Overdiagnosis and overtreatment of breast cancer

Decoding the Prevalent High-Risk Breast Cancers: Demographics, Pathological, Imaging Insights, and Long-Term Outcome

Objective: To investigate the features and outcomes of breast cancer in high-risk subgroups. Materials and Methods: REB approved an observational study of women diagnosed with breast cancer from 2010 to 2019. Three radiologists, using the BI-RADS lexicon, blindly reviewed mammogram and MRI screenings without a washout period. Consensus was reached with 2 additional reviewers. Inter-rater agreement was measured by Fleiss Kappa. Statistical analysis included Mann-Whitney U, Chi-square tests for cohort analysis, and Kaplan-Meier for survival rates, with a Cox model for comparative analysis using gene mutation as a reference. Results: The study included 140 high-risk women, finding 155 malignant lesions. Significant age differences noted: chest radiation therapy (median age 44, IQR: 37.0-46.2), gene mutation (median age 49, IQR: 39.8-58.0), and familial risk (median age 51, IQR: 44.5-56.0) (P = .007). Gene mutation carriers had smaller (P = .01), higher-grade tumours (P = .002), and more triple-negative ER- (P = .02), PR- (P = .002), and HER2- (P = .02) cases. MRI outperformed mammography in all subgroups. Substantial to near-perfect inter-rater agreement observed. Over 10 years, no deaths occurred in chest radiation group, with no significant survival difference between gene mutation and familial risk groups, HR = 0.93 (95% CI: 0.27, 3.26), P = .92. Conclusion: The study highlights the importance of age and specific tumour characteristics in identifying high-risk breast cancer subgroups. MRI is confirmed as an effective screening tool. Despite the aggressive nature of cancers in gene mutation carriers, early detection is crucial for survival outcomes. These insights, while necessitating further validation with larger studies, advocate for a move toward personalized medical care, strengthening the existing healthcare guidelines.

Evolving Treatment Paradigms for Low-Risk Ductal Carcinoma In Situ: Imaging Needs

Ductal carcinoma in situ (DCIS) is a nonobligate precursor to invasive cancer that classically presents as asymptomatic calcifications on screening mammography. The increase in DCIS diagnoses with organized screening programs has raised concerns about overdiagnosis, while a patientcentric push for more personalized care has increased awareness about DCIS overtreatment. The standard of care for most new DCIS diagnoses is surgical excision, but nonsurgical management via active monitoring is gaining attention, and multiple clinical trials are ongoing. Imaging, along with demographic and pathologic information, is a critical component of active monitoring efforts. Commonly used imaging modalities including mammography, ultrasound, and MRI, as well as newer modalities such as contrast-enhanced mammography and dedicated breast PET, can provide prognostic information to risk stratify patients for DCIS active monitoring eligibility. Furthermore, radiologists will be responsible for closely surveilling patients on active monitoring and identifying if invasive progression occurs. Active monitoring is a paradigm shift for DCIS care, but the success or failure will rely heavily on the interpretations and guidance of radiologists.

Molecular Residual Disease in Breast Cancer: Detection and Therapeutic Interception

Breast cancer remains a leading cause of cancer-related death in women despite screening and therapeutic advances. Early detection allows for resection of local disease; however, patients can develop metastatic recurrences years after curative treatment. There is no reliable blood-based monitoring after curative therapy, and radiographic evaluation for metastatic disease is performed only in response to symptoms. Advances in circulating tumor DNA (ctDNA) assays have allowed for a potential option for blood-based monitoring. The detection of ctDNA in the absence of overt metastasis or recurrent disease indicates molecular evidence of cancer, defined as molecular residual disease (MRD). Multiple studies have shown that MRD detection is strongly associated with disease recurrence, with a lead time prior to clinical evidence of recurrence of many months. Importantly, it is still unclear whether treatment changes in response to ctDNA detection will improve outcomes. There are currently ongoing trials evaluating the efficacy of therapy escalation in the setting of MRD, and these studies are being conducted in all major breast cancer subtypes. Additional therapies under study include CDK4/6 inhibitors, PARP inhibitors, HER2-targeted therapies, and immunotherapy. This review will summarize the underlying scientific principles of various MRD assays, their known prognostic roles in early breast cancer, and the ongoing clinical trials assessing the efficacy of therapy escalation in the setting of MRD.

