the concept of this treatment started in the united states in the 1980s in randomized controlled studies in different cancers , resulting in reported significant increases in survival and disease - free period.13 its efficacy is enhanced by 20%30% when cell - based immunotherapy is combined with other conventional treatment methods . interferon ( ifn ) was one of the first cytokines found to have anticancer effects , and it was introduced into the combined modality regimens used to treat small cell lung cancer ( sclc ) in the early 1980s in an attempt to overcome the problem of early relapse . ifns are a group of proteins and glycoproteins produced by cells in response to viral stimulation.4 ifns have immunoregulatory effects on antibody production , natural killer ( nk ) and t cell activation , macrophage function , delayed - type hypersensitivity , and major histocompatibility complex molecule expression.57 they have also been shown to have antiproliferative effects and antiangiogenic properties.8 type 1 ifns ( the ifn- family and ifn- ) are known to inhibit tumor cell growth and stimulate the immune system.9 it has also been demonstrated that recombinant ifn- induces immunomodulation and has antiproliferative activity . combinations of ifn- and ifn- demonstrate synergistic antiviral and antiproliferative activity.1012 in addition , synergistic or additive interactions between ifn- and cytotoxic drugs , particularly cisplatin , have been demonstrated in the experimental setting1315 and in clinical phase ii studies.16 however , only a few randomized clinical trials have been conducted to evaluate the possible advantage of adding immunomodifiers to conventional induction therapy.17 in the past , our group has reported significant antitumor activity of ifn- and improved survival in patients with sclc.18 the aim of this study was to determine whether in patients with sclc the addition of either ifn- or ifn- or their combination with standard induction chemotherapy would improve response rates and survival at acceptable toxicity . furthermore , we evaluated the immunological responses in the peripheral blood by measuring the levels of nks and some subsets of t lymphocytes ( cd4 + t cells , cd8 + t cells , and nk t cells [ ctls ] ) and determining whether these immunoregulatory observations correlated with the progress of the disease . chemo - nave patients with histology - confirmed sclc ( limited or extensive disease ) , according to the veterans administration lung study group definition modified by the international association for the study of lung cancer , were eligible . exclusion criteria included age > 72 years , karnofsky index < 70 , central nervous system metastasis at the time of diagnosis , creatinine clearance lower than 60 ml/ min , and serious concomitant disease . from our department , 170 patients were initially recruited , from whom 164 patients were finally evaluable for assessment of response and toxicity . pretreatment investigations included : general medical examination ; chest radiography and computed tomography of the chest , upper abdomen , and brain ; tissue sampling by bronchoscopy or mediastinoscopy ; and a bone scan . all patients signed an informed consent form . a randomized , nonblinded trial was conducted . randomization was stratified for stage , and patients were divided into four groups as follows : group a , the control group , received conventional chemotherapy ; group b received chemotherapy and ifn- ( 3 million iu ) subcutaneously three times a week ; group c received ifn- ( 3 million iu ) subcutaneously three times a week ; and group d received ifn- and ifn- ( 1.5 million iu of each ) 3 times a week subcutaneously . chemotherapy was the same for all groups and consisted of eight cycles with carboplatin 5.5 mg / m intravenously on day 1 , ifosfamide 3.5 g / m intravenously ( with mesna ) on day 1 , and etoposide 200 mg / m total dose taken orally on days 1 through 3 , every 28 days , which has been shown to improve overall survival compared with standard chemotherapy in the lu21 trial.1921 after the completion of eight cycles of chemotherapy , patients were restaged by computed tomography scans of the brain , thorax , and upper abdomen . those found to have limited disease received primary site irradiation ( 4550 gy in 25 fractions ) and prophylactic cranial irradiation ( 25 gy in 12 fractions).22 immunotherapy was continued throughout these treatments and during the follow - up period as maintenance therapy . antiemetic treatment consisted of 5-hydroxytryptamine receptor antagonists , and acetaminophen 500 mg was given to treat ifn - related influenza - like symptoms . blood was taken before each course of chemotherapy and during follow - up to measure the total amount of t lymphocytes and their subgroups cd4 + t cells , cd8 + t cells , nkt ( natural killer t ) cells , and nk cells . patients who showed disease progression at any time were taken off study medication but were followed up for survival analysis . the study was initiated in may 2004 , and patient enrollment ended on february 2007 . the primary end - point of the study was survival ; the secondary end points were response after induction therapy and the fluctuation of the immunologic indices during the course of the disease ( figure 1 ) . statistical analysis was performed using the statistical package for the social sciences ( spss ; ibm corporation , armonk , n y , usa ) . differences in the four groups for clinical characteristics , response , and toxicity were assessed by chi - square statistics . survival was compared using kaplan meier statistics and log - rank