Early results of a trial comparing high-dose with conventional chemotherapy for women with breast cancer show that there are no apparent differences in survival or in the rate of relapse, according to research conducted in the UK, Ireland, New Zealand, and Belgium. Speaking at the European Society for Medical Oncology Congress in Nice, France today (21 October 2002), Dr John Crown from St Vincent's University Hospital, Dublin, Ireland, said, however, that new drugs that target the molecules associated with cancer, given in conjunction with chemotherapy, offer promising prospects for clinical trials.
Breast cancer is the most common cause of death from cancer in women in most Western countries and leads to untold distress for their families. Whilst not all patients die from their disease, patients whose cancer also involves the lymph nodes have a poor prognosis. Hormone therapy and chemotherapy have helped a number of patients and reduced the risk of relapse over the last two decades.
One treatment strategy for women with breast cancer has been an intense programme of chemotherapy, in combination with the patient's own bone marrow cells. High-dose chemotherapy, however, produces severe side-effects, such as prolonged suppression of blood cells, infection and bleeding. Researchers have focused their studies on high-dose chemotherapy both in patients whose cancer has spread to other organs, as well as high-risk patients at an early stage of the disease. "There were great expectations for high-dose chemotherapy, but evidence from a number of trials show that there are no real benefits that outweigh the side-effects or improve the chances of survival," said Dr Crown.
Dr Crown and his colleague Professor Robert Leonard have conducted an investigation known as the Anglo-Celtic I Study, in which more than 600 women with severe breast cancer involving the lymph nodes participated. They were randomly assigned to one of two different treatment groups, which for some patients included a short, sharp programme of high-dose chemotherapy. The analysis presented at the ESMO Congress is based on a follow-up over an average of five years and showed no significant differences in the survival or the rate of relapse. "In truth, the results of conventional-dose chemotherapy were better than expected," he said. "However, we must keep an open mind for the rest of the data, although our results already indicate that any benefits that emerge from high-dose chemotherapy will be, at best, modest."
Far from indicating a failure of the high-dose treatment regime, Dr Crown said, "I believe that these results show us how far we can go with chemotherapy." More promising are the data from Trastuzamab, the prototype for the new molecularly targeted drugs in combination with chemotherapy produce the best results. The long road of basic biological research is likely to yield substantial benefits in the treatment of patients with breast cancer. "It would seem that the post-chemotherapy phase of the war on cancer has just begun," Dr Crown concluded.