Pilot study of human recombinant interferon gamma and accelerated hyperfractionated thoracic radiation therapy in patients with unresectable stage IIIA/B nonsmall cell lung cancer

Th1 cytokines in pediatric acute lymphoblastic leukemia

Immune milieus play an important role in various types of cancer. The present study focuses on the effect of Th1 cytokines on pediatric acute lymphoblastic leukemia (ALL). The reaction of ALL cell lines and patient-derived xenografts (PDX) to the most important Th1 cytokines TNF-α (tumor necrosis factor alpha) and IFN-γ (interferon gamma) is analyzed and correlated with the respective cytokine receptors and the intracellular signaling molecules. ALL cell lines and ALL PDX display a great heterogeneity in cell death after incubation with TNF-α and IFN-γ. Several samples show a dose-dependent and additive induction of cell death by both cytokines; others do not react at all or even display an increased viability. Apoptosis is the main type of cell death induced by Th1 cytokines in ALL cells. Over all leukemia cells analyzed, IFN-γ receptor (IFNGR) shows a higher expression than both TNF-receptors, resulting in higher phosphorylation of STAT1 (signal transducer and activator of transcription) compared to phosphorylation of NF-κB (nuclear factor kappa-light-chain-enhancer of activated B-cells) in the TNF pathway. The activation of STAT1 correlates with the amount of cell death after stimulation with Th1 cytokines. TNF-α and IFN-γ lead to heterogeneous reactions in ALL cell lines and ALL PDX but are able to induce cell death by apoptosis in the majority of ALL blasts. The correlation of a high expression of IFNGR and following activation of STAT1 with cell death indicates an important role for IFN-γ signaling in this setting.

Bridging Radiotherapy to Immunotherapy: The IFN-JAK-STAT Axis

The unprecedented successes of immunotherapies (IOs) including immune checkpoint blockers (ICBs) and adoptive T-cell therapy (ACT) in patients with late-stage cancer provide proof-of-principle evidence that harnessing the immune system, in particular T cells, can be an effective approach to eradicate cancer. This instills strong interests in understanding the immunomodulatory effects of radiotherapy (RT), an area that was actually investigated more than a century ago but had been largely ignored for many decades. With the "newly" discovered immunogenic responses from RT, numerous endeavors have been undertaken to combine RT with IOs, in order to bolster anti-tumor immunity. However, the underlying mechanisms are not well defined, which is a subject of much investigation. We therefore conducted a systematic literature search on the molecular underpinnings of RT-induced immunomodulation and IOs, which identified the IFN-JAK-STAT pathway as a major regulator. Our further analysis of relevant studies revealed that the signaling strength and duration of this pathway in response to RT and IOs may determine eventual immunological outcomes. We propose that strategic targeting of this axis can boost the immunostimulatory effects of RT and radiosensitizing effects of IOs, thereby promoting the efficacy of combination therapy of RT and IOs.

Management of Resectable Stage III-N2 Non-Small-Cell Lung Cancer (NSCLC) in the Age of Immunotherapy

Simple Summary

The treatment of resectable stage III non-small-cell lung cancer with N2 lymph node involvement is usually multimodal and is generally based on neoadjuvant chemotherapy +/− radiotherapy followed by surgery, but the cure rate is still low. Immunotherapy based on anti-PD1/PD-L1 immune checkpoint inhibitors has improved survival in advanced and stage III non-resectable NSCLC patients and is being studied in earlier stages to improve the cure rate of lung cancer. In this article, we review all therapeutic approaches to stage III-N2 NSCLC, analysing both completed and ongoing studies that evaluate the addition of immunotherapy with or without chemotherapy and/or radiotherapy.