test . a p - value of , 0.05 was considered significant . chemo - nave patients with histology - confirmed sclc ( limited or extensive disease ) , according to the veterans administration lung study group definition modified by the international association for the study of lung cancer , were eligible . exclusion criteria included age > 72 years , karnofsky index < 70 , central nervous system metastasis at the time of diagnosis , creatinine clearance lower than 60 ml/ min , and serious concomitant disease . from our department , 170 patients were initially recruited , from whom 164 patients were finally evaluable for assessment of response and toxicity . pretreatment investigations included : general medical examination ; chest radiography and computed tomography of the chest , upper abdomen , and brain ; tissue sampling by bronchoscopy or mediastinoscopy ; and a bone scan . randomization was stratified for stage , and patients were divided into four groups as follows : group a , the control group , received conventional chemotherapy ; group b received chemotherapy and ifn- ( 3 million iu ) subcutaneously three times a week ; group c received ifn- ( 3 million iu ) subcutaneously three times a week ; and group d received ifn- and ifn- ( 1.5 million iu of each ) 3 times a week subcutaneously . chemotherapy was the same for all groups and consisted of eight cycles with carboplatin 5.5 mg / m intravenously on day 1 , ifosfamide 3.5 g / m intravenously ( with mesna ) on day 1 , and etoposide 200 mg / m total dose taken orally on days 1 through 3 , every 28 days , which has been shown to improve overall survival compared with standard chemotherapy in the lu21 trial.1921 after the completion of eight cycles of chemotherapy , patients were restaged by computed tomography scans of the brain , thorax , and upper abdomen . those found to have limited disease received primary site irradiation ( 4550 gy in 25 fractions ) and prophylactic cranial irradiation ( 25 gy in 12 fractions).22 immunotherapy was continued throughout these treatments and during the follow - up period as maintenance therapy . antiemetic treatment consisted of 5-hydroxytryptamine receptor antagonists , and acetaminophen 500 mg was given to treat ifn - related influenza - like symptoms . blood was taken before each course of chemotherapy and during follow - up to measure the total amount of t lymphocytes and their subgroups cd4 + t cells , cd8 + t cells , nkt ( natural killer t ) cells , and nk cells . patients who showed disease progression at any time were taken off study medication but were followed up for survival analysis . the study was initiated in may 2004 , and patient enrollment ended on february 2007 . the primary end - point of the study was survival ; the secondary end points were response after induction therapy and the fluctuation of the immunologic indices during the course of the disease ( figure 1 ) . statistical analysis was performed using the statistical package for the social sciences ( spss ; ibm corporation , armonk , n y , usa ) . differences in the four groups for clinical characteristics , response , and toxicity were assessed by chi - square statistics . survival was compared using kaplan meier statistics and log - rank test . a p - value of , 0.05 was considered significant . from 170 patients initially recruited , 164 were finally eligible for assessment . from six patients who were not evaluated , four were excluded because of violation of protocol , and two patients in group c were lost because they did not attend . median survival was 10 months for group a ( 95% confidence interval [ ci ] , 9.310.6 months ) , 10.3 months for group b ( 95% ci , 7.1313.5 months ) , 8.3 months for group c ( 95% ci , 6.89.8 months ) , and 11 months ( 95% ci , 9.212.8 months ) for group d. if we compare all groups together , there is no significant difference in survival , even with pairwise comparison among four groups ( p . interestingly , when patients with only limited disease were considered , a significant survival benefit in group b was revealed compared with control group a ( p = 0.039 ) , group c ( p , 0.005 ) , and group d ( p = 0.038 ) . median survival for each group in all stages and for limited disease separately is shown in table 3 . ten patients in the ifn- group ( 25% ) and two in group d ( ifn- and ifn- ) , but none in the other groups , survived for 3 years or longer . assessment of fluctuations was based on three different time measurements : before treatment initiation ; before the fourth cycle of treatment ; and at the time of disease progression . the analysis of immunological measurements revealed improvement of immune markers accompanied by clinical improvement , whereas deterioration of all markers was accompanied , although not significantly , by disease progression ( time series analysis p < 0.05 ; figures 2 and 3 ) . significantly more patients in the immunotherapy groups than in the chemotherapy group experienced toxicity , but in groups b , c , and d , symptoms were mild and well manageable . assessment of fluctuations was based on three different time measurements : before treatment initiation ; before the fourth cycle of treatment ; and at the time of disease progression . the analysis of immunological measurements revealed improvement of immune markers accompanied by clinical improvement , whereas deterioration of all markers was accompanied , although not significantly , by disease progression ( time series analysis p < 0.05 ; figures 2 and 3 ) . significantly more patients in the immunotherapy groups than in the chemotherapy group experienced toxicity , but in