Statistical Methods for Estimating the Cumulative Risk of Screening Mammography Outcomes

Predicting five-year interval second breast cancer risk in women with prior breast cancer

BACKGROUND

Annual surveillance mammography is recommended for women with a personal history of breast cancer. Risk prediction models that estimate mammography failures such as interval second breast cancers could help to tailor surveillance imaging regimens to women's individual risk profiles.

METHODS

In a cohort of women with a history of breast cancer receiving surveillance mammography in the Breast Cancer Surveillance Consortium in 1996-2019, we used Least Absolute Shrinkage and Selection Operator (LASSO)-penalized regression to estimate the probability of an interval second cancer (invasive cancer or ductal carcinoma in situ) in the 1 year after a negative surveillance mammogram. Based on predicted risks from this one-year risk model, we generated cumulative risks of an interval second cancer for the five-year period after each mammogram. Model performance was evaluated using cross-validation in the overall cohort and within race and ethnicity strata.

RESULTS

In 173 290 surveillance mammograms, we observed 496 interval cancers. One-year risk models were well-calibrated (expected/observed ratio = 1.00) with good accuracy (area under the receiver operating characteristic curve = 0.64). Model performance was similar across race and ethnicity groups. The median five-year cumulative risk was 1.20% (interquartile range 0.93%-1.63%). Median five-year risks were highest in women who were under age 40 or pre- or perimenopausal at diagnosis and those with estrogen receptor-negative primary breast cancers.

CONCLUSIONS

Our risk model identified women at high risk of interval second breast cancers who may benefit from additional surveillance imaging modalities. Risk models should be evaluated to determine if risk-guided supplemental surveillance imaging improves early detection and decreases surveillance failures.

Cumulative 6-Year Risk of Screen-Detected Ductal Carcinoma In Situ by Screening Frequency

IMPORTANCE

Detection of ductal carcinoma in situ (DCIS) by mammography screening is a controversial outcome with potential benefits and harms. The association of mammography screening interval and woman's risk factors with the likelihood of DCIS detection after multiple screening rounds is poorly understood.

OBJECTIVE

To develop a 6-year risk prediction model for screen-detected DCIS according to mammography screening interval and women's risk factors.

DESIGN, SETTING, AND PARTICIPANTS

This Breast Cancer Surveillance Consortium cohort study assessed women aged 40 to 74 years undergoing mammography screening (digital mammography or digital breast tomosynthesis) from January 1, 2005, to December 31, 2020, at breast imaging facilities within 6 geographically diverse registries of the consortium. Data were analyzed between February and June 2022.

EXPOSURES

Screening interval (annual, biennial, or triennial), age, menopausal status, race and ethnicity, family history of breast cancer, benign breast biopsy history, breast density, body mass index, age at first birth, and false-positive mammography history.

MAIN OUTCOMES AND MEASURES

Screen-detected DCIS defined as a DCIS diagnosis within 12 months after a positive screening mammography result, with no concurrent invasive disease.

RESULTS

A total of 916 931 women (median [IQR] age at baseline, 54 [46-62] years; 12% Asian, 9% Black, 5% Hispanic/Latina, 69% White, 2% other or multiple races, and 4% missing) met the eligibility criteria, with 3757 screen-detected DCIS diagnoses. Screening round-specific risk estimates from multivariable logistic regression were well calibrated (expected-observed ratio, 1.00; 95% CI, 0.97-1.03) with a cross-validated area under the receiver operating characteristic curve of 0.639 (95% CI, 0.630-0.648). Cumulative 6-year risk of screen-detected DCIS estimated from screening round-specific risk estimates, accounting for competing risks of death and invasive cancer, varied widely by all included risk factors. Cumulative 6-year screen-detected DCIS risk increased with age and shorter screening interval. Among women aged 40 to 49 years, the mean 6-year screen-detected DCIS risk was 0.30% (IQR, 0.21%-0.37%) for annual screening, 0.21% (IQR, 0.14%-0.26%) for biennial screening, and 0.17% (IQR, 0.12%-0.22%) for triennial screening. Among women aged 70 to 74 years, the mean cumulative risks were 0.58% (IQR, 0.41%-0.69%) after 6 annual screens, 0.40% (IQR, 0.28%-0.48%) for 3 biennial screens, and 0.33% (IQR, 0.23%-0.39%) after 2 triennial screens.