Abstract

Stage III non-small-cell lung cancer (NSCLC) with N2 lymph node involvement is a heterogeneous group with different potential therapeutic approaches. Patients with potentially resectable III-N2 NSCLC are those who are considered to be able to receive a multimodality treatment that includes tumour resection after neoadjuvant therapy. Current treatment for these patients is based on neoadjuvant chemotherapy +/− radiotherapy followed by surgery and subsequent assessment for adjuvant chemotherapy and/or radiotherapy. In addition, some selected III-N2 patients could receive upfront surgery or pathologic N2 incidental involvement can be found a posteriori during analysis of the surgical specimen. The standard treatment for these patients is adjuvant chemotherapy and evaluation for complementary radiotherapy. Despite being a locally advanced stage, the cure rate for these patients continues to be low, with a broad improvement margin. The most immediate hope for improving survival data and curing these patients relies on integrating immunotherapy into perioperative treatment. Immunotherapy based on anti-PD1/PD-L1 immune checkpoint inhibitors is already a standard treatment in stage III unresectable and advanced NSCLC. Data from the first phase II studies in monotherapy neoadjuvant therapy and, in particular, in combination with chemotherapy, are highly promising, with impressive improved and complete pathological response rates. Despite the lack of confirmatory data from phase III trials and long-term survival data, and in spite of various unresolved questions, immunotherapy will soon be incorporated into the armamentarium for treating stage III-N2 NSCLC. In this article, we review all therapeutic approaches to stage III-N2 NSCLC, analysing both completed and ongoing studies that evaluate the addition of immunotherapy with or without chemotherapy and/or radiotherapy.

Predicting Severe Radiation Esophagitis in Patients With Locally Advanced Esophageal Squamous Cell Carcinoma Receiving Definitive Chemoradiotherapy: Construction and Validation of a Model Based in the Clinical and Dosimetric Parameters as Well as Inflammatory Indexes

Objective

Radiation esophagitis (RE) is common in patients treated with radiotherapy (RT) for locally advanced esophageal squamous cell carcinoma (ESCC). We aim to construct a nomogram predicting the severe RE (grade ≥2) in patients with ESCC receiving definitive chemoradiotherapy (dCRT).

Materials and Methods

Logistic regression was performed to evaluate the risk factors in predicting RE. Nomogram was built based on the multivariate analysis result. The model was validated using the area under the receiver operating curve (ROC) curve (AUC), calibration curves, and decision curve analyses (DCA). Spearman correlation analysis was used to evaluate the correlation between inflammation indexes.

Results

A total of 547 patients with stage II–IVA ESCC treated with dCRT from the retrospective study were included. Two hundred and thirty-two of 547 patients (42.4%) developed grade ≥2 RE. Univariate analysis indicated that gender (p = 0.090), RT dose (p < 0.001), targeted therapy (p = 0.047), tumor thickness (p = 0.013), lymphocyte-monocyte ratio (LMR, p = 0.016), neutrophil-lymphocyte ratio (NLR, p < 0.001), and platelet-lymphocyte ratio (PLR, p < 0.001) were the significant factors for a higher incidence of RE. In multivariate analysis, RT dose [p < 0.001; odds ratio (OR), 4.680; 95% confidence interval (CI), 2.841–6.709], NLR (p < 0.001; OR, 0.384; 95% CI, 0.239–0.619), and PLR (p < 0.001; OR, 3.539; 95% CI: 2.226–5.626) were independently associated grade ≥2 RE and were involved in the nomogram. ROC curves showed the AUC of the nomogram was 0.714 (95% CI, 0.670–0.757), which was greater than each factor alone (RT dose: 0.615; NLR: 0.596; PLR: 0.590). Calibration curves showed good consistency between the actual observation and the predicted RE. DCA showed satisfactory positive net benefits of the nomogram among most threshold probabilities.

Conclusions

The study demonstrated that RT dose, NLR, and PLR were independent risk factors for grade ≥2 RE in patients with locally advanced ESCC receiving dCRT. A predictive model including all these factors was built and performed better than it based on each separately. Further validation in large patient populations is still warranted.

