A study looking at DNA changes in women having treatment for ovarian, peritoneal or fallopian tube cancer

This study was looking at a cancer gene called PIK3CA, in women having chemotherapy for ovarian cancer, peritoneal cancer or fallopian tube cancer.

All body cells contain deoxyribonucleic acid or DNA. DNA is what our genes are made of. Genes control growth, development and how the body works. There are many differences in DNA from one person to the next. These differences may affect our risk of developing certain diseases, or how we respond to a particular drug.

Researchers wanted to learn more about how gene differences affect the way people respond to treatment for cancer. They were looking for an oncogene called PIK3CA.

Usually, the only way scientists can study this gene is by looking at samples of cancer tissue under a microscope. In this study, as well as looking at tissue, researchers wanted to see if they could find PIK3CA changes in samples of body fluid, which are easier to collect. This could be from cancer cells or DNA circulating in the bloodstream, or from fluid that had collected in the abdomen (ascites). The aims of this study were to

• See if it is possible to use circulating DNA to find changes in the PIK3CA oncogene
• See how often PIK3CA changes appear
• Try to link these changes with how well the treatment works
• See if circulating cancer cells and abdominal fluid are sources of cancer DNA