Topoisomerase II-dependent and -independent mechanisms of etoposide resistance in Chinese hamster cell lines.

Resistance to etoposide (VP-16), amsacrine (mAMSA), and doxorubicin (Adriamycin) was studied in two Chinese hamster cell lines primarily selected for resistance to the epipodophyllotoxin. Both lines demonstrated profound resistance to VP-16, and mAMSA stimulated DNA breakage. However, the resistance to mAMSA cytotoxicity in both lines was less than expected from the level of resistance to the effects of topoisomerase II inhibition. Similarly, resistance to the cytotoxicity of high VP-16 concentrations in one of the lines was less than expected from the resistance to inhibition of topoisomerase II. An analysis of the relation of DNA breaks to drug cytotoxicity suggests that cross-resistance to mAMSA was mainly conferred through loss of mAMSA-stimulated, topoisomerase II-mediated DNA breaks. This mechanism also contributed towards reduced VP-16 cytotoxicity. However, our studies suggest that additional mechanisms, independent of resistance to VP-16-mediated topoisomerase II effects, greatly increased the resistance to this agent. Resistance to VP-16 cytotoxicity, not dependent on resistance to drug-mediated DNA cleavage, could be overcome at high drug concentrations in one of the resistant lines and might be responsible for the greater relative resistance to VP-16 than to mAMSA. These findings suggest the presence of two distinct mechanisms of resistance to VP-16 cytotoxicity, one presumably mediated by topoisomerase II and dependent on resistance to drug-mediated DNA scission, and a second mechanism independent of the effects of the drug on topoisomerase II.

Double labeling of S-phase murine cells with bromodeoxyuridine and a second DNA-specific probe.

A rapid method has been developed which combines immunofluorescence and autoradiography and permits the double labeling of DNA. P388 murine leukemic cells were incubated with bromodeoxyuridine and tritiated thymidine simultaneously. After fixation, the sample was first processed with a monoclonal antibody to bromodeoxyuridine (RPMB I) so that any cell in S-phase was brightly fluorescent (RPMB technique). Next, tritiated thymidine grains were developed by autoradiography, and the result demonstrated fluorescence as well as black grains in each S-phase cell. P388 cells sensitive (P388S) and resistant (P388R) to 1-beta-D-arabinofuranosylcytosine (ara-C) were incubated with bromodeoxyuridine and [3H]ara-C simultaneously. Processing by autoradiography and RPMB techniques revealed that all S-phase cells in the P388S sample demonstrated vivid "double labeling," whereas P388R cells only revealed bright green fluorescence in S-phase cells, but no grains, confirming a lack of ara-C incorporation into the DNA by this line. Finally, a computerized digital analysis system attached to a microphotometer was used to quantitate fluorescence and grains per cell, and the data demonstrated that the number of [3H]ara-C grains in each P388S cell was inversely proportional to the degree of fluorescence in that cell, indicating that DNA synthesis was inhibited by ara-C. In conclusion, a simple, easy-to-use double-labeling method has been introduced which will be useful to a wide variety of researchers, because this technique together with the digital analysis system offers the possibility of measuring drug sensitivities in individual cells.

Phase I study of docetaxel dose escalation in combination with fixed weekly gemcitabine in patients with advanced malignancies.

PURPOSE: To determine the maximum-tolerated dose of monthly docetaxel combined with fixed-dose weekly gemcitabine and describe the dose-limiting toxicities (DLTs) of the combination. PATIENTS AND METHODS: Patients with refractory solid tumors were treated with gemcitabine days 1, 8, and 15 every 4 weeks at a fixed dose of 800 mg/m2. Two docetaxel administration schedules were studied, with the drug administered either day 1 or day 15 at doses of 45, 60, 75, and 100 mg/m2 per cycle. RESULTS: Forty patients received 132 cycles of chemotherapy. On the day-1 schedule, the maximum-tolerated docetaxel dose was the highest planned dose of 100 mg/m2 with two DLT episodes among 12 patients treated with 34 cycles at this dose level. On the day-15 schedule, delivery of the planned docetaxel doses was not feasible because of thrombocytopenia and hepatic dysfunction. Hematologic toxicities included grade 4 neutropenia in 16 patients, with three episodes of febrile neutropenia; grades 3 to 4 thrombocytopenia in nine patients; and anemia that required RBC transfusions in 10 patients. For patients treated at the highest docetaxel dose level, myelosuppression was not dose limiting and only one of 34 cycles was complicated by febrile neutropenia. The most common nonhematologic toxicities were asthenia, flu-like symptoms, and fluid retention. Antineoplastic activity was noteworthy, with partial responses in nine of 21 patients with pretreated non-small-cell lung cancer (NSCLC; 43%; 95% confidence interval, 22 to 66), in four of seven patients with breast cancer, and in one patient with esophageal adenocarcinoma. CONCLUSION: Gemcitabine 800 mg/m2 days 1,8, and 15 can be safely combined with docetaxel 100 mg/m2 day 1 of a 28-day cycle. The observed antitumor activity warrants phase II evaluation.