Combining Radiation Therapy With Interferons: Back to the Future

Radiation therapy has been linked to the induction of an intratumoral type I interferon (IFN) response, which positively affects the response to treatment. This has spiked the interest to combine radiation therapy with IFN-based treatment. Interestingly, this combination treatment has been considered previously, since preclinical studies demonstrated a radiosensitizing effect of interferons. As a result, multiple clinical trials have been performed combining radiation therapy with interferons in different tumor types. Although potential benefit has been suggested, the outcomes of the trials are diverse and challenging to interpret. In addition, increased grade ≥3 toxicity frequently resulted in a negative recommendation regarding the combination therapy. The latter appears premature because many studies were small and several aspects of the combination treatment have not yet been sufficiently explored to justify such a definite conclusion. This review summarizes the available literature on this combination therapy, with a focus on IFN-α and IFN-β. Based on preclinical studies and clinical trials, we evaluated the potential opportunities and describe the current challenges. In addition, we identify several issues that should be addressed to fully exploit the potential benefit of this combinatorial treatment approach.

Is the Combination of Immunotherapy and Radiotherapy in Non-small Cell Lung Cancer a Feasible and Effective Approach?

For many years, conventional oncologic treatments such as surgery, chemotherapy, and radiotherapy (RT) have dominated the field of non-small-cell lung cancer (NSCLC). The recent introduction of immunotherapy (IT) in clinical practice, especially strategies targeting negative regulators of the immune system, so-called immune checkpoint inhibitors, has led to a paradigm shift in lung cancer as in many other solid tumors. Although antibodies against programmed death protein-1 (PD-1) and programmed death ligand-1 (PD-L1) are currently on the forefront of the immuno-oncology field, the first efforts to eradicate cancer by exploiting the host's immune system date back to several decades ago. Even then, researchers aimed to explore the addition of RT to IT strategies in NSCLC patients, attributing its potential benefit to local control of target lesions through direct and indirect DNA damage in cancer cells. However, recent pre-clinical and clinical data have shown RT may also modify antitumor immune responses through induction of immunogenic cell death and reprogramming of the tumor microenvironment. This has led many to reexamine RT as a partner therapy to immuno-oncology treatments and investigate their potential synergy in an exponentially growing number of clinical trials. Herein, the authors review the rationale of combining IT and RT across all NSCLC disease stages and summarize both historical and current clinical evidence surrounding these combination strategies. Furthermore, an overview is provided of active clinical trials exploring the IT-RT concept in different settings of NSCLC.

Acute phase response before treatment predicts radiation esophagitis in non-small cell lung cancer

BACKGROUND AND PURPOSE

Radiation esophagitis (RE) represents an inflammatory reaction to radiation therapy (RT). We hypothesized that aspects of the physiologic acute phase response (APR) predicts RE.

MATERIAL AND METHODS

We retrospectively analyzed 285 patients with non-small cell lung cancer (NSCLC) treated with definitive radiation. The primary analysis was the association of pretreatment lab values reflective of the APR with symptomatic (grade ⩾ 2) RE. Univariate and multivariate odds ratios (ORs) were calculated to test associations of clinical and pretreatment lab values with RE. Optimal cutpoints and multivariable risk stratification groupings were determined via recursive partitioning analysis.

RESULTS

Pretreatment platelet counts were higher and hemoglobin levels lower in patients who developed RE (P<0.05). Based on these two pre-treatment risk factors, an APR score was defined as 0 (no risk factors), 1 (either risk factor), or 2 (both risk factors). APR score was significantly associated with RE in both univariate (OR = 2.3 for each point, 95% confidence interval [CI] 1.5-3.4, P = 0.001) and multivariate (OR = 2.1, 95% CI 1.3-3.4, P = 0.002) analyses.

CONCLUSIONS

The APR score may represent a novel metric to predict RE. However, pending validation in an independent dataset, caution is advised when interpreting these results given their retrospective and thus exploratory nature.

