Mammographic screening detects low-risk tumor biology breast cancers

Breast Cancer Stage and Size Detected with Film versus Digital Mammography in New South Wales, Australia: A Population-Based Study Using Routinely Collected Data

BACKGROUND

Digital mammography has replaced film mammography in breast-screening programs globally, including Australia. This led to an increase in the rate of detection, but whether there was increased detection of clinically important cancers is uncertain.

METHODS

In this population-wide retrospective cohort study in New South Wales, Australia spanning 2004 to 2016 and including 4,631,656 screens, there were 22,965 cancers in women screened with film (n = 11,040) or digital mammography (n = 11,925). We examined the change in tumor characteristics overall and how these rates changed over time, accounting for changes in background rates using an interrupted time-series. Comparisons were made with unscreened women (n = 26,326) during this time.

RESULTS

We found increased detection of in situ cancer (3.36 per 10,000 screens), localized invasive, and smaller-sized breast cancers attributable to the change in mammography technology, whereas screen-detected intermediate-sized and metastatic breast cancers decreased. Rates of early-stage and intermediate-sized interval cancers increased, and late-stage (-1.62 per 10,000 screens) and large interval cancers decreased. In unscreened women, there were small increases in the temporal trends of cancers across all stages.

CONCLUSIONS

At least some of the increased detection of smaller early-stage cancers may have translated into a reduction in larger and late-stage cancers, indicating beneficial detection of cancers that would have otherwise progressed. However, the increased detection of smaller early-stage and small cancers may also have increased over-diagnosis of lesions that would otherwise have not caused harm.

IMPACT

Robust evaluation of potential benefits and harms is needed after changes to screening programs. See related In the Spotlight, p. 638.

Ensemble-based classification using microRNA expression identifies a breast cancer patient subgroup with an ultralow long-term risk of metastases

BACKGROUND

Current clinical markers overestimate the recurrence risk in many lymph node negative (LNN) breast cancer (BC) patients such that a majority of these low-risk patients unnecessarily receive systemic treatments. We tested if differential microRNA expression in primary tumors allows reliable identification of indolent LNN BC patients to provide an improved classification tool for overtreatment reduction in this patient group.

METHODS

We collected freshly frozen primary tumors of 80 LNN BC patients with recurrence and 80 recurrence-free patients (mean follow-up: 20.9 years). The study comprises solely systemically untreated patients to exclude that administered treatments confound the metastasis status. Samples were pairwise matched for clinical-pathological characteristics to minimize dependence of current markers. Patients were classified into risk-subgroups according to the differential microRNA expression of their tumors via classification model building with cross-validation using seven classification methods and a voting scheme. The methodology was validated using available data of two independent cohorts (n = 123, n = 339).

RESULTS

Of the 80 indolent patients (who would all likely receive systemic treatments today) our ultralow-risk classifier correctly identified 37 while keeping a sensitivity of 100% in the recurrence group. Multivariable logistic regression analysis confirmed independence of voting results from current clinical markers. Application of the method in two validation cohorts confirmed successful classification of ultralow-risk BC patients with significantly prolonged recurrence-free survival.

CONCLUSION

Profiles of differential microRNAs expression can identify LNN BC patients who could spare systemic treatments demanded by currently applied classifications. However, further validation studies are required for clinical implementation of the applied methodology.

Systematic review and meta-analysis of prognostic characteristics for breast cancers in populations with digital vs film mammography indicate the transition may have increased both early detection and overdiagnosis

OBJECTIVES

Film mammography has been replaced by digital mammography in breast screening programs globally. This led to a small increase in the rate of detection, but whether the detection of clinically important cancers increased is uncertain. We aimed to assess the impact on tumor characteristics of screen-detected and interval breast cancers.

STUDY DESIGN AND SETTING

We searched seven databases from inception to October 08, 2023, for publications comparing film and digital mammography within the same population of asymptomatic women at population (average) risk of breast cancer. We recorded reported tumor characteristics and assessed risk of bias using the Risk Of Bias In Non-randomised Studies - of Interventions tool. We synthesized results using meta-analyses of random effects.

RESULTS

Eighteen studies were included in the analysis from 8 countries, including 11,592,225 screening examinations (8,117,781 film; 3,474,444 digital). There were no differences in tumor size, morphology, grade, node status, receptor status, or stage in the pooled differences for screen-detected and interval invasive cancer tumor characteristics. There were statistically significant increases in screen-detected ductal carcinoma in situ (DCIS) across all grades: 0.05 (0.00-0.11), 0.14 (0.05-0.22), and 0.19 (0.05-0.33) per 1000 screens for low, intermediate, and high-grade DCIS, respectively. There were similar (non-statistically significant) increases in screen-detected invasive cancer across all grades.

CONCLUSION

The increased detection of all grades of DCIS and invasive cancer may indicate both increased early detection of more aggressive disease and increased overdiagnosis.

Clinicopathological and prognostic value of calcification morphology descriptors in ductal carcinoma in situ of the breast: a systematic review and meta-analysis

BACKGROUND

Calcifications on mammography can be indicative of breast cancer, but the prognostic value of their appearance remains unclear. This systematic review and meta-analysis aimed to evaluate the association between mammographic calcification morphology descriptors (CMDs) and clinicopathological factors.

METHODS

A comprehensive literature search in Medline via Ovid, Embase.com, and Web of Science was conducted for articles published between 2000 and January 2022 that assessed the relationship between CMDs and clinicopathological factors, excluding case reports and review articles. The risk of bias and overall quality of evidence were evaluated using the QUIPS tool and GRADE. A random-effects model was used to synthesize the extracted data. This systematic review is reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA).

RESULTS

Among the 4715 articles reviewed, 29 met the inclusion criteria, reporting on 17 different clinicopathological factors in relation to CMDs. Heterogeneity between studies was present and the overall risk of bias was high, primarily due to small, inadequately described study populations. Meta-analysis demonstrated significant associations between fine linear calcifications and high-grade DCIS [pooled odds ratio (pOR), 4.92; 95% confidence interval (CI), 2.64-9.17], (comedo)necrosis (pOR, 3.46; 95% CI, 1.29-9.30), (micro)invasion (pOR, 1.53; 95% CI, 1.03-2.27), and a negative association with estrogen receptor positivity (pOR, 0.33; 95% CI, 0.12-0.89).

CONCLUSIONS

CMDs detected on mammography have prognostic value, but there is a high level of bias and variability between current studies. In order for CMDs to achieve clinical utility, standardization in reporting of CMDs is necessary.

CRITICAL RELEVANCE STATEMENT

Mammographic calcification morphology descriptors (CMDs) have prognostic value, but in order for CMDs to achieve clinical utility, standardization in reporting of CMDs is necessary.

SYSTEMATIC REVIEW REGISTRATION

CRD42022341599 KEY POINTS: • Mammographic calcifications can be indicative of breast cancer. • The prognostic value of mammographic calcifications is still unclear. • Specific mammographic calcification morphologies are related to lesion aggressiveness. • Variability between studies necessitates standardization in calcification evaluation to achieve clinical utility.

Semiannual Breast US or MRI Screening in Patients with a Personal History of Breast Cancer

Background The wide variability of screening imaging use in patients with a personal history of breast cancer (PHBC) warrants investigation of its comparative clinical effectiveness. While more intensive screening with US or MRI at an interval of less than 1 year could increase early-stage breast cancer detection, its benefit has not been established. Purpose To investigate the outcomes of semiannual multimodality screening in patients with PHBC. Materials and Methods An academic medical center database was retrospectively searched for patients diagnosed with breast cancer between January 2015 and June 2018 who had undergone annual mammography with either semiannual incidence US or MRI screening from July 2019 to December 2019 and three subsequent semiannual screenings over a 2-year period. The primary outcome was second breast cancers diagnosed during follow-up. Examination-level cancer detection and interval cancer rates were calculated. Screening performances were compared with χ2 or Fisher exact tests or a logistic model with generalized estimating equations. Results Our final cohort included 2758 asymptomatic women (median age, 53 years; range, 20-84 years). Among 5615 US and 1807 MRI examinations, 18 breast cancers were detected after negative findings on a prior semiannual incidence US screening examination; 44% (eight of 18) were stage 0 (three detected with MRI; five, with US), and 39% (seven of 18) were stage I (three detected with MRI; four, with US). MRI had a cancer detection rate up to 17.1 per 1000 examinations (eight of 467; 95% CI: 8.7, 33.4), and the overall cancer detection rates of US and MRI were 1.8 (10 of 5615; 95% CI: 1.0, 3.3) and 4.4 (eight of 1807; 95% CI: 2.2, 8.8) per 1000 examinations, respectively (P = .11). Conclusion Supplemental semiannual US or MRI screening depicted second breast cancers after negative findings at prior semiannual incidence US examination in patients with PHBC. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Berg in this issue.

