Complementary approaches to assessing risk factors for interval breast cancer.
ABSTRACT To examine risk factors for interval breast cancer among women screened in a population-based mammography program.
Risk for interval cancer was assessed in terms of both the incidence per 10,000 negative screens and the proportion of all breast cancers diagnosed among screened women. Interval (N = 557) and screen-detected cancers (N = 1,545) were identified among 208,667 women receiving mammography in Colorado (1994-2001). Logistic regression was used to assess independent effects of multiple factors.
Overall risk of interval cancer was 29.5/10,000 women screened. Incidence was higher in women >50 years (OR: 2.28, 1.86-2.80), with family history (OR: 2.23, 1.85-2.70), with dense breasts (OR: 3.84, 2.76-5.35), and using hormones (OR: 1.54, 1.20-1.97). Hispanics had lower incidence than Whites (OR: 0.52, 0.34-0.81). Interval cancers represented 26% of all cancers diagnosed. This proportion was higher in women <50 (OR: 1.41, 1.09-1.82) and in women with dense breasts (OR: 2.95, 1.94-4.48).
Incidence of interval cancer increases with age, breast density, hormone use, and family history. Attempts to reduce occurrence of these cancers through more sensitive and/or intensive screening should focus on these subgroups. The disproportionate number of interval cancers associated with young age and dense breasts suggests these cancers result from both rapid growth and difficulties in detection.
- Epidemiologia e prevenzione 37(4-5):328-35. · 1.46 Impact Factor
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ABSTRACT: The aim of this study was to compare tumor expression of prognostic biomarkers between interval breast cancers and screen-detected breast cancers overall, and according to age at diagnosis and familial risk. Tissue micro-arrays were constructed from 98 breast cancers (47 interval and 51 screen-detected) diagnosed in women in the Cancer Genetics Network. Arrays were immuno-stained to compare protein expression of six biomarkers including estrogen and progesterone receptor (ER/PR), Her2/neu, EGFR, cytokeratin 5/6, and Ki67. Fisher's Exact test was used to compare expression between interval and screen-detected cancers. Interval cancers were larger (P = 0.04), higher stage (P < 0.001), and more likely to have lobular histology (P = 0.01) than screen-detected cancers. Overall, interval cancers more often overexpressed EGFR (P = 0.01) and were somewhat more likely to be ER- (55% vs. 43%, P = 0.3), and triple negative (ER-/PR-/Her2-) (21 vs. 12%, P = 0.26). A greater difference in the proportion of interval versus screen-detected tumors that were ER- (53 vs. 35%; P = 0.29), PR- (35 vs. 21%; P = 0.25) and EGFR+ (17 vs. 0%; P = 0.02) was evident among women over 50. There was a trend toward differential expression among women with familial risk for PR- (P = 0.005) and triple negative status (P = 0.02). This study provides new data indicating that EGFR may be important in the etiology of interval cancer and be a possible therapeutic target. Our data also suggest that biological differences between interval and screen-detected cancers are more defined in older women. Future studies to confirm this finding and to elucidate novel markers for characterizing interval cancers may be more beneficial to this subgroup.Breast Cancer Research and Treatment 03/2011; 129(1):211-9. DOI:10.1007/s10549-011-1448-8 · 4.20 Impact Factor
Article: Cancer causes & controlCancer Causes and Control 06/2011; 22(8):1215. DOI:10.1007/s10552-011-9783-y · 2.96 Impact Factor