influence the risk of dying from breast cancer.

Risk of obstetric and perinatal complications in women presenting with breast cancer during pregnancy and the first year postpartum in Sweden 1973-2017: A population-based matched study.

INTRODUCTION: For women presenting with breast cancer during pregnancy, treatment guidelines were historically restricted to only surgical treatment. Over the past decades, chemotherapy administered during pregnancy has been gradually introduced. Although breast cancer treatments during ongoing pregnancy have been deemed safe, detailed information on potential obstetric risks is lacking. We aimed to assess the risk of adverse obstetric and perinatal outcomes of breast cancer in pregnancy and within 1 year postpartum and in relation to trimester at breast cancer diagnosis, tumor stage, and cancer treatment during pregnancy. MATERIAL AND METHODS: Population-based matched study. Women diagnosed with breast cancer during pregnancy in 1973-2017 were identified in the Swedish Cancer Register and the Medical Birth Register, with additional information from the National Quality Register for Breast Cancer. Each birth with maternal breast cancer (n = 208 pregnant, n = 672 postpartum) was matched by age, calendar year, and birth order to 10 unexposed births from cancer-free women in the population (n = 2080 and n = 6720). Adjusted conditional logistic and multinomial regression models were used to estimate odds ratios and relative risk ratios, commonly denoted relative risks (RR) with 95% confidence intervals (CI), of adverse obstetric and perinatal outcomes. RESULTS: Breast cancer during pregnancy was associated with higher risks of preterm birth, both planned (RR 67.1, 95% CI 33.2-135.6) and spontaneous preterm birth (RR 3.8, 95% CI 2.0-7.5), and low birthweight (<2500 g: RR 7.5, 95% CI 4.9-11.3). The associated risks were higher if the breast cancer was diagnosed in the second trimester, and of similar magnitude irrespective of stage and treatment groups. There was a higher risk of low birthweight for gestational age (<25th centile) if breast cancer was diagnosed in the first trimester (RR 2.8, 95% CI 1.1-7.3). Risks of other pregnancy complications were similar to those of unexposed women, as were risks of neonatal mortality and malformations. Postpartum breast cancer was only associated with bleeding during pregnancy (RR 1.6, 95% CI 1.0-2.8). CONCLUSIONS: Preterm birth and related adverse outcomes were more common in women diagnosed with breast cancer during pregnancy. Reassuringly, breast cancer was not associated with other maternal pregnancy complications or adverse outcomes in children.

Risk factors for the increasing incidence of pregnancy-associated cancer in Sweden - a population-based study.

INTRODUCTION: The incidence of cancer during pregnancy and within first year post-delivery, ie pregnancy-associated cancer (PAC), is increasing in many countries, but little is known about risk factors for these trends. This study quantified incidence of PAC by trimesters and post-delivery periods, and assessed the role of maternal age, parity, immigrant status, education, smoking and body mass index for the risk and incidence trends of PAC. MATERIAL AND METHODS: We used data from the national birth and cancer registers in Sweden during 1973-2017 to define a register-based cohort of women aged 15-44 years. Incidence rates of PAC during pregnancy and up to 1 year post-delivery were calculated per 100 000 deliveries per year. Poisson regression with multiple imputation estimated incidence rate ratios with 95% confidence intervals adjusted by year, age, previous parity, immigrant status, education, smoking and BMI during 1990-2017, when information on risk factors was available. RESULTS: Among 4 557 284 deliveries, a total of 1274 (during pregnancy) and 3355 (within 1 year post-delivery) cases of PAC were diagnosed, with around 50 cases/year diagnosed during pregnancy and 110 cases/year during the first year post-delivery in the latest period 2015-2017. The most common cancer types during pregnancy were malignant melanoma, breast and cervical cancer, together accounting for 57% of cases during pregnancy and 53% during the first year post-delivery. The numbers of PAC were lower during pregnancy than during post-delivery for all tumor types with lowest numbers during first trimester. The PAC incidence rates increased over calendar time. High maternal age at diagnosis, smoking, nulliparity and non-immigrant background were associated with significantly higher risks of PAC. The increasing PAC incidence was in part explained by higher maternal age over time, but not by the other factors. CONCLUSIONS: High maternal age is the strongest risk factor for PAC. We show for the first time that smoking, nulliparity and non-immigrant background are also contributing risk factors for PAC. However, only high maternal age contributed significantly to the increasing incidence. Further studies on other potential risk factors for PAC are warranted, since our results indicate that age on its own does not fully explain the increase.