Live-cell phenotypic-biomarker microfluidic assay for the risk stratification of cancer patients via machine learning

The risk stratification of prostate cancer and breast cancer tumours from patients relies on histopathology, selective genomic testing, or on other methods employing fixed formalin tissue samples. However, static biomarker measurements from bulk fixed-tissue samples provide limited accuracy and actionability. Here, we report the development of a live-primary-cell phenotypic-biomarker assay with single-cell resolution, and its validation with prostate cancer and breast cancer tissue samples for the prediction of post-surgical adverse pathology. The assay includes a collagen-I/fibronectin extracellular-matrix formulation, dynamic live-cell biomarkers, a microfluidic device, machine-vision analysis and machine-learning algorithms, and generates predictive scores of adverse pathology at the time of surgery. Predictive scores for the risk stratification of 59 prostate cancer patients and 47 breast cancer patients, with values for area under the curve in receiver-operating-characteristic curves surpassing 80%, support the validation of the assay and its potential clinical applicability for the risk stratification of cancer patients.

Value of MRI in medicine: More than just another test?

There is increasing scrutiny from healthcare organizations towards the utility and associated costs of imaging. MRI has traditionally been used as a high-end modality, and although shown extremely important for many types of clinical scenarios, it has been suggested as too expensive by some. This editorial will try and explain how value should be addressed and gives some insights and practical examples of how value of MRI can be increased. It requires a global effort to increase accessibility, value for money, and impact on patient management. We hope this editorial sheds some light and gives some indications of where the field may wish to address some of its research to proactively demonstrate the value of MRI. Level of Evidence: 5 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2019;49:e14-e25.

Surgical Upstaging Rates for Vacuum Assisted Biopsy Proven DCIS: Implications for Active Surveillance Trials

PURPOSE

This study was designed to determine invasive cancer upstaging rates at surgical excision following vacuum-assisted biopsy of ductal carcinoma in situ (DCIS) among women meeting eligibility for active surveillance trials.

METHODS

Patients with vacuum-assisted, biopsy-proven DCIS at a single center from 2008 to 2015 were retrospectively reviewed. Imaging and pathology reports were interrogated for the imaging appearance, tumor grade, hormone receptor status, and presence of comedonecrosis. Subsequent surgical reports were reviewed for upstaging to invasive disease. Cases were classified by eligibility criteria for the COMET, LORIS, and LORD DCIS active surveillance trials.

RESULTS

Of 307 DCIS diagnoses, 15 (5%) were low, 95 (31%) intermediate, and 197 (64%) high nuclear grade. The overall upstage rate to invasive disease was 17% (53/307). Eighty-one patients were eligible for the COMET Trial, 74 for the LORIS trial, and 10 for the LORD Trial, although LORIS trial eligibility also included real-time, multiple central pathology review, including elements not routinely reported. The upstaging rates to invasive disease were 6% (5/81), 7% (5/74), and 10% (1/10) for the COMET, LORIS, and LORD trials, respectively. Among upstaged cancers (n = 5), four tumors were Stage IA invasive ductal carcinoma and one was Stage IIA invasive lobular carcinoma; all were node-negative.

CONCLUSIONS

DCIS upstaging rates in women eligible for active surveillance trials are low (6-10%), and in this series, all those with invasive disease were early-stage, node-negative. The careful patient selection for DCIS active surveillance trials has a low risk of missing occult invasive cancer and additional studies will determine clinical outcomes.

Screening Uptake Differences Are Not Implicated in Poorer Breast Cancer Outcomes among Singaporean Malay Women

Purpose

This study was undertaken to examine the impact of screening and race on breast cancer outcomes in Singapore.

Methods

An institutional database was reviewed, and invasive ductal carcinoma (IDC) and ductal carcinoma in situ (DCIS) data were analyzed separately. Overall survival (OS), disease-free survival (DFS), and cancer-specific survival (CSS) were assessed.

