Ovarian cancer risk greatly increases with specific genetic mutation

28 Sep 2007
Portuguese scientists have discovered that a mutation of the COX2 gene seems to play a role in the onset of ovarian cancer, increasing its likelihood by two to three times.

The discovery, if backed up by further study, raises the possibility that drugs such as aspirin and ibuprofen may be used to prevent ovarian cancer developing in women with the COX2 mutation.

Speaking at the European Cancer Conference in Barcelona, Dr Ana Carina Pereira, from the Portuguese Institute of Oncology, said that the COX2 gene is indirectly responsible for inflammation, pain, fever and a wide range of other processes in the body: “Although the causes of ovarian cancer are not fully understood yet, inflammation is known to play an important role in the onset of both ovarian and invasive cervical cancer,” she said. “COX2 has an important role in the inflammatory process, as well as in key steps in tumour development.”

Dr Pereira identified one specific mutation, known as ‘-765G>C’, associated with many other cancers, for investigation with relation to ovarian cancer. Blood samples were taken from 727 women; 150 of which had ovarian cancer, and 351 cervical lesions, including 291 with cervical cancer. The remaining women formed the control group.

The team found no evidence that the mutation played a role in cervical cancer, but particular versions of it doubled the risk of ovarian cancer, even tripling the risk in women aged 53 or younger.

It was discovered that the mutation could enhance the expression of the COX2 gene, and so prevent cell death and promote tumour growth, spread to other areas, and the formation of new blood cells supplying the tumour. The differing cause of the two cancers was likely the reason that the same effect was not observed in cervical cancer.

“The biological mechanism involved in the carcinogenesis of different organs is not always similar. In the case of cervical cancer we know that the trigger mechanism is an oncogenic virus, HPV (human papillomavirus) and that in ovarian cancer, although not as clearly understood, inflammation and hormonal regulation are credited with playing a role in its development” said Dr Pereira.

She also noted that though the findings were very interesting and the mutation seemed to play an important role in cancer development, the results were only preliminary, and needed more complete studies from other countries, not just Portugal.

Dr Pereira concluded: “Identifying the molecular epidemiologic profile of individuals may open new windows for the development of preventive strategies and for the individualisation of therapies for patients. It would be possible to anticipate the patient’s response to therapy, increasing treatment efficacy and decreasing the incidence of adverse reactions to drugs.”