Effectiveness of accelerated radiotherapy for patients with inoperable non-small cell lung cancer (NSCLC) and borderline prognostic factors without distant metastasis: a retrospective review.

PURPOSE: The standard treatment for patients with unresectable or medically inoperable non-small cell lung cancer (NSCLC) and good prognostic factors (e.g., weight loss [WL] < or = 5% and Karnofsky performance status [KPS] > or = 70) is induction chemotherapy followed by definitive radiotherapy to the primary site at 1.8-2.0 Gy per fraction with a total dose of 60-63 Gy to the target volume. Patients with poor prognostic factors usually receive radiotherapy alone, but the fractionation schedule and total dose have not been standardized. To attempt to optimize irradiation doses and schedule, we compared the effectiveness of accelerated radiotherapy (ACRT) alone to 45 Gy at 3 Gy per fraction with standard radiation therapy (STRT) of 60-66 Gy at 2 Gy per fraction in regard to tumor response, local control, distant metastasis, toxicity, and survival. METHODS AND MATERIALS: Fifty-five patients treated with radiation for NSCLC at The University of Texas M. D. Anderson Cancer Center between 1990 and 1994 were identified. All 55 patients had node-positive, and no distant metastasis (N+, M0) of NSCLC. Two cohorts were identified. One cohort (26 patients) had borderline poor prognostic factors (KPS less than 70 but higher than 50, and/or WL of more than 5%) and was treated with radiotherapy alone to 45 Gy over 3 weeks at 3 Gy/fraction (ACRT). The second cohort (29 patients) had significantly better prognostic factors (KPS > or = 70 and WL < or = 5%) and was treated to 60-66 Gy over 6 to 6 1/2 weeks at 2 Gy per fraction (STRT) during the same period. RESULTS: In the first cohort treated by ACRT, the distribution of patients by AJCC stage was IIB 8%, IIIA 19%, and IIIB 73%. Sixty-two percent had KPS <70, and 76% had a WL of >5%. The maximum response rate as determined by chest X-ray was 60% among 45 of 55 patients who were evaluable for response: combined complete responses (20%) and partial responses (40%). Overall survival in these patients was 13% at 2 and 5 years, with a locoregional control rate of 42% and a freedom from distant metastasis rate of 54%. The ACRT cohort treated with 3 Gy per fraction had significantly lower KPS scores (p = 0.003) and greater WL (p = 0.063) than the cohort STRT treated with 2 Gy per fraction. However, treatment results and toxicity were not significantly different between the two cohorts in spite of significantly better prognostic factors in the STRT cohort. CONCLUSIONS: Despite having worse prognostic factors, the cohort treated with radiotherapy alone to 45 Gy at 3 Gy per fraction over 3 weeks (ACRT) had response rates, locoregional control, and overall survival comparable to those in the cohort treated by a total dose of 60-66 Gy at 2 Gy per fraction over 6 to 6 1/2 weeks (STRT). Given that accelerated treatment schedules decrease treatment time and cost less, these may, in the current health care environment, be important factors for health care providers to consider in treating patients who have locally advanced NSCLC and borderline poor prognostic factors.

A pilot clinical laboratory trial of paclitaxel and endobronchial brachytherapy in patients with non-small cell lung cancer.

Paclitaxel enhances microtubule assembly and causes a cell cycle arrest in mitosis, the most radiosensitive phase. We conducted this study to improve our understanding of paclitaxel effects in vivo and to determine the maximum tolerated dose of paclitaxel preceding endobronchial radiation therapy (brachytherapy). The treatment consisted of two cycles of paclitaxel infused over 24 hours followed by 192Ir brachytherapy; cycles were repeated every 3 weeks. Tumor samples were obtained at baseline, after each paclitaxel infusion, and 3 weeks after completion of therapy. Twenty-two non-small cell lung cancer patients with a documented endobronchial lesion were enrolled in the study and 20 patients received the therapy with different doses of paclitaxel, initially without and then later with granulocyte colony-stimulating factor (G-CSF) support (5 microg/kg subcutaneously on days 3 to 10). With the starting paclitaxel dose of 135 mg/m2, five of seven patients developed neutropenia and fever, which mandated a dose reduction to 120 mg/m2. At this dose level, three of three patients had neutropenic fever; thus, 120 mg/m2 of paclitaxel was considered above the maximum tolerated dose without G-CSF support. However, with G-CSF support the therapy was well-tolerated without dose-limiting toxicity and accrual is continuing at the paclitaxel 175-mg/m2 dose level. While no patient had achieved systemic tumor response, 11 patients achieved partial response of the endobronchial lesion, which represents 68.8% of 16 patients who received two courses of therapy and 91.8% of 12 patients who had full evaluation by bronchoscopy after completion of therapy. The in vivo paclitaxel effects were studied using the pre- and post-paclitaxel therapy tumor samples in eight patients. Four (50%) patients had a significant increase in mitotic cells after paclitaxel, as assessed by MPM-2 immunostaining that recognizes a large family of mitotic phosphoproteins. A substantial increase in the number of micronucleated apoptotic cells, another paclitaxel effect, was also found in six patients. These results clearly indicate that patients with endobronchial lesions from recurrent NSCLC could not tolerate this combined modality regimen without G-CSF support. However, this group of patients provided a unique opportunity to study in vivo paclitaxel effects in a clinical trial setting.

