ABSTRACT
Though widespread adoption of cervical cancer screening (CCS) in the US has been associated with a reduction in cervical cancer incidence and mortality, screening also carries with it potential risks. Newer national guidelines recommend decreased screening frequency to optimize the benefit/risk balance and to prevent over-screening. Here, we examined the alignment of US cancer center websites' public recommendations on CCS with national guidelines. We reviewed the websites of 1024 cancer centers accredited by the US Commission on Cancer during January-August 2022. We recorded the recommended frequency and type of CCS and any screening risks mentioned, comparing against national US Preventive Service Task Force (USPSTF) and American Cancer Society (ACS) guidelines. Of 1024 US cancer centers, 60% (610) provided CCS recommendations. Most centers are in alignment with the screening starting age (96%, 544/565) and stopping age (94%, 440/470) recommended by national guidelines. Of 508 centers specifying the frequency of standalone cervical cytology, 83% (419) recommended a screening interval of three years; however, 14% (73) recommended cervical cytology more frequently than the three-year interval recommended by the ACS/USPSTF. Screening risks were mentioned by 20% (124/610) of centers. Our findings highlight the importance of education on screening benefits and risks for physicians and patients to enable shared decision making based on evidence-based guidelines.
Subject(s)
Early Detection of Cancer , Guideline Adherence , Uterine Cervical Neoplasms , Humans , Uterine Cervical Neoplasms/diagnosis , Female , Early Detection of Cancer/statistics & numerical data , Early Detection of Cancer/methods , Early Detection of Cancer/standards , United States , Guideline Adherence/statistics & numerical data , Practice Guidelines as Topic , Cancer Care Facilities/statistics & numerical data , Mass Screening/standards , Mass Screening/statistics & numerical data , Mass Screening/methods , AdultABSTRACT
We performed a 318-participant validation study of an individualized risk assessment tool in women identified as having high- or highest-risk of breast cancer in the personalized arm of the Women Informed to Screen Depending on Measures of risk (WISDOM) trial. Per protocol, these women were educated about their risk and risk reducing options using the Breast Health Decisions (BHD) tool, which uses patient-friendly visuals and 8th grade reading level language to convey risk and prevention options. Prior to exposure to the educational tool, 4.7% of women were already taking endocrine risk reduction, 38.7% were reducing alcohol intake, and 62.6% were exercising. Three months after initial use of BHD, 8.4% of women who considered endocrine risk reduction, 33% of women who considered alcohol reduction, and 46% of women who considered exercise pursued the risk-reducing activities. Unlike lifestyle interventions which are under the control of the patient, additional barriers at the level of the healthcare provider may be impeding the targeted use of endocrine risk reduction medications in women with elevated breast cancer risk.
ABSTRACT
Aggressive breast cancers portend a poor prognosis, but current polygenic risk scores (PRSs) for breast cancer do not reliably predict aggressive cancers. Aggressiveness can be effectively recapitulated using tumor gene expression profiling. Thus, we sought to develop a PRS for the risk of recurrence score weighted on proliferation (ROR-P), an established prognostic signature. Using 2363 breast cancers with tumor gene expression data and single nucleotide polymorphism (SNP) genotypes, we examined the associations between ROR-P and known breast cancer susceptibility SNPs using linear regression models. We constructed PRSs based on varying p-value thresholds and selected the optimal PRS based on model r2 in 5-fold cross-validation. We then used Cox proportional hazards regression to test the ROR-P PRS's association with breast cancer-specific survival in two independent cohorts totaling 10,196 breast cancers and 785 events. In meta-analysis of these cohorts, higher ROR-P PRS was associated with worse survival, HR per SD = 1.13 (95% CI 1.06-1.21, p = 4.0 × 10-4). The ROR-P PRS had a similar magnitude of effect on survival as a comparator PRS for estrogen receptor (ER)-negative versus positive cancer risk (PRSER-/ER+). Furthermore, its effect was minimally attenuated when adjusted for PRSER-/ER+, suggesting that the ROR-P PRS provides additional prognostic information beyond ER status. In summary, we used integrated analysis of germline SNP and tumor gene expression data to construct a PRS associated with aggressive tumor biology and worse survival. These findings could potentially enhance risk stratification for breast cancer screening and prevention.