Results

The study included 6,180 IDC and 1,031 DCIS patients. The median follow-up time was 4.1 years. Among IDC patients, Malay women were the youngest when first diagnosed, and were more likely to present with advanced stage disease. Malay women also had the highest proportion of T3 and T4 tumors at 14.2%, compared with Chinese women at 8.7% and Indian women at 9.6% (p<0.001). Malay women had a higher incidence of node-positive disease at 58.3% compared with Chinese women at 46.4% and Indian women at 54.9% (p<0.001). Malay subjects also had higher-grade tumors; 61.8% had grade 3 tumors compared with 45.8% of Chinese women and 52% of Indian women (p<0.001). Furthermore, tumors in Malay subjects were less endocrine-sensitive and more human epidermal growth factor receptor 2 enriched. Malay women had the lowest 5- and 10-year OS, DFS, and CSS rates (p<0.001). After separating clinically and screen-detected tumors, multivariate analysis showed that race was still significant for outcomes. For screen-detected tumors, the OS hazard ratio (HR) for Malay women compared to Chinese women was 5.78 (95% confidence interval [CI], 2.64–12.64), the DFS HR was 2.18 (95% CI, 1.19–3.99), and the CSS HR was 5.93 (95% CI, 2.15–16.39). For DCIS, there were no statistically significant differences in the tumor size, grade, histology subtypes, or hormone sensitivity.

Conclusion

Malay race is a poor prognostic factor in both clinically and screen-detected IDC. Special attention should be given to the detection and follow-up of breast cancer in this group.

Papillary thyroid microcarcinoma: decision-making, extent of surgery, and outcomes

BACKGROUND

The optimal extent of surgery for patients with papillary thyroid microcarcinoma (PTMC), tumors ≤1 cm, is controversial because survival is excellent regardless of approach. The objective of this study was to investigate patient and surgeon decision-making about the extent of surgery for PTMC.

MATERIALS AND METHODS

We conducted a retrospective review of thyroid cancer patients operated on at a single institution from 2008-2016. To examine decision-making about the extent of surgery, we performed a discourse analysis on all available documentation looking for patient or surgeon reasons.

RESULTS

Of the 853 thyroid cancer patients, 125 (14.7%) had a PTMC as their largest tumor. Overall, 27.2% of the PTMC patients underwent a thyroid lobectomy, whereas 72.8% had a total thyroidectomy (TT). Of those patients diagnosed with PTMC preoperatively (19/125), a significantly higher proportion underwent a TT (94.7% versus 68.9%, P = 0.02). In all cases, documentation indicated that these preoperatively diagnosed patients followed the surgeon's recommendation regarding the extent of surgery. Reasons surgeons cited for recommending a TT included patient and disease factors (34.6%), belief that TT was the standard treatment (21.7%), ease of follow-up (8.7%), and referring provider preference (4.3%). Of the 19 patients diagnosed preoperatively, four (21.1%) patients had a complication, one (5.3%) of which was permanent and potentially avoidable with less extensive surgery.

CONCLUSIONS

These data suggest that surgeons drive decision-making about the extent of thyroidectomy in patients with preoperatively diagnosed PTMC. With recent guidelines recommending thyroid lobectomy, closer examination of decision-making is needed to ensure that patients make well-informed, preference-based decisions.

Long-Term Cause-Specific Mortality After Surgery for Women With Breast Cancer: A 20-Year Follow-Up Study From Surveillance, Epidemiology, and End Results Cancer Registries

BACKGROUND

Research into long-term cause-specific mortality of women diagnosed with breast cancer is important because it allows for the splitting of the population into patients who eventually die from breast cancer and from other causes. The adoption of this approach helps to identify patients with an elevated risk of eventual death from breast cancer.

OBJECTIVE

The primary aim of this study was to examine the associations between both sociodemographic and clinicopathologic characteristics and the underlying risks of death from breast cancer and from other causes for women diagnosed with breast cancer. A second aim was to propose a predictive biomarker of cause-specific mortality in terms of treatment and several important characteristics of a patient.

