Enhancement of radiation effects by combined docetaxel and carboplatin treatment in vitro

Esophageal Metal Stents with Concurrent Chemoradiation Therapy for Locally Advanced Esophageal Cancer: Safe or Not?

BACKGROUND

The purpose of this study was to review the risks and benefits of concurrent chemoradiation therapy (CCRT) with esophageal self-expandable metal stents (SEMS) for the treatment of locally advanced esophageal cancer.

MATERIALS AND METHODS

Between January 2014 and December 2016, the data from 46 locally advanced esophageal cancer patients who received CCRT at our institution were retrospectively reviewed. Eight patients who received CCRT concomitant with SEMS placement (SEMS plus CCRT group) and thirty-eight patients who received CCRT without SEMS placement (CCRT group) were identified. The risk of developing esophageal fistula and the overall survival of the two groups were analyzed.

RESULTS

The rate of esophageal fistula formation during or after CCRT was 87.5% in the SEMS plus CCRT group and 2.6% in the CCRT group. The median doses of radiotherapy in the SEMS plus CCRT group and the CCRT group were 47.5 Gy and 50 Gy, respectively. SEMS combined with CCRT was associated with a greater risk of esophageal fistula formation than CCRT alone (hazard ratio [HR], 72.30; 95% confidence interval [CI], 8.62-606.12; p < .001). The median overall survival times in the SEMS plus CCRT and CCRT groups were 6 months and 16 months, respectively. Overall survival was significantly worse in the SEMS plus CCRT group than in the CCRT group (HR, 5.72; 95% CI, 2.15-15.21; p < .001).

CONCLUSION

CCRT concomitant with SEMS for locally advanced esophageal cancer results in earlier life-threatening morbidity and a higher mortality rate than treatment with CCRT alone. Further prospective and randomized studies are warranted to confirm these observations.

IMPLICATIONS FOR PRACTICE

Patients treated with SEMS placement followed by CCRT had higher risk of esophageal fistula formation and inferior overall survival rate compared with patients treated with CCRT alone. SEMS placement should be performed cautiously in patients who are scheduled to receive CCRT with curative intent.

Can drugs enhance hypofractionated radiotherapy? A novel method of modeling radiosensitization using in vitro data

PURPOSE

Hypofractionated radiotherapy (hRT) is being explored for a number of malignancies. The potential benefit of giving concurrent chemotherapy with hRT is not known. We sought to predict the effects of combined modality treatments by using mathematical models derived from laboratory data.

METHODS AND MATERIALS

Data from 26 published clonogenic survival assays for cancer cell lines with and without the use of radiosensitizing chemotherapy were collected. The first three data points of the RT arm of each assay were used to derive parameters for the linear quadratic (LQ) model, the multitarget (MT) model, and the generalized linear quadratic (gLQ) model. For each assay and model, the difference between the predicted and observed surviving fractions at the highest tested RT dose was calculated. The gLQ model was fitted to all the data from each RT cell survival assay, and the biologically equivalent doses in 2-Gy fractions (EQD2s) of clinically relevant hRT regimens were calculated. The increase in cell kill conferred by the addition of chemotherapy was used to estimate the EQD2 of hRT along with a radiosensitizing agent. For comparison, this was repeated using conventionally fractionated RT regimens.

RESULTS

At a mean RT dose of 8.0 Gy, the average errors for the LQ, MT, and gLQ models were 1.63, 0.83, and 0.56 log units, respectively, favoring the gLQ model (p < 0.05). Radiosensitizing chemotherapy increased the EQD2 of hRT schedules by an average of 28% to 82%, depending on disease site. This increase was similar to the gains predicted for the addition of chemotherapy to conventionally fractionated RT.

CONCLUSIONS

Based on published in vitro assays, the gLQ equation is superior to the LQ and MT models in predicting cell kill at high doses of RT. Modeling exercises demonstrate that significant increases in biologically equivalent dose may be achieved with the addition of radiosensitizing agents to hRT. Clinical study of this approach is warranted.

