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Summary  Detection of metachronous contralateral breast cancer (MCBC) is an important aspect of follow-up among the many women previously diagnosed with first primary breast cancer (FPBC). While randomized studies have demonstrated the efficacy of early detection of FPBC, such findings cannot be generalized to women previously diagnosed with breast cancer since they were specifically excluded from participation. In this study, we determined if detection of MCBC at stage 0–I improves prognosis among women diagnosed with stage 0–III FPBC. Using data from the 1990–2000 Surveillance, Epidemiology, and End Results program, we defined MCBC as contralateral breast cancer that occurred at least 6 months after stage 0–III FPBC diagnosis. Women who developed a MCBC were categorized as having stage 0–I versus stage II–IV. To avoid lead-time bias, survival of MCBC was measured from the date of FPBC. Among 170,453 women who had been diagnosed with stage 0–III FPBC, 2904 were subsequently diagnosed with MCBC. Of these 2904 women, 329 died from breast cancer and 194 died from other causes. Seventy percent of women were diagnosed with stage 0–I MCBC. An 81% survival benefit existed for stage 0–I MCBC relative to those with stage II–IV MCBC in multivariable analysis (adjusted hazard ratio: 0.19; 95% confidence interval: 0.15–0.25). The findings are robust for various subpopulations. Unmeasured confounding was unlikely to explain the observed results in sensitivity analysis. For women with stage 0–III FPBC, diagnosis of stage 0–I MCBC is associated with an 81% reduction in risk of breast cancer death. [ABSTRACT FROM AUTHOR]

Objective. Breast cancer mortality has been declining in European countries and the United States since the early 1990s. Based on breast cancer screening programs in western European countries, the reduction in mortality results from a predictable pattern of increasing early-stage and subsequent declining incidence of late-stage cancers. The purpose of this study was to determine whether changes in the incidence of early-stage and late-stage breast cancers has occurred in the United States to suggest that a reduction in breast cancer mortality is the result of screening.Method. The analyses are based on women 50–69 years of age using 1990–1998 Surveillance, Epidemiology, and End Results data. Five indicators that are precursors to reductions in mortality are described: in situ breast cancer, T1 tumors (<2 cm), stage II–IV tumors, lymph node-positive cancers, and locally advanced breast cancers (LABC).Results. The rate of in situ tumors increased from 37.8 to 67.0 per 100,000 population and that of T1 tumors increased from 143.5 to 163.5 per 100,000 population during 1990–1998. The rates of stage II–IV tumors, lymph node-positive cancers, and LABC remained unchanged at about 120 per 100,000, 76 per 100,000, and 17 per 100,000 population, respectively.Conclusions. Although there has been an increase in early-stage breast cancers (in situ and T1 tumors), the prerequisite decline in late-stage cancers has not yet occurred in the United States – a pattern that was observed in European studies. Possible explanations include the lack of widespread mammography use during the 1980s and, therefore, insufficient elapsed time since mammography use has become more widespread. [ABSTRACT FROM AUTHOR]

The authors examined disparities in survival among women aged 66 years or older in association with census-tract-level poverty rate, racial distribution, and individual-level factors, including patient-, treatment-, and tumor-related factors, utilization of medical care, and mammography use. They used linked data from the 1992–1999 Surveillance, Epidemiology, and End Results (SEER) programs, 1991–1999 Medicare claims, and the 1990 US Census. A geographic information system and advanced statistics identified areas of increased or reduced breast cancer survival and possible reasons for geographic variation in survival in 2 of the 5 SEER areas studied. In the Detroit, Michigan, area, one geographic cluster of shorter-than-expected breast cancer survival was identified (hazard ratio (HR) = 1.60). An additional area where survival was longer than expected approached statistical significance (HR = 0.4; P = 0.056). In the Atlanta, Georgia, area, one cluster of shorter- (HR = 1.81) and one cluster of longer-than-expected (HR = 0.72) breast cancer survival were identified. Stage at diagnosis and census-tract poverty (and patients race in Atlanta) explained the geographic variation in breast cancer survival. No geographic clusters were identified in the 3 other SEER programs. Interventions to reduce late-stage breast cancer, focusing on areas of high poverty and targeting African Americans, may reduce disparities in breast cancer survival in the Detroit and Atlanta areas. [ABSTRACT FROM AUTHOR]