More needs to be done to inform women about this risk, say researchers.

One in five women with breast cancer who opt for breast conserving surgery rather than a mastectomy have a reoperation, according to a national study published on bmj.com today.

This increases to one in three for those women who have carcinoma in-situ (pre-cancerous tissue that may or may not develop into invasive breast cancer) which is not removed during breast conserving surgery.

Researchers led by the London School of Hygiene and Tropical Medicine say this information on the risk of reoperation should help women in making the decision about whether to undergo breast conserving surgery or mastectomy.

Lead author, Dr David Cromwell, Senior Lecturer in Health Services Research at the London School of Hygiene & Tropical Medicine, said: "Breast conserving surgery with radiotherapy is as effective as mastectomy but if women choose conserving surgery, there is a risk of having another operation. Before this study, it was unclear what that risk was but now women can be better informed."

45,000 women are diagnosed with breast cancer each year in England and in 2008, 58% chose to have part of the breast removed (breast conserving surgery) rather than the whole breast (mastectomy).

When combined with radiotherapy, breast conserving surgery produces similar survival rates to those achieved with mastectomy alone. But because some tumours are difficult to detect, breast conserving surgery may result in their inadequate removal and lead to another operation. This reoperation may involve another breast conserving operation or a mastectomy.

This is the first national study to look at breast conserving surgery reoperation rates. Researchers looked at data collected from the Hospital Episode Statistics (HES) database on 55,297 women with breast cancer who underwent breast conserving surgery in the NHS between 2005 and 2008. All women were aged 16 or over.

Rates of reoperation were looked at after three months following the first breast conserving surgery. Rates were adjusted for tumour type, age, co-morbidity and socio-economic deprivation.

Out of the 55,297 women who underwent breast conserving surgery, 45,793 (82%) were suffering from isolated invasive cancer, 6622 (12%) had isolated carcinoma in-situ (pre-cancerous disease), and 2882 (6%) had both invasive and in-situ disease. Reoperation was more likely among women with carcinoma in-situ disease (29.5%) compared to those with isolated invasive disease (18%). Around 40% of women who had a reoperation underwent a mastectomy.

Further results suggest that reoperation is less likely in older women and in those with more co-morbid conditions. Reoperation was also marginally lower in women from more deprived areas.

Reoperation rates also varied substantially between NHS trusts, but the authors stress that further research is required to understand its cause. It may partly reflect patient preferences for alternative treatment options. However, they say it does highlight the importance of women being made aware of local reoperation rates following primary breast conserving surgery.

Notes to Editors:

  1. For more information and to request interviews, please contact the London School of Hygiene & Tropical Medicine press office on 020 7927 2802 or email katie.steels@lshtm.ac.uk.
  2. Reoperation rates after breast conserving surgery for breast cancer among women in England: retrospective study of hospital episode statistics. D A Cromwell, R Jeevan, M Trivella, G Lawrence, O Kearins, J Pereira, C Sheppard, C M Caddy, J H P van der Meulen. BMJ. doi: 10.1136/bmj.e4505
  3. Some women present to doctors with an (invasive) breast cancer or tumour. Other women present with areas of in-situ (pre-cancerous) breast disease that may or may not develop into invasive breast cancer. Both invasive and in-situ disease are usually removed with surgery. Some women with invasive breast cancer also have distinct areas of in-situ disease in the same breast. These distinct areas may or may not have been identified by diagnostic imaging before surgery. If women with invasive cancer do not have these areas of in-situ disease in the same breast, they are described as having isolated invasive disease. Isolated invasive disease is easier to pinpoint and remove through surgery. Some women thought to have isolated invasive cancer will be found to have previously unidentified in situ disease as well when the breast tissue removed by their surgery is analysed.
  4. Image: Mammogram. Credit: iStock.com/photovideostock

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