METHODS

A cohort of 16 511 female patients diagnosed with breast cancer in 1990 was obtained from the Surveillance, Epidemiology, and End Results cancer registries and followed for 20 years. A mixture model for the regression analysis of competing risks was used to identify factors and confounders that affected either the eventual cause-specific mortality or conditional cause-specific hazard rates, or both. Missing data were handled with multiple imputation.

RESULTS

Curvilinear relationships of age at diagnosis along with race, marital status, breast cancer type, tumor size, estrogen receptor status, extension, lymph node status, type of surgery, and radiotherapy status were significant risk factors for the cause-specific mortality, with extension and lymph node status appearing to be confounded with the effects of both type of surgery and radiotherapy status. The score obtained from combining a set of predictors showed to be an accurate predictive biomarker.

CONCLUSIONS

In cause-specific mortality of women diagnosed breast cancer, prognosis appears to depend on both sociodemographic and clinicopathologic factors. The predictive biomarker proposed in this study may help identifying the level of seriousness of the disease earlier than traditional methods, potentially guiding future allocation of resources for better patient care and management strategies.

SMARCE1 is required for the invasive progression of in situ cancers

Advances in mammography have sparked an exponential increase in the detection of early-stage breast lesions, most commonly ductal carcinoma in situ (DCIS). More than 50% of DCIS lesions are benign and will remain indolent, never progressing to invasive cancers. However, the factors that promote DCIS invasion remain poorly understood. Here, we show that SMARCE1 is required for the invasive progression of DCIS and other early-stage tumors. We show that SMARCE1 drives invasion by regulating the expression of secreted proteases that degrade basement membrane, an ECM barrier surrounding all epithelial tissues. In functional studies, SMARCE1 promotes invasion of in situ cancers growing within primary human mammary tissues and is also required for metastasis in vivo. Mechanistically, SMARCE1 drives invasion by forming a SWI/SNF-independent complex with the transcription factor ILF3. In patients diagnosed with early-stage cancers, SMARCE1 expression is a strong predictor of eventual relapse and metastasis. Collectively, these findings establish SMARCE1 as a key driver of invasive progression in early-stage tumors.

The method of detection of ductal carcinoma in situ has no therapeutic implications: results of a population-based cohort study

Background

Population screening with mammography has resulted in increased detection of ductal carcinoma in situ (DCIS). The aim of this population-based cohort study was to assess whether the method of detection should be considered when determining prognosis and treatment in women with DCIS.

Methods

This study includes 7042 women aged 49–75 years, who were surgically treated for primary DCIS between 1989 and 2004 in the Netherlands. We calculated cumulative incidences of ipsilateral and contralateral invasive breast cancer and all-cause mortality among women with screen-detected, interval, or non-screening-related DCIS, and assessed the association between method of detection and these outcomes, using multivariable Cox regression analyses.

Results

Compared with non-screening-related DCIS, women with screen-detected DCIS had a lower risk of developing ipsilateral invasive breast cancer (hazard ratio (HR) = 0.75, 95% CI = 0.59–0.96), but a similar risk of contralateral invasive breast cancer (HR = 0.86, 95% CI = 0.67–1.10). The absolute difference in risk of ipsilateral invasive breast cancer was 1% at 15 years. Screen detection was associated with lower all-cause mortality (HR = 0.85, 95% CI = 0.73–0.98); when we additionally accounted for the occurrence of invasive breast cancer the magnitude of this effect remained similar (HR = 0.86, 95% CI = 0.75–1.00).

Conclusions

Screen detection was associated with lower risk of ipsilateral invasive breast cancer and all-cause mortality. However, the absolute difference in risk of ipsilateral invasive breast cancer was very low and the lower all-cause mortality associated with screen-detected and interval DCIS might be explained by a healthy-user effect. Therefore, our findings do not justify different treatment strategies for women with screen-detected, interval, or non-screening-related DCIS.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-017-0819-4) contains supplementary material, which is available to authorized users.

