lung cancer is the major cause of cancer - related death in many developed countries . non - small cell lung cancer ( nsclc ) is the most common type ( about 85% ) of lung cancer . however , the overall survival ( os ) of the majority of patients with nsclc receiving conventional cancer treatment such as surgery , radiotherapy , and chemotherapy remains low . immunotherapy is an attractive therapeutic option that has been increasingly used against several types of cancer targeting antigens derived from cancer cells and enforcing patient 's immune system . nevertheless , most of the clinical studies with cancer immunotherapy , so far , have failed to demonstrate a clear clinical benefit . a possible explanation is that activation of the immune system alone is not capable of inducing a sufficient response to therapy since other mechanisms , such as immune suppression , are involved . therefore , combined therapies that on one hand induce immune activation and on the other hand inhibit suppressive mechanisms could be considered necessary to develop an effective immunologic strategy against cancer . myeloid - derived suppressor cells ( mdsc ) , t regulatory cells ( tregs ) , and t helper 17 ( th17 ) cells   have been characterized as suppressive cells targeting both innate and adaptive immunity . these cells exert their suppressive action through several mechanisms including the release of inhibitory cytokines such as interleukin 10 ( il-10 )   and transforming growth factor - beta ( tgf- ) , the stimulation of inhibitory cell surface components on t cells such as programmed death-1 ( pd-1 )   and cytotoxic t - lymphocyte - associated protein 4 ( ctla-4 )   or by activation of fas / fasl pathway . among the distinct suppressor cell populations , mdscs play a key role . they represent a heterogeneous population of immature myeloid cells consisting of myeloid progenitors and precursors of macrophages , granulocytes , and dendritic cells ( dcs ) which are characterized by their functional suppressive ability . two main subpopulations of mdscs have been identified in humans ; monocytic ( m - mdsc ) and granulocytic ( g - mdsc ) . several suppressive functions of mdsc have been suggested including inhibition of t cell ( cd8 and cd4 ) activation , dc differentiation , impairment of b - cells , blocking natural killer ( nk ) cell cytotoxicity , and expansion of tregs . mdscs are also involved in angiogenesis and metastasis through production of matrix metallopeptidase 9 ( mmp9 ) and tgf-1 . however , the mechanisms leading to the suppression of the immune responses are highly dependent on the cancer 's microenvironment . in the recent years , however , there is no consensus regarding the phenotypic characterization of these cells since several distinct combinations of markers have been used in different studies . few studies have tested the expression of mdscs in nsclc patients and even less have identified them by using markers of immaturity of myeloid and lymphoid cells such as human leukocyte antigen - dr ( hla - dr ) or lineage according to the more recent definition of mdscs . it has been recently demonstrated that a granulocytic subtype ( cd15cd14cd33cd11b ) of mdscs has suppressive activity , whereas an increased number of mdscs ( cd11bcd14 cells ) was negatively associated with the frequency of cd8 t lymphocytes and responsiveness to treatment in patients with nsclc . moreover , it has been reported that cd33cd11b mdscs , a population with more mature features , were able to suppress t cell proliferation in nsclc patients . the aims of the current study were to identify phenotypically new subpopulations of mdscs , strictly in immature myeloid cells , in nsclc patients and to correlate them with the patients ' clinical outcome . peripheral blood in edta ( bd biosciences , europe ) was obtained from 110 chemotherapy - naive nsclc patients at the time of diagnosis and before the administration of any systemic or local treatment . all patients were older than 18 years and had not received any immunosuppressive drugs or g - csf injections prior to immune testing . all patients were diagnosed with inoperable , locally advanced ( stage iii with pleural effusion or severe respiratory failure ) or metastatic ( stage iv ) nsclc . the median patients ' age was 68 years , 84.5% were men , 51.8% had an adenocarcinoma , and 74.5% had stage iv disease . all patients were treated with 46 cycles of platinum - based chemotherapeutic regimen ( 13.6% and 78.3% with or without