Wbi.net.au

ht p://www.getinsidehealth.com/en/Library/Articles/en/2011/Mar/. .
Radiotherapy for DCIS: when and how
What have newly published papers added to our understanding of the management of ductal carcinoma in situ, including the role of radiotherapy? In recent months several important new papers have been published relating to the diagnosis and management of ductal carcinoma in situ (DCIS) – the pathology that accounts for about one in five of al screen-detected breast cancers. Here we present a round-up of some of the main findings and the implications for clinical practice and future research.
Update on current management
In the March 2011 issue of the journal Surgical Oncology, specialists provided an evidence-based overview of current thinking on the management of DCIS. In their review paper they highlighted the rising incidence of DCIS over the past few decades, attributed to the introduction of breast screening programs and the wider use of MRI, but noted that “progress remains limited in distinguishing non-progressive incidental lesions from their progressive and clinical y relevant counterparts”. Gaining a better understanding of the factors influencing the progression from DCIS to invasive breast cancer remains a major The authors of the review pointed out that adjuvant radiotherapy following breast-conserving surgery has been demonstrated in several randomized controlled trials to significantly reduce the risk of local recurrence, especial y in high-risk patients (such as those with a family history of breast cancer, for example). However, more research is stil needed on the precise role ofcontemporary radiotherapy regimes, they added.1 Radiotherapy in randomized trials reviewed
The published data on adjuvant radiotherapy in DCIS, mentioned in the review above, were also summarized neatly in a recent paper from the Early Breast Cancer Trialists’ Collaborative Group.
The authors compiled the findings of the four randomized trials started before 1995 that compared adjuvant radiotherapy with no radiotherapy following breast-conserving surgery for DCIS. Overal , radiotherapy significantly reduced the absolute 10-year risk of recurrent DCIS or invasive breast cancer by 15.2%, from 28.1% to 12.9%. This reduction was found to be greater in older women(aged 50 years or more) than in younger women.2 Long-term effects of radiotherapy: findings from the UK/ANZ DCIS trial
In the January 2011 issue of The Lancet Oncology, UK specialists presented new long-term findings from one of the randomized trials of radiotherapy: the UK, Australia, and New Zealand DCIS trial, in which a total of 1,701 women were randomly assigned to radiotherapy and tamoxifen, radiotherapy alone, tamoxifen alone, or no adjuvant treatment, following complete local excision of DCIS. The early results from the trial found that radiotherapy significantly reduced the incidence of ipsilateral DCIS and invasive breast cancer, compared with no radiotherapy. No significant effects of treatment with tamoxifen were observed. In the new paper, the researchers reported the findings based on a median follow-up period of 12.7 years, during which time a total of 376 invasive breast cancers, 197 new cases of DCIS, and 16 other breast cancers were observed ht p://www.getinsidehealth.com/en/Library/Articles/en/2011/Mar/. .
The researchers found that radiotherapy significantly reduced the long-term incidence of al new breast events (hazard ratio 0.41), ipsilateral invasive disease (hazard ratio 0.32), and ipsilateral DCIS (hazard ratio 0.38), but not contralateral breast cancer. Tamoxifen, meanwhile, was found to have significant long-term benefits, reducing the incidence of al new breast events, ipsilateral DCIS, and contralateral tumors, but not ipsilateral invasive disease. The researchers concluded that their updated analysis confirms the beneficial effects of radiotherapy in reducing the risk of ipsilateral breast events, and shows a significant benefit of tamoxifen that was not apparent in theinitial short-term analysis.3 Positive outcomes of external beam APBI
Also recently published was a paper describing the 3-year outcomes of a multicenter prospective study of external beam accelerated partial breast irradiation (APBI). A total of 104 women aged 40 years or more with DCIS or node-negative invasive breast cancer with treated with breast- conserving surgery and then underwent CT-based planning and subsequent APBI treatment (delivering 35 Gy, 36 Gy or 38.5 Gy). The researchers reported that there was “modest and acceptable 3-year toxicity” and “high rates of good to excel ent cosmesis”. In addition, the 3-year disease-free survival was 97%. These findings clearly support the case for ongoing trials comparingAPBI with standard whole breast irradiation, they concluded.4 Meta-analysis: predicting local recurrence
Final y, specialists have reported new findings on the factors that are important in determining the risk of local recurrence of DCIS after treatment. In a newly published meta-analysis of data from 44 relevant studies, researchers identified comedonecrosis, focality, margin size, method of detection, tumor grade, and tumor size as statistical y significant risk factors for ipsilateral breast tumor recurrence. They added that there is also limited evidence indicating that the risk of ipsilateral recurrence is higher in DCIS that is estrogen-receptor (ER)-negative, progesterone- receptor (PR)-negative, and HER2/neu receptor-positive, compared with DCIS that is ER-positive,PR-positive, and HER2/neu receptor-negative.5 1. Patani N, et al. Surg Oncol. 2011;20:e23-31.
2. Early Breast Cancer Trialists’ Collaborative Group (EBCTCG), et al. J Natl Cancer Inst Monogr.
3. Cuzick J, et al. Lancet Oncol. 2011;12:21-9.
4. Berrang TS, et al. Int J Radiat Oncol Biol Phys. 2010 Oct 23 [Epub ahead of print].
5. Wang SY, et al. Breast Cancer Res Treat. 2011 Feb 15 [Epub ahead of print].

Source: http://www.wbi.net.au/userfiles/file/pdf/news/Radiotherapy-for-DCIS.pdf