Faculty Bibliography

From the outset of their clinical testing the camptothecins have shown antitumor activity against gastrointestinal cancer. With the definition of mechanism of action and introduction of several analogs their antitumor activity spectrum has expanded to include ovarian, cervical, small-cell and non-small cell lung cancers and malignant lymphomas, among others. The wide range of trials in these disease areas have been reviewed for CPT-11, topotecan, and 9-aminocamptothecin. A therapeutic role is anticipated for these and other camptothecins in these disease sites. Issues in guiding treatment indications and clinical development include: 1) pharmacokinetics and scheduling relevant to each of the drugs, with the oral route emerging as a practical way for testing prolonged exposure; 2) dose-intensification with cytokines, and its relevance in maintaining effective doses particularly in combination with other myelosuppressive drugs; and 3) pharmacodynamic determinants of response-an area of research that is particularly attractive because topoisomerase I is the target for camptothecins.

During the past two decades, the initial treatment of an advanced ovarian malignancy has been generally uniform: it begins with an exploratory laparotomy surgically to remove as much tumor as possible (1) and to stage the cancer (2). For the 70% of patients classified as stages III and IV, surgery is then followed by combination chemotherapy. Although opinions differ as to the optimal regimen, the standard involves a platinum-based program (3), recently also including paclitaxel (4). A second-look laparotomy is often performed in all patients who achieve a clinical complete remission, that is the inability to detect disease by physical examination and non-invasive laboratory tests. This surgical procedure is able to detect clinical disease not apparent on computerized axial tomography (CT scan), ultrasound, magnetic resonance imaging (MRI), serum CA-125 levels or physical examination (5-7). Major questions, however, have arisen around the need for such a procedure, and whether one can justify it in terms of an improved outcome or merely as an assessment of prognosis (8-14). We shall review: (i) the technique; (ii) the rationale; (iii) the results that have been reported from its routine application; and (iv) controversial issues, particularly as they relate to the evolution of therapeutic strategies.

OBJECTIVE: Our objective was to describe a new method for the evaluation of peritoneal surfaces in patients with intraperitoneal carcinomatosis and sarcomatosis. CONCLUSION: Fast spin-echo T2-weighted imaging in conjuction with intraperitoneally instilled saline permits detailed evaluation of peritoneal surfaces, omentum, and mesenteries. The detection of tumor implants is facilitated by their visualization against the saline background. Additionally, normal and abnormal saline distribution patterns can be identified. This technique may also be useful in predicting response to intraperitoneally instilled chemotherapy.

UFT is an oral preparation combining the 5-fluorouracil (FU) prodrug tegafur (FT) and uracil (U) in a 1:4 ratio, which is commercially available in Japan for the treatment of breast and gastrointestinal cancers. We sought to determine the tolerance of daily oral UFT and to relate this tolerance to the pharmacokinetics of FT and/or the derived FU, while exploring the possibility of circadian FU kinetics contributing to the results. A 28-day schedule followed by 2 weeks rest was began at the initial level of 300 mg/m2/day administered either at 8 a.m. or at 6 p.m. At the following level, 400 mg/m2/day patients were randomly assigned to a split-dose administration or to the above single, timed dose administration. Intolerance to single dosing was clearly demonstrated, and only the split dosing was advanced to 500 mg/m2/day. When this level proved too toxic, 400 mg/m2 was studied further on a 7 a.m., 3 p.m., and 11 p.m. (every 8 h) schedule. Pharmacology was determined on selected patients. In the single dose administration, areas under the curves of FU were higher following p.m. dosing, although substantial interpatient variation was present. Toxicities (diarrhea and neutropenia) were more severe in patients receiving the drug in single daily doses. We conclude that the kinetics of FT are saturable, with disproportionate increases in area under the curve (and toxicities) as dose levels are increased. With divided dosing, tolerance improves. UFT at a dose of 400 mg/m2/day administered as three divided doses (every 8 h) is suitable for Phase II studies, although toxicity requiring cessation of drug administration prior to completion of 28-day cycles will occur in some patients.

Previously described methods for the determination of lometrexol in plasma used either fluorescence or ultraviolet detection. An alternative method for the determination of lometrexol utilizing electrochemical detection is described, having comparable sensitivity to fluorometric methods but not requiring pre-analytical oxidation. Following sample clean-up, separation is achieved on a phenyl column with a mobile-phase of 8% acetonitrile in 50 mM sodium acetate buffer, pH 4.0. The calibration curve in plasma is linear from 10 to 200 ng/ml with inter- and intra-day precision of 5.4 and 5.5%, respectively. The recovery of lometrexol from plasma is 81 +/- 1.5%, and the lower limit of detection is 5 ng/ml, using a signal-to-noise ratio of 3.