In modern times, how important are breast cancer stage, grade and receptor subtype for survival: a population-based cohort study.

BACKGROUND: In breast cancer, immunohistochemistry (IHC) subtypes, together with grade and stage, are well-known independent predictors of breast cancer death. Given the immense changes in breast cancer treatment and survival over time, we used recent population-based data to test the combined influence of IHC subtypes, grade and stage on breast cancer death. METHODS: We identified 24,137 women with invasive breast cancer aged 20 to 74 between 2005 and 2015 in the database of the Cancer Registry of Norway. Kaplan-Meier curves, mortality rates and adjusted hazard ratios for breast cancer death were estimated by IHC subtypes, grade, tumour size and nodal status during 13 years of follow-up. RESULTS: Within all IHC subtypes, grade, tumour size and nodal status were independent predictors of breast cancer death. When combining all prognostic factors, the risk of death was 20- to 40-fold higher in the worst groups compared to the group with the smallest size, low grade and ER+PR+HER2- status. Among node-negative ER+HER2- tumours, larger size conferred a significantly increased breast cancer mortality. ER+PR-HER2- tumours of high grade and advanced stage showed particularly high breast cancer mortality similar to TNBC. When examining early versus late mortality, grade, size and nodal status explained most of the late (> 5 years) mortality among ER+ subtypes. CONCLUSIONS: There is a wide range of risks of dying from breast cancer, also across small breast tumours of low/intermediate grade, and among node-negative tumours. Thus, even with modern breast cancer treatment, stage, grade and molecular subtype (reflected by IHC subtypes) matter for prognosis.

Predictive role of HER2-status on the effectiveness of endocrine adjuvant treatment in postmenopausal breast cancer patients: a population-based cohort study.

PURPOSE: There are conflicting results on the potential role of HER2-status on the efficacy of aromatase inhibitors (AIs) and tamoxifen (TAM) in patients with hormone receptor (HR)-positive breast cancer (BC). The purpose of this population-based cohort study was to investigate the potential benefit of AIs compared to TAM as adjuvant therapy in postmenopausal BC patients by HER2-status in the era of modern therapy with HER2-blockade. METHODS: A population-based cohort study was performed including all postmenopausal women diagnosed with HR-positive BC without distant metastasis between 2007 and 2012 in three healthcare regions in Sweden. We analyzed the breast cancer-specific survival (BCSS) and overall survival (OS) in two distinct cohorts (HER2-negative, HER2-positive) based on the type of endocrine therapy (ET) used. A propensity score matching was performed separately in the HER2-negative and HER2-positive cohorts, respectively. RESULTS: After propensity score matching, 4368 patients with HER2-negative and 214 patients with HER2-positive BC were available for analysis. In the HER2-negative cohort, an improved BCSS [Hazard Ratio (HR): 0.51; 95% confidence interval (CI): 0.34-0.77, p value < 0.001] and a trend toward improved OS (HR: 0.66; 95% CI: 0.41-1.08, p value = 0.093) in favor of AI-based therapy was observed. In the HER2-positive cohort, no statistically significant difference between AI-based ET and TAM was found in terms of either BCSS or OS, although the direction of HR was similar as in the HER2-negative cohort (HR for BCSS: 0.84; 95% CI: 0.14-5.04, p = 0.849; HR for OS: 0.62; 95% CI: 0.10-3.38, p = 0.345). CONCLUSION: Our study results, based on propensity-matched cohorts, did not support any predictive value of HER2-status on endocrine therapy in postmenopausal BC patients. AI-based ET remains the treatment of choice for postmenopausal BC patients with HR-positive disease in the modern era of HER2-directed therapy irrespective of HER2-status.

An Aggregated Comorbidity Measure Based on History of Filled Drug Prescriptions: Development and Evaluation in Two Separate Cohorts.

