SAN FRANCISCOIn stage III non-small-cell lung cancer (NSCLC), an
intensive regimen of three-times-daily (TID) radiotherapy and escalating doses
of daily cisplatin (Platinol) was found to be feasible and well accepted by
patients, according to investigators from the Mayo Clinic, Scottsdale, Arizona.
The findings were presented at the 37th Annual Meeting of the American Society
of Clinical Oncology (ASCO abstract 1320).
The novel regimen includes TID radiotherapy to a dose of 57.6 Gy in 1.5 Gy
fractions in the morning and evening with a midday dose of 1.8 Gy, given over
12 weekdays. Four hours separated the fractions. Cisplatin was administered
daily at three escalating dose levels: 0 mg/m² (5 patients); 5 mg/m² (5
patients); and 7.5 mg/m² (10 patients).
Randomized trials have shown that concurrent cisplatin and radiotherapy
improve survival compared with radiotherapy alone, and that TID radiotherapy
achieves better survival than daily radiotherapy. There has been relatively
little information, however, regarding concurrent chemotherapy and TID
radiotherapy. This pilot study incorporated both approaches, said lead
investigator Stephen Schild, MD.
"We found that you can give three-times-a-day radiation, which has not
been done before, as far as we know," Dr. Schild said. "Patients get
this for 2½ weeks, and the advantage is that treatment is over quickly, as
compared to the traditional regimen of 6 to 8 weeks. It’s a very intense 2½
weeks, but patients are able to get back to their normal lives sooner."
Overall grade 3-4 toxicities were almost identical in the three groups.
"You would think this regimen would be much more toxic, but it really is
not in terms of the overall rate of serious toxicities," he noted. No
patients died of a treatment-related toxicity, and only one patient had a grade
4 toxicity (esophagitis).
The 7.5 mg/m² dose was considered the maximum tolerated dose of daily
cisplatin that can be given with this intense regimen of TID radiotherapy.
Responses were determined with serial CT scans. Three of 20 patients (15%)
had a complete response, 11 (55%) had a partial response, and 6 (30%) had less
than a partial response. In up to 2 years of follow-up, median survival is 19
months, compared with the 15 to 17 months median survival seen in most phase
III studies of standard regimens, Dr. Schild said.