The COVID-19 Pandemic Impact on Breast Cancer Diagnosis: A Retrospective Study

OBJECTIVE

 This study aimed to evaluate the diagnostic profile of breast cancer cases during the coronavirus disease 2019 (COVID-19) pandemic compared with the previous year.

METHODS

 It is a retrospective study of cases diagnosed by a reference service in the public health system of Campinas, SP, Brazil. Two periods were analyzed: March to October 2019 (preCOVID period) and March to October 2020 (COVID-period). All women diagnosed during the periods were included. The Chi-Squared or Fisher exact and Mann-Whitney tests were used.

RESULTS

 In the preCOVID and COVID periods, breast cancers were diagnosed, respectively, in 115 vs 59 women, and the mean ages at diagnosis were 55 and 57 years (p = 0.339). In the COVID period, the family history of breast cancer was more observed (9.6% vs 29.8%, p < 0.001), cases were more frequently symptomatic (50.4% vs 79.7%, p < 0.001) and had more frequently palpable masses (56.5% vs 79.7%, p = 0.003). In symptomatic women, the mean number of days from symptom to mammography were 233.6 (458.3) in 2019 and 152.1 (151.5) in 2020 (p = 0.871). Among invasive tumors, the proportion of breast cancers in stages I and II was slightly higher in the COVID period, although not significantly (76.7% vs 82.4%, p = 0.428). Also in the COVID period, the frequency of luminal A-like tumors was lower (29.2% vs 11.8%, p = 0.018), of triple-negative tumors was twice as high (10.1% vs 21.6%, p = 0.062), and of estrogen receptor-positive tumors was lower (82.2% vs 66.0%, p = 0.030).

CONCLUSION

 During the COVID-19 pandemic, breast cancer diagnoses were reduced. Cases detected were suggestive of a worse prognosis: symptomatic women with palpable masses and more aggressive subtypes. Indolent tumors were those more sensitive to the interruption in screening.

Differences in breast cancer diagnosis by patient presentation in Ontario: a retrospective cohort study

BACKGROUND

In Ontario, patients with breast cancer typically receive their diagnoses through the Ontario Breast Screening Program (OBSP) after an abnormal screen, through screening initiated by a primary care provider or other referring physician, or through follow-up of symptoms by patients' primary care providers. We sought to explore the association of the route to diagnosis (screening within or outside the OBSP or via symptomatic presentation) with use of OBSP-affiliated breast assessment sites (O-BAS), wait times until diagnosis or treatment, health care use and overall survival for patients with breast cancer.

METHODS

In this retrospective cohort study, we used the Ontario Cancer Registry to identify adults (aged 18-105 yr) who received a diagnosis of breast cancer from 2013 to 2017. We excluded patients if they were not Ontario residents or had missing age or sex, or who died before diagnosis. We used logistic regression to evaluate factors associated with categorical variables (whether patients were or were not referred to an OBAS, whether patients were screened or symptomatic) and Cox proportional hazards regression to identify factors associated with all-cause mortality.

RESULTS

Of 51 460 patients with breast cancer, 42 598 (83%) received their diagnoses at an O-BAS. Patients whose cancer was first detected through the OBSP were more likely than symptomatic patients to be given a diagnosis at an O-BAS (adjusted odds ratio 1.68, 95% confidence interval [CI] 1.57 to 1.80). Patients screened by the OBSP were given their diagnoses 1 month earlier than symptomatic patients, but diagnosis at an O-BAS did not affect the time until either diagnosis or treatment. Patients referred to an O-BAS had significantly better overall survival than those who were not referred (adjusted hazard ratio 0.73, 95% CI 0.66 to 0.80).

INTERPRETATION

Patients screened through the OBSP were given their diagnoses earlier than symptomatic patients and were more likely to be referred to an O-BAS, which was associated with better survival. Our findings suggest that individuals with signs and symptoms of breast cancer would benefit from similar referral processes, oversight and standards to those used by the OBSP.

Clinicopathological characteristics and survival results of patients with ultralow risk breast cancer

BACKGROUND AND OBJECTIVE

To identify subgroups with good progress over an extended period, we used diagnostic screening, tumour palpability, tumour phenotype, and node involvement.

PATIENTS AND METHODS

We identified patients with good progress by means of a descriptive, observational and retrospective study.

RESULTS

Of 746 patients diagnosed with node-negative breast cancer between 2001 and 2015: 110 (14.75%) had non-palpable screening-diagnosed tumours; 88 (80%) were endocrine-sensitive, 10 (9.10%) were triple-negative and 11 (10%) were HER2. Only 3 patients developed metastases, and there were 4 deaths: 2 from breast cancer and 2 from other causes. The distant recurrence-free interval (DRFI) was 95.60%: 100% in 34 endocrine-sensitive histological grade 1 (equivalent to luminal A) tumours, and 94.40% (95% CI 86.76-102.04) in 54 grade 2-3 (luminal B) tumours. In triple-negative and HER2 cases, it was 100%. In tumours <1 cm it was 100%, and >1 cm it was 95.50% (95% CI 79.42-100.98).

CONCLUSIONS

Patients with non-palpable tumours detected by mammogram screening have ultralow risk. The good progress in the luminal A, triple-negative, HER2, and less than 1 cm subgroups may explain the efficacy of the treatment but it also makes them candidates to de-escalation of their treatment.

Outcome of Patients With an Ultralow-Risk 70-Gene Signature in the MINDACT Trial

PURPOSE

Patients with 70-gene signature ultralow-risk breast cancers have shown excellent survival in historic cohorts, including randomized trials. The ultralow-risk subgroup was characterized to help avoid overtreatment. We evaluated outcomes of ultralow-risk patients in the largest cohort to date.

METHODS

Of the 6,693 patients enrolled in the EORTC-10041/BIG-3-04 randomized phase III MINDACT trial, profiling revealed an ultralow-risk 70-gene signature in 1,000 patients (15%). Distant metastasis-free interval (DMFI) and breast cancer-specific survival (BCSS) were assessed in patients stratified by 70-gene signature result (high, low, and ultralow) by Kaplan-Meier analysis and hazard ratios with 95% CI from Cox regression.

RESULTS

Median follow-up was 8.7 years. Of the ultralow-risk patients (n = 1,000), 67% were > 50 years, 81% had tumors ≤ 2 cm, 80% were lymph node-negative, 96% had grade 1 or 2 tumors, and 99% were estrogen receptor (ER)-positive. Systemic therapy was received by 84% of patients (69% endocrine therapy, 14% endocrine therapy plus chemotherapy, 1% other) and 16% received no adjuvant systemic treatment. The 8-year DMFI for ultralow-risk patients was 97.0% (95% CI, 95.8 to 98.1), which was 2.5% higher than for patients with low-risk tumors (n = 3,295, 94.5% [95% CI, 93.6 to 95.3]). The hazard ratio for DMFI was 0.65 (95% CI, 0.45 to 0.94) for ultralow versus low risk, after adjusting for clinical-pathologic and treatment characteristics. The 8-year BCSS for ultralow-risk patients was 99.6% (95% CI, 99.1 to 100).

CONCLUSION

Patients with an ultralow-risk 70-gene signature have the best prognosis, distinctive from low risk, with 8-year BCSS above 99%, and very few patients developed distant metastases with an 8-year DMFI rate of 97%. These patients could be candidates for further de-escalation of treatment, to avoid overtreatment and the risk of side effects.

Breast Cancer Screening: Is There Room for De-escalation?

Purpose of Review

Breast cancer screening is highly controversial and different agencies have widely varying guidelines. Yet it is currently used extensively in the USA and frequently the thought is "the more, the better." The purpose of this review is to objectively assess the risks and benefits of screening mammography and consider whether there may be areas where it could be de-escalated.

Recent Findings

Over the past few years, there have been several meta-analyses that are concordant, and it is now agreed that the main benefit of screening mammography is about a 20% reduction in breast cancer mortality. This actually benefits about 5% of patients with mammographically detected tumors. We now appreciate that the main harm of screening is overdiagnosis, i.e. detection of a cancer that will not cause the patient any harm and would not have ever been detected without the screening. This currently represents about 20 to 30% of screening detected cancers. Finding extra cancers with more intense screening is not always good, because in this situation, the risk of overdiagnosis increases and the benefit decreases. In some groups, the risk of overdiagnosis approaches 75%.