BACKGROUND: The ability to account for comorbidity when estimating survival in a population diagnosed with cancer could be improved by using a drug comorbidity index based on filled drug prescriptions. METHODS: We created a drug comorbidity index from age-stratified univariable associations between filled drug prescriptions and time to death in 326,450 control males randomly selected from the general population to men with prostate cancer. We also evaluated the index in 272,214 control females randomly selected from the general population to women with breast cancer. RESULTS: The new drug comorbidity index predicted survival better than the Charlson Comorbidity Index (CCI) and a previously published prescription index during 11 years of follow-up. The concordance (C)-index for the new index was 0.73 in male and 0.76 in the female population, as compared with a C-index of 0.67 in men and 0.69 in women for the CCI. In men of age 75-84 years with CCI = 0, the median survival time was 7.1 years (95% confidence interval [CI] = 7.0, 7.3) in the highest index quartile. Comparing the highest to the lowest drug comorbidity index quartile resulted in a hazard ratio (HR) of 2.2 among men (95% CI = 2.1, 2.3) and 2.4 among women (95% CI = 2.3, 2.6). CONCLUSIONS: A new drug comorbidity index based on filled drug prescriptions improved prediction of survival beyond age and the CCI alone. The index will allow a more accurate baseline estimation of expected survival for comparing treatment outcomes and evaluating treatment guidelines in populations of people with cancer.

The Natural History of Ductal Carcinoma In Situ of the Breast - An Overview.

Ductal carcinoma in situ (DCIS) of the breast is a heterogenous disease and its natural history cannot be directly observed as surgical removal is part of the current standard of care. Studies of incompletely excised breast lesions that were considered benign after biopsy, but at review years later were recognized as DCIS, offers some insight to the natural history of DCIS. Summarizing these retrospective data; 14-53 % of the cases retrospectively diagnosed as DCIS progressed to invasive breast cancer (IBC) during follow-up. While observations from retrospective re-evaluation of biopsies and autopsies adds epidemiological input for understanding the natural history of DCIS, the most important results are still awaited from the ongoing prospective studies on active surveillance of DCIS. These studies with collected data on patient characteristics, life-style and environmental factors, as well as tumor and stromal metabolomics and genomics, will probably further elucidate the natural history of DCIS and how the disease should be treated in the future.

Local Recurrence after Treatment of Ductal Carcinoma In Situ: A Comprehensive Overview.

Patients with DCIS have an excellent long-term prognosis with a 10-year breast cancer-specific survival around 98%. Treatment has the goal to prevent the development of an invasive breast cancer and to minimize the risk for a second breast cancer event, and published studies have shown a substantial decrease in invasive local recurrence rates over time. Approximately 50% of the local recurrences after BCS for a primary DCIS are invasive and 8.5% of them node-positive. Experiencing an ipsilateral invasive recurrence after a primary DCIS does significantly increase the risk of breast cancer death, while this is not seen after a DCIS recurrence. Radical surgery remains crucial to minimize the risk of local recurrence, and adjuvant radiotherapy reduces the risk of local recurrence by at least 50%. At recurrence, a repeat-BCS should be considered as it offers a good local control in properly selected patients and an overall and breast cancer-specific survival comparable to that seen after mastectomy.

Long-term risk of ischemic heart disease after adjuvant radiotherapy in breast cancer: results from a large population-based cohort.