Combination of fludarabine and mitoxantrone in untreated stages III and IV low-grade lymphoma: S9501.

PURPOSE: To determine the efficacy of combination fludarabine and mitoxantrone (FN) in untreated stages III and IV low-grade lymphoma. The major end point was to estimate progression-free survival (PFS) in all eligible patients. PATIENTS AND METHODS: Seventy-eight eligible patients were registered. Chemotherapy courses were administered every 4 weeks with mitoxantrone 10 mg/m2 on day 1 and fludarabine 25 mg/m2 on days 1, 2, and 3 for a total of six to eight cycles. Pneumocystis carinii prophylaxis was required. RESULTS: Seventy-three patients (94%) attained an objective response. Complete remission was demonstrated in 34 patients (44%) and partial remission was demonstrated in 39 patients (50%). With a median follow-up time of 5.5 years, the median PFS was 32 months, with a 4-year PFS rate of 38%. Median survival has not been reached and 88% of all patients are alive at 4 years. The application of the International Prognostic Index and serologic staging showed significant differences in PFS in all risk groups, whereas overall survival was markedly worse for the highest-risk group in either prognostic model. Three prior Southwest Oncology Group trials using a regimen of cyclophosphamide, doxorubicin, vincristine, and prednisone or a combination of prednisone, vincristine, methotrexate, cytarabine, cyclophosphamide, etoposide, nitrogen mustard, vincristine, procarbazine, and prednisone in similar patient populations demonstrated comparable clinical outcome, although the 4-year survival for FN was better. FN was well tolerated, but mild to severe reversible myelosuppression was noted. Other complications were rare. CONCLUSION: FN is an effective, safe chemotherapy combination for patients with advanced-stage, low-grade lymphoma. Clinical outcomes were comparable to prior published data using anthracycline-based regimens.

Dose-intense chemotherapy every 2 weeks with dose-intense cyclophosphamide, doxorubicin, vincristine, and prednisone may improve survival in intermediate- and high-grade lymphoma: a phase II study of the Southwest Oncology Group (SWOG 9349).

PURPOSE: To test the hypothesis that therapy of intermediate- and high-grade (excluding Burkitt lymphoblastic) lymphoma with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) could be safely dose-intensified with routine filgrastim support. PATIENTS AND METHODS: Eligible patients were those who were previously untreated and who had either bulky stage II, or stage III or IV lymphoma with working formulation histology D, E, F, G, H, or J; performance status < or = 2; and acceptable end organ function. No upper age limit was specified. Therapy was dose-intensified CHOP (CHOP-DI) with filgrastim support. Each course was repeated every 14 days for six planned courses. RESULTS: Eighty-eight eligible patients were treated with CHOP-DI and had a median follow-up of 5.1 years on this phase II study, designated Southwest Oncology Group (SWOG) 9349. The progression-free survival was 51% at 2 years and 41% at 5 years. The overall survival was 60% at 5 years. Three fatal treatment-related events occurred. One patient with myelodysplastic syndrome was reported. CONCLUSION: Treatment with CHOP-DI can be safely administered in the cooperative group setting and results in improved survival. Estimated overall survival at 5 years was 14% better than that of patients treated with standard-dose CHOP in an earlier SWOG study, although progression-free survival of 60% at 2 years-the prespecified end point-was not achieved. CHOP-DI, given every 2 weeks at escalated doses, is a strategy that should be tested in a future randomized clinical trial in lymphoma.