bevacizumab , resp . ) . eighty - eight ( 86.3% ) patients were evaluable for assessment of clinical outcome ; the rest of them ( n = 22 ) either received only one chemotherapy cycle ( n = 14 ) because of early death or refused systemic anticancer treatment and received only supportive care ( n = 8) . for controls , blood samples were collected from 19 age- and sex - matched healthy ( 12 males and 7 females ; age 68  7 years ) volunteers . all patients and controls provided a written informed consent and the study was approved by the ethics and scientific committees of our institution . peripheral blood from chemotherapy - naive patients with advanced or metastatic nsclc blood samples underwent red blood cell lysis using red blood cell ( rbc ) lysing buffer according to the manufacturer recommendations ( bd biosciences ) . briefly , 5  ml edta - treated whole blood was added into a tube containing 45  ml rbc lysing buffer at room temperature . following 20  min incubation at room temperature , the tubes were centrifuged at 500  g for 5  min . the supernatant was discarded and the white blood cell pellet was washed twice with 15  ml flow buffer ( 1% fcs , 0.01% nan3 in pbs ; sigma , usa ) and cells were then resuspended in flow buffer ( 1  10/ml ) for immunophenotypic analysis . fluorescence - active cell sorting ( facs ) analysis was performed on freshly isolated cells . white blood cells were stained for expression of surface markers using anti - human monoclonal antibodies conjugated to fluorochrome against different molecules : ( a ) for the mdscs subsets : anti - cd14 pe cy7 ; anti - cd15 v450 ; anti - cd11b fitc ; anti - cd33 alexa 700 ; anti - hla - dr apc - h7 ; anti - lin ( cd3/cd4/cd16/cd56/cd19 ) pe , ( b ) for b and t cells : anti - cd3 pe - cf594 ; anti - cd4 v500 ; anti - cd8 apc - cy7 , anti - cd19-fitc , and ( c ) for dc and monocytes : anti - cd14 pe cy7 ; anti - cd11b fitc ; anti - hla - dr apc - h7 . after washing , cells were resuspended in 0.5  ml flow buffer and a multicolour analysis was performed using an lsrii flow cytometer ( bd biosciences ) . for intracellular staining , the cells were permeabilized by bd intrasure kit according to manufacturers ' instructions and stained for inducible nitric oxide synthase ( inos)percp ( santa - cruz , usa ) . analysis of facs data was done using facs diva software ( bd biosciences ) . for t - cell subset and b cell analysis , the acquisition and analysis gates were restricted to the lymphocyte population , whereas for mdsc analysis , all cells , but lymphocytic mononuclear cells , were included . cd3/cd4 and cd3/cd8 cells were calculated as a percentage of cd3 lymphocytes . in an attempt to be in line with the definitions of mdscs that have been used in various tumors , we defined and investigated the presence of cd14 and cd15 markers strictly gated in hla - dr and lineage negative myeloid cells ( cd33cd11bhla - drlin ) . the m - mdscs expressing hla - drlincd33cd11bcd14cd15 or cd15 ( referred to as cd14cd15hla - drlin and cd14cd15hla - drlin , resp . ) and the g - mdscs expressing hla - drlincd33cd11bcd14cd15 ( referred to as cd14hla - drlin throughout the paper ) were calculated as a percentage of cd11bcd14 and cd11bcd14 , respectively . the gating strategy for both m - mdscs and g - mdscs populations is shown in figure 1 . the intracellular oxidant intensity was determined by using 5-(and-6)-chloromethyl-2,7-dichlorodihydrofluorescein diacetate - acetyl - ester ( dcfda ; invitrogen , usa ) , which is metabolized to fluorescent 2-7-dichlorofluorescein ( dcf ) upon oxidation . single - cell suspensions from blood were incubated in rpmi1640 medium containing 2.5  m dcfda with / or without 30  ng / ml pma for 30  min at room temperature . subsequently , cells were washed twice in flow buffer and stained with mdsc mabs and the mean fluorescence intensity ( mfi ) of intracellular dfc was determined by flow cytometry . statistical analysis was performed using graphpad prism version 6.0 ( graphpad institute inc , usa ) . differences between groups were determined using the mann - whitney nonparametric test and wilcoxon matched - pairs signed rank test , as stated . spearman 's rank correlation tests were used to assess relationships between the levels of mdscs and other tested immune cells types . high expression of mdscs was defined as the percentage of the cells above the 90% percentile of the controls . median os and progression - free survival ( pfs ) were estimated using the kaplan - meier