ABSTRACT
Introduction: Breast cancer (BC) is one of the most common cancers globally. Genetic testing can facilitate screening and risk-reducing recommendations, and inform use of targeted treatments. However, genes included in testing panels are from studies of European-ancestry participants. We sequenced Hispanic/Latina (H/L) women to identify BC susceptibility genes. Methods: We conducted a pooled BC case-control analysis in H/L women from the San Francisco Bay area, Los Angeles County, and Mexico (4,178 cases and 4,344 controls). Whole exome sequencing was conducted on 1,043 cases and 1,188 controls and a targeted 857-gene panel on the remaining samples. Using ancestry-adjusted SKAT-O analyses, we tested the association of loss of function (LoF) variants with overall, estrogen receptor (ER)-positive, and ER-negative BC risk. We calculated odds ratios (OR) for BC using ancestry-adjusted logistic regression models. We also tested the association of single variants with BC risk. Results: We saw a strong association of LoF variants in FANCM with ER-negative BC (p=4.1×10-7, OR [CI]: 6.7 [2.9-15.6]) and a nominal association with overall BC risk. Among known susceptibility genes, BRCA1 (p=2.3×10-10, OR [CI]: 24.9 [6.1-102.5]), BRCA2 (p=8.4×10-10, OR [CI]: 7.0 [3.5-14.0]), and PALB2 (p=1.8×10-8, OR [CI]: 6.5 [3.2-13.1]) were strongly associated with BC. There were nominally significant associations with CHEK2, RAD51D, and TP53. Conclusion: In H/L women, LoF variants in FANCM were strongly associated with ER-negative breast cancer risk. It previously was proposed as a possible susceptibility gene for ER-negative BC, but is not routinely tested in clinical practice. Our results demonstrate that FANCM should be added to BC gene panels.
ABSTRACT
PURPOSE: The Breast Cancer Surveillance Consortium (BCSC) model is a widely used risk model that predicts 5- and 10-year risk of developing invasive breast cancer for healthy women aged 35-74 years. Women with high BCSC risk may also be at elevated risk to develop interval cancers, which present symptomatically in the year following a normal screening mammogram. We examined the association between high BCSC risk (defined as the top 2.5% by age) and breast cancers presenting as interval cancers. METHODS: We conducted a case-case analysis among women with breast cancer in which we compared the mode of detection and tumor characteristics of patients in the top 2.5% BCSC risk by age with age-matched (1:2) patients in the lower 97.5% risk. We constructed logistic regression models to estimate the odds ratio (OR) of presenting with interval cancers, and poor prognosis tumor features, between women from the top 2.5% and bottom 97.5% of BCSC risk. RESULTS: Our analysis included 113 breast cancer patients in the top 2.5% of risk for their age and 226 breast cancer patients in the lower 97.5% of risk. High-risk patients were more likely to have presented with an interval cancer within one year of a normal screening, OR 6.62 (95% CI 3.28-13.4, p < 0.001). These interval cancers were also more likely to be larger, node positive, and higher stage than the screen-detected cancers. CONCLUSION: Breast cancer patients in the top 2.5% of BCSC risk for their age were more likely to present with interval cancers. The BCSC model could be used to identify healthy women who may benefit from intensified screening.
Subject(s)
Breast Neoplasms , Adult , Aged , Breast Neoplasms/diagnosis , Breast Neoplasms/epidemiology , Early Detection of Cancer , Female , Humans , Mammography , Mass Screening , Middle Aged , Odds RatioABSTRACT
Risk-reducing endocrine therapy use, though the benefit is validated, is extremely low. The FDA has approved tamoxifen and raloxifene for a 5-year Breast Cancer Risk Assessment Tool (BCRAT) risk ≥ 1.67%. We examined the threshold at which high-risk women are likely to be using endocrine risk-reducing therapies among Athena Breast Health Network participants from 2011-2018. We identified high-risk women by a 5-year BCRAT risk ≥ 1.67% and those in the top 10% and 2.5% risk thresholds by age. We estimated the odds ratio (OR) of current medication use based on these thresholds using logistic regression. One thousand two hundred and one (1.2%) of 104,223 total participants used medication. Of the 33,082 participants with 5-year BCRAT risk ≥ 1.67%, 772 (2.3%) used medication. Of 2445 in the top 2.5% threshold, 209 (8.6%) used medication. Participants whose 5-year risk exceeded 1.67% were more likely to use medication than those whose risk was below this threshold, OR 3.94 (95% CI = 3.50-4.43). The top 2.5% was most strongly associated with medication usage, OR 9.50 (8.13-11.09) compared to the bottom 97.5%. Women exceeding a 5-year BCRAT ≥ 1.67% had modest medication use. We demonstrate that women in the top 2.5% have higher odds of medication use than those in the bottom 97.5% and compared to a risk of 1.67%. The top 2.5% threshold would more effectively target medication use and is being tested prospectively in a randomized control clinical trial.