Randomized trial comparing cisplatin with cisplatin plus vinorelbine in the treatment of advanced non-small-cell lung cancer: a Southwest Oncology Group study.

PURPOSE: Cisplatin has played a major role in the treatment of non-small-cell lung cancer (NSCLC). This randomized trial was performed by the Southwest Oncology Group (SWOG) to determine whether the combination of vinorelbine and cisplatin has any advantage with regard to response rate, survival, and time to treatment failure over single-agent cisplatin in the treatment of patients with advanced NSCLC. METHODS: Between October 1993 and April 1995, 432 patients with advanced stage NSCLC were randomized to receive arm I (cisplatin 100 mg/m2 every 4 weeks) or arm II (cisplatin 100 mg/m2 every 4 weeks and vinorelbine 25 mg/m2 weekly). All patients were chemotherapy-naive, had performance status (PS) 0 or 1, and had adequate hematologic, renal, and hepatic function. RESULTS: Four hundred fifteen patients were eligible and assessable. On arm I (cisplatin), there was a 12% partial response rate. Arm II (cisplatin and vinorelbine) had a 26% response rate (2% complete responses and 24% partial responses, P = .0002). There was a statistically significant advantage with regard to progression-free survival (median, 2 v 4 months; P = .0001) and overall survival (median, 6 v 8 months; P = .0018) for the cisplatin and vinorelbine arm. One-year survival was 20% for cisplatin alone and 36% for the combination arm. There was more hematologic toxicity on arm II of the study (81% grades 3 and 4 granulocytopenia v 5% on arm I). Other toxicities, such as renal insufficiency, ototoxicity, and nausea and vomiting, and neuropathy were similar. CONCLUSION: The results of this study indicate that the combination of cisplatin and vinorelbine is a superior treatment when compared with single-agent cisplatin in the treatment of advanced NSCLC. Cisplatin and vinorelbine is the new standard for SWOG against which new therapies will be evaluated.

Randomized trial of vinorelbine compared with fluorouracil plus leucovorin in patients with stage IV non-small-cell lung cancer.

PURPOSE: This prospective randomized trial was performed to compare the effectiveness of intravenous vinorelbine tartrate with intravenous fluorouracil and leucovorin (5-FU/LV) on the primary end points of survival, quality of life (QOL), and relief of cancer-related symptoms in patients with advanced non-small-cell lung cancer (NSCLC). Secondary end points included tumor response rates and time to treatment failure. In addition, the safety of both treatment regimens was evaluated in this multicenter study. PATIENTS AND METHODS: Two hundred sixteen patients with stage IV NSCLC were enrolled onto this study from 18 centers. Vinorelbine was administered at a dose of 30 mg/m2/wk. 5-FU/LV was administered at a dose of 425 mg/m2 and 20 mg/m2, respectively, for 5 consecutive days every 4 weeks. Patients with progressive disease or toxicity were removed from study while responding and stable patients were continued on therapy. RESULTS: The median survival time of patients who received vinorelbine was 30 weeks, with 25% of patients alive at 1 year, compared with a median survival time of 22 weeks and 16% of patients alive at 1 year for those treated with 5-FU/LV (P = .03, log-rank test). This improvement in survival was associated with a higher objective response rate (12% v 3%) and time to treatment failure (10 weeks v 8 weeks) for vinorelbine versus 5-FU/LV. The dose-limiting toxicity of vinorelbine was granulocytopenia, with 54% of patients experiencing grade 3/4 granulocytopenia. Nonhematologic toxicity of vinorelbine was generally grade 1 or 2. The most common grade 3 toxicities were related to injection-site reactions. CONCLUSION: This trial confirms the efficacy of vinorelbine in patients with advanced NSCLC. The clinical activity and relatively favorable toxicity profile of this agent make it a reasonable and useful treatment option in the management of patients with this disease.

Docetaxel and gemcitabine combinations in non-small cell lung cancer.

