A study of surgically resected peripheral non-small cell lung cancer with a tumor diameter of 1.0 cm or less.

BACKGROUND AND AIMS: The widespread use of high resolution computed tomography has increased the number of small peripheral lung cancers. This study reviewed the clinicopathological features of the patients with non-small cell lung cancer (NSCLC) with a tumor diameter of 1 cm or less, in order to explore the adequate management of such small sized lung cancers. MATERIAL AND METHODS: This study was a retrospective analysis of consecutive 58 patients (5.3% out of 1095 patients) who underwent a complete resection for a peripheral NSCLC with a diameter of 1.0 cm or less. The clinical features and outcomes were compared with 203 patients with NSCLC with a diameter between 1.1 and 2.0 cm. RESULTS: The mean age was 64.5 years and there were 26 males and 32 females. Clinical stage was IA in 57 (98%) and IIIA in 1. Lobectomy was performed in 39 patients, segmentectomy in nine, and nonanatomic wedge resection in ten. Two patients, who underwent systemic lymph node dissection, had mediastinal lymph node metastasis and were diagnosed as pathological stage IIIA; however they did not relapse after surgery. One patient with pathological stage IA papillary adenocarcinoma died due to brain metastases. The five-year overall survival rate and disease free survival rate was 95.0% and 95.3%, respectively. Patients with NSCLC of 1.0 cm or less showed significantly better survival than those with tumors measuring 1.1-2.0 cm in size (p = 0.048). DISCUSSION: The indications for avoiding systemic lymph node dissection for operable NSCLC should not be based on the size of the tumor. A small-sized lung cancer might be surgically treated before the tumor enlarges to more than 1.0 cm in size.

Results of a surgical resection for patients with thymic carcinoma.

OBJECTIVES: This study investigated the clinical features of patients with complete resection of thymic carcinoma. PATIENTS AND METHODS: The clinical records from 11 patients who underwent a complete re-section of thymic carcinoma were retrospectively reviewed. RESULTS: Twelve of 22 patients underwent a resection (a complete resection in 11 and an in-complete in 1). Six of the 11 patients with complete had confirmed recurrent tumors. The 5-year survival rate was 45.4%, and the median survival time was 50.6 months. The patients who underwent complete resection showed significantly better prognosis than cases with incomplete resection and inoperable cases (p = 0.048). Three of the 6 patients had a recurrence within 1 year. Frequent sites of recurrence were the pleura, pericardium, and lung. CONCLUSIONS: A complete resection improved the prognosis of thymic carcinoma. Further prospective studies regarding postoperative adjuvant therapy are necessary to prevent local recurrence after a surgical resection for thymic carcinoma.

Prognostic significance of lymphovascular invasion for patients with stage I non-small cell lung cancer.

AIMS: This study retrospectively investigated the clinical significance of lymphovascular invasion (LVI) following a complete resection for stage I non-small cell lung cancer (NSCLC). METHODS: A total of 226 patients who underwent a complete resection for pathological stage I NSCLC were examined. RESULTS: Lymphatic invasion was pathologically diagnosed as ly0 in 156 patients, ly1 in 65, and ly2 in 5 patients. The pathological vascular invasion was diagnosed as v0 in 178 patients, v1 in 35, v2 in 10, and v3 in 3 patients. The 5-year survival rate after surgery of the patients with and without lymphatic invasion was 76.8 and 90.6%, respectively. There was a significantly more unfavorable prognosis in patients with lymphatic invasion (p = 0.042). The 5-year survival rate of the patients with vascular invasion was also significantly more unfavorable (67.8%) than that of patients without vascular invasion (90.4%; p = 0.004). LVI was found to significantly correlate with tumor size and the presence of pleural invasion. CONCLUSION: The LVI of NSCLC is a significant prognostic factor in patients with stage I tumors. In future clinical trials, it is necessary to evaluate the efficacy of adjuvant therapy for the selection of patients according to this criterion.

[Surgical treatment for patients with descending necrotizing mediastinitis].