Cytogenetic effects of recombinant interferon-gamma on lymphocytes cultures from patients with non-small cell lung cancer

Therapeutic effects of human interferons (IFN) on malignancies and infectious diseases have been demonstrated in several clinical trials. The effects of IFN alone or combined with other treatment modalities (radiotherapy and chemotherapy) in lung cancer are under investigation. Experimental data suggest that some cytokines, such as IFN-alpha and IFN-gamma, exhibit cytogenetic properties in human normal lymphocytes from peripheral blood, but the mechanisms are not clear. The aim of the present study was to investigate the in vivo cytotoxic and cytostatic activity of IFN-gamma. Patients with certain cases of non-small cell lung cancer not eligible for chemotherapy or chemoradiotherapy were treated with thoracic radiotherapy. After tumor relapse, local treatment with instillations of IFN-gamma through the fiberoptic bronchoscope followed. To clarify the cytogenetic activity of IFN-gamma, sister chromatid exchange (SCE) and proliferation rate index (PRI) were evaluated in lymphocyte cultures from these patients' peripheral blood samples immediately after diagnosis (baseline), 30 days after radiotherapy, and after the fifth instillation of IFN-gamma. Our results show a decrease in SCE frequency and PRI values in lymphocytes after treatment with IFN-gamma, suggesting that IFN-gamma does not have cytotoxic activity but, in contrast, may induce repair mechanisms, as shown in earlier studies in other biologic models.

The radiosensitizing effect of immunoadjuvant OM-174 requires cooperation between immune and tumor cells through interferon-gamma and inducible nitric oxide synthase

PURPOSE

To explore whether antitumor immunoadjuvant OM-174 can stimulate immune cells to produce interferon-gamma (IFN-gamma) and thereby radiosensitize tumor cells.

METHODS AND MATERIALS

Splenocytes from BALB/c mice were stimulated by OM-174 at plasma-achievable concentrations (0.03-3 mug/mL), and afterward analyzed for the expression and secretion of IFN-gamma by reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Stimulated splenocytes were used as a source of IFN-gamma to radiosensitize hypoxic EMT-6 tumor cells through the cytokine-inducible isoform of nitric oxide synthase (iNOS).

RESULTS

OM-174 activated the production of IFN-gamma at high levels that reached 70 ng/mL in normoxia (21% oxygen) and 27 ng/mL in tumor-relevant hypoxia (1% oxygen). This caused up to 2.1-fold radiosensitization of EMT-6 tumor cells, which was associated with the iNOS-mediated production of the radiosensitizing molecule nitric oxide, as confirmed by accumulation of its oxidative metabolite nitrite, Western blot analysis, and reverse transcriptase-polymerase chain reaction. Both iNOS activation and radiosensitization were counteracted by neutralizing antibodies against IFN-gamma. The same mechanism of radiosensitization through the IFN-gamma secretion pathway was identified for IL-12 + IL-18, which are known to mediate IFN-gamma responses. Hypoxia displayed a dual effect on the immune-tumor cell interaction, by downregulating the expression of the IFN-gamma gene while upregulating iNOS at transcriptional level.

CONCLUSION

Immunoadjuvant OM-174 is an efficient radiosensitizer of tumor cells through activation of the IFN-gamma secretion pathway in immune cells. This finding indicates a rationale for combining immunostimulatory and radiosensitizing strategies and extends the potential therapeutic applications of OM-174.

[Drug treatments for idiopathic pulmonary fibrosis]

Idiopathic pulmonary fibrosis is a disease of unknown cause characterized by cough, progressive dyspnea, restrictive respiratory disorder, a typical honeycomb aspect on the high-resolution CT-scan, and usual interstitial pneumonia at histological examination of the lung biopsy. Most patients die 3 to 8 years after diagnosis. Current treatment is based on a combination of corticosteroids and immunosuppressants, but the efficacy of treatment remains a matter of debate. New therapeutics currently under evaluation in controlled clinical trials include interferon-gamma, pirfenidone, N-acetylcysteine, etanercept (anti-TNFalpha), bosentan (endothelin receptor antagonist), imatinib (tyrosine-kinases inhibitor of the PDGF receptor), etc. At the same time, new compounds showing efficacy in experimental models of fibrosis and the development of new pathophysiological concepts open new perspectives both in terms of concept and clinical practice.