BACKGROUND: Adjuvant radiotherapy (RT) for breast cancer (BC) has been associated with an increased risk of ischemic heart disease (IHD). We examined the incidence of IHD in a large population-based cohort of women with BC. METHODS: The Breast Cancer DataBase Sweden (BCBaSe) includes all women diagnosed with BC from 1992 to 2012 (n = 60,217) and age-matched women without a history of BC (n = 300,791) in three Swedish health care regions. Information on comorbidity, educational level, and incidence of IHD was obtained through linkage with population-based registries. The risk of IHD was estimated by Cox proportional hazard regression analyses and cumulative incidence by the Kaplan-Meier method. RESULTS: Women with BC had a lower risk of IHD compared to women without BC with a hazard ratio (HR) of 0.91 (95% CI 0.88-0.95). When women with left-sided BC were compared to right-sided BC, an increased HR for IHD of 1.09 (95% CI 1.01-1.17) was seen. In women receiving RT, a HR of 1.18 (95% CI 1.06-1.31) was seen in left-sided compared to right-sided BC, and the HRs increased with more extensive lymph node involvement and with the addition of systemic therapy. The cumulative IHD incidence was increased in women receiving left-sided RT compared to right-sided RT, starting from the first years after RT and sustained with longer follow-up. CONCLUSIONS: Women given RT for left-sided BC during 1992 to 2012 had an increased risk of IHD compared to women treated for right-sided BC. These women were treated in the era of three-dimensional conformal RT (3DCRT), and the results emphasize the importance of further developing and implementing RT techniques that lower the cardiac doses, without compromising the beneficial effects of RT.

Mammography screening reduces rates of advanced and fatal breast cancers: Results in 549,091 women.

BACKGROUND: It is of paramount importance to evaluate the impact of participation in organized mammography service screening independently from changes in breast cancer treatment. This can be done by measuring the incidence of fatal breast cancer, which is based on the date of diagnosis and not on the date of death. METHODS: Among 549,091 women, covering approximately 30% of the Swedish screening-eligible population, the authors calculated the incidence rates of 2473 breast cancers that were fatal within 10 years after diagnosis and the incidence rates of 9737 advanced breast cancers. Data regarding each breast cancer diagnosis and the cause and date of death of each breast cancer case were gathered from national Swedish registries. Tumor characteristics were collected from regional cancer centers. Aggregated data concerning invitation and participation were provided by Sectra Medical Systems AB. Incidence rates were analyzed using Poisson regression. RESULTS: Women who participated in mammography screening had a statistically significant 41% reduction in their risk of dying of breast cancer within 10 years (relative risk, 0.59; 95% CI, 0.51-0.68 [P < .001]) and a 25% reduction in the rate of advanced breast cancers (relative risk, 0.75; 95% CI, 0.66-0.84 [P < .001]). CONCLUSIONS: Substantial reductions in the incidence rate of breast cancers that were fatal within 10 years after diagnosis and in the advanced breast cancer rate were found in this contemporaneous comparison of women participating versus those not participating in screening. These benefits appeared to be independent of recent changes in treatment regimens.

Impact of chemotherapy, radiotherapy, and endocrine therapy on sick leave in women with early-stage breast cancer during a 5-year period: a population-based cohort study.

PURPOSE: To examine the influence of type of oncological treatment on sick leave in women of working age with early-stage breast cancer. METHODS: We identified 8870 women aged 30-64 diagnosed with stage I-II breast cancer between 2005 and 2012 in the Breast Cancer Data Base Sweden. Associations between type of oncological treatment (radiotherapy, endocrine therapy, and chemotherapy) and sick leave were estimated by hazard ratios, probabilities, and length of sick leave using multi-state survival analysis. RESULTS: During the first 5 years after diagnosis, women aged 50-54 years at diagnosis receiving chemotherapy spent on average 182 (95% CI 151-218) additional days on sick leave compared with women not receiving chemotherapy, but with otherwise similar characteristics. Correspondingly, women initiating endocrine therapy spent 30 (95% CI 18-44) additional days on sick leave and women receiving post-mastectomy radiotherapy 53 (95% CI 37-69) additional days. At year five, the rate of sick leave was increased in women who had received chemotherapy (HR 1.19, 95% CI 1.11-1.28) or endocrine therapy (HR 1.15, 95% CI 1.05-1.26). Chemotherapy and endocrine therapy were associated with increased rates of sick leave due to depression or anxiety. CONCLUSION: Our findings of increased long-term risks of sick leave after oncological treatment for breast cancer warrant attention from caregivers taking part in cancer rehabilitation. In light of the ongoing debate about overtreatment of early-stage breast cancer, our findings point to the importance of properly selecting patients for chemotherapy not only for the medical toxicity but also the possible impact on their livelihood.

Bleeding risk in breast cancer patients during concomitant administration of warfarin and tamoxifen: A population-based nested case-control study.