Docetaxel and gemcitabine have been shown to be active as single agents in a variety of solid tumors. These two agents have been studied in combination with several different treatment schedules. Two phase I studies used a novel 2-week administration schedule that involved a 1-hour infusion of 35 mg/m2 to 65 mg/m2 docetaxel and gemcitabine administered as either a 30-minute infusion (2,000 to 4,000 mg/m2) or a 10 mg/m2/min infusion (1,000 to 1,200 mg/m2 total dose). Another novel phase I study evaluated the effect of drug sequence on toxicities. Patients received 30 to 40 mg/m2 docetaxel and 800 to 1,250 mg/m2 gemcitabine on days 1 and 8 every 21 days. Two phase I studies of a monthly docetaxel regimen have been conducted. Patients received 800 mg/m2 gemcitabine on days 1, 8, and 15 and 100 mg/m2 docetaxel on day 1 of a 28-day cycle. Finally, in a phase II study, patients received 900 mg/m2 gemcitabine on days 1 and 8 and 100 mg/m2 docetaxel on day 8, with granulocyte colony-stimulating factor administered on days 9 through 15. In these studies, antitumor responses were observed in lung cancer as well as a number of other histologies. Neutropenia was the most frequent dose-limiting toxicity and no difference in clinical toxicity was observed with either sequence of administration. The emerging evidence suggests, therefore, that the combination of gemcitabine and docetaxel is active in a variety of solid tumors and is well tolerated.

Photodynamic therapy for esophageal malignancy: a prospective twelve-year study.

BACKGROUND: We wanted to determine factors affecting survival rates of benefits to, and complications in patients with esophageal cancer treated with photodynamic therapy. METHODS: From 1982 to January 1994, we used photodynamic therapy to treat 77 patients with esophageal carcinoma and evaluated survival to July 1994. All patients had failed, refused, or were ineligible for surgical intervention, ionizing radiation therapy, or chemotherapy. RESULTS: The only significant variable affecting survival was clinical stage. Median survival after photodynamic therapy was as follows: all patients, 6.3 months (mean survival, 9.2 months); stage I, not reached; stage II, 12 months; stage III, 6.2 months; and stage IV, 3.5 months. For stages III and IV, a Karnofsky performance status of 70 or higher had a significant effect. For stage III, the median survival was 6.3 months when the Karnofsky performance status was equal to or greater than 70 and 3.5 months when it was less than 70. For stage IV, the median survival was 5.5 months when the Karnofsky performance status was equal to or greater than 70 and 2.5 months when it was lower than 70. Seven stage I patients with no treatment prior to photodynamic therapy had an estimated 5-year survival rate of 62%. Three patients with stage I invasive adenocarcinoma and Barrett's mucosa diagnosed when they underwent endoscopy for dysphagia were alive with no evidence of disease 17, 44, and 59 months after photodynamic therapy. CONCLUSIONS: Photodynamic therapy for esophageal carcinoma caused minimal complications and no procedure-related deaths. Photodynamic therapy can be considered an alternative treatment for patients with Barrett's esophagus with severe dysplasia or patients with stage I carcinoma who are under consideration for operation but are high surgical risks. The length of palliation for patients having "noncurative" treatment was equal to or better than that reported historically for most other treatment regimens.

Docetaxel and gemcitabine combinations in chemotherapy-pretreated non small-cell lung cancer.

Both docetaxel and gemcitabine are active against chemotherapy-pretreated non small-cell lung cancer (NSCLC). We previously demonstrated that weekly gemcitabine can be safely combined with monthly docetaxel with promising antineoplastic activity. In a recently completed phase II trial, 38 NSCLC patients failing upfront chemotherapy were treated with gemcitabine 800 mg/m2 on days 1, 8, and 15 and docetaxel 100 mg/m2 on day 1 every 4 weeks. The intent-to-treat response rate was 33% (95% CI: 19%-55%), with one complete and 11 confirmed partial responses. Responses were seen at all disease sites and in 31% of patients refractory to front-line chemotherapy. The median time to disease progression for the responders was 8 months, and two have remained progression-free for longer than a year. Hematological toxicities included grade 4 neutropenia in half of patients, febrile neutropenia in 10%, and grade 3-4 thrombocytopenia in 25%. The most prominent nonhematological toxicity was asthenia. We conclude that this doublet is active and safe, producing durable responses at all disease sites and in patients with platinum-refractory NSCLC.

