The number of women who have volunteered to take part in a Cancer Research UK breast cancer prevention study called IBIS-II has reached 2,000 but more volunteers are needed. Speaking at the National Cancer Research Institute Conference in Birmingham today, the study’s co-chairman announced that another 8,000 eligible women are needed to join the study by 2008.

Professor Jack Cuzick, the IBIS-II co-chairman who is based at Cancer Research UK’s Centre for Epidemiology, Mathematics and Statistics, said: “It is encouraging news that so many women have come forward so far to take part, as this study could provide them and future generations with a valuable option in helping to prevent and control the disease. But in order for us to gather conclusive evidence about the role of anastrozole in the prevention of breast cancer in increased risk women, we need more eligible women to come forward.”

The study* which is split into two arms has been ongoing in the UK since 2004. The IBIS-II prevention arm is the first worldwide trial to investigate whether the breast cancer treatment drug anastrozole** can prevent the disease in postmenopausal women at increased risk of breast cancer. Previous research on anastrozole as a treatment for early breast cancer

suggested that it could prevent up to 70-80 per cent of new tumours*** but to confirm its role in preventing the disease in women at increased risk, a large study on thousands of women must be conducted.

The IBIS-II prevention arm is open to women aged 40-70 years old, who have passed the menopause and are at increased risk of breast cancer, primarily because they have a family history of breast cancer. This includes women whose mother or sister had breast cancer or ovarian cancer at the age of 50 or under. Other risk factors including atypical benign breast disease may also make women eligible.

The second arm of the study, IBIS-II DCIS is the largest international trial to compare tamoxifen and anastrozole in the prevention of breast cancer recurrence in women with an early form of breast cancer called Ductal Carcinoma In-Situ (DCIS)****. Many breast cancer experts believe that hormone therapies, like tamoxifen or anastrozole, may be effective in protecting women with DCIS from developing breast cancer in the future, although they are still unclear on which therapy is best.

Professor Nigel Bundred, Professor of Surgical Oncology at Wythenshawe Hospital, Manchester said: “Anastrozole may also be the ideal candidate for women who have had a DCIS removed because it has already been proven to be better than tamoxifen at reducing disease recurrence in women diagnosed with invasive breast cancer. Now we need to see whether anastrozole will do better, and have fewer side effects, than tamoxifen for women with DCIS.”

He continued: “The DCIS trial will help to confirm which treatment is more effective in helping to prevent the disease from returning and helping women to live free from breast cancer. So we encourage more postmenopausal women who have had DCIS diagnosed and removed in the last 6 months to speak to their surgeons or consultants about volunteering for the study.”

The IBIS-II DCIS trial is open to postmenopausal women aged between 40 and 70 and who have had surgery to remove a hormone receptor positive DCIS in the last six months. Women who are found to be suitable to take part in the trial will receive either anastrozole or tamoxifen for five years.

Women can find out more about the IBIS-II study by visiting the IBIS-II website or calling the Cancer Research UK nurses on 0207 0618355.


For media enquiries or to interview an IBIS-II spokesperson or a woman on the study please contact Rita Martins on 0207 014 0223.


IBIS-II is being coordinated by Cancer Research UK and sponsored by Queen Mary, University of London. The trial is taking place in 21 countries, including Australia, India, Chile, Germany and Italy.

There are IBIS-II study centres currently open for recruitment in 47 UK hospitals. These are:

  • Tameside General Hospital, Ashton-Under-Lyne
  • Belfast City Hospital, Belfast
  • Royal Bolton Hospital, Bolton
  • Royal Bournemouth Hospital, Bournemouth
  • Royal Sussex County Hospital, Brighton
  • Frenchay Breast Care Centre, Bristol
  • Bristol Royal Infirmary, Bristol
  • Queens Hospital, Burton
  • University of Wales College of Medicine, Cardiff
  • Chelmsford & Essex Centre, Chelmsford
  • Cheltenham General Hospital, Cheltenham
  • Countess of Chester Hospital, Breast Unit, Chester
  • Essex County Hospital, Colchester
  • Ninewells Hospital, Dundee
  • Eastbourne District General Hospital, Eastbourne (DCIS only)
  • Western General Hospital, Edinburgh
  • Frimley Park Hospital, Frimley
  • Northwick Park & St Marks Hospitals, Harrow
  • Harlow and St. Margaret’s Hospital, Harlow
  • Conquest Hospital, Hastings
  • The Academic Surgical Unit, University of Hull, Hull
  • Western Infirmary, Glasgow (Prevention only)
  • Airedale General Hospital, Keighley
  • Leeds General Infirmary, Leeds
  • St James’s University Hospital, Leeds
  • Royal Liverpool University Hospital, Liverpool
  • Guy’s Hospital, London
  • Royal Marsden, London
  • University College Hospital, London
  • Macclesfield Hospital, Macclesfield
  • Christies and Withington Hospitals, Manchester
  • Royal Victoria Infirmary, Newcastle
  • Northampton General Hospital, Northampton (DCIS only)
  • City Hospital, Nottingham
  • Royal Oldham Hospital, Oldham
  • Derriford Hospital, Plymouth
  • Dorset Cancer Centre, Poole Hospital, Poole
  • St Mary’s Hospital, Portsmouth (DCIS only)
  • Hope Hospital, Salford
  • Cancer Research Centre, Weston Park Hospital, Sheffield
  • Royal South Hants Hospital, Southampton (DCIS only)
  • Staffordshire General Hospital, Stafford
  • Morriston Hospital, Swansea
  • Mermaid centre, Truro
  • Cookridge Hospital, Wakefield (DCIS only)
  • Worthing Hospital, Worthing (DCIS only)
  • Yeovil Hospital, Yeovil

* IBIS-2 (International Breast cancer Intervention Study II)

  • The IBIS-2 Prevention part of the study aims to recruit 6,000 post-menopausal women who are at increased risk of developing breast cancer. A number of factors for increased risk can make a woman eligible to enter the study and these are set according to the different age groups. Women can take part in the trial if they are aged between 40-70 years and are not on HRT. There are 1232 participants worldwide in this arm.
  • IBIS-2 DCIS will recruit 4,000 postmenopausal women who have been diagnosed with and had surgery to remove DCIS (Ductal carcinoma in situ). This part of the trial is designed to determine which of the two drugs, anastrozole or tamoxifen, can best prevent new cancers, both in the breast affected by DCIS and in the opposite breast. Women who have had a mastectomy to remove their DCIS cannot join this arm of the trial but they can be part of the prevention part. There are 776 participants worldwide in this arm.

**Anastrozole (trade name Arimidex) and Tamoxifen

  • Anastrozole is one of a group of drugs called aromatase inhibitors. In post-menopausal women, an enzyme called aromatase is the main source of oestrogen. Aromatase inhibitors block the action of aromatase, reducing the levels of oestrogen in the body.
  • In August 2006, the National Institute of Clinical Excellence (NICE) recommended aromatase inhibitors as options for the adjuvant treatment of early oestrogen-receptor-positive invasive breast cancer in postmenopausal women.
  • Anastrozole is known to have some side effects which include hot flushes, vaginal dryness, hair thinning, joint pains and an increased risk of osteoporosis (weakened bones).
  • Tamoxifen is also a hormone treatment but works differently from anastrozole by preventing breast cancer cells from picking up oestrogen.
  • Side effects reported on tamoxifen include hot flushes, vaginal bleeding, an increase in blood clots and rarely endometrial cancer.

*** ATAC study – Arimidex and Tamoxifen Alone or in Combination, results published ATAC Trialists’ Group. Results of the ATAC (Arimidex, Tamoxifen, Alone or in Combination) trial after completion of 5 years’ adjuvant treatment for breast cancer. Lancet 2005; 365 (9453): 60-62.

**** Ductal carcinoma in situ (DCIS)

  • DCIS is often removed by a lumpectomy or wide local excision. Some patients are also given radiotherapy following surgery to kill off any abnormal cells left behind.
  • According to new figures release in January 2006, the number of registered cases of DCIS has increased. In 2002 nearly 3800 women in the United Kingdom were diagnosed with DCIS compared with 2910 five years earlier.