Summary

Our goal should be not only to find more cancers, but to avoid finding cancers that would never have caused the patient any harm and lead to unnecessary treatment. The authors suggest some situations where it may be reasonable to de-escalate screening.

Deep Learning Predicts Interval and Screening-detected Cancer from Screening Mammograms: A Case-Case-Control Study in 6369 Women

Background The ability of deep learning (DL) models to classify women as at risk for either screening mammography-detected or interval cancer (not detected at mammography) has not yet been explored in the literature. Purpose To examine the ability of DL models to estimate the risk of interval and screening-detected breast cancers with and without clinical risk factors. Materials and Methods This study was performed on 25 096 digital screening mammograms obtained from January 2006 to December 2013. The mammograms were obtained in 6369 women without breast cancer, 1609 of whom developed screening-detected breast cancer and 351 of whom developed interval invasive breast cancer. A DL model was trained on the negative mammograms to classify women into those who did not develop cancer and those who developed screening-detected cancer or interval invasive cancer. Model effectiveness was evaluated as a matched concordance statistic (C statistic) in a held-out 26% (1669 of 6369) test set of the mammograms. Results The C statistics and odds ratios for comparing patients with screening-detected cancer versus matched controls were 0.66 (95% CI: 0.63, 0.69) and 1.25 (95% CI: 1.17, 1.33), respectively, for the DL model, 0.62 (95% CI: 0.59, 0.65) and 2.14 (95% CI: 1.32, 3.45) for the clinical risk factors with the Breast Imaging Reporting and Data System (BI-RADS) density model, and 0.66 (95% CI: 0.63, 0.69) and 1.21 (95% CI: 1.13, 1.30) for the combined DL and clinical risk factors model. For comparing patients with interval cancer versus controls, the C statistics and odds ratios were 0.64 (95% CI: 0.58, 0.71) and 1.26 (95% CI: 1.10, 1.45), respectively, for the DL model, 0.71 (95% CI: 0.65, 0.77) and 7.25 (95% CI: 2.94, 17.9) for the risk factors with BI-RADS density (b rated vs non-b rated) model, and 0.72 (95% CI: 0.66, 0.78) and 1.10 (95% CI: 0.94, 1.29) for the combined DL and clinical risk factors model. The P values between the DL, BI-RADS, and combined model's ability to detect screen and interval cancer were .99, .002, and .03, respectively. Conclusion The deep learning model outperformed in determining screening-detected cancer risk but underperformed for interval cancer risk when compared with clinical risk factors including breast density. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Bae and Kim in this issue.

The impact of tumor detection method on genomic and clinical risk and chemotherapy recommendation in early hormone receptor positive breast cancer

BACKGROUND

Symptomatic breast cancers share aggressive clinico-pathological characteristics compared to screen-detected breast cancers. We assessed the association between the method of cancer detection and genomic and clinical risk, and its effect on adjuvant chemotherapy recommendations.

PATIENTS AND METHODS

Patients with early hormone receptor positive (HR+) HER2neu-negative (HER2-) breast cancer, and known OncotypeDX Breast Recurrence Score test were included. A natural language processing (NLP) algorithm was used to identify the method of cancer detection. The clinical and genomic risks of symptomatic and screen-detected tumors were compared.

RESULTS

The NLP algorithm identified the method of detection of 401 patients, with 216 (54%) diagnosed by routine screening, and the remainder secondary to symptoms. The distribution of OncotypeDX recurrence score (RS) varied between the groups. In the symptomatic group there were lower proportions of low RS (13% vs 23%) and higher proportions of high RS (24% vs. 13%) compared to the screen-detected group. Symptomatic tumors were significantly more likely to have a high clinical risk (59% vs 40%). Based on genomic and clinical risk and current guidelines, we found that women aged 50 and under, with a symptomatic cancer, had an increased probability of receiving adjuvant chemotherapy recommendation compared to women with screen-detected cancers (60% vs. 37%).

CONCLUSIONS

We demonstrated an association between the method of cancer detection and both genomic and clinical risk. Symptomatic breast cancer, especially in young women, remains a poor prognostic factor that should be taken into account when evaluating patient prognosis and determining adjuvant treatment plans.

Poor Biological Factors and Prognosis of Interval Breast Cancers: Long-Term Results of Bahçeşehir (Istanbul) Breast Cancer Screening Project in Turkey

PURPOSE

The Turkish Bahçeşehir Breast Cancer Screening Project was a 10-year, organized, population-based screening program carried out in Bahçeşehir county, Istanbul. Our aim was to examine the biologic features and outcome of screen-detected and interval breast cancers during the 10-year study period.

METHODS

Between 2009 and 2019, 2-view mammograms were obtained at 2-year intervals for women aged 40 to 69 years. Clinicopathological characteristics including ER, PR, HER2-neu, and Ki-67 status were analyzed for those diagnosed with breast cancer.

RESULTS

In 8,758 screened women, 131 breast cancers (1.5%) were detected. The majority of patients (82.3%) had prognostic stage 0-I disease. Contrarily, patients with interval cancers (n = 15; 11.4%) were more likely to have a worse prognostic stage (II-IV disease; odds ratio [OR], 3.59, 95% CI, 0.9 to 14.5) and high Ki-67 scores (OR, 3.14; 95% CI, 0.9 to 11.2). Interval cancers detected within 1 year were more likely to have a luminal B (57.1% v 31.9%) and triple-negative (14.3% v 1%) subtype and less likely to have a luminal A subtype (28.6% v 61.5%; P = .04). Patients with interval cancers had a poor outcome in 10-year disease-specific (DSS) and disease-free survival (DFS) compared with those with screen-detected cancers (DSS: 68.2% v 98.1%, P = .002; DFS: 78.6% v 96.5%, P = .011).

CONCLUSION

Our findings suggest the majority of screen-detected breast cancers exhibited a luminal A subtype profile with an excellent prognosis. However, interval cancers were more likely to have aggressive subtypes such as luminal B subtype or triple-negative cancers associated with a poor prognosis requiring other preventive strategies.

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

PURPOSE

Studies have shown that screen detection by national screening programs is independently associated with better prognosis of breast cancer. The aim of this study is to evaluate the association between tumor biology according to the 70-gene signature (70-GS) and survival of patients with screen-detected and interval breast cancers.

METHODS

All Dutch breast cancer patients enrolled in the MINDACT trial (EORTC-10041/BIG3-04) accrued 2007-2011, who participated in the national screening program (biennial screening, ages 50-75) were included (n = 1102). Distant Metastasis-Free Interval (DMFI) was evaluated according to the 70-GS for patients with screen-detected (n = 754) and interval cancers (n = 348).

RESULTS

Patients with screen-detected cancers had 8-year DMFI rates of 98.2% for 70-GS ultralow-, 94.6% for low-, and 93.8% for high-risk tumors (p = 0.4). For interval cancers, there was a significantly lower 8-year DMFI rate for patients with 70-GS high-risk tumors (85.2%) compared to low- (92.2%) and ultralow-risk tumors (97.4%, p = 0.0023). Among patients with 70-GS high-risk tumors, a significant difference in 8-year DMFI rate was observed between interval (85.2%, n = 166) versus screen-detected cancers (93.8%, n = 238; p = 0.002) with a HR of 2.3 (95%CI 1.2-4.4, p = 0.010) adjusted for clinical-pathological characteristics and adjuvant systemic treatment.

CONCLUSION

Among patients with 70-GS high-risk tumors, a significant difference in DMFI was observed between screen-detected and interval cancers, suggesting that method of detection is an additional prognostic factor in this subgroup and should be taken into account when deciding on adjuvant treatment strategies.

PET/CT in breast cancer staging is useful for evaluation of axillary lymph node and distant metastases

INTRODUCTION

Breast cancer outcome is dependent on disease stage. The aim of the study was to assess the role of PET/CT in the evaluation of axillary lymph node and distant metastases in women with newly diagnosed primary breast cancer.

MATERIALS AND METHODS

We assessed, among patients with newly diagnosed primary breast cancer, associations of [¹⁸F] fluorodeoxyglucose (FDG) uptake (maximum standardized uptake value [SUV_max]) with clinical variables of the primary tumor, including regional nodal status and the presence of distant metastases.

