The relative contributions of screen-detected in situ and invasive breast carcinomas in reducing mortality from the disease
| Autor: | Bedrich Vitak, Hsiu-Hsi Tony Chen, Ming Fang Yen, László Tabár, Robert A. Smith, Nicholas E. Day, Stephen W. Duffy |
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| Rok vydání: | 2003 |
| Předmět: |
Adult
Oncology Cancer Research medicine.medical_specialty Mammary gland Population Breast Neoplasms Breast cancer screening Breast cancer Risk Factors Internal medicine medicine Humans Mass Screening Mammography Neoplasm Invasiveness skin and connective tissue diseases education Aged Sweden Gynecology education.field_of_study medicine.diagnostic_test business.industry Incidence Mortality rate Carcinoma Ductal Breast Middle Aged Ductal carcinoma medicine.disease Survival Rate medicine.anatomical_structure Population study Female business Carcinoma in Situ |
| Zdroj: | European Journal of Cancer. 39:1755-1760 |
| ISSN: | 0959-8049 |
| Popis: | We aimed to quantify the benefits of detecting ductal carcinoma in situ (DCIS) and of downwards stage-shifting within invasive tumours in mammographic screening. Using data from the Swedish Two-County Trial of breast cancer screening, we examined the 20-year death rates from invasive tumours of stage II or worse, invasive tumours of stage I and DCIS. We then used these rates and their respective incidences in invited (active study population, ASP) and control (passive study population, PSP) arms of the trial, to estimate the numbers of deaths avoided by downward stage-shifting the larger stage II or worse tumours to stage I and the stage I cancers to DCIS. We also studied the association between the mortality reduction achieved and the proportion of DCIS cases detected in the randomised trials of breast cancer screening. In the Swedish Two County Trial, 141 breast cancer deaths were avoided in the ASP compared with the PSP at approximately 20 years of follow-up. Of these, 65% (91/141) were avoided as a result of stage-shifting from invasive stage II or worse to invasive stage I, and 5% (7/141) as a result of stage-shifting from invasive stage I to DCIS. If we assumed that 10% of stage II or worse tumours avoided were shifted not to stage I, but to DCIS, the estimated number of deaths prevented by shifting from invasive disease to in situ was 17, which is 12% of all deaths prevented. When the results of all the randomised trials of breast cancer screening were reviewed, there was no clear association between the percentage of DCIS cases diagnosed and the observed mortality reduction. We conclude that compared with downward stage-shifting of invasive tumours, detection of DCIS plays a small part in saving lives from breast cancer. Treatment decisions in DCIS, as in invasive carcinoma, should take full account of histopathological, clinical and radiological attributes of the tumour. |
| Databáze: | OpenAIRE |
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