Home » Health & Wellness  » Cancer » Cathepsin D- a precursor to Breast Cancer What can be learnt from the death of 12 women in a breast cancer research might lead to something very positive - a way to prevent deaths caused by cancer in the future.

Since the early 1990s, Dr Jack Alhadeff of Lehigh University, USA, and fellow researchers have been studying the role of an enzyme called cathepsin D in breast cancer. They found that 12 women with breast cancer had significantly higher levels of a form of the enzyme in their breast tissue than other women. All 12 women died by 1999.

The obvious conclusion was that the level of cathepsin D could help in predicting which breast cancer patients might not survive.

Cathepsin D is one of the several enzymes present in most mammalian cells within structures called lysosomes. Normally, the enzymes digest proteins within the cell. But with breast cancer, abnormally secreted cathepsin D is believed to eat away proteins it should not from tissues underlying the breast. The enzyme thus may help cancer cells travel to distant sites and continue to wreak havoc.

In a study, high levels of a form of cathepsin D in breast tissue predicted decreased overall survival in certain breast cancer patients. The patient's cancer already had spread to their lymph nodes. The study tracked the patients for upto 75 months.

The study opens up the possibility of designing a drug that would inhibit the enzyme's action because cathepsin D is a protease - an enzyme that digests proteins.A research group in the University of California, Berkeley, is working to develop cathepsin D inhibitors.