Descending necrotizing mediastinitis (DNM) originating from deep cervical infection is a rare and serious clinical condition with a high mortality rate. Clinical feature of 5 patients undergone surgical drainage for DNM, between 2006 and 2009 were assessed. There were 3 male and 2 female patients whose age ranged from 57 to 83 years old (mean 69.8). All 5 patients had no underlying disease except for 1 patient with severe dental caries. The primary infections of these patients were tonsillitis and pharyngitis. The mean duration from onset of symptom to the referral to our hospital was 14 days (ranged 2 to approximately 41). Two patients underwent cervical drainage for upper mediastinum, and 3 patients were required mediastinal drainage by thoracotomy. There was no post-operative death. Early and aggressive surgical drainage of the neck and mediastinum by a multidisciplinary team of surgeons is very important in the treatment of DNM.

[Molecular targeted therapy and tailor-made therapy for lung cancer].

Somatically acquired mutations in the epidermal growth factor receptor (EGFR) gene in lung cancer are associated with significant clinical responses to gefitinib, a tyrosine kinase inhibitor (TKI) that targets EGFR. In our previous report, 42.2% of adenocarcinoma patients has EGFR mutations, and these mutations were more frequently found in women than in men, in well differentiated tumors than poorly differentiated tumors, and in patients who were never smokers than in patients who were current/former smokers. Retrospectively, we screened the EGFR gene of tumors in 37 NSCLC patients who had been treated with gefitinib. EGFR mutations were found in 22 patients. Gefitinib was effective (CR/PR) in 15 of 22 (68.2%) patients with mutations compared with none of 15 patients without mutations. Patients with EGFR mutations survived for a longer period than without the mutations after initiation of gefitinib treatment (p = 0.0005). Gefitinib was not effective in 3 patients with K-ras mutations. Three of 4 tumors obtained from patients with acquired resistant to gefitinib, had a secondary T790M mutation. No T790M mutation was detected in pretreatment tumors. Molecular targeted therapy using TKI indicates an effective therapy specifically in lung cancer patients with EGFR mutations, and analyses of mechanisms of resistance to TKI are necessary for establishment of tailor-made therapy.

Mutations within the tyrosine kinase domain of EGFR gene specifically occur in lung adenocarcinoma patients with a low exposure of tobacco smoking.

Somatically acquired mutations in the epidermal growth factor receptor (EGFR) gene in lung cancer are associated with significant clinical responses to gefitinib, a tyrosine kinase inhibitor that targets EGFR. We screened the EGFR in 469 resected tumours of patients with lung cancer, which included 322 adenocarcinomas, 102 squamous cell carcinomas, 27 large cell carcinomas, 13 small cell carcinomas, and five other cell types. PCR with a specific condition was performed to identify any deletion in exon 19, while mutant-allele-specific amplification was performed to identify a mutation in codon 858 of exon 21. EGFR mutations were found in 136 cases (42.2%) with adenocarcinoma, in one case with large cell carcinoma, and in one case with pleomorphic carcinoma. An in-frame deletion in exon 19 was found in 62 cases while an L858R mutation was found in 77 cases. In the 322 cases with adenocarcinoma, these mutations were more frequently found in women than in men (P=0.0004), in well differentiated tumours than in poorly differentiated tumours (P=0.0014), and in patients who were never smokers than in patients who were current/former smokers (P<0.0001). The mutation was more frequently observed in patients who smoked

Generation of autologous tumor-specific T cell clones from a patient with adenosquamous carcinoma of the lung.

BACKGROUND: Adenosquamous carcinoma of the lung is not a common cancer, but its prognosis is worse than that of adenocarcinoma or squamous cell carcinoma. Therefore, new therapeutic strategies need to be developed to treat this type of lung cancer. Recently, vaccination using tumor antigens which are recognized by cytotoxic T lymphocytes (CTL) has been applied mainly to melanoma patients. We therefore attempted to establish T cell clones specific for autologous tumor cells (AT) from a patient with adenosquamous carcinoma in order to analyze the specific immune responses against AT. METHODS: A lung adenosquamous carcinoma cell line was established from a resected tumor obtained from a 72-year-old patient. Regional lymph node lymphocytes were stimulated weekly with CD80-transfected AT to induce CTL. The CTL activities were assessed by a standard (51)Cr release assay and by cytokine release. RESULTS: We succeeded in inducing an AT-specific CTL line. Using a limiting dilution method, eight T cell clones were established. AT-specific activity was observed in three CD8(+) T cell clones and one CD4(+) T cell clone out of the eight clones tested. Anti-HLA class I and anti-HLA-B/C mAbs inhibited IFN-gamma production from the AT-specific CD8(+) clones co-cultured with AT, thus indicating the restriction element to be HLA-B*5201 or HLA-Cw*1202. In contrast, the CD4(+) T cell clone recognized AT in an HLA class II-restricted manner. CONCLUSIONS: These results are the first demonstration of a successful induction of AT-specific T cell clones from a patient with lung adenosquamous carcinoma. It may therefore supply a possible way to apply specific immunotherapy to this type of lung cancer.

