21 oktober 2011: Bron: The Lancet

Wanneer na een borstbesparende operatie bij borstkanker stadium I en II nog bestraald wordt dan blijkt de kans op een recidief (terugkeer van de kanker) beduidend kleiner (statistisch significant - 15.7% (P < .0001).dan zonder bestraling. Ook de kans de 10 jaar te overleven is iets groter dan zonder bestraling, al is die kans voor vrouwen na de overgang miniem in vergelijking met hormoontherapie na een operatie en het verschil, is niet statistisch significant. Dit blijkt uit de resultaten van de grote EBCTCG studie onder ruim 10800 vrouwen en gepubliceerd in The Lancet van deze week. De resultaten zijn gecorrigeerd naar het krijgen van andere vormen van kanker door de bestraling dat minder vaak bljkt voor te komen dan het niet terugkomen van de borstkanker. Hier het abstract van de studie en als u hier klikt kunnen de lezers van The Lancet of geregistreerden het volledige studierapport inzien of anderen tegen betaling.

Effect of radiotherapy after breast-conserving surgery on 10-year recurrence and 15-year breast cancer death: meta-analysis of individual patient data for 10 801 women in 17 randomised trials

Summary

Background

After breast-conserving surgery, radiotherapy reduces recurrence and breast cancer death, but it may do so more for some groups of women than for others. We describe the absolute magnitude of these reductions according to various prognostic and other patient characteristics, and relate the absolute reduction in 15-year risk of breast cancer death to the absolute reduction in 10-year recurrence risk.

Methods

We undertook a meta-analysis of individual patient data for 10 801 women in 17 randomised trials of radiotherapy versus no radiotherapy after breast-conserving surgery, 8337 of whom had pathologically confirmed node-negative (pN0) or node-positive (pN+) disease.

Findings

Overall, radiotherapy reduced the 10-year risk of any (ie, locoregional or distant) first recurrence from 35·0% to 19·3% (absolute reduction 15·7%, 95% CI 13·7—17·7, 2p<0·00001) and reduced the 15-year risk of breast cancer death from 25·2% to 21·4% (absolute reduction 3·8%, 1·6—6·0, 2p=0·00005). In women with pN0 disease (n=7287), radiotherapy reduced these risks from 31·0% to 15·6% (absolute recurrence reduction 15·4%, 13·2—17·6, 2p<0·00001) and from 20·5% to 17·2% (absolute mortality reduction 3·3%, 0·8—5·8, 2p=0·005), respectively. In these women with pN0 disease, the absolute recurrence reduction varied according to age, grade, oestrogen-receptor status, tamoxifen use, and extent of surgery, and these characteristics were used to predict large (≥20%), intermediate (10—19%), or lower (<10%) absolute reductions in the 10-year recurrence risk. Absolute reductions in 15-year risk of breast cancer death in these three prediction categories were 7·8% (95% CI 3·1—12·5), 1·1% (—2·0 to 4·2), and 0·1% (—7·5 to 7·7) respectively (trend in absolute mortality reduction 2p=0·03). In the few women with pN+ disease (n=1050), radiotherapy reduced the 10-year recurrence risk from 63·7% to 42·5% (absolute reduction 21·2%, 95% CI 14·5—27·9, 2p<0·00001) and the 15-year risk of breast cancer death from 51·3% to 42·8% (absolute reduction 8·5%, 1·8—15·2, 2p=0·01). Overall, about one breast cancer death was avoided by year 15 for every four recurrences avoided by year 10, and the mortality reduction did not differ significantly from this overall relationship in any of the three prediction categories for pN0 disease or for pN+ disease.

Interpretation

After breast-conserving surgery, radiotherapy to the conserved breast halves the rate at which the disease recurs and reduces the breast cancer death rate by about a sixth. These proportional benefits vary little between different groups of women. By contrast, the absolute benefits from radiotherapy vary substantially according to the characteristics of the patient and they can be predicted at the time when treatment decisions need to be made.

Funding

Cancer Research UK, British Heart Foundation, and UK Medical Research Council.

Plaats een reactie ...

Reageer op "Bestraling - radiotherapie na borstbesparende operatie bij borstkanker reduceert significant de kans op een recidief en geeft grotere kans op overall overleving, aldus grote EBCTCG studie bij 10800 borstkankerpatienten"


Gerelateerde artikelen