Daily megavoltage computed tomography in lung cancer radiotherapy: correlation between volumetric changes and local outcome

PURPOSE

To assess the predictive or comparative value of volumetric changes, measured on daily megavoltage computed tomography during radiotherapy for lung cancer.

PATIENTS AND METHODS

We included 80 patients with locally advanced non-small-cell lung cancer treated with image-guided intensity-modulated radiotherapy. The radiotherapy was combined with concurrent chemotherapy, combined with induction chemotherapy, or given as primary treatment. Patients entered two parallel studies with moderately hypofractionated radiotherapy. Tumor volume contouring was done on the daily acquired images. A regression coefficient was derived from the volumetric changes on megavoltage computed tomography, and its predictive value was validated. Logarithmic or polynomial fits were applied to the intratreatment changes to compare the different treatment schedules radiobiologically.

RESULTS

Regardless of the treatment type, a high regression coefficient during radiotherapy predicted for a significantly prolonged cause-specific local progression free-survival (p = 0.05). Significant differences were found in the response during radiotherapy. The significant difference in volumetric treatment response between radiotherapy with concurrent chemotherapy and radiotherapy plus induction chemotherapy translated to a superior long-term local progression-free survival for concurrent chemotherapy (p = 0.03). An enhancement ratio of 1.3 was measured for the used platinum/taxane doublet in comparison with radiotherapy alone.

CONCLUSION

Contouring on daily megavoltage computed tomography images during radiotherapy enabled us to predict the efficacy of a given treatment. The significant differences in volumetric response between treatment strategies makes it a possible tool for future schedule comparison.

A phase II study of concurrent chemoradiation with weekly docetaxel, carboplatin, and radiation therapy followed by consolidation chemotherapy with docetaxel and carboplatin for locally advanced inoperable non-small cell lung cancer (NSCLC)

INTRODUCTION

The current standard of care for good performance status patients with locally advanced non-small cell lung carcinoma is concurrent chemoradiation, although a clearly superior regimen has not been identified. Docetaxel has been shown to possess good single-agent activity against non-small cell lung cancer (NSCLC) and radiosensitizing properties, both alone and synergistically with carboplatin. We undertook this phase II study to determine the safety and efficacy of weekly docetaxel-carboplatin and concurrent radiation therapy followed by docetaxel-carboplatin consolidation for the treatment of locally advanced NSCLC.

METHODS

Sixty-seven patients having previously untreated stage IIIA or IIIB unresectable NSCLC were enrolled, with 61 patients evaluated for endpoints. Docetaxel 20 mg/m IV infusion over 30 minutes followed by carboplatin area under the curve = 2 over 30 minutes was administered weekly during concurrent thoracic radiotherapy. After 3 week rest, consolidation docetaxel 75 mg/m(2) IV infusion over 60 minutes and carboplatin area under the curve = 6 over 30 minutes was administered every 3 weeks for two cycles. Concurrent thoracic radiation consisted of 45 Gy (1.8 Gy fractions 5 d/wk for first 5 weeks) followed by 18 Gy boost (2.0 Gy fractions 5 d/wk for 2 weeks) for a total dose of 63 Gy.

RESULTS

One and 2 years overall survival rates were 45 and 20%, respectively. Progression free survival at 1 year was 27%. Median survival time was 12 months. Median time to progression was 8 months. The primary hematologic toxicity was leukopenia. The primary nonhematologic toxicity was esophagitis.

CONCLUSION

The administered regimen of weekly docetaxel-carboplatin and concurrent radiation therapy followed by docetaxel-carboplatin consolidation has acceptable toxicity profile. However, the overall survivals at 1 and 2 years are somewhat disappointing.