RESULTS

Of 324 patients, 265 (81.8%) had focal uptake of FDG that corresponded with the cancerous lesion, and 21 (6.5%) had no FDG-avid findings. The remaining 38 patients had diffuse or nonspecific uptake of FDG. Among patients with a focal uptake of FDG (n = 265), the mean tumor size was 2.6 ± 1.9 (range 0.5-13.5), and the mean SUV_max was 5.3 ± 4.9 (range 1.2-25.0). In 83 patients (25.6%), PET/CT demonstrated additional suspected foci in the same breast. FDG-avid lymphadenopathy was observed in 156 patients (48.1%). Further assessment of lymph node involvement was available for 55/156 patients (axillary lymph node dissection [n = 21]; core needle biopsy [n = 34]) and confirmed axillary lymph node metastases in 47 (85.5%)). Thirteen patients (4.0%) had FDG-avid supraclavicular lymph nodes and six (1.9%) had FDG-avid internal mammary lymph nodes. Distant FDG-avid lesions were detected in 33 patients (10.2%).

CONCLUSION

PET/CT is a useful diagnostic tool for staging breast cancer patients, but its use should be limited to specific clinical situations; further evaluation is needed.

Personalized early detection and prevention of breast cancer: ENVISION consensus statement

The European Collaborative on Personalized Early Detection and Prevention of Breast Cancer (ENVISION) brings together several international research consortia working on different aspects of the personalized early detection and prevention of breast cancer. In a consensus conference held in 2019, the members of this network identified research areas requiring development to enable evidence-based personalized interventions that might improve the benefits and reduce the harms of existing breast cancer screening and prevention programmes. The priority areas identified were: 1) breast cancer subtype-specific risk assessment tools applicable to women of all ancestries; 2) intermediate surrogate markers of response to preventive measures; 3) novel non-surgical preventive measures to reduce the incidence of breast cancer of poor prognosis; and 4) hybrid effectiveness-implementation research combined with modelling studies to evaluate the long-term population outcomes of risk-based early detection strategies. The implementation of such programmes would require health-care systems to be open to learning and adapting, the engagement of a diverse range of stakeholders and tailoring to societal norms and values, while also addressing the ethical and legal issues. In this Consensus Statement, we discuss the current state of breast cancer risk prediction, risk-stratified prevention and early detection strategies, and their implementation. Throughout, we highlight priorities for advancing each of these areas.

The Evolution of Our Understanding of the Biology of Cancer Is the Key to Avoiding Overdiagnosis and Overtreatment

There has been a tremendous evolution in our thinking about cancer since the 1880s. Breast cancer is a particularly good example to evaluate the progress that has been made and the new challenges that have arisen due to screening that inadvertently identifies indolent lesions. The degree to which overdiagnosis is a problem depends on the reservoir of indolent disease, the disease heterogeneity, and the fraction of the tumors that have aggressive biology. Cancers span the spectrum of biological behavior, and population-wide screening increases the detection of tumors that may not cause harm within the patient's lifetime or may never metastasize or result in death. Our approach to early detection will be vastly improved if we understand, address, and adjust to tumor heterogeneity. In this article, we use breast cancer as a case study to demonstrate how the approach to biological characterization, diagnostics, and therapeutics can inform our approach to screening, early detection, and prevention. Overdiagnosis can be mitigated by developing diagnostics to identify indolent disease, incorporating biology and risk assessment in screening strategies, changing the pathology rules for tumor classification, and refining the way we classify precancerous lesions. The more the patterns of cancers can be seen across other cancers, the more it is clear that our approach should transcend organ of origin. This will be particularly helpful in advancing the field by changing both our terminology for what is cancer and also by helping us to learn how best to mitigate the risk of the most aggressive cancers.See all articles in this CEBP Focus section, "NCI Early Detection Research Network: Making Cancer Detection Possible."

Artificial neural network models to predict nodal status in clinically node-negative breast cancer

BACKGROUND

Sentinel lymph node biopsy (SLNB) is standard staging procedure for nodal status in breast cancer, but lacks therapeutic benefit for patients with benign sentinel nodes. For patients with positive sentinel nodes, individualized surgical strategies are applied depending on the extent of nodal involvement. Preoperative prediction of nodal status is thus important for individualizing axillary surgery avoiding unnecessary surgery. We aimed to predict nodal status in clinically node-negative breast cancer and identify candidates for SLNB omission by including patient-related and pathological characteristics into artificial neural network (ANN) models.

METHODS

Patients with primary breast cancer were consecutively included between January 1, 2009 and December 31, 2012 in a prospectively maintained pathology database. Clinical- and radiological data were extracted from patient's files and only clinically node-negative patients constituted the final study cohort. ANN-based models for nodal prediction were constructed including 15 risk variables for nodal status. Area under the receiver operating characteristic curve (AUC) and Hosmer-Lemeshow goodness-of-fit test (HL) were used to assess performance and calibration of three predictive ANN-based models for no lymph node metastasis (N0), metastases in 1-3 lymph nodes (N1) and metastases in ≥ 4 lymph nodes (N2). Linear regression models for nodal prediction were calculated for comparison.

RESULTS

Eight hundred patients (N0, n = 514; N1, n = 232; N2, n = 54) were included. Internally validated AUCs for N0 versus N+ was 0.740 (95% CI = 0.723-0.758); median HL was 9.869 (P = 0.274), for N1 versus N0, 0.705 (95% CI = 0.686-0.724; median HL: 7.421; P = 0.492) and for N2 versus N0 and N1, 0.747 (95% CI = 0.728-0.765; median HL: 9.220; P = 0.324). Tumor size and vascular invasion were top-ranked predictors of all three end-points, followed by estrogen receptor status and lobular cancer for prediction of N2. For each end-point, ANN models showed better discriminatory performance than multivariable logistic regression models. Accepting a false negative rate (FNR) of 10% for predicting N0 by the ANN model, SLNB could have been abstained in 27.25% of patients with clinically node-negative axilla.

CONCLUSIONS

In this retrospective study, ANN showed promising result as decision-supporting tools for estimating nodal disease. If prospectively validated, patients least likely to have nodal metastasis could be spared SLNB using predictive models.

TRIAL REGISTRATION

Registered in the ISRCTN registry with study ID ISRCTN14341750 . Date of registration 23/11/2018. Retrospectively registered.

Molecular subtypes of screen-detected breast cancer

BACKGROUND

Detection of breast cancers by mammographic screening confers a survival advantage of 20-50% compared to symptomatic presentations. The improved prognosis is only partly explained by stage migration. The distribution of the molecular subtypes of screen-detected breast cancer (SDBC) or their HER2 status has not been studied extensively. We wished to address these issues through the study of a large series of SDBC, with other presentations serving as controls.

DESIGN

Deidentified cases of female invasive cancer, diagnosed in Australia and New Zealand during 2005-2015, were retrieved from the BreastSurgANZ Quality Audit (BQA). Method of detection and selected patient, tumour and treatment data were assessed. Immunohistochemical surrogates for molecular subtypes were defined as Luminal A (ER+ and/or PR+, HER2-), Luminal B (ER+ and/or PR+, HER2+), HER2-enriched (ER-, PR- and HER2+) and basal-like (triple negative). Results were compared with the findings of controls and previous studies.

RESULT

100983 invasive cancers were diagnosed, including 32493 (32.7%) SDBC and 66907 (67.3%) with other presentations. The biomarker profile for SDBC versus other presentations in the same population was ER 89.3 versus 80.3%, PR 78.8 versus 69.8% and for HER2 11 versus 15.6%. The distribution of molecular subtypes was Luminal A 81.9 versus 70.74%, Luminal B 7.39 versus 9.52%, HER2-enriched 3.63 versus 6.06% and Basal-like 7.08 versus 13.68%. These differences were significant (p < 0.0001).

CONCLUSION

Molecular profiles of SDBC are significantly different from those of symptomatic cancers, with over-representation of the Luminal A and proportionately lower rates of all other subtypes. We have shown, for the first time, significantly lower rates of HER2 positivity in SDBC. These differences may contribute to the better survival of SDBC and have implications for prognostication, targeted therapy decisions and for laboratory quality assurance programs in setting target ranges for proportions of ER-positive and HER2 results in heavily screened populations.

Mammography-detected ultrasound-negative asymptomatic micro-calcifications in Chinese women: Would it be safe to watch and wait?