ABSTRACT
Breast cancer risk reduction has been validated by large-scale clinical trials, but uptake remains low. A risk communication tool could provide personalized risk-reduction information for high-risk women. A low-literacy-friendly, visual, and personalized tool was designed as part of the Women Informed to Screen Depending On Measures of risk (WISDOM) study. The tool integrates genetic, polygenic, and lifestyle factors, and quantifies the risk-reduction from undertaking medication and lifestyle interventions. The development and design process utilized feedback from clinicians, decision-making scientists, software engineers, and patient advocates. We piloted the tool with 17 study participants, collecting quantitative and qualitative feedback. Overall, participants felt they better understood their personalized breast cancer risk, were motivated to reduce their risk, and considered lifestyle interventions. The tool will be used to evaluate whether risk-based screening leads to more informed decisions and higher uptake of risk-reduction interventions among those most likely to benefit.
Subject(s)
Anticarcinogenic Agents/therapeutic use , Aromatase Inhibitors/therapeutic use , Breast Neoplasms/prevention & control , Primary Prevention/methods , Selective Estrogen Receptor Modulators/therapeutic use , Anticarcinogenic Agents/adverse effects , Aromatase Inhibitors/adverse effects , Female , Humans , Raloxifene Hydrochloride/adverse effects , Raloxifene Hydrochloride/therapeutic use , Selective Estrogen Receptor Modulators/adverse effects , Tamoxifen/adverse effects , Tamoxifen/therapeutic use , Uterine Neoplasms/chemically induced , Venous Thromboembolism/chemically inducedABSTRACT
BACKGROUND: More than 180 single nucleotide polymorphisms (SNPs) associated with breast cancer susceptibility have been identified; these SNPs can be combined into polygenic risk scores (PRS) to predict breast cancer risk. Because most SNPs were identified in predominantly European populations, little is known about the performance of PRS in non-Europeans. We tested the performance of a 180-SNP PRS in Latinas, a large ethnic group with variable levels of Indigenous American, European, and African ancestry. METHODS: We conducted a pooled case-control analysis of US Latinas and Latin American women (4658 cases and 7622 controls). We constructed a 180-SNP PRS consisting of SNPs associated with breast cancer risk (P < 5 × 10-8). We evaluated the association between the PRS and breast cancer risk using multivariable logistic regression, and assessed discrimination using an area under the receiver operating characteristic curve. We also assessed PRS performance across quartiles of Indigenous American genetic ancestry. All statistical tests were two-sided. RESULTS: Of 180 SNPs tested, 142 showed directionally consistent associations compared with European populations, and 39 were nominally statistically significant (P < .05). The PRS was associated with breast cancer risk, with an odds ratio per SD increment of 1.58 (95% confidence interval [CI = 1.52 to 1.64) and an area under the receiver operating characteristic curve of 0.63 (95% CI = 0.62 to 0.64). The discrimination of the PRS was similar between the top and bottom quartiles of Indigenous American ancestry. CONCLUSIONS: The 180-SNP PRS predicts breast cancer risk in Latinas, with similar performance as reported for Europeans. The performance of the PRS did not vary substantially according to Indigenous American ancestry.
