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Post-operative radiotherapy for ductal carcinoma in situ of the breast

  • Review
  • Intervention

Authors


Abstract

Background

The addition of radiotherapy (RT) following breast conserving surgery (BCS) was first shown to reduce the risk of ipsilateral recurrence in the treatment of invasive breast cancer. Ductal carcinoma in situ (DCIS) is a pre-invasive lesion. Recurrence of ipsilateral disease following BCS can be either DCIS or invasive breast cancer. Randomised controlled trials (RCTs) have shown that RT can reduce the risk of recurrence, but assessment of potential long-term complications from addition of RT following BSC for DCIS has not been reported for women participating in RCTs.

Objectives

To summarise the data from RCTs testing the addition of RT to BCS for treatment of DCIS to determine the balance between the benefits and harms.

Search methods

We searched the Cochrane Breast Cancer Group Specialised Register (January 2008), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 1), MEDLINE (February 2008), and EMBASE (February 2008). Reference lists of articles and handsearching of ASCO (2007), ESMO (2002 to 2007), and St Gallen (2005 to 2007) conferences were performed.

Selection criteria

RCTs of breast conserving surgery with and without radiotherapy in women at first diagnosis of pure ductal carcinoma in situ (no invasive disease present).

Data collection and analysis

Two authors independently assessed each potentially eligible trial for inclusion and its quality. Two authors also independently extracted data from published Kaplan-Meier analysis (survival curves) and reported summary statistics. Data were extracted and pooled for four trials. Data for planned subgroups were extracted and pooled for analysis.There were insufficient data to pool for long-term toxicity from radiotherapy.

Main results

Four RCTs involving 3925 women were identified and included in this review. All were high quality with minimal risk of bias. Three trials compared the addition of RT to BCS. One trial was a two by two factorial design comparing the use of RT and tamoxifen, each separately or together, in which participants were randomised in at least one arm. Analysis confirmed a statistically significant benefit from the addition of radiotherapy on all ipsilateral breast events (hazards ratio (HR) 0.49; 95% CI 0.41 to 0.58, P < 0.00001), ipsilateral invasive recurrence (HR 0.50; 95% CI 0.32 to 0.76, p=0.001) and ipsilateral DCIS recurrence (HR 0.61; 95% CI 0.39 to 0.95, P = 0.03). All the subgroups analysed benefited from addition of radiotherapy. No significant long-term toxicity from radiotherapy was found. No information about short-term toxicity from radiotherapy or quality of life data were reported.

Authors' conclusions

This review confirms the benefit of adding radiotherapy to breast conserving surgery for the treatment of all women diagnosed with DCIS. No long-term toxicity from use of radiotherapy was identified.

摘要

背景

乳腺管原位癌的術後放射治療

在乳房保留手術(BCS)後增加的放射治療(RT),可以減少侵犯性乳腺癌同側復發的風險。乳腺管原位癌(DCIS)是一個侵犯前病變。不論乳腺管原位癌(DCIS)或侵犯性乳腺癌在乳房保留手術(BCS)後都有可能同側復發。隨機對照試驗(RCT)顯示,放射治療(RT)可以減少復發的風險,但尚未見到評估乳腺管原位癌(DCIS)以乳房保留手術(BCS)後的放射治療(RT)潛在長期併發症的隨機對照試驗(RCT)報導。

目標

總結乳腺管原位癌(DCIS)在乳房保留手術(BCS)後增加的放射治療(RT)的隨機對照試驗(RCT)數據,以確定利益和危害之間的平衡。

搜尋策略

我們檢索了Cochrane乳癌團隊專業註冊資料(2008年1月),Cochrane圖書館臨床對照試驗(CENTRAL)(Cochrane圖書館 008年,第1期),MEDLINE(2008年2月)和EMBASE(2008年2月)。參考文獻目錄的文章和人力檢索的美國臨床腫瘤學會(2007年),ESMO(2002年至2007年),和聖加侖(2005年至2007年)的會議。

選擇標準

女性首次診斷純乳腺管原位癌(至今無侵犯性疾病)的乳房保留手術(BCS)後有和無放射治療的隨機對照試驗。

資料收集與分析

兩位作者獨立評估每個潛在可能合格試驗的包容性和品質。兩位作者還獨立擷取試驗條件之Kaplan  Meier分析(存活曲線),並報告摘要統計數字。摘錄和匯集了四項試驗的數據。計劃分組進行提取和匯集進行分析的數據。放射治療的長期毒性是沒有足夠的數據。

主要結論

4篇隨機對照試驗(RCT),確定包括3925名女性並納入本審查。全部都是高品質的最低偏差風險。另外3項試驗比較了乳房保留手術(BCS)後增加的放射治療(RT)。一項試驗是兩個對兩個因子設計單獨或同時利用放射治療(RT)和他莫昔芬(tamoxifen) 的比較,每個參加者被隨機至少在一個組。分析證實所有同側乳房增加的放射治療結果有顯著意義。(危險比值(HR)為 0.49,95%CI為 0.41至0.58,P < 0.00001),同側侵犯性復發率(HR為0.50 5% CI 為0.32至0.76, p = 0.001) 和同側乳腺管原位癌(DCIS)的復發率(HR為0.61 5% CI 0.39 to 0.95, P = 0.03)。所有的分組分析增加放射治療是有益的。沒有發現放射治療的重大長期毒性。沒有信息關於放射治療短期毒性或生活品質數據的報告。

