Shares in Genomic Health gained by about one-third in pre-market trading following the publication of a study showing a genetic test made by the company could be used to predict which women with early stage breast cancer would benefit from chemotherapy.
The study, based on a trial of more than 10,000 patients, showed chemotherapy did not improve their survival prospects in about 70 per cent of cases and could mean hundreds of thousands of women diagnosed with the disease could be spared the gruelling post-surgery treatment.
Genomic Health makes the genetic test, called Oncotype DX.
Shares in the Californian diagnostics company were up 33.5 per cent in pre-market trading on the Nasdaq.
Among companies that are major players in the oncology drugs market, shares in Novartis were up 0.7 per cent in pre-market trade, Celgene was up 1 per cent, Johnson & Johnson was up 0.3 per cent. Bristol-Myers Squibb was down 0.9 per cent.
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