CONCLUSIONS AND RELEVANCE

In this cohort study, 6-year screen-detected DCIS risk was higher with annual screening compared with biennial or triennial screening intervals. Estimates from the prediction model, along with risk estimates of other screening benefits and harms, could help inform policy makers' discussions of screening strategies.

Cumulative Advanced Breast Cancer Risk Prediction Model Developed in a Screening Mammography Population

BACKGROUND

Estimating advanced breast cancer risk in women undergoing annual or biennial mammography could identify women who may benefit from less or more intensive screening. We developed an actionable model to predict cumulative 6-year advanced cancer (prognostic pathologic stage II or higher) risk according to screening interval.

METHODS

We included 931 186 women aged 40-74 years in the Breast Cancer Surveillance Consortium undergoing 2 542 382 annual (prior mammogram within 11-18 months) or 752 049 biennial (prior within 19-30 months) screening mammograms. The prediction model includes age, race and ethnicity, body mass index, breast density, family history of breast cancer, and prior breast biopsy subdivided by menopausal status and screening interval. We used fivefold cross-validation to internally validate model performance. We defined higher than 95th percentile as high risk (>0.658%), higher than 75th percentile to 95th or less percentile as intermediate risk (0.380%-0.658%), and 75th or less percentile as low to average risk (<0.380%).

RESULTS

Obesity, high breast density, and proliferative disease with atypia were strongly associated with advanced cancer. The model is well calibrated and has an area under the receiver operating characteristics curve of 0.682 (95% confidence interval = 0.670 to 0.694). Based on women's predicted advanced cancer risk under annual and biennial screening, 69.1% had low or average risk regardless of screening interval, 12.4% intermediate risk with biennial screening and average risk with annual screening, and 17.4% intermediate or high risk regardless of screening interval.

CONCLUSION

Most women have low or average advanced cancer risk and can undergo biennial screening. Intermediate-risk women may consider annual screening, and high-risk women may consider supplemental imaging in addition to annual screening.

Cumulative Probability of False-Positive Results After 10 Years of Screening With Digital Breast Tomosynthesis vs Digital Mammography

Importance

Breast cancer screening with digital breast tomosynthesis may decrease false-positive results compared with digital mammography.

Objective

To estimate the probability of receiving at least 1 false-positive result after 10 years of screening with digital breast tomosynthesis vs digital mammography in the US.

Design, Setting, and Participants

An observational comparative effectiveness study with data collected prospectively for screening examinations was performed between January 1, 2005, and December 31, 2018, at 126 radiology facilities in the Breast Cancer Surveillance Consortium. Analysis included 903 495 individuals aged 40 to 79 years. Data analysis was conducted from February 9 to September 7, 2021.

Exposures

Screening modality, screening interval, age, and Breast Imaging Reporting and Data System breast density.

Main Outcomes and Measures

Cumulative risk of at least 1 false-positive recall for further imaging, short-interval follow-up recommendation, and biopsy recommendation after 10 years of annual or biennial screening with digital breast tomosynthesis vs digital mammography, accounting for competing risks of breast cancer diagnosis and death.

Results

In this study of 903 495 women, 2 969 055 nonbaseline screening examinations were performed with interpretation by 699 radiologists. Mean (SD) age of the women at the time of the screening examinations was 57.6 (9.9) years, and 58% of the examinations were in individuals younger than 60 years and 46% were performed in women with dense breasts. A total of 15% of examinations used tomosynthesis. For annual screening, the 10-year cumulative probability of at least 1 false-positive result was significantly lower with tomosynthesis vs digital mammography for all outcomes: 49.6% vs 56.3% (difference, -6.7; 95% CI, -7.4 to -6.1) for recall, 16.6% vs 17.8% (difference, -1.1; 95% CI, -1.7 to -0.6) for short-interval follow-up recommendation, and 11.2% vs 11.7% (difference, -0.5; 95% CI, -1.0 to -0.1) for biopsy recommendation. For biennial screening, the cumulative probability of a false-positive recall was significantly lower for tomosynthesis vs digital mammography (35.7% vs 38.1%; difference, -2.4; 95% CI, -3.4 to -1.5), but cumulative probabilities did not differ significantly by modality for short-interval follow-up recommendation (10.3% vs 10.5%; difference, -0.1; 95% CI, -0.7 to 0.5) or biopsy recommendation (6.6% vs 6.7%; difference, -0.1; 95% CI, -0.5 to 0.4). Decreases in cumulative probabilities of false-positive results with tomosynthesis vs digital mammography were largest for annual screening in women with nondense breasts (differences for recall, -6.5 to -12.8; short-interval follow-up, 0.1 to -5.2; and biopsy recommendation, -0.5 to -3.1). Regardless of modality, cumulative probabilities of false-positive results were substantially lower for biennial vs annual screening (overall recall, 35.7 to 38.1 vs 49.6 to 56.3; short-interval follow-up, 10.3 to 10.5 vs 16.6 to 17.8; and biopsy recommendation, 6.6 to 6.7 vs 11.2 to 11.7); older vs younger age groups (eg, among annual screening in women ages 70-79 vs 40-49, recall, 39.8 to 47.0 vs 60.8 to 68.0; short-interval follow-up, 13.3 to 14.2 vs 20.7 to 20.9; and biopsy recommendation, 9.1 to 9.3 vs 13.2 to 13.4); and women with entirely fatty vs extremely dense breasts (eg, among annual screening in women aged 50-59 years, recall, 29.1 to 36.3 vs 58.8 to 60.4; short-interval follow-up, 8.9 to 11.6 vs 19.5 to 19.8; and biopsy recommendation, 4.9 to 8.0 vs 15.1 to 15.3).

