Skin Biopsies and DNA Analysis in Patients Receiving Irinotecan or Gemcitabine For Advanced Solid Tumors

OBJECTIVES: Primary * Determine the level of p-Chk1 and phospho-histone 2AX (p-H2AX), an indicator of DNA damage, and possibly downstream pathway markers in hair follicles from skin biopsies of patients treated with gemcitabine hydrochloride or irinotecan hydrochloride for advanced solid tumors. Secondary * Characterize the method for measurement (immunohistochemistry). * Measure inter- and intra-patient variability for the biomarker. * Partially characterize the dynamic time course of p-Chk1 and p-H2AX after administration of a DNA-damaging agent. OUTLINE: This is a multicenter study. Patients undergo collection of 2 skin biopsies with hair follicles at 4 and 8 hours or at 4 and 6 hours after the start of irinotecan hydrochloride or gemcitabine hydrochloride treatment on day 1 of course 1. Repeat biopsies will be taken at 4, 6, or 8 hours after the start of irinotecan hydrochloride or gemcitabine hydrochloride on day 1 of 2 successive courses. Tissue is examined by immunohistochemistry and possibly other methods for changes in p-Chk1 and pH2AX. PROJECTED ACCRUAL: A total of 60 patients will be accrued for this study.