Research gives idea of cancer genome

Breast cancer kills 450,000 women a year. Hürriyet photo

Scientists have mapped the complete genetic codes of 21 breast cancers and created a catalogue of the mutations that accumulate in breast cells, raising hopes that the disease may be able to be spotted earlier and treated more effectively in future.

The research, the first of its kind, untangles the genetic history of how cancer evolves, allowing scientists to identify mutational patterns that fuel the growth of breast tumors, and start to work out the processes behind them.

“These findings have implications for our understanding of how breast cancers develop over the decades before diagnosis in adults and might help to find possible targets for improved diagnosis or therapeutic intervention in the future,” said Mike Stratton, who led the research team.

Most common cancer

Breast cancer kills more than 450,000 women a year worldwide and is the most common cancer among women, according to the World Health Organization (WHO).

“This is the first time we’ve been able to delve fully into breast cancer genomes in such a thorough way,” said Peter Campbell, head of cancer genetics and genomics at the Wellcome Trust Sanger Institute in Cambridge, where the studies were led.

The work had given scientists “a full panoramic view of the cancer genome” and helped them identify “mutational patterns rather than individual mutations in specific genes”, he added. “We’ve known for many years now that all cancers are due to abnormalities of DNA...that occur in every single cell of the body over the course of a lifetime,” said Stratton.

“But although we’ve known that, it’s remarkable how rudimentary our knowledge is about what the processes are that cause these abnormalities, these mutations in our DNA.” (LONDON - Reuters)

Aspirin may lower risk of lung cancer

Women who take aspirin at least a couple of times a week have a much lower risk of developing lung cancer, whether or not they smoke, according to a study of more than a thousand Asian women.

The findings, published in the journal Lung Cancer, linked regularly taking aspirin to a risk reduction of 50 percent or more, although researchers cautioned that they did not prove aspirin directly protects against lung cancer.

The study included 398 Chinese women diagnosed with lung cancer and 814 cancer-free women, and Lim’s team found that women who had used aspirin regularly, at least twice a week for a month or longer, were less likely to have lung cancer.

Among women who had never smoked, the odds were 50 percent lower for aspirin users versus non-users. Among smokers, aspirin use was tied to a 62 percent lower risk of lung cancer. There was a fairly large relative difference in cancer risk between aspirin users and non-users in the study, but the absolute reduction in any one person’s risk, if there is one, might be small.

There are biological reasons that aspirin might offer protection against cancer. It blocks an enzyme called cyclooxygenase-2, or COX-2, which promotes inflammation and cell division, and is found in high levels in tumors. But Andrew Chan at Harvard Medical School, who was not involved in the study, said that the evidence on aspirin and lung cancer has been “mixed.”

“The number one thing a person can do to minimize the risk of lung cancer is to not smoke,” he said.
There is stronger evidence that aspirin may be protective against colon cancer, according to Chan, a gastroenterologist. (Reuters)