Primary lung cancer occurring concomitantly with the cicatrized and calcified ova of a parasite: report of a case.

We report herein a rare case of primary lung cancer that occurred concomitantly with the calcified ova of a parasite. A 58-year-old man was referred to our department after a pulmonary abnormal shadow had been seen on a chest X-ray done at mass screening. A transbronchial lung biopsy (TBLB) revealed the calcified ova of a parasite. Because the possibility of concomitant lung cancer could not be ruled out, a lung biopsy was taken via video-assisted thoracic surgery (VATS). The pathological diagnosis was squamous cell carcinoma, and a left upper lobectomy was serially performed through a posterolateral thoracotomy. The patient recovered uneventfully and has remained in good health without any sign of recurrence for over 9 months. Following this case report, we review three other cases of this unusual disease combination documented in the literature.

Pleural retraction and intra-tumoral air-bronchogram as prognostic factors for stage I pulmonary adenocarcinoma following complete resection.

BACKGROUND AND OBJECTIVES: We have retrospectively analyzed the postoperative prognostic factors for 116 patients with stage I adenocarcinoma, with special reference to pleural retraction and intra-tumoral air-bronchogram imaged by computed tomography, which may represent the biological features of pulmonary adenocarcinoma for the retraction of surrounding tissues due to central necrosis and air space-lining growth, respectively. METHODS: The subgroups divided according to the presence of pleural retraction and/or intra-tumoral air-bronchogram on pre-operative CT were compared with respect to the postoperative disease-free survival (DFS) and other clinico-pathological factors. RESULTS: The rates of DFS at 5 years associated with 61 patients with pleural retraction and with 55 patients without pleural retraction were 64.4% and 91.3%, respectively (P = 0.0052), and those associated with 83 patients with air-bronchogram-positive tumors and with 33 patients with air-bronchogram-negative tumors were 81.8% and 64.8%, respectively (P = 0.0040). The DFS at 5 years associated with T1 (73 patients) and T2 (43 patients) were 83.6% and 64.3%, respectively (P = 0.0153). The Cox proportional hazards model analysis revealed that the presence of pleural retraction and the absence of air-bronchogram were independent factors for poor prognosis with relative risks of 7.8 and 5.1, respectively. Pathological T factor was also a significant prognostic factor with a relative risk of 3.2. Seventeen patients with pleural retraction-positive and air-bronchogram-negative tumors showed the high recurrence rate of 47.5% and a poor prognosis with DFS at 5 years of 35.1%. CONCLUSION: These results suggested that, in stage I adenocarcinoma, the degree of malignant potential may be well figured by radiological imaging, with a significant affect on susceptibility of recurrence following complete resection.

Heterogeneous response patterns of alveolar macrophages from patients with lung cancer by stimulation with interferon-gamma.

BACKGROUND: Macrophages are considered to play an important role in the host defense against malignant tumors. In this study, cytotoxic activity of alveolar macrophages (AM) derived from 32 patients with lung cancer was investigated. METHODS: AM were aseptically obtained by lavage from resected lung and subsequently tested for cytolytic activity against QG56, a lung squamous cell line, following treatment with recombinant interferon-gamma (IFN-gamma). RESULTS: In seven patients (21.9%), AM showed no cytotoxicity even though AM were incubated with IFN-gamma. In 20 (62.5%), AM showed substantial cytotoxicity in response to IFN-gamma in a dose-dependent manner. In the other five (15.6%), relatively strong cytotoxicity was observed even without preincubation with IFN-gamma. Such a heterogeneous profile of the cytotoxicity of AM might be a reflection of various activated states of AM since the potential of cytotoxicity and that of IL-1 secretion were almost parallel. Both IFN-gamma dependent and -independent cytotoxicity were partially blocked either by anti-tumor necrosis factor-alpha (TNF-alpha) antibody or by the inhibitor of nitric oxide synthesis. However, those activities were completely abrogated by both treatments. Since the supernatant of AM culture exhibited TNF-alpha-mediated but not NO-mediated cytolysis, TNF-alpha could mediate a bystander killing whereas NO acts in close contact with tumor cells. CONCLUSION: The AM have anti-tumor cytotoxicity in lung cancer although the cytolytic potential is heterogeneous and that the tumor lysis by AM is mediated by both TNF-alpha and NO production.