Enhanced radiation-induced cytotoxic effect by 2-ME in glioma cells is mediated by induction of cell cycle arrest and DNA damage via activation of ATM pathways

Glioblastoma multiform is the most common malignant primary brain tumor in adults, but there remains no effective therapeutic approach. 2-methoxyestradiol (2-ME), which is a naturally occurring metabolite of 17beta-estradiol, was shown to enhance radiotherapeutic effect in certain tumors; however, whether 2-ME can also enhance the sensitivity of glioma cells to radiotherapy remains unknown. The present study, therefore, was to address this issue using two human glioma cell lines (T98G and U251MG). These cells were irradiated with and without 2-ME and then clonogenic assay, apoptosis assay, DNA damage, and cell cycle change were examined. Results showed that 2-ME significantly enhances radiation-induced cell death in both glioma cells, shown by decreasing cell viability and increasing apoptotic cell death. No such radiosensitizing effect was observed if cells pre-treated with Estrodiol, suggesting the specifically radiosensitizing effect of 2-ME rather than a general effect of estrodials. The enhanced radio-cytotoxic effect in glioma cells by 2-ME was found to be associated with its enhancement of G(2)/M arrest and DNA damage, and phosphorylated ATM protein kinases as well as cell cycle checkpoint protein Chk2. Furthermore, inhibition of ATM by ATM inhibitor abolished 2-ME-activated Chk2 and enhanced radio-cytotoxic effects. These results suggest that 2-ME enhancement of the sensitivity of glioma cell lines to radiotherapy is mediated by induction of G2/M cell cycle arrest and increased DNA damage via activation of ATM kinases.

The role of docetaxel in N2 locally advanced non-small-cell lung cancer

Patients with locally advanced non-small-cell lung cancer (NSCLC) are a heterogeneous group often treated with multimodality therapy. Docetaxel has an established role in the treatment of advanced-stage NSCLC and has demonstrated promising activity in the locally advanced setting. Herein, we review the available data on the role of docetaxel in locally advanced NSCLC. The phase I/II data regarding the use of docetaxel concomitantly with radiation as a single agent or combined with platinum compounds are reviewed. In addition, we discuss the role of docetaxel induction therapy before surgery or definitive radiation therapy. Additionally, we address the role of docetaxel in consolidation therapy in patients with locally advanced NSCLC.

High pathological response rate in locally advanced esophageal cancer after neoadjuvant combined modality therapy: dose finding of a weekly chemotherapy schedule with protracted venous infusion of 5-fluorouracil and dose escalation of cisplatin, docetaxel and concurrent radiotherapy

BACKGROUND

This phase I study was aimed at defining the toxicity profile and pathological response rate of a neoadjuvant schedule including weekly docetaxel and cisplatin, protracted venous infusion (PVI) of 5-FU and concomitant radiotherapy (RT) in locally advanced esophageal cancer.

PATIENTS AND METHODS

The schedule consisted of a first phase of chemotherapy alone and a second phase of concurrent chemoradiation. Initial doses were: docetaxel and cisplatin 20 mg/m2 on days 1, 8, 15, 29, 36 and 43 plus 5-FU 150 mg/m2 PVI on days 1-21 and 29-49; RT (40 Gy) started on day 29. In the following steps the doses were escalated up to docetaxel 35 mg/m2 and cisplatin 25 mg/m2 on days 1, 8, 15, 29, 36, 43, 50 and 57 plus 5-FU 180 mg/m2 PVI on days 1-21 and 150 mg/m2 PVI on days 29-63 concurrently with RT 50 Gy.

RESULTS

Forty-seven patients were enrolled and 46 completed the planned treatment. During the concomitant phase, grade 3-4 hematological toxicities occurred in three patients (6.5%) (or 3/174 cycles) and non-hematological toxicities in six patients (13%) (or 7/179 cycles). A pathological downstaging was obtained in 59.6% of the cases (28/47): complete remission (pCR) in 14 patients, near pCR (residual microfoci on the primary pN0) in eight patients, pT2 pN0 in three patients and partial response on the primary with positive lymph nodes in three patients. Six (13%) and 13 (28%) patients were considered stable and non-responders, respectively. In the last dose level, eight pCR and four near-pCR were obtained out of 15 patients. The maximum tolerable dose was not formally defined because dose escalation was stopped at the last dose level.