method with groups compared using the log - rank test . pfs was defined as the time between the enrolment and the first date of first observation of clinical progression or death . a univariate cox regression analysis , with hazard ratios ( hr ) and 95% confidence intervals ( 95% ci ) , was used to assess the association between each potential prognostic factor with os and pfs . all variables significant on univariate analysis were considered further in a multivariate cox proportional hazards regression model to evaluate the independent significance of different variables on os and pfs . initially , we sought the mdsc subpopulations that have been described by other groups in nsclc patients . indeed , we determined the percentages of cd33cd11b , cd14cd11b , cd11bcd14cd15 , cd11bcd33cd14cd15 , and cd14hla - dr population ( table 2(a ) ) . next , we identified , phenotypically , two newly monocytic subpopulations ( cd14cd15hla - drlin and cd14cd15hla - drlin , resp . ) and one granulocytic ( cd14hla - drlin ) based on the expression of cd15 and cd14 markers in the immature myeloid cell population ( cd33cd11bhla - drlin ) in the peripheral blood of chemotherapy - naive nsclc patients ( table 2(b ) ) . the percentages of cd33cd11b ( 41.4  4% versus 24.4  5% ; p = 0.03 ) , cd14cd11b ( 66.1  3% versus 48.02  6% ; p = 0.01 ) , cd11bcd14cd15 ( 83.3  2.3% versus 78.4  4% ; p = 0.02 ) , and cd11bcd33cd14cd15 ( 40.3  3% versus 21.3  5% ; p = 0.01 ) cells were significantly increased in patients compared to healthy donors ( figures s1(a  d ) in supplementary material available online at http://dx.doi.org/10.1155/2014/659294 ) , with an exception of the cd14cd11bhla - dr population which did not differ ( 25.2  2% versus 24.4  6% ; p = 0.2 ; figure s1(e ) ) . elevated levels of m - mdsc subpopulations , defined as cd14cd11bcd33cd15hla - drlin ( cd14cd15hla - drlin ; 3.5  0.5% versus 0.5  0.2% ; p  0.0001 ) and cd14cd11bcd33cd15hla - drlin ( cd14cd15hla - drlin ; 5.2  0.5% versus 3  0.8% ; p = 0.04 ) , were observed in patients compared to healthy donors ( figures 2(a ) and 2(b ) ) . similarly , the levels of the g - mdsc subpopulation ( cd14cd11bcd33cd15hla - drlin ; cd14hla - drlin ) were significantly increased in patients ( 2  0.5% , n = 102 ) compared to healthy controls ( 0.1  0.02% , p  0.0001 ; figure 2(c ) ) . the differences between normal volunteers and patients with stage iii and stage iv solid tumours were also statistically significant ( p < 0.0001 ) . however , the differences of the mdscs ' percentages between locally advanced cancer patients ( stage iii ) and stage iv were not significant ( figure s2 ) . subsequently , we investigated whether these subpopulations are equally expanded in the peripheral blood of nsclc patients in nsclc favour of one subpopulation over the other . indeed , the frequency of cd14cd15hla - drlin subpopulation was more prevalent ( 5.2  0.5% ) in the whole blood of patients compared to the other two subpopulations ( cd14cd15hla - drlin : 3.5  0.5% , p  0.0001 , and cd14hla - drlin : 2  0.5% , p = 0.0001 ) ( figure 2(d ) ) . however , there were significant positive correlations between each mdsc subpopulation ( cd14cd15hla - drlin versus cd14cd15hla - drlin , spearman r = 0.5 , p  0.0001 ; cd14cd15hla - drlin versus cd14hla - drlin , spearman r = 0.2 , p  0.05 ; cd14cd15hla - drlin versus cd14hla - drlin , spearman r = 0.3 , p  0.003 ) indicating that all mdscs subtypes are equally increased . in contrast , the percentages of all subtypes of mdscs did not statistically differ in the normal control ( figure 2(d ) ) . in order to investigate if these new subpopulations of nsclc mdscs are functional as well as their possible mechanisms of action , we assessed the expression of ros and inos in all of our subpopulations by flow cytometry ( figure 3(a ) ) . a higher frequency of both subpopulations of m - mdscs ( cd14cd15hla - drlin and cd14cd15hla - drlin ) expressed inos [ 0.3  0.1% , ( n = 6 ) and 0.4  0.2% , ( n = 6 ) , resp . , p < 0.02 ] in nsclc patients compared to normal controls [ 0.002  0.001% , ( n = 6 ) and 0.02  0.017% , ( n = 6 ) , resp . ] . in contrast , neither nsclc patients nor healthy controls did have inos - expressing cd14hla - drlin mdscs ( figure 3(b ) ) . the expression levels of inos , as determined by mean fluorescence intensity ( mfi ) , were also higher only in nsclc cd14cd15hla - drlin [ 453  99 , ( n = 6 ) ; p < 0.03 ] compared with healthy donors [ 75  50 , ( n = 6 ) ; figure 3(c ) ] . next , we assessed