Although mammography (MG) has been widely used for breast cancer screening in the western world, over-diagnosis remains controversial. Milestone studies showed that ultrasound (US) was an effective primary screening test for breast cancer both in the western world and in China. US improves the sensitivity of screening in Chinese women who have denser breasts and develop breast cancer earlier than Caucasian counterparts, and is used as the primary imaging test in the hospital-based opportunistic screening among asymptomatic self-referred women. Our previous work showed that US result might further differentiate the MG-detected breast cancers into low risk (US+) and ultra-low risk (US-). Indeed, most of the MG+/US- breast cancers would be ultra-low risk cancers and almost always present as MG micro-calcifications. Furthermore, majority of the commonest MG+/US- abnormal finding of micro-calcification is usually benign. Biopsy of benign breast disease increases not only the risk of breast cancer, but the expenses of screening and healthcare. Our hypothesis proposes that mammography-positive ultrasound-negative (MG+/US-) asymptomatic micro-calcifications might not need immediate invasive procedures and be safe to observe until the micro-calcifications increase significantly or become US-positive. If this hypothesis is proved, US would serve as the primary imaging test for breast cancer screening in China, with MG as the selective screening test and diagnostic tool for surgical plan. Unnecessary biopsy or surgery might be avoided with screening expenses considerably decrease.

Tumor biology, clinicopathological characteristics and prognosis of screen detected T1 invasive non-palpable breast cancer in asymptomatic Chinese women (2001-2014)

Background

Mammography screening usually detects low-risk breast cancer in the western world. However, little is known about the ultrasound and mammography screen-detected T1 invasive non-palpable breast cancer (NPBC) in asymptomatic Chinese women.

Results

With the increase of tumor size (T1a, b, c), lymph node positivity (8.7%, 18.3%, 26.0%, p = 0.018), pN (p = 0.028) and TNM stage (p = 0.035) increased accordingly. Tumor size (T1a, b, c) was correlated with high Ki-67 index (defined as ≥ 14%, 37.9%, 45.8%, 56.2%, p = 0.017), chemotherapy (20.4%, 35.2%, 57.3%, p < 0.001) and targeted therapy (2.9%, 9.9%, 15.1%, p = 0.008). T1a disease had higher chance of being luminal A and accompanied with ductal carcinoma in situ (DCIS), while T1c tumor being triple-negative and without DCIS. The 5-year disease free survival (DFS) of T1a, b, c NPBC were 99.0%, 96.9% and 92.9%, whereas the 5-year overall survival (OS) were 100.0%, 100.0% and 97.9% respectively. There was no significant difference in 5-year DFS or OS among the T1 NPBC subgroups or subtypes/immunophenotypes.

Patients and methods

From 2001 to 2014, 4,574 screening positive women received biopsies in Peking Union Medical College (PUMC) Hospital, and 729 NPBC including 437 T1 unilateral invasive NPBC were diagnosed. With a median follow-up time of 32 months (6–163 months), the clinicopathological characteristics, treatment choice, 5-year DFS and OS were compared between T1a, T1b and T1c NPBC. The DFS and OS prognostic factors were identified.

Conclusion

Screen-detected T1 invasive NPBC could be regarded as low-risk cancer in Chinese women. TNM stage and LN metastasis instead of molecular subtype was identified as the DFS prognostic factors while radiotherapy as the OS predictor.

Primary Care Provider Experience with Breast Density Legislation in Massachusetts

BACKGROUND

Dense breasts on mammography independently increases breast cancer risk and decreases mammography sensitivity. Thirty-two states have adopted notification laws to raise awareness among women with dense breasts about supplemental screening. Little is known about these policies' impact on clinical practice among primary care providers (PCPs).

MATERIALS AND METHODS

This study explores PCP attitudes, knowledge, and the impact of the Massachusetts dense breast notification legislation on clinical practice after its enactment in 2015. An anonymous, online survey at two urban safety-net hospitals was administered in 2015-2016. Practicing MDs and nurse practitioners in primary care were invited to participate.

RESULTS

All 145 PCPs in general internal medicine at the two sites were e-mailed a survey link and 80 (55%) were completed. While 64 of 80 PCPs surveyed (80%) had some familiarity with the legislation, none identified the 8 required components of notifications contained in the Massachusetts legislation. Forty-nine percent (39/80) did not feel prepared to respond to patient questions about dense breasts. Forty-one percent (33/80) correctly identified that no current guidelines recommend the use of supplemental screening tests solely based on breast density and 85% (68/80) indicated interest in further training. Female and less experienced providers were more likely to be in favor of the legislation (49% vs. 11% by gender; 76% <5 years vs. 9%> 20 years). Women practitioners (55%) who were more likely than men (17%, p = 0.01) to agree with the policy changed their discussions of mammography results with patients.

CONCLUSIONS

PCPs feel underprepared to counsel women about breast density identified on mammography and its implications.

Mammography screening: A major issue in medicine

Breast cancer mortality is declining in most high-income countries. The role of mammography screening in these declines is much debated. Screening impacts cancer mortality through decreasing the incidence of number of advanced cancers with poor prognosis, while therapies and patient management impact cancer mortality through decreasing the fatality of cancers. The effectiveness of cancer screening is the ability of a screening method to curb the incidence of advanced cancers in populations. Methods for evaluating cancer screening effectiveness are based on the monitoring of age-adjusted incidence rates of advanced cancers that should decrease after the introduction of screening. Likewise, cancer-specific mortality rates should decline more rapidly in areas with screening than in areas without or with lower levels of screening but where patient management is similar. These two criteria have provided evidence that screening for colorectal and cervical cancer contributes to decreasing the mortality associated with these two cancers. In contrast, screening for neuroblastoma in children was discontinued in the early 2000s because these two criteria were not met. In addition, overdiagnosis - i.e. the detection of non-progressing occult neuroblastoma that would not have been life-threatening during the subject's lifetime - is a major undesirable consequence of screening. Accumulating epidemiological data show that in populations where mammography screening has been widespread for a long time, there has been no or only a modest decline in the incidence of advanced cancers, including that of de novo metastatic (stage IV) cancers at diagnosis. Moreover, breast cancer mortality reductions are similar in areas with early introduction and high penetration of screening and in areas with late introduction and low penetration of screening. Overdiagnosis is commonplace, representing 20% or more of all breast cancers among women invited to screening and 30-50% of screen-detected cancers. Overdiagnosis leads to overtreatment and inflicts considerable physical, psychological and economic harm on many women. Overdiagnosis has also exerted considerable disruptive effects on the interpretation of clinical outcomes expressed in percentages (instead of rates) or as overall survival (instead of mortality rates or stage-specific survival). Rates of radical mastectomies have not decreased following the introduction of screening and keep rising in some countries (e.g. the United States of America (USA)). Hence, the epidemiological picture of mammography screening closely resembles that of screening for neuroblastoma. Reappraisals of Swedish mammography trials demonstrate that the design and statistical analysis of these trials were different from those of all trials on screening for cancers other than breast cancer. We found compelling indications that these trials overestimated reductions in breast cancer mortality associated with screening, in part because of the statistical analyses themselves, in part because of improved therapies and underreporting of breast cancer as the underlying cause of death in screening groups. In this regard, Swedish trials should publish the stage-specific breast cancer mortality rates for the screening and control groups separately. Results of the Greater New York Health Insurance Plan trial are biased because of the underreporting of breast cancer cases and deaths that occurred in women who did not participate in screening. After 17 years of follow-up, the United Kingdom (UK) Age Trial showed no benefit from mammography screening starting at age 39-41. Until around 2005, most proponents of breast screening backed the monitoring of changes in advanced cancer incidence and comparative studies on breast cancer mortality for the evaluation of breast screening effectiveness. However, in an attempt to mitigate the contradictions between results of mammography trials and population data, breast-screening proponents have elected to change the criteria for the evaluation of cancer screening effectiveness, giving precedence to incidence-based mortality (IBM) and case-control studies. But practically all IBM studies on mammography screening have a strong ecological component in their design. The two IBM studies done in Norway that meet all methodological requirements do not document significant reductions in breast cancer mortality associated with mammography screening. Because of their propensity to exaggerate the health benefits of screening, case-control studies may demonstrate that mammography screening could reduce the risk of death from diseases other than breast cancer. Numerous statistical model approaches have been conducted for estimating the contributions of screening and of patient management to reductions in breast cancer mortality. Unverified assumptions are needed for running these models. For instance, many models assume that if screening had not occurred, the majority of screen-detected asymptomatic cancers would have progressed to symptomatic advanced cancers. This assumption is not grounded in evidence because a large proportion of screen-detected breast cancers represent overdiagnosis and hence non-progressing tumours. The accumulation of population data in well-screened populations diminishes the relevance of model approaches. The comparison of the performance of different screening modalities - e.g. mammography, digital mammography, ultrasonography, magnetic resonance imaging (MRI), three-dimensional tomosynthesis (TDT) - concentrates on detection rates, which is the ability of a technique to detect more cancers than other techniques. However, a greater detection rate tells little about the capacity to prevent interval and advanced cancers and could just reflect additional overdiagnosis. Studies based on the incidence of advanced cancers and on the evaluation of overdiagnosis should be conducted before marketing new breast-imaging technologies. Women at high risk of breast cancer (i.e. 30% lifetime risk and more), such as women with BRCA1/2 mutations, require a close breast surveillance. MRI is the preferred imaging method until more radical risk-reduction options are eventually adopted. For women with an intermediate risk of breast cancer (i.e. 10-29% lifetime risk), including women with extremely dense breast at mammography, there is no evidence that more frequent mammography screening or screening with other modalities actually reduces the risk of breast cancer death. A plethora of epidemiological data shows that, since 1985, progress in the management of breast cancer patients has led to marked reductions in stage-specific breast cancer mortality, even for patients with disseminated disease (i.e. stage IV cancer) at diagnosis. In contrast, the epidemiological data point to a marginal contribution of mammography screening in the decline in breast cancer mortality. Moreover, the more effective the treatments, the less favourable are the harm-benefit balance of screening mammography. New, effective methods for breast screening are needed, as well as research on risk-based screening strategies.

