A composition comprising a dendritic cell therapy/vaccine (DC vaccine) for use in treating or delaying progression of squamous cell carcinoma of the lungs in an individual, wherein the treatment comprises administration of the composition in combination with a second composition comprising a myeloid-derived suppressor cell (MDSC)-inhibiting agent and an optional pharmaceutically acceptable carrier, wherein the DC vaccine has been prepared with an antigen source selected from tumor associated peptide(s), whole antigens from DNA or RNA, whole antigen-protein, idiotype protein, tumor lysate/whole tumor cells or viral vector-delivered whole antigen, wherein the MDSC-inhibiting agent blocks or inhibits differentiation/maturation of MDSCs, blocks or inhibits migration of MDSCs or induces depletion of MDSCs/apoptosis of MDSCs, or inhibits expansion of MDSCs, or inhibits MDSC effector functions, and wherein the MDSC-inhibiting agent that blocks or inhibits differentiation/maturation of MDSCs is selected from all-trans-retinoic acid, Curcumin derivatives; wherein the inhibitor of migration of MDSCs is selected from Zolendronic acid, anti-glycan antibodies and CSF-1R inhibitors; wherein the inducer of depletion or apoptosis of MDSCs is selected from tyrosine kinase inhibitors, preferably Sunitinib, anti-Gr1 antibodies, IL4Rα aptamer, Gemcitabine, Cisplatin, Paclitaxel, 17-Dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) or 5-fluorouracil (5-FU); wherein the inhibitor of expansion of MDSCs is selected from Bevacizumab, Celecoxib and Pimozide; and wherein the inhibitor of MDSC effector functions is an inducer of oxidative stress and is selected from N-hydroxyl-L-Arginine (NOHA), Nitroaspirin, N-acetyl cysteine, CpG oligodeoxy-nucleotides, Bardoxolone methyl (CDDO-Me), Withaferin A or Stattic. administration of the composition in combination with a second composition comprising a myeloid-derived suppressor cell (MDSC)-inhibiting agent and an optional pharmaceutically acceptable carrier, wherein the DC vaccine has been prepared with an antigen source selected from tumor associated peptide(s), whole antigens from DNA or RNA, whole antigen-protein, idiotype protein, tumor lysate/whole tumor cells or viral vector-delivered whole antigen, wherein the MDSC-inhibiting agent blocks or inhibits differentiation/maturation of MDSCs, blocks or inhibits migration of MDSCs or induces depletion of MDSCs/apoptosis of MDSCs, or inhibits expansion of MDSCs, or inhibits MDSC effector functions, and wherein the MDSC-inhibiting agent that blocks or inhibits differentiation/maturation of MDSCs is selected from all-trans-retinoic acid, Curcumin derivatives; wherein the inhibitor of migration of MDSCs is selected from Zolendronic acid, anti-glycan antibodies and CSF-1R inhibitors; wherein the inducer of depletion or apoptosis of MDSCs is selected from tyrosine kinase inhibitors, preferably Sunitinib, anti-Gr1 antibodies, IL4Rα aptamer, Gemcitabine, Cisplatin, Paclitaxel, 17-Dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) or 5-fluorouracil (5-FU); wherein the inhibitor of expansion of MDSCs is selected from Bevacizumab, Celecoxib and Pimozide; and wherein the inhibitor of MDSC effector functions is an inducer of oxidative stress and is selected from N-hydroxyl-L-Arginine (NOHA), Nitroaspirin, N-acetyl cysteine, CpG oligodeoxy-nucleotides, Bardoxolone methyl (CDDO-Me), Withaferin A or Stattic.