CONCLUSION

This schedule represents a feasible treatment and the high pathological response rate is extremely encouraging; the doses found in the last dose-level are the basis for an ongoing phase II study at our institution.

Docetaxel, Carboplatin and Concomitant Radiotherapy for Unresectable Squamous Cell Carcinoma of the Head and Neck

Concomitant chemoradiotherapy is the most effective treatment of unresectable head and neck cancer. Docetaxel and carboplatin are two active drugs that potentiate radiotherapy. Thirty patients (median age = 56 years; median Eastern Cooperative Oncology Group performance status = 1) received radiotherapy (70 Gy, 2 Gy/d, 5 d/wk) concurrent with carboplatin AUC 0.3 to 0.5 on day 1-5, weeks 1, 3, 5, 7, and docetaxel 15 to 25 mg/m2 on day 4 of weeks 2, 4, and 6. Site of unresectable squamous cell carcinoma was as follows: oropharynx, 41%; hypopharynx, 27%; oral cavity, 16%; and larynx, 16%. Stage was III in 13% and IV in 87%. In 11 patients, pharmacokinetic parameters were evaluated. Acute G4 toxicity was as follows: neutropenia, 20%; mucositis, 33%. We had the following acute G3 toxicities: mucositis, 40%; neutropenia, 37%; dermatitis, 23%; and anemia, 13%. The maximum tolerated dosage was area under the curve 0.5 for carboplatin and 20 mg/m2 for docetaxel. Median radiotherapy dose was 69 Gy, and 175 out of 210 courses (83%) were administered. At the end of the treatment, we had 20 complete responses (CR) (67%), 9 partial responses (30%), and 1 no change (3%). After radial neck dissection, 2 patients achieved a CR (overall CR = 73%). After a median follow-up of 2.5 years, we had a 3-year local progression-free survival of 85%, failure-free survival of 69%, and overall survival of 60%. A significant increase of Cmax of carboplatin concentration was noted at the beginning of weeks 3, 5, and 7. Total plasma platinum raises during each course of 5 days of carboplatin without reaching a steady state. Carboplatin, docetaxel, and concomitant conventional radiotherapy is a feasible and effective treatment of unresectable head and neck cancer. The concurrent administration of two drugs does not alter pharmacokinetic drug behavior compared with single-agent data.

Docetaxel-based combined-modality chemoradiotherapy for locally advanced non-small cell lung cancer

The cytotoxic agent docetaxel not only has proven activity in non-small cell lung cancer-when used alone or in combination-but is also a potent radiosensitizer, and improved treatments are needed in all stages of this disease. In patients with locoregionally advanced (stage III) disease, docetaxel has shown efficacy with manageable toxicities when used alone or in combination with a platinum compound in a sequential manner before localized radical radiotherapy/surgery. Presently, therapeutic gains appear to be maximized by the use of concurrent chemotherapy and irradiation. This review focuses on research with combinations of docetaxel with either cisplatin or carboplatin and radiotherapy. Overall response and survival rates to date provide data worth pursuing. From phase I data, weekly docetaxel at 20 mg/m(2) plus cisplatin at 25 mg/m(2) or carboplatin to an area under the concentration time curve of 2 mg/ml*min with concurrent radiotherapy to 60 Gy over 6 weeks appear to be suitable for phase II trials. Predominant toxicities are esophagitis and neutropenia, but a low frequency of pulmonary toxicity is reported. Induction, concurrent, and consolidation docetaxel-based chemoradiotherapy in potentially resectable disease are all being investigated. Future research could include the investigation of computed tomography/ positron emission tomography-derived target volume radiotherapy, dose-escalated therapy, and alternative fractionation schedules in combination with docetaxel-based cytotoxic chemotherapy.

