The importance of overdiagnosis in breast-cancer screening

Are there sustained psychological impacts in women diagnosed with in-situ or early invasive breast cancers?

Purpose

The detection of a ductal carcinoma in-situ (DCIS) or an early invasive breast cancer (EIBC), particularly by population-wide mammography-screening-programs, is controversial as an unknown proportion of these cases may be due to overdiagnosis. We investigated whether women with such potentially overdiagnosed breast cancers suffer from sustained adverse psycho-social consequences.

Methods

Standardized questionnaires were mailed to 900 survivors, diagnosed with either DCIS or EIBC, requesting self-reports on quality of life using EORTC Quality of Life Questionnaire C-30. Levels of anxiety and depression were assessed using the HADS questionnaires. Item score values in the study group were compared to reference data obtained from normative studies in the German female reference population.

Results

The 577 women who returned completed questionnaires had a mean age of 65.1 years, 387 (67%) had been diagnosed by mammography screening. Median time since diagnosis was 5.9 years. There were no substantial differences between the study sample and the reference population for most of the items. While most score values were even slightly more favorable in the study group, the scores for cognitive function were moderately lower, especially among younger patients. Score values for anxiety were generally higher among younger women (50 to 59 years) from the study group, while depression scores were lower irrespective of age.

Conclusions

This study indicates that the diagnosis of DCIS or EIBC, which is predominantly a result of screening, does not seem to induce sustained, adverse psychological impacts in affected women when compared with the respective general female population. Only anxiety levels remained elevated among younger women.

Plasma extracellular vesicle long RNA profiles in the diagnosis and prediction of treatment response for breast cancer

A large number RNAs are enriched and stable in extracellular vesicles (EVs), and they can reflect their tissue origins and are suitable as liquid biopsy markers for cancer diagnosis and treatment efficacy prediction. In this study, we used extracellular vesicle long RNA (exLR) sequencing to characterize the plasma-derived exLRs from 112 breast cancer patients, 19 benign patients and 41 healthy participants. The different exLRs profiling was found between the breast cancer and non-cancer groups. Thus, we constructed a breast cancer diagnostic signature which showed high accuracy with an area under the curve (AUC) of 0.960 in the training cohort and 0.900 in the validation cohort. The signature was able to identify early stage BC (I/II) with an AUC of 0.940. Integrating the signature with breast imaging could increase the diagnosis accuracy for breast cancer patients. Moreover, we enrolled 58 patients who received neoadjuvant treatment and identified an exLR (exMSMO1), which could distinguish pathological complete response (pCR) patients from non-pCR with an AUC of 0.790. Silencing MSMO1 could significantly enhance the sensitivity of MDA-MB-231 cells to paclitaxel and doxorubicin through modulating mTORC1 signaling pathway. This study demonstrated the value of exLR profiling to provide potential biomarkers for early detection and treatment efficacy prediction of breast cancer.

Assessment of Radiologist Performance in Breast Cancer Screening Using Digital Breast Tomosynthesis vs Digital Mammography

Importance

Many US radiologists have screening mammography recall rates above the expert-recommended threshold of 12%. The influence of digital breast tomosynthesis (DBT) on the distribution of radiologist recall rates is uncertain.

Objective

To evaluate radiologists' recall and cancer detection rates before and after beginning interpretation of DBT examinations.

Design, Setting, and Participants

This cohort study included 198 radiologists from 104 radiology facilities in the Breast Cancer Surveillance Consortium who interpreted 251 384 DBT and 2 000 681 digital mammography (DM) screening examinations from 2009 to 2017, including 126 radiologists (63.6%) who interpreted DBT examinations during the study period and 72 (36.4%) who exclusively interpreted DM examinations (to adjust for secular trends). Data were analyzed from April 2018 to July 2019.

Exposures

Digital breast tomosynthesis and DM screening examinations.

Main Outcomes and Measures

Recall rate and cancer detection rate.

Results

A total of 198 radiologists interpreted 2 252 065 DM and DBT examinations (2 000 681 [88.8%] DM examinations; 251 384 [11.2%] DBT examinations; 710 934 patients [31.6%] aged 50-59 years; 1 448 981 [64.3%] non-Hispanic white). Among the 126 radiologists (63.6%) who interpreted DBT examinations, 83 (65.9%) had unadjusted DM recall rates of no more than 12% before using DBT, with a median (interquartile range) recall rate of 10.0% (7.5%-13.0%). On DBT examinations, 96 (76.2%) had an unadjusted recall rate of no more than 12%, with a median (interquartile range) recall rate of 8.8% (6.3%-11.3%). A secular trend in recall rate was observed, with the multivariable-adjusted risk of recall on screening examinations declining by 1.2% (95% CI, 0.9%-1.5%) per year. After adjusting for examination characteristics and secular trends, recall rates were 15% lower on DBT examinations compared with DM examinations interpreted before DBT use (relative risk, 0.85; 95% CI, 0.83-0.87). Adjusted recall rates were significantly lower on DBT examinations compared with DM examinations interpreted before DBT use for 45 radiologists (35.7%) and significantly higher for 18 (14.3%); 63 (50.0%) had no statistically significant change. The unadjusted cancer detection rate on DBT was 5.3 per 1000 examinations (95% CI, 5.0-5.7 per 1000 examinations) compared with 4.7 per 1000 examinations (95% CI, 4.6-4.8 per 1000 examinations) on DM examinations interpreted before DM use (multivariable-adjusted risk ratio, 1.21; 95% CI, 1.11-1.33).