PURPOSE: To investigate the feasibility, toxicity, and pharmacokinetics of intraperitoneal (i.p.) carboplatin (CB) with concomitant abdomino-pelvic hyperthermia (HT) in advanced ovarian cancer patients. METHODS AND MATERIALS: Patients with residual disease mainly confined to the peritoneal cavity after platinum based chemotherapy received an initial course of i.p. CB for baseline pharmacokinetics followed by three cycles of i.p. CB with concomitant regional hyperthermia. The goal of HT was to achieve at least 45 min of intraperitoneal temperature > 42 degrees but < 50 degrees C while maintaining normal tissue temperatures < 43 degrees C and systemic body temperatures < 38 degrees C. No analgesic premedication was used. Thermometry was recorded by multisensor fiberoptic probes placed within the peritoneal cavity, bladder, vagina, and oral cavity. RESULTS: Thirteen patients received a total of 31 sessions. Our intraperitoneal temperature goal could not be achieved because of patient intolerance. At best, we could maintain intraperitoneal temperatures > 40 degrees C, for more than 40 min in 7 of 31 sessions. The average values of thermal variables were T90 = 40 degrees C, TAVE = 41 degrees C, TMIN = 38.2 degrees C, and TMAX = 42.9 degrees C. The mean maximum systemic temperature was 38 degrees C. Acute thermal toxicities requiring early interruption of hyperthermia were systemic temperature exceeding 38 degrees C (11 of 31), abdominal pain or generalized distress (20 of 31), and vomiting (2 of 31). Hematological toxicities were not increased by hyperthermia. Pharmacokinetics were consistent with enhanced clearance of CB by HT. Lower radio frequencies (< 75 MHz) achieved better heat deposition in the peritoneal cavity than higher frequencies (> 75 MHz). Two of the 13 patients (a Stage III and a Stage IV patient) are alive with no evidence of disease at 40 and 43 months from treatment. CONCLUSIONS: Intraperitoneal temperatures in the range of 40 degrees C maintained for approximately 40 min can be achieved within the described setting. The probability of successful induction of therapeutic intraperitoneal temperatures appears to be higher when frequencies below 75 MHz are used. Patients who are potentially platinum sensitive and have minimal residual disease could potentially benefit from the combined treatment under the conditions studied. However, this temperature-time range appears inadequate against platinum resistant disease, and/or bulky residual pelvic disease. Alternative approaches such as whole body hyperthermia and carboplatin are warranted to overcome some of the obstacles observed

A randomized phase II study of intraperitoneal (ip) mitoxantrone or floxuridine (FUDR) was performed for the treatment of minimal residual epithelial ovarian cancer found at second-look laparotomy after initial platinum-based chemotherapy. Entry was to take place within 30 days of reassessment laparotomies, with documentation of peritoneal metastases either microscopic or gross with cytoreduction to less than or equal to 1 cm in largest diameter. Patients were stratified by the site of the largest disease present (microscopic to 0.5 cm maximum diameter versus greater than 0.5 to 1 cm maximum diameter), by time of registration (< 14 days versus up to 30), and by serum CA-125 (< or = 35 versus >35 units/ml) prior to randomization to either ip mitoxantrone 10 mg/m2 every 2 weeks X 9 or ip floxuridine (FUDR) 3 g (total dose)/ day X 3 days every 3 weeks X 6 cycles. Implantable ip systems and 1.5-2 liters of normal saline were used to deliver the drugs of 83 patients registered between December 1988 and January 1994; there were 6 pathology exclusions and 9 surgical exclusions, and 1 nonevaluable patient for a total of 39 evaluable on mitoxantrone and 28 on FUDR being evaluable. FUDR is the choice for further study because of a progression-free survival exceeding 15% at 1 year over mitoxantrone and a median overall survival of 38 months. It should be emphasized again that the goal of a randomized phase II selection design is to select a winner for phase III testing should there be a substantial difference between the treatments with respect to the primary endpoint. Comparative conclusions between the treatment arms should not be attempted due to the inherently much smaller sample sizes. This should reemphasize the limitations in a comparison of efficacy; however, the toxicologic differences still emerge quite clearly.

AD-32 (N-trifluoroacetyladriamycin-14-valerate), an analogue of doxorubicin, was examined for intraperitoneal (ip) administration in a phase 2 trial involving 25 patients with advanced gynecologic malignancies. At an AD-32 dose of 600 mg/m2, the limiting toxicity was grade 4 neutropenia (64% of patients), while severe abdominal pain was relatively uncommon (12%). Intraperitoneal AD-32 administration was associated with a 200-fold pharmacokinetic advantage for cavity exposure, compared to the systemic compartment. At the 600 mg/m2 dose level, 4 of 9 patients (44%) with ascites experienced control of malignant fluid reaccumulation. Based on the results of this phase 1 trial, further exploration of a possible role for the ip administration of AD-32 in individuals with gynecological malignancies appears indicated, particularly in patients with either small volume residual disease after initial systemic chemotherapy or in those with intractable ascites.