Additive effects of radiation and docetaxel on murine SCCVII tumors in vivo: special reference to changes in the cell cycle

The purpose of the present study was to investigate the effects of a combination of docetaxel and irradiation in vivo with special reference to docetaxel-arrested G(2)/M-phase cells. At 24 and 48 h after intraperitoneal administration of docetaxel (90 mg/kg), tumor-bearing mice were irradiated with (60)Co gamma rays. Cell cycle distribution was analyzed by a DNA-Ki-67 double staining method using flow cytometry. An accumulation of cells in the G(2)/M phase of up to approximately 40% was observed 24 h after administration of docetaxel. Between 24 and 72 h, the percentage of cells arrested in G(2)/M phase that expressed Ki-67 decreased from 37.2% to 13.8%, in accordance with the increase in the Ki-67-negative G(2)/M-phase fraction. More than half of the cells arrested in G(2)/M phase lost their expression of Ki-67 protein between 24 and 72 h. The G(1)-phase fraction decreased from 28.4% to 8.6% at 24 h after docetaxel treatment; this remained unchanged at 72 h. These flow cytometry data suggested that docetaxel-arrested G(2)/M-phase cells did not enter the next cell cycle and were killed by docetaxel alone. Our data showed that arrest of cells in G(2)/M phase does not contribute to the synergism that has been reported for combinations of docetaxel and radiation in in vivo tumor models.

Phase I trial of outpatient weekly docetaxel, carboplatin and concurrent thoracic radiation therapy for stage III unresectable non-small-cell lung cancer: a Vanderbilt cancer center affiliate network (VCCAN) trial

PURPOSE

Docetaxel, an active agent for non-small cell lung cancer (NSCLC), has demonstrated activity as a radiosensitizer in numerous pre-clinical studies. We conducted a phase I trial to determine the maximum-tolerated dose (MTD) and dose-limiting toxicities (DLT) of weekly Docetaxel, Carboplatin with concurrent thoracic radiation therapy (TRT) in patients with unresectable stage III NSCLC.

PATIENTS AND METHODS

In this phase I clinical trial, Docetaxel was administered weekly as a 1-h intravenous infusion for 6 weeks with a starting dose of 20 mg/m(2). Docetaxel doses were escalated by 10 mg/m(2) increments in successive cohorts of three patients. DLT was defined as grade >or=3 nonhematologic and hematologic toxicity according to RTOG toxicity criteria. Once the DLT of Docetaxel alone was reached, weekly Carboplatin (AUC 2) was added at a DLT-2 dose of Docetaxel (two dose levels below that of dose limiting toxicity). Docetaxel doses were again escalated at 10 mg/m(2) increments in successive cohorts of three new patients to define further DLT and MTD of Docetaxel/Carboplatin with TRT. TRT was administered to the primary tumor and regional lymph nodes (40 Gy) followed by a boost to the tumor (20 Gy).

RESULTS

Fifteen patients were entered onto this study with Docetaxel alone through three dose escalations (from 20 to 40 mg/m(2) weekly). The DLT of weekly Docetaxel/TRT was esophagitis and the MTD was 30 mg/m(2) per week for 6 weeks. Nine more patients were added with the Docetaxel/Carboplatin/TRT regimen. The DLT of weekly Docetaxel/Carboplatin with TRT was esophagitis and the MTD of Docetaxel was 20 mg/m(2) per week with weekly Carboplatin (AUC 2). There were 2 complete responses and 13 partial responses in 25 evaluable patients (RR 60%).

CONCLUSIONS

This combination regimen has activity with manageable toxicity in patients with stage III NSCLC. A phase II study is planned to define activity.

