Scientists reported a number of studies involving combinations of radiotherapy and chemotherapy (drug therapy) in the treatment of common cancers. Cisplatin, a clear fluid administered as an infusion, featured in two of the presentations.
Radiotherapy was discovered nearly a 100 years ago. Cisplatin was discovered by accident in the mid-60s by scientists studying the effect of electric current on the E.Coli bacterium; and has been used to treat cervical, testicular, ovarian, bladder and small cell lung cancer.
Radical radiation therapy has been the accepted standard of care for advanced cervical cancer. But combining radiotherapy with cisplatin seems to achieve better results. Survival rates for combined treatment were 9 to 18 per cent higher in five phase III clinical trials.
Commenting on these results, Dr. Gillian Thomas, of the Sunnybrook Regional Cancer Center, Toronto, Canada, told the Lisbon meeting "Seldom do we seem to have so many results from several clinical trials pointing in the same direction."
The trials compared various doses and schedules of cisplatin and radiotherapy to radiotherapy alone, extended radiotherapy, or radiation and hydroxyurea, another anti-cancer drug.
But Dr. Thomas pointed out that the evidence in favour of concurrent chemotherapy and radiotherapy was not entirely clear-cut. Two large Canadian studies showed no detectable benefit: the results suggested that the optimal regimens of concurrent "chemo-radiation" were ill defined. Dr. Thomas also asked if cisplatin was the key, or if other combinations of chemotherapy and radiotherapy would achieve similar results.
A Dutch team reported success in using combination of intra-arterial cisplatin and radiotherapy in treating advanced, inoperable head and neck cancer. Dr. Coen Rasch, of the Netherlands Cancer Institute, reported that about 90 per cent of the 85 patients went into complete remission. A phase III trial comparing systemic and intra-arterial chemoradiation is ongoing, currently with 80 patients.
Combination success stories were not restricted to cisplatin. A US team demonstrated a 52 per cent improvement in relapse free survival among patients with gastric cancer who received post-operative combined radiotherapy and chemotherapy with Leucovorin. Dr. John Macdonald, of the Saint Vincent's Comprehensive Cancer Care Center, New York, reported a 32 per cent improvement in survival among patients in the combination arm of the study (median survival of 35 months compared with 26 months).
Abstracts No: Dr. Rasch, 33; Dr. Macdonald, 34; Dr. Thomas, 36.
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