Use of Molecular Tools to Identify Patients With Indolent Breast Cancers With Ultralow Risk Over 2 Decades

Importance

The frequency of cancers with indolent behavior has increased with screening. Better tools to identify indolent tumors are needed to avoid overtreatment.

Objective

To determine if a multigene classifier is associated with indolent behavior of invasive breast cancers in women followed for 2 decades.

Design, Setting, and Participants

This is a secondary analysis of a randomized clinical trial of tamoxifen vs no systemic therapy, with more than 20-year follow-up. An indolent threshold (ultralow risk) of the US Food and Drug Administration-cleared MammaPrint 70-gene expression score was established above which no breast cancer deaths occurred after 15 years in the absence of systemic therapy. Immunohistochemical markers (n = 727 women) and Agilent microarrays, for MammaPrint risk scoring (n = 652 women), were performed from formalin-fixed paraffin-embedded primary tumor blocks. Participants were postmenopausal women with clinically detected node-negative breast cancers treated with mastectomy or lumpectomy and radiation enrolled in the Stockholm tamoxifen (STO-3) trial, 1976 to 1990.

Exposures

After 2 years of tamoxifen vs no systemic therapy, regardless of hormone receptor status, patients without relapse who reconsented were further randomized to 3 additional years or none.

Main Outcomes and Measures

Breast cancer-specific survival assessed by Kaplan-Meier analyses and multivariate Cox proportional hazard modeling, adjusted for treatment, patient age, year of diagnosis, tumor size, grade, hormone receptors, and ERBB2/HER2 and Ki67 status.

Results

In this secondary analysis of node-negative postmenopausal women, conducted in the era before mammography screening, among the 652 women with MammaPrint scoring available (median age, 62.8 years of age), 377 (58%) and 275 (42%) were MammaPrint low and high risk, respectively, while 98 (15%) were ultralow risk. At 20 years, women with 70-gene high and low tumors but not ultralow tumors had a significantly higher risk of disease-specific death compared with ultralow-risk patients by Cox analysis (hazard ratios, 4.73 [95% CI, 1.38-16.22] and 4.54 [95% CI, 1.40-14.80], respectively). There were no deaths in the ultralow-risk tamoxifen-treated arm at 15 years, and these patients had a 20-year disease-specific survival rate of 97%, whereas for untreated patients the survival rate was 94%. Recursive partitioning identified ultralow risk as the most significant predictor of good outcome. In tumors "not ultralow risk," tumor size greater than 2 cm was the most predictive of outcome.

Conclusions and Relevance

The ultralow-risk threshold of the 70-gene MammaPrint assay can identify patients whose long-term systemic risk of death from breast cancer after surgery alone is exceedingly low.

A breast cancer gene signature for indolent disease

PURPOSE

Early-stage hormone-receptor positive breast cancer is treated with endocrine therapy and the recommended duration of these treatments has increased over time. While endocrine therapy is considered less of a burden to patients compared to chemotherapy, long-term adherence may be low due to potential adverse side effects as well as compliance fatigue. It is of high clinical utility to identify subgroups of breast cancer patients who may have excellent long-term survival without or with limited duration of endocrine therapy to aid in personalizing endocrine treatment.

METHODS

We describe a new ultralow risk threshold for the 70-gene signature (MammaPrint) that identifies a group of breast cancer patients with excellent 20 year, long-term survival prognosis. Tumors of these patients are referred to as "indolent breast cancer." We used patient series on which we previously established and assessed the 70-gene signature high-low risk threshold.

RESULTS

In an independent validation cohort, we show that patients with indolent breast cancer had 100% breast cancer-specific survival at 15 years of follow-up.

CONCLUSIONS

Our data indicate that patients with indolent disease may be candidates for limited treatment with adjuvant endocrine therapy based on their very low risk of distant recurrences or death of breast cancer.

Impact of the Introduction of Digital Mammography in an Organized Screening Program on the Recall and Detection Rate

In 2012, the Reggio Emilia Breast Cancer Screening Program introduced digital mammography in all its facilities at the same time. The aim of this work is to analyze the impact of digital mammography introduction on the recall rate, detection rate, and positive predictive value. The program actively invites women aged 45-74 years. We included women screened in 2011, all of whom underwent film-screen mammography, and all women screened in 2012, all of whom underwent digital mammography. Double reading was used for all mammograms, with arbitration in the event of disagreement. A total of 42,240 women underwent screen-film mammography and 45,196 underwent digital mammography. The recall rate increased from 3.3 to 4.4% in the first year of digital mammography (relative recall adjusted by age and round 1.46, 95% CI = 1.37-1.56); the positivity rate for each individual reading, before arbitration, rose from 3 to 5.7%. The digital mammography recall rate decreased during 2012: after 12 months, it was similar to the recall rate with screen-film mammography. The detection rate was similar: 5.9/1000 and 5.2/1000 with screen-film and digital mammography, respectively (adjusted relative detection rate 0.95, 95% CI = 0.79-1.13). The relative detection rate for ductal carcinoma in situ remained the same. The introduction of digital mammography to our organized screening program had a negative impact on specificity, thereby increasing the recall rate. The effect was limited to the first 12 months after introduction and was attenuated by the double reading with arbitration. We did not observe any relevant effects on the detection rate.

Breast cancer incidence: Decreasing trend in large tumours in women aged 50-74

Objective A decrease in advanced breast cancer incidence is considered an early indicator of breast cancer mortality reduction in a screening programme. We describe trends in breast cancer incidence according to tumour size and age in three French administrative areas, where an organized screening programme was implemented during the 1990s. Methods Our study included all 28,092 invasive breast cancers diagnosed from 2000 to 2010 in women living in three areas (Hérault, Isère, Loire-Atlantique). Age, year of diagnosis, and size of tumour at diagnosis was provided by the three area cancer registries. Poisson regression models were fitted to estimate changes in incidence over time, after adjustment for age and administrative area. Results From 2000 to 2010, the incidence rate of large (tumour size >20 mm) breast cancer linearly decreased in women aged 50-74 (target age of the screening programme) from 108.4 to 84.1/100,000 (annual percent change = -1.9%, p < 0.001). No change in large breast cancer incidence rate was found in women aged 20-49, or older than 74. Conclusions A decreasing trend in incidence of large tumour size breast cancer in the target age of the screening programme is demonstrated for the first time in France. The overall 20.9% linear decrease over 11 years in these three areas is encouraging and should be closely monitored and extended to other areas of France, where the screening programme was generally implemented only in 2004.

