A preliminary study by doctors has shown that roughly a quarter of women who were receiving chemotherapy for advanced breast cancer experienced an improvement in their overall wellbeing.

Chemotherapy has been used for more than 20 years to treat advanced breast cancer.

It can shrink tumours, relieve some of the symptoms such as breathlessness and bone pain, improve quality of life and increase survival in some women by months or even years.

However, a considerable number of women who undergo chemotherapy develop severe side effects such as nausea and extreme fatigue, and may not benefit much from the treatment.

Women felt better

Until now doctors have had no satisfactory way of predicting which patients are likely on balance to benefit from chemotherapy, and which will not.

The new study, organised by Professor Amanda Ramirez and Professor Robert Rubens, of the Imperial Cancer Research Fund, found that 26% of women with terminal breast cancer who underwent chemotherapy said they felt better after treatment.

They found that women who reported having high levels of psychological distress before treatment were significantly more likely to feel worse after receiving it.

Chemotherapy was also less likely to benefit women who lacked energy, and complained of a dry mouth and breathlessness before treatment.

Distress link

Professor Ramirez said: "Psychological distress may be an indicator of the fact that a patient is generally more unwell before they start chemotherapy, and, if that is the case, then it is perhaps not surprising that they do less well once they start treatment.

"Or it could be that the psychological distress is some kind of anticipatory reaction to the chemotherapy itself."

Professor Ramirez said it was hoped to improve the accuracy of the predictions about who was unlikely to benefit. In combination with factors such as the patient's age, and the number of cancer sites, the predictions could be used to decide whether treatment was worthwhile.

"It is important to pick up people who will not benefit from chemotherapy. To put them through traumatic treatment for no benefit is the worst of all worlds," she said.

However, Professor Ramirez warned that a proportion of the women who took part in the study had said they were pleased that they had undergone chemotherapy despite the fact that they felt worse after doing so.

She said the use of predictors could lead to difficult ethical decisions about when to ration treatment.