Chemotherapy-induced lung disease

The lung has significant susceptibility to injury from a variety of chemotherapeutic agents. The clinician must be familiar with classic chemotherapeutic agents with well-described pulmonary toxicities and must also be vigilant about a host of new agents that may exert adverse effects on lung function. The diagnosis of chemotherapy-associated lung disease remains an exclusionary process, particularly with respect to considering usual and atypical infections, as well as recurrence of the underlying neoplastic process in these immune compromised patients. In many instances, chemotherapy-associated lung disease may respond to withdrawal of the offending agent and to the judicious application of corticosteroid therapy.

Acute respiratory failure after interferon-gamma therapy of end-stage pulmonary fibrosis

Interferon (IFN)-gamma was recently proposed as a treatment for idiopathic pulmonary fibrosis. We report on four patients who developed acute respiratory failure with new alveolar opacities after 2 (two patients), 6, and 35 injections of IFN-gamma-1b. All four patients had advanced idiopathic pulmonary fibrosis (total lung capacity less than 45% predicted or carbon monoxide diffusion capacity less than 30% predicted), and two patients had familial pulmonary fibrosis. No other cause of deterioration was found. Refractory hypoxemia led to death in three cases and to lung transplantation in one case. Pathologic studies in two patients showed diffuse alveolar damage lesions with preexisting usual interstitial pneumonia. These cases suggest that IFN-gamma therapy can induce an acute respiratory failure in patients with end-stage idiopathic pulmonary fibrosis.

Tumour response and radiation-induced lung injury in patients with recurrent small cell lung cancer treated with radiotherapy and concomitant interferon-alpha

The aim of this study was to determine whether either natural or recombinant interferon (IFN)-alpha can improve the response to radiotherapy (RT) in patients with small cell lung cancer (SCLC), and to assess the role of IFN in radiation-induced lung injury. All patients had previously participated in a randomised trial of chemotherapy alone or in combination with IFN-alpha in three arms (arm O: no IFN, arm I: natural IFN-alpha, arm II: recombinant IFN-alpha). Patients with locally progressive disease in the lungs following chemotherapy were treated with RT and they continued with their concomitant IFN-alpha. The RT dose was 50 Gy. Radiation-induced lung injury was assessed by lung function tests, computed tomography and bronchoalveolar lavage fluid (BALF) analysis which included cell findings, Interleukin (IL)-1 alpha/-1 beta expression by alveolar macrophages and surfactant components. Seventeen patients were entered in the study, 16 of whom were evaluable. Response rates in Arms O, I and II were 50, 67 and 50%, respectively. Median survival was 18.5, 7 and 23 months respectively, and 1-year survival was 67, 29 and 75% respectively. Long-term survival as assessed by 2- and 3-year survival rates was 29% in patients receiving natural IFN-alpha as compared to 17% in patients not receiving IFN (not statistically significant findings). Every patient had abnormal results when assessed for radiation-induced lung injury. No statistically significant difference was found in toxicity between the treatment arms. A high surfactant protein (SP)-A/phospholipid ratio and a high level of SP-A in BALF before RT was associated with a high degree of radiation-induced lung injury measured by lung function tests and computed tomography in all arms of the study. Thus, we could not show that the combination of IFN-alpha and RT induced more lung toxicity than RT alone as we did in our previous study. The role of high SP-A/phospholipid ratios and high SP-A levels in BALF before RT as predictors of the development of lung injury after RT needs to be determined in the future.

