Rolf Issels, a professor of medical oncology at Klinikum Grosshadern Medical Center at the University of Munich in Germany, says that a study has shown that the addition of the chemotherapy innovative technique of heat therapy more than doubles the proportion of patients whose tumors respond to chemotherapy, without increasing toxicity.
This is the first time that any study has shown that any treatment other than surgery, followed by radiation, can prolong survival of this type of patient.
"These findings provide a new standard treatment option and we believe they are likely to change the way many specialists treat these tumors," said Professor Issels, who presented the results on September 22 in Berlin at Europe's largest cancer congress, ECCO 15 - ESMO 34.
"But the implications of these findings are more far-reaching.
This is also the first clear evidence that targeted heat therapy adds to chemotherapy. We expect our findings will encourage other researchers to test the approach in other locally advanced cancers. Targeted heat therapy has already shown promise in recurrent breast and locally advanced cervical cancer in combination with radiation and studies combining it with chemotherapy in other localized tumors such as those in the pancreas and rectum are ongoing," Prof Issels said.
The phase III study involved 341 patients being treated at several centers in Europe and the US between July 1997 and November 2006 for locally advanced soft tissue sarcomas that were at high risk of recurrence and spread.
Over half of the tumors were located in the abdomen, while the rest were in the arms and legs. All patients were given chemotherapy before and after surgery and radiotherapy.
Half randomly received targeted heat treatment along with the chemotherapy.
Also known as regional hyperthermia, the technique uses focused electromagnetic energy to warm the tissue in and around the tumor to between 40 and 43 degrees Celsius (104 - 109.4 degrees Fahrenheit).
The heat not only kills cancer cells, but it also seems to make chemotherapy work better by making cancer cells more sensitive. It also improves blood flow, which allows chemotherapy to be more effective.
After an average follow-up of 34 months, only 153 patients (44.9 per cent) in total had died.
According to the researchers, those who got the heat therapy were 44 per cent less likely to die during the follow-up period than those who got chemotherapy alone.
"The patients receiving the targeted heat therapy fared better on all outcome measurements. Almost three years after starting treatment, they were 42 per cent less likely to experience a recurrence of their cancer at the same site or to die than those who were getting chemotherapy alone, surviving an estimated 120 months before local progression of their disease, compared with an estimated 75 months. Similarly, the average length of time that patients remained disease free was 32 months in the group that got both treatments, compared with 18 months in the group that got chemotherapy alone - an improvement of 30 per cent," Prof Issels said.
At two years, 76 percent of the patients in the heat therapy group were still alive without local progression of their cancer, compared with 61 percent in the chemotherapy alone group.
The proportion of patients who experienced tumor shrinkage rose from 12.7 per cent in the chemotherapy alone group to 28.8 per cent, while the proportion of patients who saw their tumor grow was 6.8 per cent in the heat therapy group, compared with 20 per cent in the chemotherapy alone group.
The most frequent side effect of the heat therapy was mild to moderate discomfort, reported in 45 per cent of patients. The most serious side effect was severe burns, seen in one patient. Blisters occurred in 17.8 per cent.
In their future studies, the researchers want to find out whether targeted heat therapy can play a role in stimulating the immune system to more effectively attack cancer, for studies of heat shock protein therapy have indicated that they may activate the immune system against the disease.