Phase I/II trial of docetaxel and concurrent radiation therapy in localized high risk prostate cancer (AGUSG 03-10)

Abstract 

Purpose

A Phase I/II trial was conducted to assess the radiosensitizer docetaxel administered weekly (20 mg/m²) with concurrent intensity modulated radiation therapy (72 Gy at 1.8 Gy/fraction) in high risk prostate cancer.

Patients and Methods

Patients with high risk prostate cancer (clinical stage ≥T3; Gleason score 8, 9, or 10; Gleason score 7 and PSA > 10) received IMRT (Clinac 600 CD with 6 MV photons and sliding window technique) and concurrent weekly docetaxel (20 mg/m²) as a continuous 30 minute infusion for 8 weeks. Patients desirous of concurrent androgen suppression were not excluded.

Results

Twenty men (median age: 64 years; range, 50–78 years) were enrolled in the chemoradiation protocol. Three patients experienced treatment interruptions: dehydration requiring inpatient hydration (n = 2); NSAID induced GI bleed (n = 1). An additional patient required outpatient hydration (<24 hours) with no treatment interruption. Overall, the most frequently observed toxicities were grade 2 diarrhea (40%), grade 2 fatigue (40%), grade 2 urinary frequency (35%), taste aversion (20%), grade 2 constipation (20%), and rectal bleeding (15%). No significant hematologic toxicity (grades 2–4) was encountered among the 20 patients. Although the follow-up interval was relatively short, no significant subacute gastrointestinal toxicities have been observed. At a median follow-up duration of 11.7 months, 17 patients were free of biochemical disease recurrence, and all patients are alive.

Conclusion

The radiosensitizer docetaxel administered weekly (20 mg/m²) with concurrent IMRT is well tolerated with acceptable toxicity. Early oncologic outcomes in this challenging patient cohort are encouraging.

Keywords: Prostate cancer, Docetaxel, Radiosensitization