ros levels in m - mdscs and g - mdscs subpopulations by measurement of 2-7-dichlorofluorescein ( dcf ) ( figure 3(d ) ) . even though the percentage of g - mdscs ( cd14hla - drlin- ) producing ros was numerically higher in patients compared to other subpopulations and healthy controls , this difference could not reach statistical significance ( figure 3(e ) ) . however , in patients , the levels of ros production by g - mdscs following pma stimulation was significantly higher [ 1  0.03 , ( n = 6 ) , p < 0.005 ] than the healthy controls ' g - mdscs [ 0.6  0.08 , ( n = 6 ) ; figure 3(f ) ] . phenotypic analysis of other immune cells demonstrated a decrease in the percentages of cd3cd4 t helper cells ( 36  2.1% versus 58.7  4.5% , p  0.0001 ) , cd14cd11b monocytes ( 18.8  1.7% versus 34.4  4.6% , p  0.0004 ) , and mature cd14hla - dr dc ( 47.6  2.6% versus 63.1  5.2 , p = 0.015 ) in nsclc patients compared to normal controls . on the contrary , there was no difference in the expression of cd19 b cells ( 8.2  0.8% versus 20.1  2% , p = 0.6 ) and cd3cd8 cytotoxic t cells ( 20.6  1.2% versus 7.4  0.9% , p = 0.9 ; table 3 ) . further analysis revealed that the percentage of both subpopulations of m - mdscs , but not of g - mdscs subpopulation , was inversely correlated with dc / monocytes percentages ( cd14cd15hla - drlin versus dc / monocytes : spearman r = 0.3 , p  0.001 ; cd14cd15hla - dr - lin versus dc / monocytes : r = 0.201 , p  0.04 ) . moreover , the g - mdscs subpopulation , but not the m - mdscs subpopulations , was inversely correlated with the levels of cd4 t cells ( cd14hla - dr - lin versus cd4 t : r = 0.3 , p = 0.006 ) . patients with progressive disease ( pd ) upon front - line chemotherapy had significantly increased percentages of both m - mdsc subpopulations of ( cd14cd15hla - drlin : 1.1  0.3% ; cd14cd15hla - drlin : 5.5  1.1% ) compared to those with disease control ( dic ) ( 0.6  0.07% , p = 0.02 ; 2.9  0.3% ; p = 0.02 , resp . ; figures 4(a ) and 4(b ) ) . in contrast , the g - mdscs did not correlate with the response to treatment ( pd versus dic : 1.1  0.2% versus 0.6  0.07% , p = 0.3 , resp . ; figure 4(c ) ) . assuming increased levels of mdscs those that were over the 90% percentile of the controls ( outliers excluded ) patients were dichotomized into those with above normal range of mdsc percentage ( high expression > 2.2% ) and those within the normal range ( 2.2% ) . the detection of cd14cd15hla - drlin mdscs within the normal levels at baseline was associated with longer pfs and os compared to those with high levels ( 10.87 versus 5.3 months p = 0.005 and 12.9 versus 7.1 months , p = 0.008 , resp . ; on the other hand , neither the levels of cd14cd15hla - drlin nor cd14hla - drlin subpopulation correlated with the clinical outcome of the patients . univariate analysis revealed that high expression of cd14cd15hla - drlin m - mdscs ( p = 0.003 ) and disease stage ( p = 0.03 ) significantly correlated with decreased pfs whereas only high expression of cd14cd15hla - drlin m - mdscs was significantly associated with decreased os ( table 4(a ) ) . the multivariate analysis showed that high levels of cd14cd15hla - drlin m - mdscs emerged as an independent prognostic factor for decreased pfs ( hr = 2.41 ; 95% ci , 1.374.24 , p = 0.002 ) and os ( hr = 2.35 ; 95% ci , 1.254.41 , p = 0.008 ; table 4(b ) ) . nowadays , it is widely accepted that there are distinct tumor - mediated mechanisms observed in cancer patients and impede the adequate immune response against tumor cells . among them , mdscs play a crucial role and their importance is a subject of extensive investigation . phenotypic and functional heterogeneity of these cells creates many difficulties in the identification of mdscs in humans . studies in cancer patients with different tumor types suggest various mdscs definitions based , mainly , on the expression of cd33 , cd11b , and cd15 molecules and by the absence or low levels of the hla - dr molecule . two major subtypes of mdscs have been described in humans , the m - mdscs that express predominantly the cd14 molecule and the g - mdscs that express cd15 molecule . in prostate cancer   and melanoma patients , increased levels of cd14cd11bhla - dr m - mdscs have been associated with poor immune response to an antitumor vaccine . in addition , high percentages of cd14hla - dr m - mdscs in patients with hepatocellular carcinoma were shown to induce the production of cd4cd25foxp3 regulatory t cells . on the other hand , in