A woman's chance of surviving breast cancer may be reduced if she has cosmetic breast implants, a new study suggests.

According to Canadian scientists, previous studies have indicated that it can be slightly more difficult to detect early stage breast cancer in women with implants because the implants can create shadows on mammograms that obscure some breast tissue.

They set out to investigate whether the stage at which women are diagnosed with breast cancer differs between those with implants and those without. They also assessed survival rates.

The scientists carried out a detailed analysis of 12 studies which had been carried out mainly in northern Europe, the US and Canada. All were published after the mid-1990s.

The analysis revealed that women with implants had a 26% increased risk of being diagnosed with breast cancer when they had already reached a later stage the disease, compared to women without implants.

The scientists then carried out an analysis of five more studies and found that women with implants had a 38% higher risk of death from breast cancer compared to women without implants.

The team from Quebec warned that these results ‘should be interpreted with caution, as some studies on survival did not adjust for potential confounders'. In other words, they did not take into account other factors that may have influenced the results.

However, the scientists emphasised that current evidence suggests that cosmetic breast implants ‘adversely affect breast cancer specific survival following the diagnosis of such disease'.

"Further investigations are warranted into the long-term effects of cosmetic breast implants on the detection and prognosis of breast cancer, adjusting for potential confounders," they said.

Details of these findings are published in the British Medical Journal.