Conclusions and Relevance

In this comparative effectiveness study, 10-year cumulative probabilities of false-positive results were lower on digital breast tomosynthesis vs digital mammography. Biennial screening interval, older age, and nondense breasts were associated with larger reductions in false-positive probabilities than screening modality.

Cumulative risk of a false-positive screening result: A retrospective cohort study using empirical data from 10 biennial screening rounds in BreastScreen Norway

BACKGROUND

False-positive screening results are an inevitable and commonly recognized disadvantage of mammographic screening. This study estimated the cumulative probability of experiencing a first false-positive screening result in women attending 10 biennial screening rounds in BreastScreen Norway, which targets women aged 50 to 69 years.

METHODS

This retrospective cohort study analyzed screening outcomes from 421,545 women who underwent 1,894,523 screening examinations during 1995-2019. Empirical data were used to calculate the cumulative risk of experiencing a first false-positive screening result and a first false-positive screening result that involved an invasive procedure over 10 screening rounds. Logistic regression was used to evaluate the effect of adjusting for irregular attendance, age at screening, and number of screens attended.

RESULTS

The cumulative risk of experiencing a first false-positive screening result was 18.04% (95% confidence interval [CI], 18.00%-18.07%). It was 5.01% (95% CI, 5.01%-5.02%) for experiencing a false-positive screening result that involved an invasive procedure. Adjusting for irregular attendance or age at screening did not appreciably affect these estimates. After adjustments for the number of screens attended, the cumulative risk of a first false-positive screening result was 18.28% (95% CI, 18.24%-18.32%), and the risk of a false-positive screening result including an invasive procedure was 5.11% (95% CI, 5.11%-5.22%). This suggested that there was minimal bias from dependent censoring.

CONCLUSIONS

Nearly 1 in 5 women will experience a false-positive screening result if they attend 10 biennial screening rounds in BreastScreen Norway. One in 20 will experience a false-positive screening result with an invasive procedure.

LAY SUMMARY

A false-positive screening result occurs when a woman attending mammographic screening is called back for further assessment because of suspicious findings, but the assessment does not detect breast cancer. Further assessment includes additional imaging. Usually, it involves ultrasound, and sometimes, it involves a biopsy. This study has evaluated the chance of experiencing a false-positive screening result among women attending 10 screening examinations over 20 years in BreastScreen Norway. Nearly 1 in 5 women will experience a false-positive screening result over 10 screening rounds. One in 20 women will experience a false-positive screening result involving a biopsy.

False-Positive Results in a Population-Based Colorectal Screening Program: Cumulative Risk from 2000 to 2017 with Biennial Screening

BACKGROUND

The aim of this study was to estimate the cumulative risk of a false-positive (FP) result in a fecal occult blood test (FOBT) through 7 screening rounds and to identify its associated factors in a population-based colorectal cancer screening program.

METHODS

Retrospective cohort study, which included participants ages 50 to 69 years of a colorectal cancer screening program in Catalonia, Spain. During this period, 2 FOBTs were used (guaiac and immunochemical). A discrete-time survival model was performed to identify risk factors of receiving a positive FOBT with no high-risk adenoma or colorectal cancer in the follow-up colonoscopy. We estimated the probability of having at least 1 FP over 7 screening rounds.