Bronchiolitis obliterans organizing pneumonia syndrome primed by radiation therapy to the breast. The Groupe d'Etudes et de Recherche sur les Maladies Orphelines Pulmonaires (GERM"O"P)

Reports of bronchiolitis obliterans organizing pneumonia (BOOP) occurring in women after radiation therapy for breast cancer have suggested that radiation to the lung could participate in the development of BOOP. We now describe the clinical, radiographic, functional, and bronchoalveolar lavage characteristics of this syndrome in a series of 15 patients reported to the Groupe d'Etudes et de Recherche sur les Maladies "Orphelines" Pulmonaires (GERM"O"P) in France. All 15 women (60 +/- 6 yr of age) fulfilled the following inclusion criteria: (1) radiation therapy to the breast within 12 mo, (2) general and/or respiratory symptoms lasting for at least 2 wk, (3) lung infiltrates outside the radiation port, and (4) no specific cause. The patients presented with fever, nonproductive cough, mild dyspnea, and peripheral alveolar opacities on chest radiograph with a characteristic migratory pattern. In five patients, BOOP was found at lung pathologic analysis. In all the patients dramatic improvement was obtained with corticosteroids, but relapses occurred in 12 patients while tapering or after stopping corticosteroids. This report demonstrates that a characteristic BOOP syndrome may occur after radiation therapy to the breast, including tangential radiation to the lung, thus suggesting that radiation therapy may prime the development of BOOP.

[Treatment of stage IIIB loco-regionally advanced non-small-cell bronchial carcinomas with radiation and interferon-beta. Preliminary results of a phase II study]

BACKGROUND

In-vitro and in-vivo studies demonstrated the radiosensitizing effect of interferon beta on malignant tumor tissue as well as simultaneously a radioprotective effect on normal lung tissue. In this phase II study the outcome of combining radiotherapy with interferon beta in patients with advanced non-small cell lung cancer was evaluated.

PATIENTS AND METHOD

From February 1994 until November 1996 14 patients with non-small cell lung cancer, stage IIIB were treated with locoregional radiation up to 59.4 Gy, with daily doses of 1.8 Gy and 5 fractions per week. Five million units of interferon beta (Fiblaferon) were given intravenously immediately preceding radiotherapy on the first 3 days of week 1, 3 and 5.

RESULTS

Four of 14 patients (28.6%) showed complete response and 7 patients (50%) partial response, resulting in an overall response rate of 78.6%. After a mean follow-up time of 23.3 months the 1-, 2- and 3-year survival rates were 56.3%, 37.5% and 37.5%, respectively. The median survival time was 13 months. Three of 14 patients (21.4%) suffered from 7 Grade-3 acute side effects and 2 patients (14.3%) from 1 Grade-3 late toxicity in each case. One further patient, whose right lung was resected 3 months after completion of radiotherapy, developed as a consequence of this operation 2 Grade-4 complications.

CONCLUSION

Considering the toxicity and the preliminary results of combining irradiation and interferon beta in the treatment of locally advanced non-small cell lung cancer it seems, that this procedure is worth to be tested in a phase III study.

[The inhalation versus systemic prevention of pneumonitis during thoracic irradiation]

BACKGROUND

Pneumonitis is a typical subacute reaction of healthy bronchial tissue to thoracic irradiation. The purpose of the present trial was to show whether prophylactic application of steroids in the course of and following radiotherapy would reduce the incidence of pneumonitis.

PATIENTS AND METHODS

Fifty-seven patients receiving thoracic irradiation for bronchial carcinoma were assigned to 2 therapeutic groups; half of the patients were given 10 mg of oral prednisolone per day, while the other half received daily inhalative beclomethasone. All patients were evaluated for radiographic signs of pneumonitis. Thirty-two patients received additional investigations for pulmonary diffusion capacity of carbon monoxide.

RESULTS

The overall incidence of pneumonitis was 17.6% (10/57 patients). Neither total radiation dose nor mode of fractionation did significantly contribute to the incidence of pneumonitis. Those patients showing a pulmonary diffusion capacity for carbon monoxide of less than 60% prior to radiotherapy had a significantly higher risk of developing pneumonitis (4/7) than patients with a higher diffusion capacity (3/25, p = 0.026). In follow-up period we did not see significant changes in diffusion capacity neither with patients who developed pneumonitis nor with those patients showing no evidence of pulmonary injury. Comparing the chest X-ray there were less radiographic changes consistent with pneumonitis in the inhalative beclomethasone (2/28) than in the oral prednisolone group (8/29, p = 0.045).