We aimed to investigate whether the concomitant use of tamoxifen with warfarin is associated with higher risk for bleeding among patients with early estrogen-receptor (ER)-positive breast in a population-based nested case-control study. We identified 1787 patients taking warfarin and 92 cases hospitalized for bleeding and found an adjusted odds ratio (OR) of 1.42 (95% confidence interval (CI): 0.84-2.40) for the risk of bleeding in patients treated with warfarin that initiated tamoxifen within the previous 30 days. As a result, we could not definitively rule out a potential association between tamoxifen use during warfarin and bleeding risk in patients with breast cancer.

Diagnostic pathways and management in women with pregnancy-associated breast cancer (PABC): no evidence of treatment delays following a first healthcare contact.

BACKGROUND: Women with pregnancy-associated breast cancer (PABC), i.e. diagnosed during or within 2 years of pregnancy, have a poor prognosis. We compared symptoms, diagnostics, treatments, and waiting times from first symptoms to treatment initiation in women diagnosed with PABC and non-PABC. MATERIALS AND METHODS: Women diagnosed with PABC and non-PABC at ages 15-44 were identified in Swedish healthcare registers. Chart information was retrieved for 546 women (273 PABC cases and 273 age- and hospital-matched non-PABC controls) treated at 11 hospitals across Sweden between 1992 and 2009. Distributions of symptoms, diagnostics and treatments were compared. Median waiting times from initial symptoms to start of treatment, and time periods within, were estimated from Kaplan-Meier curves. RESULTS: Initial symptoms in women with PABC and non-PABC were similar. Women with PABC more often underwent biopsy and ultrasound than mammography at initial examination. Compared to non-PABC, rates of mastectomy and axillary clearance were higher in women with PABC, while endocrine treatment was less common. The time from symptoms to first healthcare contact was non-significantly longer in women diagnosed during or within 6 months of pregnancy. Waiting times from contact with healthcare to diagnosis and treatment were shorter or similar in women with PABC compared to women with non-PABC. CONCLUSIONS: These findings do not support the notion that diagnostic and treatment delays following a first healthcare contact are more common in women diagnosed with breast cancer during or shortly after pregnancy. However, there was some evidence of delays in seeking healthcare among pregnant and lactating women.

Identification and validation of single-sample breast cancer radiosensitivity gene expression predictors.

BACKGROUND: Adjuvant radiotherapy is the standard of care after breast-conserving surgery for primary breast cancer, despite a majority of patients being over- or under-treated. In contrast to adjuvant endocrine therapy and chemotherapy, no diagnostic tests are in clinical use that can stratify patients for adjuvant radiotherapy. This study presents the development and validation of a targeted gene expression assay to predict the risk of ipsilateral breast tumor recurrence and response to adjuvant radiotherapy after breast-conserving surgery in primary breast cancer. METHODS: Fresh-frozen primary tumors from 336 patients radically (clear margins) operated on with breast-conserving surgery with or without radiotherapy were collected. Patients were split into a discovery cohort (N = 172) and a validation cohort (N = 164). Genes predicting ipsilateral breast tumor recurrence in an Illumina HT12 v4 whole transcriptome analysis were combined with genes identified in the literature (248 genes in total) to develop a targeted radiosensitivity assay on the Nanostring nCounter platform. Single-sample predictors for ipsilateral breast tumor recurrence based on a k-top scoring pairs algorithm were trained, stratified for estrogen receptor (ER) status and radiotherapy. Two previously published profiles, the radiosensitivity signature of Speers et al., and the 10-gene signature of Eschrich et al., were also included in the targeted panel. RESULTS: Derived single-sample predictors were prognostic for ipsilateral breast tumor recurrence in radiotherapy-treated ER+ patients (AUC 0.67, p = 0.01), ER+ patients without radiotherapy (AUC = 0.89, p = 0.02), and radiotherapy-treated ER- patients (AUC = 0.78, p < 0.001). Among ER+ patients, radiotherapy had an excellent effect on tumors classified as radiosensitive (p < 0.001), while radiotherapy had no effect on tumors classified as radioresistant (p = 0.36) and there was a high risk of ipsilateral breast tumor recurrence (55% at 10 years). Our single-sample predictors developed in ER+ tumors and the radiosensitivity signature correlated with proliferation, while single-sample predictors developed in ER- tumors correlated with immune response. The 10-gene signature negatively correlated with both proliferation and immune response. CONCLUSIONS: Our targeted single-sample predictors were prognostic for ipsilateral breast tumor recurrence and have the potential to stratify patients for adjuvant radiotherapy. The correlation of models with biology may explain the different performance in subgroups of breast cancer.