作者結論

這項複審證實所有女性診斷為乳腺管原位癌以乳房保留手術(BCS)治療後增加放射治療是有益的。沒有長期使用放射線治療的毒性鑑定報告。

翻譯人

本摘要由中山醫學大學附設醫院陳幹珍翻譯。

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

乳腺管原位癌的術後放射治療用於乳腺管原位癌(DCIS)的特點是在乳房乳腺中發展的癌細胞,通常可以乳房攝影篩檢診斷。乳房切除手術提供了一個良好的預後,但許多女性和醫生喜歡乳房保留手術(BCS),切除了原位癌加上邊緣的正常乳腺組織,並沒有辦法保證原位癌侵犯性癌的進展。這種方法意味著大多數正常乳房被保存。所有乳腺管原位癌(DCIS)切除不足的主要風險,包含乳腺管原位癌的復發或者是在稍後時間發展為侵犯性乳腺癌,這都可以造成轉移性疾病(癌症擴散)。放射治療(RT)是利用電離子輻射的處理。乳房保留手術(BCS)後給予放射治療(RT)是能降低疾病復發風險的發展(無論是原位癌或浸潤性乳腺癌)。 這次審查目的是評估,加入放射線治療的益處和任何潛在的長期或短期的危害可能原因。短期傷害包括皮疹和紅腫,或肺組織炎症。潛在的長期副作用包括血管疾病(心臟和大血管疾病),肺部損害,如發展為肺癌,或放射性骨壞死(骨損傷導致死亡)。 此審查確定了四個大型隨機對照試驗(3925名婦女)中,單獨作乳房保留手術後和手術後放射治療的比較。在增加放射治療可降低原位癌或侵犯性癌復發風險的51%。 過去試驗表示,侵犯性乳腺癌保乳手術後的放射治療具有長期毒性。我們發現沒有證據證實放射治療的使用會增加毒性,雖然有些試驗沒有報告此為非乳腺癌死亡的原因(死亡的潛在可能與副作用)。放射治療組和對照組中,非乳腺癌死亡的報告是相似的。過去和最近的試驗中可能發現到考慮放射治療減少對正常組織的照射。更長追蹤的試驗,需要可以得出不斷提高的放射治療技術和未來病人有可能經歷進一步減少在附近正常組織暴露的一個明確結論。各組之間是否使用放療與否其整體存活率皆高且相似的。並沒有因使用放射治療後造成短期毒性或生活品質數據的報告。

Plain language summary

Post-operative radiotherapy for ductal carcinoma in situ

Ductal carcinoma in situ (DCIS) is characterised by the development of cancerous cells in the milk ducts of the breast and is commonly diagnosed by mammography screening. Surgical removal of the breast offers a good prognosis, however many women and clinicians prefer breast conserving surgery (BCS), the removal of the DCIS plus a rim of normal breast tissue, as there is no guarantee that DCIS will progress to invasive cancer. This approach means that most of the normal breast is saved. The main risk of inadequately removing all the DCIS is either a recurrence of DCIS or the development of invasive breast cancer at a later time with the risk that this can progress to metastatic disease (cancer that has spread). Radiotherapy (RT) is treatment using ionising radiation. Giving RT after BCS is thought to reduce the risk of developing recurrent disease (either DCIS or invasive breast cancer).

This review aimed to assess both the benefit of adding RT to treatment and any potential long or short-term harm it may cause. Short-term harm includes skin rash and redness, or inflammation of lung tissue. Potential long-term side effects from RT include vascular disease (heart and major blood vessel disease), damage to the lungs, development of lung cancer, or osteoradionecrosis (bone damage resulting in bone death).

The review identified four large randomised controlled trials (3925 women) that compared treatment with breast conserving surgery alone and breast conserving surgery with the addition of RT. The addition of RT reduced the risk of a recurrence of either DCIS or invasive cancer in the treated breast by 51%.

Older trials of breast conserving surgery followed by RT for invasive breast cancer have shown long-term toxicity from the addition of RT. We found no evidence of increased toxicity from the use of RT although some trials did not report on the causes of non-breast cancer deaths (deaths which potentially could be related to side effects). The number of non-breast cancer deaths reported were similar in both radiotherapy and control groups. Changes in delivery of RT between older and more recent trials and a subsequent decrease in exposure of normal tissue may account for this finding. Longer follow up of trial participants is required before a definite conclusion can be drawn, however radiotherapy techniques are continuing to improve and future patients are likely to experience a further decrease in exposure of nearby normal tissues. Overall survival was high and similar between each group whether radiotherapy was used or not. There were no reports of short-term toxicity from use of radiotherapy, or quality of life data.

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