A phase I trial of concomitant chemoradiotherapy with cisplatin dose intensification and granulocyte-colony stimulating factor support for advanced malignancies of the chest.

UNLABELLED: Concomitant chemoradiotherapy with cisplatin and combination chemotherapy in the neoadjuvant setting have both shown promising results.
PURPOSE: To identify a locally and systemically active concomitant chemoradiotherapy regimen incorporating high-dose cisplatin, interferon alfa-2a (IFN), fluorouracil (5-FU), hydroxyurea (HU) and radiotherapy.
METHODS: Phase I cohort design establishing the maximal tolerated dose (MTD) of cisplatin with and without granulocyte colony stimulating factor (GCSF). For the first six dose levels, a 4-week cycle consisted of escalating doses of cisplatin during weeks 1 and 2, IFN (week 1), and 5-FU and HU (week 2) with single daily radiation fractions of 200 cGy during days 1-5 of weeks 1-3 and no treatment in week 4. When dose-limiting neutropenia was encountered. GCSF was added during weeks 1, 3, and 4. Finally, to decrease esophagitis, the radiotherapy schedule was altered to 150 cGy twice daily during weeks 1 and 2, followed by a 2-week break (level 7).
RESULTS: Forty-nine patients with refractory chest malignancies were treated. The MTD of this regimen without GCSF was cisplatin 50 mg/m2 in weeks 1 and 2, IFN 5 million Units (MU)/m2 per day on days 1-5 in week 1, 5-FU 800 mg/m2 per day for 5 days by continuous infusion, and HU 500 mg every 12 h for 11 doses during week 2. The addition of GCSF during weeks 1, 3, and 4 allowed for escalation of cisplatin to 100 mg/m2 during weeks 1 and 2, with a decreased dose of IFN at 2.5 MU/m2 per day to avoid renal toxicity. Dose-limiting toxicity (DLT) included severe neutropenia, thrombocytopenia, and esophagitis in 5 of 13 patients. Increased thrombocytopenia in patients receiving GCSF was not observed. During hyperfractionated radiotherapy (level 7) chemotherapy doses were as above except for a reduction of 5-FU to 600 mg/m2 per day. While severe esophagitis was reduced, grade 4 thrombocytopenia became more prevalent and was seen in 6 of 7 patients. In-field tumor responses were observed in 17 of 28 evaluated patients with non-small-cell lung cancer. The median times to progression and survival were 4 and 6 months, respectively. When only patients with all known disease confined to the radiotherapy field were considered the corresponding times were 6 and 15 months, respectively. Most treatment failures occurred outside of the irradiated field.
CONCLUSIONS: (1) This intensive multimodality regimen can be given with aggressive supportive care incorporating GCSF. The recommended phase II doses for a 4-week cycle are cisplatin 50 mg/m2 week 1, and 100 mg/m2 week 2, IFN 2.5 MU, HU 500 mg every 12 h x 11 and 5-FU 800 mg/m2 per day with single fraction radiotherapy during weeks 1-3 and GCSF during weeks 1, 3, and 4. (2) GCSF can be safely administered and provides effective support of neutrophils when administered simultaneously with IFN, cisplatin, and chest radiotherapy. (3) There is synergistic renal toxicity when high doses of IFN and cisplatin are given together. (4) Hyperfractionated radiotherapy decreases the severity of esophagitis but increases thrombocytopenia. (5) Although highly toxic, response rates, time to progression and survival figures with this regimen are encouraging and support its investigation in the phase II setting.