Influence of abnormal screens on delays and prognostic indicators of screen-detected breast carcinoma.

BACKGROUND: Delay to diagnosis following an abnormal screening result is associated with morbidity such as anxiety, but its effect on prognosis is unknown.
METHODS: Using data from the Somme area breast cancer screening programme (France), we identified 29,511 women aged 50-69 years who underwent screening between 1996 and 2000. We prospectively followed women with an abnormal screening result until completion of the assessment process and evaluated the effect of delay to notification, diagnosis and treatment on prognostic indicators.
RESULTS: Women with high-suspicion screens (n=976) compared with those with intermediate-suspicion screens (n=1008) were investigated more promptly, presented larger tumours (62% vs 42%, p=0.03), and were more likely to be lymph node positive (36% vs 17%, p=0.02). Compared with a delay to diagnosis </=1 month, the odds ratio for tumour size greater than 10 mm was 1.4 (95% confidence interval[CI], 0.90-1.90) for a delay of 1 to </=6 months, and 1.8 (95% CI, 1.02-2.85) for a delay >6 months. Similarly, a 1.4-fold and 2-fold increased risk of lymph node involvement was observed for delays of >3 to </=6 months and >6 months, respectively, compared with the reference interval.
CONCLUSION: The authors' findings suggest that women with high-suspicion mammograms were investigated more promptly, and that delays to diagnosis of asymptomatic breast carcinoma >6 months were associated with progression of the cancer measured by tumour size >10 mm and lymph node metastasis.