Integration of filgrastim into chemoradiation for limited small cell lung cancer: a Phase I study.

PURPOSE: Recent studies document the value of early combined modality therapy of small cell lung cancer, but also indicate that early thoracic radiation adds to myelosuppression and can complicate further chemotherapy. Other studies indicate that simultaneous use of growth factors with thoracic radiation may be deleterious. However, temporal separation of growth factor use from cytotoxic therapy may allow dose intensity to be maintained/enhanced during combined modality treatment. We sought to integrate filgrastim into a novel chemoradiation regimen for patients with limited small cell lung cancer using an approach that separated growth factor administration from both chemotherapy and thoracic radiation. METHODS AND MATERIALS: Twenty-seven patients with limited disease small cell lung cancer were enrolled in a Phase I trial of cisplatin, ifosfamide/mesna, oral etoposide, and thoracic radiation (1.5 Gy b.i.d. x 30 fractions days 1-19 cycle 1) +/- filgrastim (5 microg/kg/day). Filgrastim was given on days 20-25 of cycle 1 after completion of radiation and following completion of oral etoposide in subsequent cycles. The primary end point was determination of maximum tolerated dose (MTD) of chemotherapy. Serial cohorts were treated with and without filgrastim. RESULTS: Because of dose-limiting thrombocytopenia, primarily, and nonhematologic toxicity, the MTDs with and without filgrastim were identical (cisplatin 20 mg/m2 i.v. and ifosfamide 1200 mg/m2 i.v., both given days 1-3, and etoposide 40 mg/m2 p.o. days 1-14). Filgrastim use shortened the duration of neutropenia at the MTD (median 4 vs. 7 days), but was not associated with a reduction in febrile neutropenia. Although growth factor administration did not allow dose escalation of this regimen, it did allow chemotherapy doses to be maintained at the MTD more frequently through four cycles of therapy. In the 24 evaluable patients, the overall response rate was 100% (71% partial and 29% complete). CONCLUSIONS: Despite careful attention to the timing of growth factor with chemoradiation, the administration of filgrastim with this regimen did not allow dose escalation. As in many other recent studies of hematopoietic growth factors given prophylactically with chemotherapy, the duration of neutropenia at the MTD was shortened and the need for dose reduction throughout treatment was reduced in patients receiving filgrastim at the MTD.

Paclitaxel/carboplatin chemotherapy as primary treatment of brain metastases in non-small cell lung cancer: a preliminary report.

Chemotherapy has been rarely considered an important treatment modality for brain metastases. Based on the hypothesis that the lack of efficacy of chemotherapy, rather than the blood-brain barrier itself, may be the major hindrance to the successful chemotherapeutic treatment of brain metastases, we started a trial in which a selected group of non-small cell lung cancer patients with brain metastases received primary treatment with systemic chemotherapy. The treatment consisted of three courses of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) 225 mg/m2 given intravenously over 3 hours and carboplatin dosed to an area under the concentration-time curve of 6, with close monitoring of the lesion by computed tomography or magnetic resonance imaging of the brain after each chemotherapy course. Any radiographic or clinical evidence of progression in the brain during treatment or no improvement in the brain after three cycles of chemotherapy mandated whole brain irradiation (30 Gy in 10 fractions). Responding patients received three additional courses of chemotherapy; whole brain irradiation was given after completion of all six chemotherapy cycles. To date, five patients have been enrolled, and one has achieved partial remission both in the brain and at the extracranial site. Other patients did not achieve major objective responses either in the brain or at the extracranial sites. These preliminary results, which are consistent with the study hypothesis, support the feasibility of our approach. We therefore continue to accrue patients for this study.

Retrovirus-mediated wild-type p53 gene transfer to tumors of patients with lung cancer.

A retroviral vector containing the wild-type p53 gene under control of a beta-actin promoter was produced to mediate transfer of wild-type p53 into human non-small cell lung cancers by direct injection. Nine patients whose conventional treatments failed were entered into the study. No clinically significant vector-related toxic effects were noted up to five months after treatment. In situ hybridization and DNA polymerase chain reaction showed vector-p53 sequences in posttreatment biopsies. Apoptosis (programmed cell death) was more frequent in posttreatment biopsies than in pretreatment biopsies. Tumor regression was noted in three patients, and tumor growth stabilized in three other patients.

Limited-stage small-cell lung cancer: patient survival after combined chemotherapy and radiation therapy with and without treatment protocols.