Phase II evaluation of low-dose continuous 5-fluorouracil and weekly cisplatin in advanced adenocarcinoma of the stomach. A Southwest Oncology Group study.

We have conducted a Phase II trial in patients with metastatic gastric cancer utilizing low-dose continuous infusion 5-fluorouracil (5FU) and weekly cisplatin (CDDP). The 5FU was administered at a dose of 200 mg/m2 per day by 24-hour continuous infusion via a permanent central venous catheter. The CDDP was administered at a dose of 20 mg/m2/week for the first 8 weeks, then every other week thereafter. Patients were evaluated for response every 8 weeks. There were 2 complete and 2 partial responses out of 39 eligible and evaluable patients for an overall response rate of 10% (95% CI = 3-24%). The primary toxicities were nausea, hyponatremia, and anemia. Overall, treatment was well tolerated. We conclude that, although the treatment is relatively well tolerated, the regimen has minimal activity in this disease and does not deserve further study.

Phase II trial of merbarone in pancreatic carcinoma. A Southwest Oncology Group study.

Twenty-nine patients with advanced pancreatic adenocarcinoma were treated with merbarone, utilizing a daily intravenous schedule for 5 days. Only two partial responses of short duration were observed. The major toxicities were renal, with an increase in creatinine or proteinuria in 17 patients, and mild to moderate nausea and vomiting seen in 22 patients. Merbarone in this dose and schedule has minimal activity in pancreatic cancer.

CODE (cisplatin, vincristine, doxorubicin, etoposide) plus granulocyte colony-stimulating factor in advanced non-small-cell lung cancer: a Hoosier Oncology Group phase II trial.

This phase II trial investigated the activity and toxicity of CODE (cisplatin, vincristine, doxorubicin, etoposide) chemotherapy with the addition of granulocyte colony-stimulating factor (G-CSF) in patients who had chemotherapy-naive, advanced, or metastatic non-small-cell lung cancer. Treatment consisted of cisplatin, 25 mg/m2, administered weeks 1 through 9; vincristine, 1 mg/m2, weeks 1, 2, 4, 6, and 8; doxorubicin, 40 mg/m2, weeks 1, 3, 5, 7, and 9; and etoposide, 80 mg/m2 intravenously day 1 and 160 mg/m2 orally, days 2 and 3 on weeks 1, 3, 5, 7, and 9. Granulocyte colony-stimulating factor, 5 microg/kg, was administered subcutaneously on all days that patients were not receiving chemotherapy. From April 1992 through April 1993, 42 patients were entered on study. The principal toxicities were hematologic. Grade 3-4 anemia was seen in 21 patients. Grade 3-4 thrombocytopenia was seen in 9 patients. Grade 3-4 neutropenia occurred in 29 patients. Eight patients experienced a neutropenic febrile episode requiring antibiotics. Nonhematologic toxicities included weight loss and fatigue. Responses were seen in 10 of 42 patients, for an overall response rate of 24% (95% confidence interval, 12%-39%) and a median survival of 7.1 months. The CODE chemotherapy regimen has activity similar to other previously described cisplatin-based regimens, with a significant amount of both hematologic and nonhematologic toxicity. Its continued use in patients who have previously untreated non-small-cell lung cancer cannot be recommended, based on the results of this study.

Phase II study of gemcitabine and cisplatin in patients with previously untreated extensive stage small cell lung cancer: Southwest Oncology Group Study 9718.