patients with renal cell carcinoma , an increased expression of a g - mdsc subtype was detected , whereas other studies in colon carcinoma and melanoma have shown increased levels of both g - mdsc and m - mdsc subtypes . recent reports in nsclc have defined mdscs as cd33cd11b , cd14cd11b , cd15cd14cd33cd11b , cd14hla - dr , and cd15cd14cd33cd11b   cells . in the current study , we investigated all the above mentioned subpopulations of mdscs in patients with nsclc and we confirmed that many of them were significantly increased compared to the healthy control ( figures s1(a  d ) ) . interestingly , it is demonstrated , for the first time , the presence of two monocytic cd14cd11bcd33cd15hla - drlin and cd14cd11bcd33cd15hla - drlin and a granulocytic cd14cd11bcd33cd15hla - drlin subpopulation of mdscs associated with the clinical outcome in nsclc patients ( table 4 ) , although there was no difference in the frequency of the distinct subpopulations of mdscs according to the histology , stage , and subsequent chemotherapy treatment ( data not shown ) . the m - mdsc subpopulations were the predominant subtypes , as they were markedly increased compared to g - mdsc in contrast with the data coming from preclinical studies which reported that the g - mdsc subtype was predominant in tumor - bearing mice . however , movahedi et al . showed that both subtypes were equally increased in mice bearing t cell lymphoma . this observation seems to indicate that regulation of mdscs differentiation can be tumor - driven by taking into consideration that different tumor - factors are released in different cancer types . therefore , the significance of the increased levels of m - mdscs over the granulocytic subtype in nsclc needs to be further investigated by a direct comparison of their expression in distinct cancers . several studies have suggested a negative impact of mdsc in the effector cells of the immune system of cancer patients , including nk cells , dcs , both lymphocytic populations ( cd4 and cd8 t cells ) , b cells , and monocytes [ 34 , 35 ] . indeed , in the present study a dramatic reduction in the numbers of mature dc ( cd14hla - dr ) , the key regulators in the activation of lymphocyte subsets to control or eliminate tumors , was observed . in addition , the levels of monocytes ( cd14cd11b ) , as well as of cd3cd4 t cells were also found significantly decreased compared to healthy controls . on the contrary , the levels of cd3cd8 cytotoxic t cells , as well as cd19 b cells did not differ between the nsclc patients and controls . moreover , the reduced levels of the effector cells were inversely correlated with the presence of the mdscs suggesting that the circulating mdscs exert a negative regulation on the effector immune cells . whether this negative regulation could be attributed to direct contact of mdscs and the effector cells or other underlying indirect mechanisms such as identification of specific prognostic / predictive markers in nsclc is of high importance in order to facilitate the selection of patients who most likely will respond to the treatment or even those who might need an immune intervention . only few studies , so far , have provided evidence for the prognostic and/or predictive value of the elevated levels of mdsc in cancer patients . have shown increased expression of cd14hla - dr m - mdsc in the blood of multiple myeloma patients at the time of diagnosis compared to patients with disease remission . similarly , increased levels of cd11bcd33hla - drlin mdsc were shown as an independent prognostic factor in pancreatic , oesophageal , and gastric cancers and recently , two clinical studies have shown that high levels of cd14hla - dr and cd11bcd14cd15 mdscs were negatively associated with survival in renal cell carcinoma patients . in nsclc patients few studies have correlated the high mdsc levels with the clinical outcome and none of them has reported a correlation of mdsc levels with the os . liu et al .   