Subject(s)
Breast Neoplasms/ethnology , Breast Neoplasms/genetics , Hispanic or Latino/genetics , Aged , Case-Control Studies , Female , Genetic Predisposition to Disease , Humans , Logistic Models , Middle Aged , Polymorphism, Single NucleotideABSTRACT
BACKGROUND: Obesity and elevated breast density are common risk factors for breast cancer, and their effects may vary by estrogen receptor (ER) subtype. However, their joint effects on ER subtype-specific risk are unknown. Understanding this relationship could enhance risk stratification for screening and prevention. Thus, we assessed the association between breast density and ER subtype according to body mass index (BMI) and menopausal status. METHODS: We conducted a case-control study nested within two mammography screening cohorts, the Mayo Mammography Health Study and the San Francisco Bay Area Breast Cancer SPORE/San Francisco Mammography Registry. Our pooled analysis contained 1538 ER-positive and 285 ER-negative invasive breast cancer cases and 4720 controls matched on age, menopausal status at time of mammogram, and year of mammogram. Percent density was measured on digitized film mammograms using computer-assisted techniques. We used polytomous logistic regression to evaluate the association between percent density and ER subtype by BMI subgroup (normal/underweight, < 25 kg/m2 versus overweight/obese, ≥ 25 kg/m2). We used Wald chi-squared tests to assess for interactions between percent density and BMI. Our analysis was stratified by menopausal status and hormone therapy usage at the time of index mammogram. RESULTS: Percent density was associated with increased risk of overall breast cancer regardless of menopausal status or BMI. However, when analyzing breast cancer across ER subtype, we found a statistically significant (p = 0.008) interaction between percent density and BMI in premenopausal women only. Specifically, elevated percent density was associated with a higher risk of ER-negative than ER-positive cancer in overweight/obese premenopausal women [OR per standard deviation increment 2.17 (95% CI 1.50-3.16) vs 1.33 (95% CI 1.11-1.61) respectively, Pheterogeneity = 0.01]. In postmenopausal women, elevated percent density was associated with similar risk of ER-positive and ER-negative cancers, and no substantive differences were seen after accounting for BMI or hormone therapy usage. CONCLUSIONS: The combination of overweight/obesity and elevated breast density in premenopausal women is associated with a higher risk of ER-negative compared with ER-positive cancer. Eighteen percent of premenopausal women in the USA have elevated BMI and breast density and may benefit from lifestyle modifications involving weight loss and exercise.
Subject(s)
Body Mass Index , Breast Density , Breast Neoplasms/epidemiology , Breast Neoplasms/etiology , Receptors, Estrogen/genetics , Aged , Biomarkers, Tumor , Breast Neoplasms/pathology , Case-Control Studies , Female , Humans , Middle Aged , Odds Ratio , Prevalence , Risk Assessment , Risk FactorsSubject(s)
Breast Neoplasms/epidemiology , Ovarian Neoplasms/epidemiology , Precision Medicine , Breast Neoplasms/diagnosis , Breast Neoplasms/prevention & control , Breast Neoplasms/therapy , Early Detection of Cancer , Female , Health Care Costs , Humans , Ovarian Neoplasms/diagnosis , Ovarian Neoplasms/prevention & control , Ovarian Neoplasms/therapy , Population Health , Precision Medicine/methodsABSTRACT
BACKGROUND: Models that predict the risk of estrogen receptor (ER)-positive breast cancers may improve our ability to target chemoprevention. We investigated the contributions of sex hormones to the discrimination of the Breast Cancer Surveillance Consortium (BCSC) risk model and a polygenic risk score comprised of 83 single nucleotide polymorphisms. METHODS: We conducted a nested case-control study of 110 women with ER-positive breast cancers and 214 matched controls within a mammography screening cohort. Participants were postmenopausal and not on hormonal therapy. The associations of estradiol, estrone, testosterone, and sex hormone binding globulin with ER-positive breast cancer were evaluated using conditional logistic regression. We assessed the individual and combined discrimination of estradiol, the BCSC risk score, and polygenic risk score using the area under the receiver operating characteristic curve (AUROC). RESULTS: Of the sex hormones assessed, estradiol (OR 3.64, 95% CI 1.64-8.06 for top vs bottom quartile), and to a lesser degree estrone, was most strongly associated with ER-positive breast cancer in unadjusted analysis. The BCSC risk score (OR 1.32, 95% CI 1.00-1.75 per 1% increase) and polygenic risk score (OR 1.58, 95% CI 1.06-2.36 per standard deviation) were also associated with ER-positive cancers. A model containing the BCSC risk score, polygenic risk score, and estradiol levels showed good discrimination for ER-positive cancers (AUROC 0.72, 95% CI 0.65-0.79), representing a significant improvement over the BCSC risk score (AUROC 0.58, 95% CI 0.50-0.65). CONCLUSION: Adding estradiol and a polygenic risk score to a clinical risk model improves discrimination for postmenopausal ER-positive breast cancers.