BACKGROUND: This phase II study (S9718) evaluated the antineoplastic activity and tolerability of the combination of gemcitabine and cisplatin in previously untreated patients with extensive stage small cell lung cancer (ES-SCLC). METHODS: Chemonaive patients with ES-SCLC, received gemcitabine 1250 mg/m intravenously (IV) over 30 minutes on days 1 and 8 and cisplatin 75 mg/m IV over 30 to 60 minutes on day 1. Treatments were repeated every 21 days for a maximum of six cycles. RESULTS: A total of 88 patients were enrolled in the study; seven patients were not eligible and one did not receive treatment; 80 patients were fully assessable for survival, response, and toxicity. Objective response was observed in 42 patients (53%; 95% confidence interval [CI]: 41%-64%) with two patients (3%; 95% CI: 0%-8%) achieving a complete response. Median PFS was 5 months (CI, 4.2-5.9 months), and median overall survival was 8.8 months (95% CI: 7.8-9.5 months). The 1- and 2-year survival rates were 27.5% (95% CI: 17.7%-37.3%) and 4% (95% CI: 0%-8%), respectively. The most common toxicity was neutropenia. Grade 3 and 4 neutropenia was noted in 17 (21%) and 17 (21%) patients, respectively. Two patients developed febrile neutropenia, with subsequent full recovery. Twenty-one patients (23%) developed grade 3 thrombocytopenia. Grade 4 thrombocytopenia was seen in only one patient. The most common nonhematologic toxicities included grade 3 and 4 vomiting in 12 (21%) patients and fatigue in nine (10%) patients. Two patients (3%) died of respiratory infections while on treatment. CONCLUSION: The combination of gemcitabine and cisplatin is an active and reasonably well tolerated regimen for the treatment of ES-SCLC. It does not appear to offer any compelling advantages over other commonly used two drug regimens in this disease.

Evaluating the effectiveness of epoetin alfa in community oncology practices.

PURPOSE: This retrospective case-series review studied the effectiveness of epoetin alfa in community oncology practices, which until now has not been well documented. METHODS: We reviewed the medical records of 118 cancer patients treated between 1999 and 2001 with cyclic chemotherapy plus epoetin alfa in 27 US community-based oncology practices. Two analysis sets were examined: one including all patients (n=118) and one including only those patients with no concurrent events impacting hemoglobin data interpretation (n=73). Efficacy of epoetin alfa was evaluated by hemoglobin response (aS2 g/dl increase in hemoglobin from baseline) at weeks 12 and 16, the time to hemoglobin response, and change in hemoglobin concentrations from baseline at specific time points. RESULTS: After 12 weeks of treatment, 43% (95% confidence interval [CI], 33-54%) of patients had a hemoglobin response, and the proportion of responders further rose to 61% (95% CI, 49-72%) after 16 weeks. The median time to response was 92 days (lower 95% confidence limit, 74 days; upper bound not estimable). Hemoglobin increased from baseline at all time points evaluated during epoetin alfa treatment, with a mean increase of 1.1 g/dl (95% CI, 0.77-1.4 g/dl) by the last observation. CONCLUSION: These results indicate that epoetin alfa is effective in community practice, but most patients take longer than 3 months to respond. Because slow responses may negatively impact on the quality of life in these patients, alternative treatment approaches providing faster and perhaps better responses may provide greater clinical benefit.

Improved rapid autoradiography with elimination of background.

A method has been developed to improve the quality of autoradiography. In addition to using high specific activity thymidine (3HTdr), low temperature exposure and scintillation fluid, FdUR was added to the cell suspension during incubation. It led to an increased amount of 3HTdr incorporation by the cells. By this method, the grain density over positive cells was increased and the background was minimal.

Daily times four vinorelbine plus cisplatin in advanced non-small-cell lung cancer: a phase II trial of a novel schedule.

PURPOSE: To evaluate the efficacy of a novel multiday schedule of vinorelbine and displatin in patients with advanced NSCLC. PATIENTS AND METHODS: Thirty patients were enrolled, including 27 patients with stage IV disease, and 11 patients with performance status of 2. They received a maximum of four chemotherapy cycles with cisplatin 20 mg/m2/day and vinorelbine 15 mg/m2/day intravenously (i.v.) for four consecutive days, every three weeks, with prophylactic filgrastim. RESULTS: Sixteen patients responded (53%, 95% confidence interval (95% CI): 34%-72%), including two complete and fourteen partial confirmed responses. Median survival for all patients was 8.1 months, with actuarial one-year and two-year survival rates of 40% and 15%. Despite prophylactic filgrastim, the delivered vinorelbine dose intensity of 16.8 mg/m2/week caused febrile neutropenia in 48% of patients (16% of cycles), resulting in one treatment-related death. Common nonhematologic toxicities included delayed emesis, asthenia, and constipation. CONCLUSIONS: This multiday vinorelbine-cisplatin schedule is highly active against advanced NSCLC but results in frequent neutropenic complications. The myelotoxicity and antitumor efficacy of vinorelbine in NSCLC patients may be schedule-dependent.