groups b , c , and d , symptoms were mild and well manageable . the aim of this study was to investigate , in a randomized trial , the efficacy of adjunctive immunotherapy in sclc therapy . our previous pilot study17 has shown that combination therapy with ifn- is effective for sclc , particularly in those patients with limited disease . the present trial has confirmed that the addition of ifn- provides a good survival benefit in limited sclc , whereas administration of ifn- has no place as monotherapy in sclc treatment.23,24 immunomodulatory activity of ifn- and ifn- concerned in intensification of major histocompatibility complex i and ii molecule expression in cancer cells surface , thereby increasing the recognition and killing of these cells . ifns also directly activate other immune cells , such as macrophages and nk cells , with the difference being that ifn- protects cancer cells from the lytic activity of nk cells,25 which partly explains the absence of therapeutic effect in patients in group c , who received ifn- only . ifn- seems to have lower direct antitumor activity compared with either ifn- alone or ifn- and ifn- in combination , as shown in cancer cell lines.26 clinically , ifn- proved to be effective in the treatment of hairy cell leukemia and chronic myelogenous leukemia.27 in contrast , many other tumors , among them sclc , seem to resist cytokines , but they respond to ifns in their early stage.28 one hypothesis is that the reset of the immune system in limited disease is faster than in extensive disease ; this is also an explanation for the better response of limited disease in general . another possible explanation could be that despite chemotherapy affecting the immune system of the host negatively , ifns exert a positive influence on the immune system , and patients with limited disease have more reserve to respond to ifn stimuli . fischer et al29 found significant reduction of interleukin 2 , ifn- , ifn- , and tumor necrosis factor in patients with sclc , which improved after tumor control with chemotherapy . this immunomodulatory activity of chemotherapy seems to partly explain both the improvement of immune marker levels in patients who responded in chemotherapy and also the deterioration of them when patients experienced progressive disease in the control group . however , the lack of clinical effect is an indication of insufficient activation of cells produced or weakness of migration at the tumor site , evidenced by their appearance in large numbers in the peripheral blood . first , the total number of patients investigated was small ; this is the main limitation of the study . second , relatively low doses of cytotoxic agents were chosen to avoid a potentiation of the myelosuppressive effect by ifns.14 toxicity was characterized by fever and a higher grade of myelosuppression in the ifn groups , as could have been expected . increased neutropenia in group d shows increased toxicity when ifns are combined rather than received alone , even if their total dose remains the same . that is why sclc is uncommon in women and why the vast majority of patients enrolled in the study are men.30 in summary , among the cytokines used in this study , only ifn- appears to confer a survival benefit to patients with sclc who have limited disease . because of the low number of randomized patients , the clinical relevance of these findings remains to be defined . further clinical studies on the efficacy of ifn- as an adjunctive and/or maintenance treatment are warranted , as immunotherapy remains a challenge for the treatment of lung neoplasms .
purposeto evaluate the effect of immunotherapy on response , survival , and certain immune markers in patients with small cell lung cancer ( sclc ) who are receiving chemotherapy.patients and methodspatients with sclc ( n = 164 ) were assigned to receive either chemotherapy alone ( group a ) or a combination of chemotherapy and immunotherapy as follows : interferon  ( ifn- ; 3 million iu ) 3 times per week ( group b ) ; ifn- ( 3 million iu ) 3 times per week ( group c ) ; and ifn- and ifn- ( 1.5 million iu of each ) 3 times per week ( group d ) . chemotherapy was the same for all groups and consisted of eight cycles with carboplatin 5.5 mg / m2 intravenously on day 1 , ifosfamide 3.5 mg / m2 intravenously on day 1 , and etoposide 200 mg / m2 total dose taken orally on days 1 through 3 , every 28 days . 
 patients completing chemotherapy were restaged , and those who were found to have limited disease received primary site and prophylactic cranial irradiation . 
 immunotherapy was continued throughout these treatments and during the follow - up period . 
 blood was taken before each course of chemotherapy and during follow - up to measure cd3 + lymphocytes , cd3+cd4 + lymphocytes , cd3+cd8 + lymphocytes , natural killer cells , and natural killer t cells.resultsdifferences in response and survival were not significantly different when all patients were considered . 
 however , among patients with limited disease , kaplan 
 meier analysis disclosed a survival benefit for group b ( p , 0.05 ) . 
 the analysis of immunologic measurements revealed that the improvement of immune markers was always accompanied by clinical improvement , whereas deterioration of all markers was accompanied by disease progression ( result not statistically significant except for group c ; p , 0.05).conclusionamong cytokines used in the study , only ifn- seems to confer a survival benefit to patients with sclc with limited disease . 
 however , immunotherapy remains a challenge in the treatment of lung neoplasms and should be further explored .