Impact of provider-patient communication on cancer screening adherence: A systematic review

Cancer screening is critical for early detection and a lack of screening is associated with late-stage diagnosis and lower survival rates. The goal of this review was to analyze studies that focused on the role of provider-patient communication in screening behavior for cervical, breast, and colorectal cancer. A comprehensive search was conducted in four online databases between 1992 and 2016. Studies were included when the provider being studied was a primary care provider and the communication was face-to-face. The search resulted in 3252 records for review and 35 articles were included in the review. Studies were divided into three categories: studies comparing recommendation status to screening compliance; studies examining the relationship between communication quality and screening behavior; and intervention studies that used provider communication to improve screening behavior. There is overwhelming evidence that provider recommendation significantly improves screening rates. Studies examining quality of communication are heterogeneous in method, operationalization and results, but suggest giving information and shared decision making had a significant relationship with screening behavior. Intervention studies were similarly heterogeneous and showed positive results of communication interventions on screening behavior. Overall, results suggest that provider recommendation is necessary but not sufficient for optimal adherence to cancer screening guidelines. Quality studies suggest that provider-patient communication is more nuanced than just a simple recommendation. Discussions surrounding the recommendation may have an important bearing on a person's decision to get screened. Research needs to move beyond studies examining recommendations and adherence and focus more on the relationship between communication quality and screening adherence.

Do LORIS Trial Eligibility Criteria Identify a Ductal Carcinoma In Situ Patient Population at Low Risk of Upgrade to Invasive Carcinoma?

BACKGROUND

The Surgery Versus Active Monitoring for Low-Risk DCIS (LORIS) trial is studying the safety of monitoring core-biopsy diagnosed low-risk ductal carcinoma in situ (DCIS) without excision. We sought to determine the incidence and characteristics of synchronous invasive carcinoma found in LORIS-eligible women who underwent excision, as this knowledge is essential in assessing the safety of observation alone.

METHODS

Women meeting LORIS eligibility criteria (age ≥46 years, screen-detected calcifications, non-high-grade DCIS diagnosed by core biopsy, absence of nipple discharge, or strong family history of breast cancer) who underwent surgical excision from 2009 to 2012 were identified. Histologic findings of excision specimens were reviewed.

RESULTS

Overall, 296 LORIS-eligible cases were identified; 58 (20 %) had invasive carcinoma on final pathology (90 % invasive ductal, 78 % >1 mm in size, 21 % high grade, 3 % triple negative, 9 % HER2 amplified). Of these, 18 (31 %) were pT1b or larger and 3 (5 %) were pN1. Among eligible upgraded cases, 90 % received radiation, 89 % received endocrine therapy, and 18 % were recommended chemotherapy. Women upgraded to invasive carcinoma were more likely to have intermediate-grade DCIS on core biopsy and to have undergone mastectomy.

CONCLUSIONS

Among LORIS-eligible women, 20 % had invasive carcinoma at surgical excision that was heterogeneous in grade, size, and receptor status. Information gained from surgical excision influenced receipt of adjuvant radiation and endocrine therapy in most patients, and indicated benefit from chemotherapy in 18 % of patients. Surgical excision is warranted until additional risk stratification is available to identify a cohort of DCIS patients at lower risk for clinically significant synchronous invasive carcinoma.

Breast Cancers Detected at Screening MR Imaging and Mammography in Patients at High Risk: Method of Detection Reflects Tumor Histopathologic Results