Adoptive immunotherapy using specific cytotoxic T lymphocytes against human lung-cancer-engrafted severe combined immunodeficiency mice.

OBJECTIVE: We studied the ability of human lung-cancer-specific cytotoxic T lymphocytes to suppress the growth of human lung adenocarcinoma (PC-9) engrafted in severe combined immunodeficiency mice. METHODS: PC-9-specific cytotoxic T lymphocytes were generated by multiple stimulation with irradiated PC-9 cells of regional lymph node lymphocytes from lung cancer patients expressing the same human leukocyte antigen-A locus haplotype as PC-9 following expansion due to the administration of immobilized anti cluster of differentiation 3 mAb and interleukin-2. Cytotoxic T lymphocytes showed specific cytotoxicity against PC-9 cells in vitro. Severe combined immunodeficiency mice with a subcutaneous graft of PC-9 were treated with a PC-9-specific cytotoxic T lymphocyte by i.v. injection and/or with interleukin-2 by s.c. injection. RESULTS: Cytotoxic T lymphocyte treatment suppressed PC-9 graft growth significantly an effect, significantly enhanced when combined with interleukin-2 injection. To evaluate the in vivo specificity of anti-PC-9 cytotoxic T lymphocytes, each mouse was subcutaneously inoculated in the right flank with PC-9, and in the left flank with A549 or Sq-1. Cytotoxic T lymphocytes plus interleukin-2 treatment was found to suppress PC-9 growth selectively, but not A549 or Sq-1 growth. CONCLUSIONS: These results provide sufficient rationale for conducting further clinical trials on immunotherapy using cytotoxic T lymphocyte for lung cancer patients.

Bone metastasis after a resection of stage I and II primary lung cancer.

In the present study, we reviewed the patients who developed bone metastases after a surgical resection of primary lung cancer and evaluated their clinicopathological features. From 1992 to 1995, 177 patients with stage I and II primary lung cancer underwent a surgical resection at the Kitakyushu Municipal Medical Center. Bone metastases were detected in 14 patients (7.9%) by follow-up examinations including bone scintigraphy (scan). Bone metastasis was one of the most frequent extra-thoracic recurrent forms. Patients with adenocarcinoma tended to develop bone metastases more frequently than those with squamous cell carcinoma. In the preoperative bone scans, an abnormal uptake was observed in 76 patients (42.9%), and 10 (13.1%) of them were found to develop bone metastases in the follow-up studies. A microscopic examination of the primary tumor demonstrated close correlation between intratumoral and peritumoral lymphatic vessel invasion and postoperative development of bone metastases. A bone scan is a very useful and indispensable procedure for diagnosing bone metastases. However, this scan may also show false positive finding in a number of benign conditions. Therefore, a surgical resection should be considered as the first-line treatment for patients with positive findings in the bone scan when the diagnosis of bone metastasis can not be confirmed based on both their symptoms and other clinical examinations.

Unfavorable prognosis of patients with stage II non-small cell lung cancer associated with macroscopic nodal metastases.

BACKGROUND: Patients with stage II-N1 non-small cell lung cancer (NSCLC) make up an intermediate group of patients with an unsatisfactory prognosis even though complete resection is usually possible. We retrospectively analyzed postoperative prognostic factors to devise guidelines for the proper management of this patient population. STUDY DESIGN: Among 546 patients with NSCLC who underwent surgical resection from 1979 to 1995, 43 patients were pathologically defined to be at stage II-N1 (T1-2N1M0). The influence of the following variables on postoperative survival was analyzed: gender, age, cell type, pathologic T factor, number of metastatic nodes, station of metastatic nodes (hilar or pulmonary nodes), status of nodal metastasis (macroscopic, gross involvement confirmed histologically; or microscopic, metastasis first defined by histologic examination), surgical methods, and adjuvant therapy (including 18 of chemotherapy and 2 of radiotherapy). RESULTS: The 5-year survival rates (5YSRs) of patients with microscopic (n = 21) and macroscopic nodal metastasis (n = 22) were 76.0% and 27.6%, respectively (p = 0.001). The 5YSRs of 20 patients who received adjuvant therapy and 23 who did not receive adjuvant therapy were 57.6% and 46.6%, respectively (p = 0.036). Other variables did not affect survival. The Cox proportional hazards model analysis indicated that the presence of a macroscopic nodal metastasis and postoperative adjuvant therapy were independent prognostic factors. Among patients with macroscopic N1 NSCLC, 9 patients who had undergone adjuvant therapy showed a more favorable prognosis than the 13 patients who had not received adjuvant therapy (3-year survival rate, 55.6% vs 18.5%; p = 0.037; and recurrence rate, 30.0% vs 77.8%), whereas no significant influence of adjuvant therapy on survival was observed among patients with microscopic N1 NSCLC. CONCLUSIONS: Stage II-N1 NSCLC was categorized into microscopic and macroscopic N1 diseases. The latter had a poor prognosis, which might be improved by adjuvant therapy, although a suitable regimen has not been established.