PURPOSE: To compare survival of patients who undergo treatment in protocols versus survival of patients not in protocols. MATERIALS AND METHODS: Records of 81 adult patients with small-cell lung cancer who underwent chemotherapy and radiation therapy in 1987-1992 were reviewed retrospectively. Forty-one patients were in a protocol; 40 patients were not. Patient demographics and prognostic factors were not statistically significantly different. RESULTS: Median overall survival was 16.7 months in the nonprotocol group versus 29.0 months in the protocol group (P = .0023). Median disease-specific survival was 18.3 months in the nonprotocol group versus 27.1 months in the protocol group (P = .0176). Survival was not statistically significantly influenced by Karnofsky performance status, weight loss, or thoracic radiation dose. CONCLUSION: There was a highly statistically significant difference in survival outcome in the nonprotocol group versus the protocol group (P = .0023). Differences in chemotherapy-radiation therapy timing and other treatment-related factors may have contributed substantially to the improved survival in the protocol group.

Enhanced induction of tissue-type plasminogen activator in normal human cells compared to cancer-prone cells following ionizing radiation.

Normal human fibroblast (i.e., GM2936B, GM2907A, and IMR-90) and cancer-prone human fibroblast (i.e., Fanconi's anemia, Bloom's syndrome, and Ataxia telangiectasia) cells demonstrated the induction of intracellular and extracellular levels of tissue-type plasminogen activator (t-PA) at 6 and 12 hr, respectively, following ionizing radiation. Induced t-PA enzymatic activities following ionizing radiation were blocked by actinomycin D treatments. t-PA enzymatic activities were induced over 14-fold in Ataxia telangiectasia cells, over 9-fold in Bloom's syndrome cells, and over 6-fold in Fanconi's anemia cells, as compared to normal human fibroblasts. Similarly, the induction of t-PA mRNA levels in cancer-prone cells were between 5- to 10-fold higher than those observed in normal cells following equitoxic doses of ionizing radiation. Temporal induction of t-PA mRNA levels for normal and cancer-prone human cells were consistent with quantifiable enzymatic activities. The elevated induction of an intracellular protease (i.e., t-PA) in cancer-prone human cells is reminiscent of an "SOS"-like response observed in yeast and bacteria.

Magnetic resonance imaging during intracavitary gynecologic brachytherapy.

The cases of three patients, two with Stage III-B and one with Stage II-B carcinoma of the cervix, are cited to illustrate specific advantages of magnetic resonance (MR) imaging over computed tomography (CT) during intracavitary gynecologic brachytherapy. CT and MR were performed during the first of two intracavitary implants. To obtain artifact-free images with the intracavitary implant in place, a CT- and MR-compatible Fletcher system applicator was used. Although CT failed to differentiate the cervical tumor clearly from surrounding tissues, the area of pathology could be identified on MR by comparing the T1-weighted (T1W) and T2-weighted (T2W) images. Cervical tumors typically exhibit low-signal intensity on T1W and high-signal intensity on T2W scans, whereas paracervical soft tissues demonstrate high intensity on both T1W and T2W images. This contrast permits the size, location, and paracervical involvement of the tumor to be defined by MR. Multiplanar MR images obtained during the patients' intracavitary brachytherapy help demonstrate the actual anatomic relationship between the tumor and the applicator. Isodose distributions displayed on these images show that, in two cases, the tumor margin extended beyond the prescribed isodose line. Thus, MR may prove to be a clinically useful reference during intracavitary brachytherapy for ascertaining radiation dose to actual tumor volume.

Posttreatment exposure to camptothecin enhances the lethal effects of x-rays on radioresistant human malignant melanoma cells.

Little is known about the molecular mechanisms responsible for the survival recovery process(es) (known as potentially lethal damage repair), which occurs in mammalian cells following ionizing radiation. Previously, we presented data indicating a role for the DNA unwinding enzyme, topoisomerase I, in DNA repair. We now demonstrate that camptothecin, a specific inhibitor of topoisomerase I, causes dramatic radiosensitization of an extremely resistant human melanoma (U1-Mel) cell line. Camptothecin radiosensitized U1-Mel cells when it was administered either during or immediately following x-irradiation. U1-Mel cells were optimally radiosensitized with 4 microM camptothecin for a period of 4-6 hrs after x-irradiation. Enhanced cell killing by camptothecin was proportional to the initial extent of damage created by x-irradiation; the higher the dose of ionizing radiation, the greater the radiosensitization. The apparent synergy observed with camptothecin and x-rays was irreversible; camptothecin-treated U1-Mel cells were not able to carry out PLDR in a 48 hr period after the drug was removed. We hypothesize that the administration of camptothecin causes lesion modification through a topoisomerase I-mediated mechanism. These data support a role for topoisomerase I in DNA repair and indicate that camptothecin, or more effective derivatives, may have clinical use.