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Cochrane Database of Systematic Reviews: Plain Language Summaries [Internet]. Chichester, UK: John Wiley & Sons, Ltd; 2003-.

Cochrane Database of Systematic Reviews: Plain Language Summaries [Internet].

Fraction size in radiation treatment for breast conservation in early breast cancer

This version published: 2011; Review content assessed as up-to-date: June 22, 2009.

Link to full article: [Cochrane Library]

Plain language summary

Breast cancer is an important disease for women, with one in eight women in the United States and Australia and one in nine women in the United Kingdom being diagnosed with the condition by age 85 years. Breast conserving therapy (removing the tumour but keeping an intact breast) has proven to be as effective as mastectomy (removing the breast tissue) in terms of survival for women with cancer confined to the breast (or the local lymph nodes, or both), as long as a five to six‐week course of radiation therapy is delivered. This involves 25 to 30 visits to a radiation oncology department. Without radiation therapy after breast conserving surgery there is a significant risk of breast cancer returning in the breast (local recurrence) in as many as 30 to 40 women per 100. Furthermore, for every local recurrence avoided with radiation, one death is avoided at 15 years. Many women prefer breast conservation which has resulted in an increased demand for radiation services. Giving fewer radiation treatments (fractions) would be beneficial to women if this has the same effect on tumour control and survival and cosmetic outcome. In order to reduce the number of treatments, the radiation dose delivered per fraction is increased. This may also reduce demand on radiation resources and be more convenient for women.

Four trials, involving 7095 women, were included in this review. Local recurrence was not significantly different for women having fewer treatments. Breast appearance was not significantly different for women undergoing fewer treatments. Survival was not altered by having fewer treatments and there was no significant difference in late skin toxicity or radiation toxicity. Acute skin toxicity is decreased with fewer treatments. Most of the women in the trials (89.8%) had tumours less than 3 cm in size, all had complete removal of the tumour on pathology and 79% had no evidence of cancer in their lymph nodes. Where the breast size was known, 87% had small or medium breasts. This review indicates that for women who fit these criteria, using fewer radiation treatments after tumour removal is a safe and effective option. Long‐term follow up (> 5 years) is available for a small proportion of the total number of patients randomised. Ongoing follow up is required for a more complete assessment of the impact of larger than standard fraction size on local recurrence rates, toxicity and breast appearance.

Abstract

Background: Shortening the duration of radiation therapy would benefit women with early breast cancer treated with breast conserving surgery. It may also improve access to radiation therapy by improving efficiency in radiation oncology departments globally. This can only happen if the shorter treatment is as effective and safe as conventional radiation therapy. This is an updated version of the original Cochrane Review published in Issue 3, 2008.

Objectives: To determine the effect of altered radiation fraction size on outcomes for women with early breast cancer who have undergone breast conserving surgery.

Search methods: We searched the Cochrane Breast Cancer Group Specialised Register, MEDLINE, EMBASE and the WHO ICTRP search portal to June 2009, reference lists of articles and relevant conference proceedings. We applied no language constraints.

Selection criteria: Randomised controlled trials of unconventional versus conventional fractionation in women with early breast cancer who had undergone breast conserving surgery.

Data collection and analysis: The authors performed data extraction independently, with disagreements resolved by discussion. We sought missing data from trial authors.

Main results: Four trials reported on 7095 women. The women were highly selected: tumours were node negative and 89.8% were smaller than 3 cm. Where the breast size was known, 87% had small or medium breasts. The studies were of low to medium quality. Unconventional fractionation (delivering radiation therapy in larger amounts each day but over fewer days than with conventional fractionation) did not affect: (1) local recurrence risk ratio (RR) 0.97 (95% CI 0.76 to 1.22, P = 0.78), (2) breast appearance RR 1.17 (95% CI 0.98 to 1.39, P = 0.09), (3) survival at five years RR 0.89 (95% CI 0.77 to 1.04, P = 0.16). Acute skin toxicity was decreased with unconventional fractionation: RR 0.21 (95% CI 0.07 to 0.64, P = 0.007).

Authors' conclusions: Two new studies have been published since the last version of the review, altering our conclusions. We have evidence from four low to medium quality randomised trials that using unconventional fractionation regimens (greater than 2 Gy per fraction) does not affect local recurrence, is associated with decreased acute toxicity and does not seem to affect breast appearance or late toxicity for selected women treated with breast conserving therapy. These are mostly women with node negative tumours smaller than 3 cm and negative pathological margins. Long‐term follow up (> 5 years) is available for a small proportion of the patients randomised. Longer follow up is required for a more complete assessment of the effect of altered fractionation.

Editorial Group: Cochrane Breast Cancer Group.

Publication status: New search for studies and content updated (conclusions changed).

Citation: James ML, Lehman M, Hider PN, Jeffery M, Hickey BE, Francis DP. Fraction size in radiation treatment for breast conservation in early breast cancer. Cochrane Database of Systematic Reviews 2010, Issue 11. Art. No.: CD003860. DOI: 10.1002/14651858.CD003860.pub3. Link to Cochrane Library. [PubMed: 21069678]

Copyright © 2010 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.

PMID: 21069678

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