Bronchial arterial infusion is an effective therapeutic modality for centrally located early-stage lung cancer: results of a pilot study.

OBJECTIVE: This pilot study was done to assess the effectiveness of bronchial arterial infusion (BAI) as a therapeutic modality for centrally located early-stage lung cancer. PATIENTS AND METHODS: Seven patients who had endoscopically evaluated, centrally located early-stage squamous cell lung carcinoma, including three patients with synchronous multiple primary lung cancers, were offered BAI with cis-diamminedichloroplatinum (CDDP; dosage, 50 to 150 mg/body, 35 to 100 mg/m2), a radical therapeutic method, as an alternative to a resection. RESULTS: All early-stage lesions showed complete remission within 1 to 6 weeks (median, 3.3 weeks) after BAI. In the three patients with multiple lung cancers, BAI was used to treat accessible early-stage lesions, although a surgical resection was required for advanced lesions. Three of the seven patients suffered from severe bronchial ulcers after BAI. Six of the patients in the study had no disease relapse to date at a median follow-up time of 19.8 months (range, 11 to 32 months), but the other patient died of a pulmonary hemorrhage 3 months after BAI. CONCLUSION: Based on our findings, BAI with CDDP should be reappraised as an effective therapeutic modality for centrally located early-stage lung cancer and as an acceptable primary treatment.

Results of surgical treatment of lung cancer in octogenarians.

The treatment of potentially resectable lung cancer in octogenarians has become a frequent clinical problem, due to the increasing number of elderly people maintaining an active daily life. In the present study, we reviewed the clinical records of patients to evaluate the results of the surgical treatment of lung cancer in octogenarians. From 1992 to 1995, 18 patients aged 80 years or older (octogenarians) with primary lung cancer underwent surgical resections including: three (16.7%) sleeve lobectomies, nine (50.0%) lobectomies, one (5.5%) segmentectomy, and five (27.8%) partial resections. The postoperative complication rate was 50% in octogenarians; however, no fatal complications were observed. The 5-year survival rate was 42.6%, which was similar to that obtained in younger patients. Based on our findings, the surgical treatment of lung cancer can thus be performed in selected octogenarians without increasing either morbidity or mortality, while also obtaining long-term survival.

Fas expression in non-small cell lung cancer: its prognostic effect in completely resected stage III patients.

The aim of this study was to examine Fas expression in non-small cell lung cancer (NSCLC) and examine its correlation with clinicopathological features and prognosis. Fas expression was determined by an immunohistochemical analysis using the labelled streptavidin-biotin method from 220 paraffin specimens of completely resected primary stage I-III NSCLC. 80 (36%) of 220 cases were positive for Fas immunostaining. These 80 cases included 44 adenocarcinomas (33%) and 30 squamous cell carcinomas (40%). 33 stage I (33%) 13 (43%) stage II and 34 (37%) stage III tumours were Fas positive. No statistically significant differences were observed regarding the Fas status with respect to age, sex, histological type, or stage of disease. There was no significant difference in survival between early stage (stages I-II) disease patients with positive Fas expression and those with a negative expression (P = 0.719). However, for patients with completely resected stage III tumours, the patients with positive Fas staining were found to survive for a longer period than those with negative staining (P = 0.026).

A syndrome of inappropriate secretion of antidiuretic hormone associated with pleuritis caused by OK-432.

