PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No more than 1 prior chemotherapy or chemoradiotherapy regimen No prior gemcitabine or irinotecan Endocrine therapy: Not specified Radiotherapy: No more than 1 prior chemoradiotherapy regimen At least 2 weeks since prior cranial radiotherapy for CNS metastases No concurrent cranial radiotherapy Surgery: Not specified