The novel taxane analogs, BMS-184476 and BMS-188797, potentiate the effects of radiation therapy in vitro and in vivo against human lung cancer cells

PURPOSE

To evaluate the novel taxane analogs, BMS-184476 and BMS-188797, as potential radiosensitizers in vitro and in vivo.

METHODS AND MATERIALS

Human H460 lung cancer cells were incubated with either paclitaxel or a taxane analog and irradiated at various times. Surviving fractions were then determined using a clonogenic assay. Three different schedules were used: (A) 1-h drug incubation with radiation at t = 8 h, (B) 1-h drug incubation with radiation at t = 24 h, (C) 24-h drug incubation with radiation immediately after. Cell cycle redistribution by taxanes alone was measured with propidium iodide and flow cytometry. Percent apoptosis was also measured using 7-aminoactinomycin D (7-AAD) staining with flow cytometry. For in vivo studies, H460 cell xenografts were used in nude mice. Tumors were grown s.c. on the flank and then treated with BMS-184476 (10 mg/kg i.p. injection, Days 0, 2, and 4) and/or radiation (2 Gy/day, Days 0-4). Tumor growth delay was then measured for each treatment group.

RESULTS

The mean in vitro radiation dose enhancement ratios of BMS-184476, BMS-188797, and paclitaxel were 1.76, 1.49, and 1.31 for Schedules A, B, and C, respectively. Isobologram analysis showed that BMS-184476 was synergistic with radiation using Schedule A. Treatment with taxanes caused an increase in the percentage of G2/M cells at the time of irradiation. The mean fold increases in the %G2/M above control values for all three drugs were 5.6, 2.5, and 1.7 for Schedules A, B, and C, respectively. The combined effects of taxanes plus radiation on the induction of apoptosis were additive for all three drugs. In vivo studies showed that BMS-184476 can enhance the effects of fractionated radiotherapy, with an average enhancement factor of 1.66 obtained from three independent experiments.

CONCLUSIONS

These results demonstrated that the novel taxane analogs, BMS-184476 and BMS-188797, can enhance the effects of radiation in human lung cancer cells both in vitro and in vivo. These data also support the hypothesis that a G2/M block is involved in the radiosensitization caused by the taxanes.

A preliminary pharmacokinetic study of docetaxel, carboplatin and concurrent radiotherapy for regionally advanced squamous cell carcinoma of the head and neck

This work investigates the pharmacokinetics and toxicity resulting from the concomitant use of low dose carboplatin (CBCA)/docetaxel (DTX) plus concurrent radiotherapy in patients with head and neck cancer. The study comprised 11 patients with stage III-IV head and neck cancer. All patients received 2 Gy radiotherapy daily, 5 fractions per week, up to a planned total of 70 Gy over 7 weeks. CBCA (AUC 0.4 mg/ml, min/day) was also administrated as 20 min i.v. infusion, starting 1 day before the first radiotherapy fraction. CBCA was administered for 5 consecutive days every 2 weeks (weeks 1, 3, 5 and 7). DTX 30 mg/m2 (1 h i.v. infusion) was given as a single dose on days 10, 24 and 38. CBCA on day 1 and DTX on day 10 were analysed to determine the concentration-time curves during the first 24 h. CBCA Cmax and Cmin in 2-5 days and on day 15 and 29, as well as total plasma platinum on days 2, 3, 4, 5, 29 and 43 were also assayed. By calculating the non-compartmental pharmacokinetic parameters of the two drugs from the available plasma concentrations we found in the first week values similar to those reported in the literature as single agents. In contrast, during subsequent weeks (weeks 3 and 5), a significant and progressive increase of platinum levels was observed. So, it could be assumed that after 2 weeks of CBCA and DTX treatment a bias in dose calculation occurred because the linear relationship between creatinine clearance (used to calculate the expected AUC through the Calvert formula) and CBCA clearance was no longer observed.