Comparison of Mortality Among Participants of Women’s Health Initiative Trials With Screening-Detected Breast Cancers vs Interval Breast Cancers

Abstract

IMPORTANCE Interval breast cancers (IBCs) are cancers that emerge after a mammogram with negative results but before the patient's next scheduled screening. Interval breast cancer has a worse prognosis than cancers detected by screening; however, it is unknown whether the length of the interscreening period is associated with prognostic features and mortality.OBJECTIVE To compare the prognostic features and mortality rate of women with IBCs diagnosed within 1 year or between 1 and 2.5 years of a mammogram with negative results with the prognostic features and mortality rate of women with breast cancers detected by screening. DESIGN, SETTING, AND PARTICIPANTSThis cohort study used mammography data, tumor characteristics, and patient demographic data from the Women's Health Initiative study, which recruited participants from 1993 to 1998 and followed up with participants for a median of 19 years. The present study sample for these analyses included women aged 50 to 79 years who participated in the Women's Health Initiative study and includes data collected through March 31, 2018. There were 5455 incidents of breast cancer; only 3019 women compliant with screening were retained in analyses. Statistical analysis was performed from October 25, 2018, to November 24, 2019. Breast cancers detected by screening and IBCs were defined based on mammogram history, date of last mammogram, type of visit, and results of examination. Interval breast cancers were subdivided into those occurring within 1 year or between 1 and 2.5 years after the last protocol-mandated mammogram with negative results. MAIN OUTCOMES AND MEASURESThe primary outcome of this study was breast cancer-specific mortality for each case of breast cancer detected by screening and IBCs detected within 1 year or between 1 and 2.5 years from a mammogram with negative results. Secondary outcomes included prognostic and tumor characteristics for each group. Comparisons between groups were made using the t test, the χ 2 test, and Fine-Gray multivariable cumulative incidence regression analyses. RESULTS Among the 3019 participants in this analysis, all were women with a mean (SD) age of 63.1 (6.8) years at enrollment and 68.5 (7.1) years at diagnosis. A total of 1050 cases of IBC were identified, with 324 (30.9%) diagnosed within 1 year from a mammogram with negative results and 726 (69.1%) diagnosed between 1 and 2.5 years after last mammogram with negative results. The remaining 1969 cases were breast cancers detected by screening. Interval breast cancers diagnosed within 1 year from a mammogram with negative results had significantly more lobular histologic characteristics (13.0% vs. 8.1%), a larger tumor size (1.97 cm vs 1.43 cm), a higher clinical stage (28.4% vs 17.3% regional and 3.7% vs 0.6% distant), and more lymph node involvement (27.1% vs 17.0%) than cancers detected by screening. Unadjusted breast cancer-specific mortality hazard ratios were significantly higher for IBCs diagnosed within 1 year from a mammogram with negative results compared with breast ...

Breast Cancer Incidence and Early Diagnosis in a Family History Risk and Prevention Clinic: 33-Year Experience in 14,311 Women

“…Most presented within 12-months with known poorer survival. [29] Interestingly stage 2 or more Breast cancer was not different between incident and prevalent cases (27.6% versus 26.7%) among screened population and this is re ected by similar survival rates. This is partly explained by the higher rates of DCIS (33% versus 20.5%).…”

Trends in delayed breast cancer diagnosis after recall at screening mammography

“…Therefore, the prognosis of both groups will most likely be comparable, whereas the diagnostic delay will have a certain negative impact on survival due to increase in tumour size and the development of nodal involvement during the diagnostic delay [13]. Several studies have shown that interval cancers have a significantly worse prognosis than screen-detected cancers [20,21]. However, our paper focuses on cancers diagnosed in recalled women and we did not evaluate interval cancers.…”

Breast cancer incidence and early diagnosis in a family history risk and prevention clinic: 33-year experience in 14,311 women

“…As expected, women with interval breast cancers had higher mortality. Most presented within 12-months with known poorer survival [ 35 ]. Interestingly stage 2 or higher breast cancer was not different between incident and prevalent cases (27.6% vs 26.7%) among the screened population and this is reflected by similar survival rates.…”