Equivalence of MammaPrint array types in clinical trials and diagnostics

MammaPrint is an FDA-cleared microarray-based test that uses expression levels of the 70 MammaPrint genes to assess distant recurrence risk in early-stage breast cancer. The prospective RASTER study proved that MammaPrint Low Risk patients can safely forgo chemotherapy, which is further subject of the prospective randomized MINDACT trial. While MammaPrint diagnostic results are obtained from mini-arrays, clinical trials may be performed on whole-genome arrays. Here we demonstrate the equivalence and reproducibility of the MammaPrint test. MammaPrint indices were collected for breast cancer samples: (i) on both customized certified array types (n = 1,897 sample pairs), (ii) with matched fresh and FFPE tissues (n = 552 sample pairs), iii) for control samples replicated over a period of 10 years (n = 11,333), and iv) repeated measurements (n = 280). The array type indicated a near perfect Pearson correlation of 0.99 (95 % CI: 0.989-0.991). Paired fresh and FFPE samples showed an excellent Pearson correlation of 0.93 (95 % CI 0.92-0.94), in spite of the variability introduced by intratumoral tissue heterogeneity. Control samples showed high consistency over 10 year's time (overall reproducibility of 97.4 %). Precision and repeatability are overall 98.2 and 98.3 %, respectively. Results confirm that the combination of the near perfect correlation between array types, excellent equivalence between tissue types, and a very high stability, precision, and repeatability demonstrate that results from clinical trials (such as MINDACT and I-SPY 2) are equivalent to current MammaPrint FFPE and fresh diagnostics, and can be used interchangeably.

St Gallen molecular subtypes in screening-detected and symptomatic breast cancer in a prospective cohort with long-term follow-up

Background

Diagnosis by screening mammography is considered an independent positive prognostic factor, although the data are not fully in agreement. The aim of the study was to explore whether the mode of detection (screening‐detected versus symptomatic) adds prognostic information to the St Gallen molecular subtypes of primary breast cancer, in terms of 10‐year cumulative breast cancer mortality (BCM).

Methods

A prospective cohort of patients with primary breast cancer, who had regularly been invited to screening mammography, were included. Tissue microarrays were constructed from primary tumours and lymph node metastases, and evaluated by two independent pathologists. Primary tumours and lymph node metastases were classified into St Gallen molecular subtypes. Cause of death was retrieved from the Central Statistics Office.

Results

A total of 434 patients with primary breast cancer were included in the study. Some 370 primary tumours and 111 lymph node metastases were classified into St Gallen molecular subtypes. The luminal A‐like subtype was more common among the screening‐detected primary tumours (P = 0·035) and corresponding lymph node metastases (P = 0·114) than among symptomatic cancers. Patients with screening‐detected tumours had a lower BCM (P = 0·017), and for those diagnosed with luminal A‐like tumours the 10‐year cumulative BCM was 3 per cent. For patients with luminal A‐like lymph node metastases, there was no BCM. In a stepwise multivariable analysis, the prognostic information yielded by screening detection was hampered by stage and tumour biology.

Conclusion

The prognosis was excellent for patients within the screening programme who were diagnosed with a luminal A‐like primary tumour and/or lymph node metastases. Stage, molecular pathology and mode of detection help to define patients at low risk of death from breast cancer.

Low‐risk group identified

Less Is More: The Evolving Surgical Approach to Breast Cancer

Personalized medicine is emerging as an important guiding principle in diagnosis and treatment. This means not just doing more for some, but safely doing less for others. The lessons learned about the biology of breast cancer over the last 2 decades have enabled us to understand the incredible heterogeneity of breast cancer and its associated behavior. Although much work remains, there is an emerging opportunity to identify and recognize more indolent forms of breast cancer, made more prevalent through the widespread adoption of screening. With our improving systemic therapies and improved molecular tools, we now have the opportunity to reduce the burden of treatment in women with lower-risk tumors. Our surgical treatments have evolved, with less morbid and more cosmetic procedures. In this article, we review the indications for further reducing local therapy, including adjuvant radiation.

Breast Cancer Characteristics Associated With Digital Versus Film-Screen Mammography for Screen-Detected and Interval Cancers

OBJECTIVE

The purpose of this study was to determine whether pathologic findings of screen-detected and interval cancers differ for digital versus film mammography.

MATERIALS AND METHODS

Breast Cancer Surveillance Consortium data from 2003-2011 on 3,021,515 screening mammograms (40.3% digital, 59.7% film) of women 40-89 years old were reviewed. Cancers were considered screen detected if diagnosed within 12 months of an examination with positive findings and interval if diagnosed within 12 months of an examination with negative findings. Tumor characteristics for screen-detected and interval cancers were compared for digital versus film mammography by use of logistic regression models to estimate the odds ratio and 95% CI with adjustment for age, race and ethnicity, hormone therapy use, screening interval, examination year, and registry. Generalized estimating equations were used to account for correlation within facilities.

RESULTS

Among 15,729 breast cancers, 85.3% were screen detected and 14.7% were interval. Digital and film mammography had similar rates of screen-detected (4.47 vs 4.42 per 1000 examinations) and interval (0.73 vs 0.79 per 1000 examinations) cancers for digital versus film. In adjusted analyses, interval cancers diagnosed after digital examinations with negative findings were less likely to be American Joint Committee on Cancer stage IIB or higher (odds ratio, 0.69; 95% CI, 0.52-0.93), have positive nodal status (odds ratio, 0.78; 95% CI, 0.64-0.95), or be estrogen receptor negative (odds ratio, 0.71; 95% CI, 0.56-0.91) than were interval cancers diagnosed after a film examination with negative findings.

CONCLUSION

Screen-detected cancers diagnosed after digital and film mammography had similar rates of unfavorable tumor characteristics. Interval-detected cancers diagnosed after a digital examination were less likely to have unfavorable tumor features than those diagnosed after film mammography, but the absolute differences were small.

Screening mammography: update and review of publications since our report in the New England Journal of Medicine on the magnitude of the problem in the United States

RATIONALE AND OBJECTIVES

After a half century of clinical trials, expansive observations, vigorous advocacy and debate, screening mammography could not be in a more controversial condition, especially the potential harm of overdiagnosis. Despite a simple rationale (catch the cancer early and either prevent death or at least decrease the amount of therapy needed for cure), the estimates to date of overdiagnosis rates are conflicting and the interpretations complex.

MATERIALS AND METHODS

Since the author's 2012 publication in the New England Journal of Medicine (NEJM), the peer-reviewed publications on overdiagnosis caused by screening mammography are reviewed and the NEJM analyses updated with three additional calendar years of results.

RESULTS

The recent peer-reviewed medical literature on screening mammography induced overdiagnosis of breast cancer has increased exponentially, nearly 10-fold in 10 years. The average estimate of overdiagnosis is about 30%, but the range extends from 0% to 70+%. An update of the NEJM report estimates that in the US, 78,000 women and 30%-31% of those diagnosed with breast cancer at the age of 40 years or older during 2011 were overdiagnosed.

CONCLUSIONS

Until we have better screening procedures that identify who really has cancer and needs to be treated, the risk of overdiagnosis relative to the benefit of screening merits more effective public and professional education. Radiologists, pathologists, and other professionals involved with screening mammography should recognize that the potential harm of overdiagnosis is downplayed or not discussed with the patient and family, despite agreement that the objective is informed choice.

Identifying women with dense breasts at high risk for interval cancer: a cohort study

BACKGROUND

Twenty-one states have laws requiring that women be notified if they have dense breasts and that they be advised to discuss supplemental imaging with their provider.

OBJECTIVE

To better direct discussions of supplemental imaging by determining which combinations of breast cancer risk and Breast Imaging Reporting and Data System (BI-RADS) breast density categories are associated with high interval cancer rates.

DESIGN

Prospective cohort.

SETTING

Breast Cancer Surveillance Consortium (BCSC) breast imaging facilities.

PATIENTS

365,426 women aged 40 to 74 years who had 831,455 digital screening mammography examinations.

MEASUREMENTS

BI-RADS breast density, BCSC 5-year breast cancer risk, and interval cancer rate (invasive cancer ≤12 months after a normal mammography result) per 1000 mammography examinations. High interval cancer rate was defined as more than 1 case per 1000 examinations.

RESULTS

High interval cancer rates were observed for women with 5-year risk of 1.67% or greater and extremely dense breasts or 5-year risk of 2.50% or greater and heterogeneously dense breasts (24% of all women with dense breasts). The interval rate of advanced-stage disease was highest (>0.4 case per 1000 examinations) among women with 5-year risk of 2.50% or greater and heterogeneously or extremely dense breasts (21% of all women with dense breasts). Five-year risk was low to average (0% to 1.66%) for 51.0% of women with heterogeneously dense breasts and 52.5% with extremely dense breasts, with interval cancer rates of 0.58 to 0.63 and 0.72 to 0.89 case per 1000 examinations, respectively.

LIMITATION

The benefit of supplemental imaging was not assessed.