RESULTS

During the period of 2000 to 2017, the cumulative FP risk was 16.3% (IC_95%: 14.6%-18.3%), adjusted by age, sex, and type of test. The median number of screens was 2. Participants who began screening at age 50 years had a 7.3% [95% confidence interval (CI), 6.35-8.51] and a 12.4% (95% CI, 11.00-13.94) probability of an FP with 4 screening rounds of guaiac-based test and immunochemical test, respectively. Age, the fecal immunochemical test, first screening, and number of personal screens were factors associated with an FP result among screenees.

CONCLUSIONS

The cumulative risk of an FP in colorectal screening using FOBT seems acceptable as the colonoscopy, with its high accuracy, lengthens the time until additional colorectal screening is required, while complication rates remain low.

IMPACT

It is useful to determine the cumulative FP risk in cancer screening for both advising individuals and for health resources planning.

Cumulative Risk Distribution for Interval Invasive Second Breast Cancers After Negative Surveillance Mammography

Purpose The aim of the current study was to characterize the risk of interval invasive second breast cancers within 5 years of primary breast cancer treatment. Methods We examined 65,084 surveillance mammograms from 18,366 women with a primary breast cancer diagnosis of unilateral ductal carcinoma in situ or stage I to III invasive breast carcinoma performed from 1996 to 2012 in the Breast Cancer Surveillance Consortium. Interval invasive breast cancer was defined as ipsilateral or contralateral cancer diagnosed within 1 year after a negative surveillance mammogram. Discrete-time survival models-adjusted for all covariates-were used to estimate the probability of interval invasive cancer, given the risk factors for each surveillance round, and aggregated across rounds to estimate the 5-year cumulative probability of interval invasive cancer. Results We observed 474 surveillance-detected cancers-334 invasive and 140 ductal carcinoma in situ-and 186 interval invasive cancers which yielded a cancer detection rate of 7.3 per 1,000 examinations (95% CI, 6.6 to 8.0) and an interval invasive cancer rate of 2.9 per 1,000 examinations (95% CI, 2.5 to 3.3). Median cumulative 5-year interval cancer risk was 1.4% (interquartile range, 0.8% to 2.3%; 10th to 90th percentile range, 0.5% to 3.7%), and 15% of women had ≥ 3% 5-year interval invasive cancer risk. Cumulative 5-year interval cancer risk was highest for women with estrogen receptor- and progesterone receptor-negative primary breast cancer (2.6%; 95% CI, 1.7% to 3.5%), interval cancer presentation at primary diagnosis (2.2%; 95% CI, 1.5% to 2.9%), and breast conservation without radiation (1.8%; 95% CI, 1.1% to 2.4%). Conclusion Risk of interval invasive second breast cancer varies across women and is influenced by characteristics that can be measured at initial diagnosis, treatment, and imaging. Risk prediction models that evaluate the risk of cancers not detected by surveillance mammography should be developed to inform discussions of tailored surveillance.

Cumulative risk of breast cancer screening outcomes according to the presence of previous benign breast disease and family history of breast cancer: supporting personalised screening

BACKGROUND

Our aim was to assess the cumulative risk of false-positive screening results, screen-detected cancer, and interval breast cancer in mammography screening among women with and without a previous benign breast disease and a family history of breast cancer.

METHODS

The cohort included 42 928 women first screened at the age of 50-51 years at three areas of the Spanish Screening Programme (Girona, and two areas in Barcelona) between 1996 and 2011, and followed up until December 2012. We used discrete-time survival models to estimate the cumulative risk of each screening outcome over 10 biennial screening exams.

RESULTS

The cumulative risk of false-positive results, screen-detected breast cancer, and interval cancer was 36.6, 5.3, and 1.4 for women with a previous benign breast disease, 24.1, 6.8, and 1.6% for women with a family history of breast cancer, 37.9, 9.0, and 3.2%; for women with both a previous benign breast disease and a family history, and 23.1, 3.2, and 0.9% for women without either of these antecedents, respectively.

CONCLUSIONS

Women with a benign breast disease or a family history of breast cancer had an increased cumulative risk of favourable and unfavourable screening outcomes than women without these characteristics. A family history of breast cancer did not increase the cumulative risk of false-positive results. Identifying different risk profiles among screening participants provides useful information to stratify women according to their individualised risk when personalised screening strategies are discussed.