Conclusions and Relevance

In this study, DBT was associated with an overall decrease in recall rate and an increase in cancer detection rate. However, our results indicated that there is wide variability among radiologists, including a subset of radiologists who experienced increased recall rates on DBT examinations. Radiology practices should audit radiologist DBT screening performance and consider additional DBT training for radiologists whose performance does not improve as expected.

Differential Burden of Rare and Common Variants on Tumor Characteristics, Survival, and Mode of Detection in Breast Cancer

Genetic variants that increase breast cancer risk can be rare or common. This study tests whether the genetic risk stratification of breast cancer by rare and common variants in established loci can discriminate tumors with different biology, patient survival, and mode of detection. Multinomial logistic regression tested associations between genetic risk load [protein-truncating variant (PTV) carriership in 31 breast cancer predisposition genes-or polygenic risk score (PRS) using 162 single-nucleotide polymorphisms], tumor characteristics, and mode of detection (OR). Ten-year breast cancer-specific survival (HR) was estimated using Cox regression models. In this unselected cohort of 5,099 patients with breast cancer diagnosed in Sweden between 2001 and 2008, PTV carriers (n = 597) were younger and associated with more aggressive tumor phenotypes (ER-negative, large size, high grade, high proliferation, luminal B, and basal-like subtype) and worse outcome (HR, 1.65; 1.16-2.36) than noncarriers. After excluding 92 BRCA1/2 carriers, PTV carriership remained associated with high grade and worse survival (HR, 1.76; 1.21-2.56). In 5,007 BRCA1/2 noncarriers, higher PRS was associated with less aggressive tumor characteristics (ER-positive, PR-positive, small size, low grade, low proliferation, and luminal A subtype). Among patients with low mammographic density (<25%), non-BRCA1/2 PTV carriers were more often interval than screen-detected breast cancer (OR, 1.89; 1.12-3.21) than noncarriers. In contrast, higher PRS was associated with lower risk of interval compared with screen-detected cancer (OR, 0.77; 0.64-0.93) in women with low mammographic density. These findings suggest that rare and common breast cancer susceptibility loci are differentially associated with tumor characteristics, survival, and mode of detection.Significance: These findings offer the potential to improve screening practices for breast cancer by providing a deeper understanding of how risk variants affect disease progression and mode of detection. Cancer Res; 78(21); 6329-38. ©2018 AACR.

Preventing overdiagnosis in mammography screening - a public health perspective

Prevention and management of breast cancer in order to provide high quality health care is an important public health issue. The existence of overdiagnosis for breast-cancer was controversial for a long time but is now broadly accepted. Overdiagnosis is defined as the diagnosis of "disease" that will never cause symptoms or death during a patient's ordinarily expected lifetime. Estimates of the overdiagnosis rate for breast cancer range up to 54% of screen-detected localized tumors. New approaches, such as the identification of high risk groups or primary prevention approaches could be more relevant from the public health perspective.

Wherein the authors attempt to minimize the confusion generated by their study "Breast cancer mortality after a diagnosis of ductal carcinoma in situ" by several commentators who disagree with them and a few who don't: a qualitative study

Various parties might wish to measure the impact of a given paper for the purpose of assigning merit to an author or institution [...]

Cause-specific mortality in women with breast cancer in situ

The long-term mortality remains unknown in women diagnosed with breast cancer in situ (BCIS). Here, we assessed the cause-specific mortality in BCIS patients. This population-based cohort study included 12,243 women diagnosed with BCIS in Sweden between 1980 and 2011. Patients were followed until death, emigration, or 31 December 2013, whichever came first. The 30-year cumulative incidence of breast cancer-specific mortality was 6.3%, which is considerably lower than 49.7% observed for other-cause mortality. Women diagnosed with BCIS were more likely to die from breast cancer (standardized mortality ratio [SMR], 3.85; 95% CI, 3.47-4.27) but less likely to die from cardiovascular disease (SMR, 0.88; 95% CI, 0.82-0.95) than women in the general population. Specifically, the SMRs for breast cancer-specific mortality decreased over time from 5.19 (95% CI, 3.95-6.81) among BCIS diagnosed during 1980-1989 to 3.03 (95% CI, 2.35-3.91) among those diagnosed during 2000-2011. Furthermore, higher risk of death from other causes was seen among those with older age at BCIS diagnosis, lower levels of education, nulliparity, higher Charlson Comorbidity Index, and being hospitalized before BCIS diagnosis; whereas, lower risk of death from breast cancer was seen among BCIS diagnosed in the later time period and those with younger age at first birth. We conclude that most women diagnosed with BCIS die from causes other than breast cancer, which highlights the need for actions not only to reduce nonbreast cancer mortality but also to identify patient where extensive curative BCIS treatment is not adding to survival.