Early breast cancer diagnoses up

Scans have helped pick up more cases

There has been a rise in the number of diagnosed UK cases of an early form of breast cancer, figures show.

Nearly 3,800 women were diagnosed with ductal carcinoma in situ in 2002, compared to 2,910 five years earlier.

Experts believe the national breast cancer screening programme has helped to spot more cases.

The charity Cancer Research UK is launching a study to assess which of two hormone therapy drugs is best at preventing the disease returning.

The international trial will analysis the relative benefits of anastrozole and tamoxifen.

DUCTAL CARCINOMA IN SITU

Removed through surgery, often by taking a lump out of the breast

Some patients are given radiotherapy following surgery to kill off any remaining abnormal cells

DCIS occurs when the cells inside the ducts of the breast have started to turn into cancer cells.

Some doctors describe DCIS as a very early form of breast cancer, others call it a 'pre-cancerous condition'.

It often develops into an invasive cancer if not treated.

Women who have had DCIS are at higher risk of getting cancer in the same breast, the opposite breast, as well as being more likely to develop more advanced forms of breast cancer.

Screening success

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.

However, they are still unclear on which therapy is best.

Professor Tony Howell, who will lead the study into the drugs, said: "Although screening must continue, it is of vital importance that we find the best treatment to prevent breast cancer from coming back in this rising number of women."

THE DRUGS

Both drugs act to cut levels of the hormone oestrogen, which is linked to breast cancer

Anastrozole blocks an enzyme called aromatase, which is the main source of production of oestrogen

Tamoxifen is also a hormone treatment but works by preventing breast cancer cells from picking up oestrogen

Professor Jack Cuzick, of Cancer Research UK, said: "The uncertainty around which is the most appropriate treatment for DCIS could mean that there are women who are potentially missing out on drugs to prevent this cancer from returning.

"We know from previous research that tamoxifen reduces the risk of invasive breast cancer by over 50% in women with DCIS.

"We also believe that anastrozole could be the ideal candidate for these women because it has already been proven to be better than tamoxifen at reducing disease recurrence in women diagnosed with invasive breast cancer."

In a large international trial of over 9,000 women with invasive early breast cancer, anastrozole was shown to be better than tamoxifen at reducing recurrence of the disease.

The results from this trial also suggested that up to 80% of new tumours could be prevented by anastrozole.

Researchers want to recruit 4,000 post-menopausal women from around the world, who have had a DCIS in the last six months.

To be eligible to enter the study, women must be aged between 40 and 70 and 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.

Twenty countries taking part in the DCIS trial and 42 centres in the UK are now open for recruitment.

Information can be found on the trial website (see related internet links).