demonstrated that a g - mdsc subtype ( cd15cd14cd33cd11b ) was negatively associated with responsiveness to treatment . however , in our study , the g - mdcs subpopulation did not correlate with the clinical outcome of the patients which might be interpreted by the fact that this subpopulation in liu 's study had been defined in pbmcs after ficoll isolation . two other studies have correlated the increased levels of circulating cd14hla - dr and cd11bcd14s100a9 cells with worse pfs and response to treatment [ 29 , 30 ] , but none with the os . moreover , all of the studies did not defined mdscs as strictly immature myeloid cells defined by the complete lack of the hla - dr and lineage molecules . an interesting finding of the present study is that baseline m - mdscs levels had a clear predictive denotation since disease progression during or after chemotherapy was correlated to elevated values of these cells . in our study , it is emerged for the first time the independent predictive and prognostic value of cd14cd15hla - drlin but not the cd14cd15hla - drlin monocytic mdcss , as revealed by multivariate analysis . normal levels of cd14cd15hla - drlin mdscs at baseline were associated with a better patients ' pfs and os compared to patients with high levels . a limitation of the current study is the absence of functional data demonstrating the suppressive activity of the newly identified subpopulations of mdscs . this was beyond the scope of the study which was the clarification of new , more specific , subpopulations of mdscs and interestingly , their possible correlation with the patients ' clinical outcome . several studies have clearly shown that the immunosuppressive effect of the mdscs is mediated by distinct mechanisms . the function of mdsc is highly depended on the cancer microenvironment and mediates its suppressive activity on the immune system through multiple mechanisms such as the production of ros , nitric oxide ( no ) , and arginase ( arg-1 ) and secretion of the cytokines il-10 and tgf-1 . the activity of ros with no forms peroxynitrite affects the conformational flexibility of tcr and its interaction with peptide - mhc complex . on the other hand , arg-1 contributes to the downregulation of the cd3 chain expression of the t cell receptor causing t cell arrest . in the present study , we demonstrated that g - mdsc subpopulation exerts its function by producing ros , while m - mdscs work rather through expression of inos ( figure 3 ) . apparently , further functional studies are required for determination of specific immune suppressive activity of these novel mdsc subpopulations . to conclude , in the present study , for first time , three distinct subpopulations of mdscs were identified in nsclc patients , two of monocytic and one of granulocytic origin . these subsets were independently associated with the patients ' clinical outcome and thus they could be considered as potential , predictive , and/or prognostic factors . the observation that their increased expression was correlated with reduced percentages of effector cells , such as dendritic and t - helper cells could lead to the hypothesis that their elimination would likely restore the host 's antitumor immune activity and consequently would improve the clinical outcome .
myeloid - derived suppressor cells ( mdscs ) represent a heterogeneous population of cells with immunosuppressive properties and might confer to worse prognosis in cancer patients . 
 the presence of phenotypically newly described subpopulations of mdscs and their association with the clinical outcome were investigated in non - small cell lung cancer ( nsclc ) patients . 
 the percentages and correlation between mdscs and distinct immune cells in the peripheral blood of 110 chemotherapy - naive patients before treatment and healthy controls were investigated using flow cytometry . 
 two monocytic [ cd14+cd15cd11b+cd33+hla - drlin and cd14+cd15+cd11b+cd33+hla - drlin ] and a granulocytic [ cd14cd15+cd11b+cd33+hla - drlin ] subpopulations of mdscs were identified , expressing inducible nitric oxide synthase , and reactive oxygen species , respectively . 
 increased percentages of both monocytic - mdscs ' subpopulations were inversely correlated to dendritic / monocyte levels ( p  0.04 ) , while granulocytic - mdscs were inversely correlated to cd4 + t cells ( p = 0.006 ) . increased percentages of monocytic - mdscs were associated with worse response to treatment ( p = 0.02 ) and patients with normal levels of cd14+cd15+cd11b+cd33+hla - drlin had longer overall survival and progression free - survival compared to those with high levels ( p = 0.008 and p = 0.005 , resp . ) . 
 multivariate analysis revealed that the increased percentages of cd14+cd15+cd11b+cd33+hla - drlin mdscs were independently associated with decreased progression free - survival and overall survival . 
 the data provide evidence that increased percentages of new monocytic - mdscs ' subpopulations in advanced nsclc patients are associated with an unfavourable clinical outcome .