We here report a case presenting with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) after having been treated for pleurodesis with OK-432, which is a lyophilized preparation of an attenuated strain of Streptococcus pyogenes. The patient, who had undergone a subtotal esophagectomy 4 years previously, was referred to our department after the diagnosis of a metastatic lung tumor. A right lower lobectomy of the lung was performed, and prolonged air leakage from a pulmonary fistula thereafter developed because of the dissection of severe pleural adhesion. OK-432 (5 klinische einheiten) was administered to the pleural cavity 3 times. On the 13th postoperative day, the patient began to complain of general fatigue and nausea. SIADH was diagnosed based on laboratory findings such as hyponatremia, serum hypo-osmolality and a high excretion of sodium in the urine. A restriction of the fluid intake with a sodium supplement resulted in the return to a normal serum level within 2 weeks. We therefore concluded that the intrapleural instillation of OK-432 had apparently caused SIADH in this case, because no other causes could be found.

Constitutive up-regulation of integrin-mediated adhesion of tumor-infiltrating lymphocytes to osteoblasts and bone marrow-derived stromal cells.

Tumor-reactive T cells, known as tumor-infiltrating lymphocyte(TIL)s are known to infiltrate various tumors. Although TILs exert cytotoxic activities against tumor cells, only a small percentage of tumors usually contain TILs that specifically react to tumor antigens. Because the exact role of these lymphocytes is unclear, we investigated the mechanisms of migration and adhesion of TILs to bone metastatic tumors, particularly to osteoblasts and bone marrow-derived stromal cell(BMSC)s. Histopathological examination showed that most TILs in secondary bone metastatic tumors (from primary tumors in the lung or breast) were found in the supporting tissue stroma between the bone and tumor mass. Cultured TILs (obtained from breast tumors) adhered spontaneously to osteoblasts and BMSCs (obtained from patients with osteoarthritis) without exogenous stimulation. Adhesion was further enhanced by chemokines macrophage inflammatory protein (MIP)-1alpha and MIP-1beta. TILs highly expressed activation antigens CD25 and CD69. A spontaneous activation of an integrin, lymphocyte function-associated antigen-1 (LFA-1), was also detected on TILs. TILs produced high concentrations of MIP-1alpha and MIP-1beta and spontaneous polymerization of cytoskeletal F-actin was observed in these cells. Adhesion of TILs to osteoblasts and BMSCs via LFA-1 and very late antigen-4 was associated with the production of osteoclastogen interleukin 6 by the latter cells. Our results indicate that integrins on TILs are activated in an autocrine manner by MIP-1alpha and MIP-1beta, and that treatment with the chemokines increases the binding of TILs on osteoblasts and stromal cells via a mechanism involving intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 as targets for the integrin. Our data also indicated that interactions between TILs and osteoblasts/stromal cells lead to the secretion by the latter of the osteoclastogenic cytokine interleukin 6.

Effects of interleukin-12 on the induction of cytotoxic T lymphocytes from the regional lymph node lymphocytes of patients with lung adenocarcinoma.

Lung cancer-specific cytotoxic T lymphocytes (CTL) were induced by repeated stimulations of regional lymph node lymphocytes (RLNL) in lung cancer patients with either autologous or HLA-A-locus-matched tumor cells. To investigate the effect of interleukin-12 (IL-12), IL-12 was added during the stimulation of RLNL from HLA A24/adenocarcinoma patients with either autologous tumor cells or HLA A24-positive adenocarcinoma cells (PC-9) in combination with, or instead of interleukin-2 (IL-2), and then the cytotoxic activity, cytokine production and populations of the lymphocyte subsets were examined. The addition of IL-12, or the substitution of IL-2 by IL-12 was found to enhance the cytotoxic activity and the cytokine production (IFN-gamma, GM-CSF) of the CTL as compared with IL-2 alone. The cytotoxic activity and cytokine production were both partially inhibited by anti-MHC-class I monoclonal antibody. The CTL thus induced by IL-12 had a higher proportion of CD3+/CD56+ cells than the CTL induced with IL-2 alone. The positively selected CD8+/CD56- lymphocytes showed PC-9-specific cytotoxic activity, because the population did not show any cytotoxicity to K562 or A549 (HLA-A26/A30). However, the CD3+/CD56+ lymphocytes were cytotoxic to both PC-9 and K562. In conclusion, IL-12 is considered to be a useful cytokine for both the induction of lung-cancer specific CTL and the augmentation of non-MHC-restricted cytotoxicity against tumor cells, and may be applicable for adoptive immunotherapy using CTL.