Subject(s)
Breast Neoplasms/genetics , Gonadal Steroid Hormones/metabolism , Multifactorial Inheritance , Receptors, Estrogen/metabolism , Breast Neoplasms/metabolism , Case-Control Studies , Female , Humans , Logistic Models , Models, Theoretical , Polymorphism, Single Nucleotide , Postmenopause , Risk Factors , Sex Hormone-Binding Globulin/metabolismABSTRACT
Lung cancer screening with low-dose CT (LDCT) scan was shown to reduce lung cancer mortality in the National Lung Screening Trial, a large randomized controlled trial of high-risk current and former smokers. Despite ongoing uncertainty over the effectiveness of LDCT scan in the real-world setting, the Centers for Medicare and Medicaid Services (CMS) decided to cover LDCT scan as a preventive service. As part of its National Coverage Determination, CMS set forth a series of requirements for reimbursement of LDCT scan, including a counseling and shared decision-making visit prior to a LDCT scan being ordered. During this visit, providers must determine patient eligibility, engage in shared decision-making around LDCT scan, discuss the importance of adherence to screening, and provide smoking cessation counseling (if applicable). Two new billing codes were introduced for the counseling and shared decision-making visit and subsequent LDCT scan. In this review, we summarize the evidence around lung cancer screening and describe practical aspects of the counseling and shared decision-making, including billing considerations. We conclude with a discussion of the greater implications of CMS National Coverage Determination, especially as it pertains to quality assurance around new screening tests.
Subject(s)
Counseling/organization & administration , Early Detection of Cancer , Lung Neoplasms/diagnosis , Tomography, X-Ray Computed/methods , Decision Making , Early Detection of Cancer/methods , Early Detection of Cancer/standards , Humans , Quality Assurance, Health Care , Radiation DosageABSTRACT
Ongoing controversy over the optimal approach to breast cancer screening has led to discordant professional society recommendations, particularly in women age 40 to 49 years. One potential solution is risk-based screening, where decisions around the starting age, stopping age, frequency, and modality of screening are based on individual risk to maximize the early detection of aggressive cancers and minimize the harms of screening through optimal resource utilization. We present a novel approach to risk-based screening that integrates clinical risk factors, breast density, a polygenic risk score representing the cumulative effects of genetic variants, and sequencing for moderate- and high-penetrance germline mutations. We demonstrate how thresholds of absolute risk estimates generated by our prediction tools can be used to stratify women into different screening strategies (biennial mammography, annual mammography, annual mammography with adjunctive magnetic resonance imaging, defer screening at this time) while informing the starting age of screening for women age 40 to 49 years. Our risk thresholds and corresponding screening strategies are based on current evidence but need to be tested in clinical trials. The Women Informed to Screen Depending On Measures of risk (WISDOM) Study, a pragmatic, preference-tolerant randomized controlled trial of annual vs personalized screening, will study our proposed approach. WISDOM will evaluate the efficacy, safety, and acceptability of risk-based screening beginning in the fall of 2016. The adaptive design of this trial allows continued refinement of our risk thresholds as the trial progresses, and we discuss areas where we anticipate emerging evidence will impact our approach.
Subject(s)
Breast Neoplasms/diagnostic imaging , Breast Neoplasms/genetics , Early Detection of Cancer/standards , Mammography/standards , Age Factors , Breast Density , Female , Genotype , Humans , Magnetic Resonance Imaging , Penetrance , Polymorphism, Single Nucleotide , Practice Guidelines as Topic , Pragmatic Clinical Trials as Topic , Precision Medicine , Risk Assessment/methods , Risk Factors , Time FactorsABSTRACT
Breast cancer risk assessment can inform the use of screening and prevention modalities. We investigated the performance of the Breast Cancer Surveillance Consortium (BCSC) risk model in combination with a polygenic risk score (PRS) comprised of 83 single nucleotide polymorphisms identified from genome-wide association studies. We conducted a nested case-control study of 486 cases and 495 matched controls within a screening cohort. The PRS was calculated using a Bayesian approach. The contributions of the PRS and variables in the BCSC model to breast cancer risk were tested using conditional logistic regression. Discriminatory accuracy of the models was compared using the area under the receiver operating characteristic curve (AUROC). Increasing quartiles of the PRS were positively associated with breast cancer risk, with OR 2.54 (95 % CI 1.69-3.82) for breast cancer in the highest versus lowest quartile. In a multivariable model, the PRS, family history, and breast density remained strong risk factors. The AUROC of the PRS was 0.60 (95 % CI 0.57-0.64), and an Asian-specific PRS had AUROC 0.64 (95 % CI 0.53-0.74). A combined model including the BCSC risk factors and PRS had better discrimination than the BCSC model (AUROC 0.65 versus 0.62, p = 0.01). The BCSC-PRS model classified 18 % of cases as high-risk (5-year risk ≥3 %), compared with 7 % using the BCSC model. The PRS improved discrimination of the BCSC risk model and classified more cases as high-risk. Further consideration of the PRS's role in decision-making around screening and prevention strategies is merited.