No association between low-dose aspirin use and breast cancer outcomes overall: a Swedish population-based study.

BACKGROUND: Results from previous studies indicate that use of low-dose aspirin may improve breast cancer prognosis. We evaluated aspirin use and breast cancer outcomes in relation to clinical characteristics as well as dose and duration of aspirin use. METHODS: We used information from the Regional Breast Cancer Quality-of-Care Registries in three Swedish regions to identify 21,414 women diagnosed with a first stage I-III breast cancer between 1 April 2006 and 31 December 2012. The cohort was further linked to nationwide registers to retrieve information about dispensing low-dose aspirin before and after breast cancer diagnosis, comorbidity and causes of death. In a separate analysis, we investigated time to breast cancer death among 621 women with stage IV disease at diagnosis. Associations were evaluated using a multivariable Cox proportional hazards model. RESULTS: Among women with stage I-III breast cancer, 2660 (12.4%) used low-dose aspirin shortly before breast cancer diagnosis and 4091 (19.1%) were users during follow-up. Women were followed for a median of 3.8 years after diagnosis. There was no association between aspirin use and breast cancer-specific death in multivariable analyses (use before diagnosis: hazard ratio (HR) 0.93, 95% confidence interval (CI) 0.77-1.12; use after diagnosis: HR 1.00, 95% CI 0.74-1.37). Similarly, aspirin use was not associated with risk of first recurrence/metastases in a subgroup of stage I-III breast cancer patients (HR 0.97, 95% CI 0.86-1.10). However, in analyses stratified by stage, an inverse association between low-dose aspirin use after diagnosis and breast cancer death was found for women with stage I tumors (HR 0.53, 95% CI 0.29-0.96). Among women with stage IV disease at diagnosis, aspirin use was not associated with time to breast cancer death (HR 0.91, 95% CI 0.67-1.23). CONCLUSION: In this large population-based cohort study there was no evidence that low-dose aspirin use before or after breast cancer diagnosis is associated with a reduced risk of adverse outcomes overall in breast cancer. However, a potential benefit was noted among women with stage I tumors, warranting further investigation.

Tumor characteristics and prognosis in women with pregnancy-associated breast cancer.

There is evidence of poor prognosis in women with pregnancy-associated breast cancer (PABC) diagnosed during pregnancy or within 2 years of delivery. Using a large, population-based cohort, we examined clinicopathologic features and survival in women with PABC. A cohort of women diagnosed with invasive breast cancer between 1992 and 2009 at ages 15-44 years was identified in the Swedish Cancer Register and the Breast Cancer Quality Registers. Dates of childbirths for each woman were retrieved from the Swedish Multi-Generation Register. Age-standardized distributions of tumor stage (tumor size, nodal status, metastasis), Elston grade and ER/PR/HER2 status were compared between nulliparous women and women with breast cancer during pregnancy and up to 10 years postdelivery. Adjusted hazard ratios for all-cause mortality rates among patients were estimated using Cox regression. We identified 1,661 nulliparous women with breast cancer, 778 women with PABC (97 during pregnancy, 270 within first and 411 within second year postdelivery) and 3,598 during 2-10 years postdelivery. Compared to nulliparous women, women with PABC, and especially women diagnosed 0-12 months after delivery, had more advanced T and N stage, and higher proportions of ER/PR negative, HER2 positive and triple-negative tumors. Increased hazard ratios were observed in women diagnosed within 5 years of delivery after adjustment for age, year, education and region. Following additional adjustment for tumor characteristics, the hazard ratios were attenuated and nonsignificant. The poorer prognosis observed in women with PABC appears to be largely explained by more adverse tumor characteristics at diagnosis.