DISCUSSION

In order to reduce the incidence of pneumonitis in patients receiving thoracic irradiation we support a continuous application of steroids in the course of and following radiotherapy. The inhalative use of beclomethasone has proved to be superior to oral prednisolone due to better local efficacy and decreased unwanted side effects.

Role of recombinant interferon-gamma maintenance in responding patients with small cell lung cancer. A randomised phase III study of the EORTC Lung Cancer Cooperative Group

This study was undertaken to determine if recombinant interferon-gamma (rIFN-gamma) given every other day as maintenance therapy could prolong the survival of patients with small cell lung cancer (SCLC) who achieved a complete or nearly-complete response to induction therapy. A secondary endpoint was to assess the toxicity of alternate day doses of this treatment. One hundred and seventy seven patients in complete or nearly-complete response following chemotherapy with or without thoracic radiotherapy were studied. Patients were randomised to receive either rIFN-gamma 4 million units (0.2 mg) subcutaneously every other day for 4 months or observation. One hundred and twenty of the 127 registered patients were eligible; 59 patients received IFN and 61 patients without maintenance therapy were followed. Alternate day IFN was reasonably well tolerated by the majority of patients, but in 12% substantial non-haematological toxicity (including flu-like syndrome) occurred. One of 3 patients with pneumonitis died after having received 3.6 mg IFN. The median survival time from the date of randomisation was 8.9 months for the IFN arm and 9.9 months for the observation arm. rIFN-gamma at the dose and schedule used in this study failed to prolong response duration and survival in SCLC patients in complete or nearly-complete response. The toxicity seen with every other day doses of IFN was less than that reported with daily dosing. The hypothesis that this agent may increase the deleterious effects of radiation on normal lung tissue was supported by the development of pneumonitis in 3 cases of whom 1 had a fatal outcome. The results do not warrant further studies with rIFN-gamma on maintaining response in SCLC.

Local low-dose interleukin-2 induces systemic immunity when combined with radiotherapy of cancer. A pre-clinical study

Tumor recurrence and outgrowth of metastases limit the therapeutical effect of radiotherapy. We have tested whether these problems can be overcome by supplementing radiotherapy with locoregional interleukin-2 (IL-2) treatment. The SL2 lymphoma and the M8013 mammary carcinoma were used. Mice bearing a 10-day-old s.c. tumor were locally irradiated and were treated daily with IL-2 peritumorally for 5 or 10 days. Low-dose IL-2 therapy improved local response (LR) and increased disease-free survival (DFS) in both tumor models following either single-dose irradiation or fractionated irradiation. For example, 93% of SL2-bearing mice treated with single-dose irradiation and 10 days of IL-2 experienced long-term DFS, compared with 17% for irradiation alone (p < 0.0001). Additionally, treatment of one tumor with irradiation +IL-2 led to anti-tumor effects in a second, untreated tumor in 80% of SL2-bearing mice. LR was increased to 100% and DFS to 70% when the second, non-irradiated tumor was also treated with peritumoral IL-2. We conclude that supplementing local radiotherapy with low doses of IL-2 results in increased local tumor control and regression of distant, non-irradiated tumors. This type of radioimmunotherapy is a promising new approach for the clinic.