CONCLUSION

Breast density should not be the sole criterion for deciding whether supplemental imaging is justified because not all women with dense breasts have high interval cancer rates. BCSC 5-year risk combined with BI-RADS breast density can identify women at high risk for interval cancer to inform patient-provider discussions about alternative screening strategies.

PRIMARY FUNDING SOURCE

National Cancer Institute.

Effect of treatment and mammography detection on breast cancer survival over time: 1990-2007

BACKGROUND

The extent to which improvements over time in breast cancer survival are related to earlier detection by mammography or to more effective treatments is not known.

METHODS

At a comprehensive cancer care center, the authors conducted a retrospective cohort study of women ages 50 to 69 years who were diagnosed with invasive breast cancer (stages I through III) and were followed over 3 periods (1990-1994, 1995-1999, and 2000-2007). Data were abstracted from patient charts and included detection method, diagnosis, treatment, and follow-up for vital status in the institutional breast cancer registry (n = 2998). The method of detection was categorized as patient or physician detected or mammography detected. Cox proportional hazards models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for 5-year disease-specific survival in relation to detection method and treatment factors, and differences in survival were analyzed using the Kaplan-Meier method.

RESULTS

Fifty-eight percent of breast cancers were mammography detected, and 42% were patient or physician detected; 56% of tumors were stage I, 31% were stage II, and 13% were stage III. The average length of follow-up was 10.71 years. The combined 5-year disease-specific survival rate was 89% from 1990 to 1994, 94% from 1995 to 1999, and 96% from 2000 to 2007 (P < .001). In an adjusted model, mammography detection (HR, 0.43; 95% CI, 0.27-0.70), hormone therapy (HR, 0.47; 95% CI, 0.30-0.75), and taxane-containing chemotherapy (HR, 0.61; 95% CI, 0.37-0.99) were significantly associated with a decreased risk of disease-specific mortality.

CONCLUSIONS

Better breast cancer survival over time was related to mammography detection, hormone therapy, and taxane-containing chemotherapy. Treatment improvements alone are not sufficient to explain the observed survival improvements over time.

Overdiagnosis in breast cancer chemoprevention trials

Several randomized controlled trials have demonstrated that the preventive use of an antiestrogen agent such as tamoxifen, raloxifene, anastrozole, or exemestane will reduce the incidence of estrogen receptor (er)–positive breast cancers by 50% or more. The reduction in risk becomes apparent shortly after tamoxifen initiation. However, no mortality benefit has yet been demonstrated with tamoxifen or any other agent, an effect that might be statistical: that is, the statistical power to detect a difference in mortality could be lacking because deaths from breast cancer are far fewer in number than cases of breast cancer, and because the average time to cancer is much shorter than the time to death. In other words, it could be too early to see an effect. However, the lack of an observed survival benefit might also be a result of chemoprevention agents preferentially preventing cancers that would rarely lead to death. That paradigm extends the (controversial) concepts of overdiagnosis and of the potential for spontaneous regression of some lowgrade breast cancers [...]

Does digital mammography suppose an advance in early diagnosis? Trends in performance indicators 6 years after digitalization

Purpose

To provide a complete evaluation of the long-term impact of full-field digital mammography (FFDM) on the improvement of early diagnosis in a population-based screening program.

Methods

We included 82,961 screen-film mammograms (SFM) and 79,031 FFDM from women aged 50–69 screened biennially from 1995–2010 in Spain and followed-up to 2012. The first screening round of the program was excluded. Rates of cancer detection, interval cancer, tumoral characteristics and other quality indicators were compared between SFM and FFDM periods using the Chi-square test. Multivariate logistic regression models were fitted.

Results

Detection of ductal carcinoma in situ (DCIS) significantly increased with FFDM (0.05 % vs 0.09 %; p = 0.010), along with the proportion of small invasive cancers (<20 mm) (69.37 % vs 78.90 %; p = 0.040). The false-positive rate decreased with FFDM (4.79 % vs 3.38 %; p < 0.001) without differences in the cancer detection rate (0.42 % vs 0.43 %; p = 0.685) or in the interval cancer rate (0.14 % vs 0.14 %; p = 0.816). Adjusted models showed a significant increase in the detection of DCIS in the FFDM periods.

Conclusion

Digitalization has supposed an improvement in early diagnosis because DCIS and small invasive cancers increased without a change in detection rate. Moreover, false-positive reduction without an increase in the interval cancer rate was confirmed.

Key Points

• Cancer detection did not increase after 6 years of digital mammography

• Ductal carcinoma in situ rates remained higher throughout the digital period

• The proportion of small invasive cancers was higher with digital mammography

• We observed an improvement in early diagnosis with digital mammography

• False-positive rates remained lower throughout the digital period without interval cancer increase

Screening mammography--early detection or over-diagnosis? Contribution from Australian data

OBJECTIVE

The aim of this review was to examine the benefits and harms of organized screening mammography, with particular reference to data from Australia.

METHODS

Published literature was examined relating to the impact of screening mammography on breast cancer-specific mortality, the trends in use of adjuvant treatments for breast cancer, the effectiveness of adjuvant treatment in terms of breast cancer-specific mortality, the impact of breast cancer treatment on non-breast cancer mortality and the magnitude of the issue of over-diagnosis.

RESULTS

Most of the recent reduction in breast cancer-specific mortality is explained by use of adjuvant therapy rather than screening mammography. The impact of screening mammography in countries where women present with early disease and have access to adjuvant treatment is modest. There is a wide range of estimates for the magnitude of over-diagnosis. All-cause mortality (rather than breast cancer-specific mortality) should be used when assessing the impact of mammographic screening as otherwise the harm of breast cancer treatment in women who are over-diagnosed will be missed.

CONCLUSIONS

The benefits and harms of screening mammography are finely balanced. The impact of screening mammography is at best neutral but may result in overall harm. Women should be informed of the issue of over-diagnosis. It is time to review whether organized mammographic screening programs should continue.

EMAS position statement: individualized breast cancer screening versus population-based mammography screening programmes

INTRODUCTION

Breast cancer is the most prevalent cancer in women, with slightly more than ten percent developing the disease in Western countries. Mammography screening is a well established method to detect breast cancer.

AIMS

The aim of the position statement is to review critically the advantages and shortcomings of population based mammography screening.

MATERIALS AND METHODS

Literature review and consensus of expert opinion.

RESULTS AND CONCLUSION

Mammography screening programmes vary worldwide. Thus there are differences in the age at which screening is started and stopped and in the screening interval. Furthermore differences in screening quality (such as equipment, technique, resolution, single or double reading, recall rates) result in a sensitivity varying from 70% to 94% between studies. Reporting results of screening is subject to different types of bias such as overdiagnosis. Thus because of the limitations of population-based mammography screening programmes an algorithm for individualized screening is proposed.

Digital compared to screen-film mammography: breast cancer prognostic features in an organized screening program

Our previous study found cancer detection rates were equivalent for direct radiography compared to screen-film mammography, while rates for computed radiography were significantly lower. This study compares prognostic features of invasive breast cancers by type of mammography. Approved by the University of Toronto Research Ethics Board, this study identified invasive breast cancers diagnosed among concurrent cohorts of women aged 50-74 screened by direct radiography, computed radiography, or screen-film mammography from January 1, 2008 to December 31, 2009. During the study period, 816,232 mammograms were performed on 668,418 women, and 3,323 invasive breast cancers were diagnosed. Of 2,642 eligible women contacted, 2,041 participated (77.3 %). The final sample size for analysis included 1,405 screen-detected and 418 interval cancers (diagnosed within 24 months of a negative screening mammogram). Polytomous logistic regression was performed to evaluate the association between tumour characteristics and type of mammography, and between tumour characteristics and detection method. Odds ratios (OR) and 95 % confidence intervals (CI) were recorded. Cancers detected by computed radiography compared to screen-film mammography were significantly more likely to be lymph node positive (OR 1.94, 95 %CI 1.01-3.73) and have higher stage (II:I, OR 2.14, 95 %CI 1.11-4.13 and III/IV:I, OR 2.97, 95 %CI 1.02-8.59). Compared to screen-film mammography, significantly more cancers detected by direct radiography (OR 1.64, 95 %CI 1.12-2.38) were lymph node positive. Interval cancers had worse prognostic features compared to screen-detected cancers, irrespective of mammography type. Screening with computed radiography may lead to the detection of cancers with a less favourable stage distribution compared to screen-film mammography that may reflect a delayed diagnosis. Screening programs should re-evaluate their use of computed radiography for breast screening.