Purpose To compare the clinical, imaging, and histopathologic features of breast cancers detected at screening magnetic resonance (MR) imaging, screening mammography, and those detected between screening examinations (interval cancers) in women at high risk. Materials and Methods This retrospective institutional review board-approved, HIPAA-compliant review of 7519 women at high risk for breast cancer who underwent screening with MR imaging and mammography between January 2005 and December 2010 was performed to determine the number of screening-detected and interval cancers diagnosed. The need for informed consent was waived. Medical records were reviewed for age, risk factors (family or personal history of breast cancer, BRCA mutation status, history of high-risk lesion or mantle radiation), tumor histopathologic results, and time between diagnosis of interval cancer and most recent screening examination. The χ(2) test and logistic regression methods were used to compare the features of screening MR imaging, screening mammography, and interval cancers. The Wilcoxon signed-rank test was used to calculate P values. Results A total of 18 064 screening MR imaging examinations and 26 866 screening mammographic examinations were performed. Two hundred twenty-two cancers were diagnosed in 219 women, 167 (75%) at MR imaging, 43 (19%) at mammography, and 12 (5%) interval cancers. Median age at diagnosis was 52 years. No risk factors were associated with screening MR imaging, screening mammography, or interval cancer (P > .06). Cancers found at screening MR imaging were more likely to be invasive cancer (118 of 167 [71%]; P < .0001). Of the 43 cancers found at screening mammography, 38 (88%) manifested as calcifications and 28 (65%) were ductal carcinoma in situ. Interval cancers were associated with nodal involvement (P = .005) and the triple-negative subtype (P = .03). Conclusion In women at high risk for breast cancer who underwent screening with mammography and MR imaging, invasive cancers were more likely to be detected at MR imaging, whereas most cancers detected at screening mammography were ductal carcinoma in situ. Interval cancers were found infrequently and were more likely to be node positive and of the triple-negative subtype. (©) RSNA, 2016.

Imaging-based screening: maximizing benefits and minimizing harms

Advanced imaging technologies play a central role in screening asymptomatic patients. However, the balance between imaging-based screening's potential benefits versus risks is sometimes unclear. Radiologists will have to address ongoing concerns, including high false-positive rates, incidental findings outside the organ of interest, overdiagnosis, and potential risks from radiation exposure. In this article, we provide a brief overview of these recurring controversies and suggest the following as areas that radiologists should focus on in order to tip the balance toward more benefits and less harms for patients undergoing imaging-based screening: interpretive variability, abnormal finding thresholds, and personalized, risk-based screening.

Ductal carcinoma in situ: a brief review of treatment variation and impacts on patients and society

Nearly 20% of all breast cancer cases are ductal carcinoma in situ (DCIS), with over 60,000 cases diagnosed each year. Many of these cases would never cause clinical symptoms or threaten the life of the woman; however, it is currently impossible to distinguish which lesions will progress to invasive disease from those that will not. DCIS is generally associated with an excellent prognosis regardless of the treatment pathway, but there is variation in treatment aggressiveness that seems to exceed the medical uncertainty associated with DCIS management. Therefore, it would seem that a significant proportion of women with DCIS receive more extensive treatment than is needed. This overtreatment of DCIS is a growing concern among the breast cancer community and has implications for both the patient (via adverse treatment-related effects, as well as out-of-pocket costs) and society (via economic costs and the public health and environmental harm resulting from health care delivery). This article discusses DCIS treatment pathways and their implications for patients and society and calls for further research to examine the factors that are leading to such wide variation in treatment decisions.

How do I screen patients for breast cancer?

Breast cancer is a complex, heterogeneous disease. Approximately 230,000 women are diagnosed with breast cancer in the United States each year and approximately 40,000 women die each year with breast cancer. Although prevention of the disease would be preferred, no real prospects are available in the near future that would be applicable to the majority of women who are at risk for breast cancer. Early detection remains an effective way to decrease mortality from breast cancer, treating it at an early stage when it is likely curable. Unfortunately, screening does have its limitations. Not all breast cancers can be identified with routine screening. Some breast cancers despite early detection still result in poor outcomes. Furthermore, false-positive results are not infrequently seen in women undergoing screening mammography. Most patients experience significant anxiety when called back for additional studies or a biopsy. Not to mention the additional cost and potential side effects and complications of invasive procedures. In addition, there are breast cancers that may be indolent and otherwise not a threat to patients. In fact, some studies show that up to one quarter of cancers detected by screening may represent overdiagnosis. Currently, however, there are no proven methods to discern with complete certainty the cancers that would progress to lethal disease from those that would not. Women should be counseled regarding the risks and benefits of screening. Women at average risk should initiate screening mammography annually at the age of 40 years. Women at significant increased risk for breast cancer should be screened earlier. MRI has been shown to increase detection of breast cancer in women at increased risk and should be used as an adjunct to mammography in this high-risk patient population.