Recombinant human interferon-beta (rHuIFN-beta) and radiation therapy for inoperable non-small cell lung cancer

Fifteen patients with stage II, IIIA, and IIIB non-small cell lung cancer (NSCLC) received subcutaneous (s.c.) recombinant, glycosylated, human interferon-beta 1a (Rebif; rHuIFN-beta 1a) on each day of conventionally fractionated radiation therapy (RT) given in 2.0 Gy fractions to 60 Gy in 6 weeks. The rHuIFN-beta 1a was generated in CHO cells by recombinant DNA technology and is identical to natural IFN-beta produced by fibroblasts in primary sequence and glycosylation. Cohorts of three patients each were treated with escalating doses of rHuIFN-beta 1a: 1.5, 3, 6, 12, and 24 MIU/m2 per treatment day. Acute toxicity was assessed according to modified WHO criteria; late toxicity was graded using RTOG late toxicity criteria. The maximum tolerated dose (MTD) of rHuIFN-beta 1a was defined as the dose level immediately below that in which dose-limiting toxicity occurred in > or = two of six patients. Immunomodulatory effects and antigenicity of rHuIFN-beta 1a were assessed by 2-5A synthetase, beta 2-microglobulin, and neopterin levels and by measurement of anti-rHuIFN-beta antibodies, respectively. Fourteen of fifteen patients experienced grades 1-3 acute (early) toxicity (< or = 90 days), which was primarily gastrointestinal: dysphagia/esophagitis (14/15), nausea/vomiting (12/15), anorexia (7/15), and liver transaminasemia (6/15). One of three patients treated with 24 MIU/m2 per treatment day (total rHuIFN-beta 1a dose 672 MIU) died of complications secondary to pneumonia, sepsis, adult respiratory distress syndrome (ARDS), and radiation pneumonitis. Twelve patients were evaluable for late toxicity (> 90 days). Maximum toxicity was grade 0 in five patients, grade 1 in four patients, and grade 5 in one patient (radiation pneumonitis). Clinical responses from the combination were 1/15 CR, 6/15 PR, 6/15 stable disease, and 1/15 progressive disease. The MTD of rHuIFN-beta 1a has been estimated at 12 MIU/m2 per treatment day when given daily during conventional RT to 60 Gy in 6 weeks. Biologic response by rHuIFN-beta 1a alone was reflected by significant and dose-related increases in 2-5A synthetase, beta 2-microglobulin, and neopterin. Radiation therapy alone had no effect on these immune response parameters and did not diminish their augmentation by rHuIFN-beta 1a. There was no association of biologic modulation with clinical response or survival.

Effect of interfraction interval in hyperfractionated radiotherapy with or without concurrent chemotherapy for stage III nonsmall cell lung cancer

PURPOSE

To explore the influence of interfraction interval in hyperfractionated radiotherapy (HFX RT) with or without concurrent chemotherapy for Stage III nonsmall cell lung cancer.

METHODS AND MATERIALS

One hundred sixty-nine patients treated in a randomized study were retrospectively analyzed. Group I patients were treated by HFX RT with 1.2 Gy twice daily with a total dose of 64.8 Gy in 27 treatment days, while Groups II and III patients were treated by the same HFX RT and concurrent chemotherapy with carboplatin and etoposide (every week in Group II and every other week in Group III). Interfraction intervals of either 4.5-5 h or 5.5-6 h were used for each patient.

RESULTS

Patients treated with shorter interfraction intervals (4.5-5 h) had a better prognosis than those treated with longer intervals (5.5-6 h) (median survival: 22 vs. 7 months; 5-year survival rate: 27% vs. 0%, p = 0.00000). This phenomenon was observed in all treatment groups. Patients > or = 60 years of age, with Stage IIIA disease, or with previous weight loss < or = 5% were treated more often with the shorter intervals than those < 60 years, with Stage IIIB disease, or with weight loss > 5%, respectively, but in all of these subgroups of patients, the shorter intervals were associated with a better prognosis. Multivariate analysis showed that the interfraction interval was an independent prognostic factor, together with sex, age, performance status, and stage. The shorter intervals were associated with an increased incidence of acute high grade toxicity, but not with an increase in late toxicity.

CONCLUSION

Patients treated with shorter interfraction intervals (4.5-5 h) appeared to have a better survival than those treated with longer intervals (5.5-6 h). Prospective randomized studies are warranted to further investigate the influence of interfraction interval in HFX RT.