OBJECTIVES: I. Determine the maximum tolerated dose (MTD) of irinotecan administered in combination with paclitaxel in patients with metastatic or recurrent malignancies. II. Evaluate the toxicity and safety of this combination regimen in this patient population. III. Determine the pharmacokinetic profile of irinotecan in combination with paclitaxel on a weekly schedule and if the sequence of administration influences irinotecan pharmacokinetics in these patients. IV. Determine pharmacodynamic models of irinotecan and its SN-38 and SN-38G metabolites when administered in this weekly combination schedule.