Subject(s)
Breast Neoplasms/diagnosis , Breast Neoplasms/genetics , Genetic Predisposition to Disease , Polymorphism, Single Nucleotide , Adult , Aged , Aged, 80 and over , Area Under Curve , Bayes Theorem , Breast Neoplasms/epidemiology , Case-Control Studies , Female , Genome-Wide Association Study , Humans , Logistic Models , Middle Aged , Multifactorial Inheritance , Risk AssessmentABSTRACT
Several important lessons have been learnt from our experiences in screening for various cancers. Screening programmes for cervical and colorectal cancers have had the greatest success, probably because these cancers are relatively homogenous, slow-growing, and have identifiable precursors that can be detected and removed; however, identifying the true obligate precursors of invasive disease remains a challenge. With regard to screening for breast cancer and for prostate cancer, which focus on early detection of invasive cancer, preferential detection of slower-growing, localized cancers has occurred, which has led to concerns about overdiagnosis and overtreatment; programmes for early detection of invasive lung cancers are emerging, and have faced similar challenges. A crucial consideration in screening for breast, prostate, and lung cancers is their remarkable phenotypic heterogeneity, ranging from indolent to highly aggressive. Efforts have been made to address the limitations of cancer-screening programmes, providing an opportunity for cross-disciplinary learning and further advancement of the science. Current innovations are aimed at identifying the individuals who are most likely to benefit from screening, increasing the yield of consequential cancers on screening and biopsy, and using molecular tests to improve our understanding of disease biology and to tailor treatment. We discuss each of these concepts and outline a dynamic framework for continuous improvements in the field of cancer screening.
Subject(s)
Early Detection of Cancer/methods , Neoplasms/prevention & control , Age Distribution , Early Detection of Cancer/standards , Female , Health Policy , Health Promotion , Humans , Incidence , Male , Mammography/methods , Mass Screening/methods , Neoplasms/diagnosis , Practice Guidelines as Topic , Precancerous Conditions/prevention & control , Quality Improvement , Risk AssessmentSubject(s)
Breast Neoplasms/diagnostic imaging , Breast Neoplasms/epidemiology , Carcinoma, Ductal, Breast/diagnostic imaging , Carcinoma, Ductal, Breast/epidemiology , Carcinoma, Intraductal, Noninfiltrating/diagnostic imaging , Carcinoma, Intraductal, Noninfiltrating/epidemiology , Female , Humans , RadiographyABSTRACT
We sought to compare the molecular signature of node negative cancers from two cohorts 15 years apart, to determine if there is molecular evidence of increase in low and ultralow risk cancers over time. We studied the impact of age, time period of diagnosis, and mammographic screening on biology of tumors where The Netherlands Cancer Institute 70-gene prognosis signature was generated as part of 2 validation series, one retrospective (1984-1992), Cohort 1, and one prospective (2004-2006), Cohort 2. A total of 866 patients were analyzed. Regardless of time period of diagnosis, the proportion of T1, grade 1, hormone receptor positive (HR) tumors, and good prognosis by 70-gene signature significantly increases as age increases (P < 0.01). In women aged 49-60, the time period of diagnosis significantly affects the proportion of cancers that were NKI 70-gene low risk: 40.6% (67/165) compared with 58% (119/205) for Cohorts 1 and 2, respectively. This is in contrast to the absence of a significant change for women under age 40, where 25% (17/68) and 30% (17/56) were low risk in Cohorts 1 and 2, respectively. In women aged 49-60, using an ultralow risk threshold of the 70-gene signature, 10% of tumors in Cohort 1 were ultralow risk compared with 30% for women with screen-detected cancers in Cohort 2. Older age and method of detection (screening) are associated with a higher likelihood of a biologically low risk tumor. In women over age 50, biologically low risk tumors are frequent and tools that classify risk may minimize overtreatment.