Randomized phase II study of concurrent versus sequential alternating gefitinib and chemotherapy in previously untreated non-small cell lung cancer with sensitive EGFR mutations: NEJ005/TCOG0902.

BACKGROUND: The first-line combination of an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) and platinum-based doublet chemotherapy has not been sufficiently evaluated for patients with EGFR-mutant non-small cell lung cancer (NSCLC). This randomized phase II study was designed to select a combination regimen for phase III evaluation. PATIENTS AND METHODS: Chemotherapy-naïve patients with advanced non-squamous, EGFR-mutant NSCLC were randomly assigned to receive either a concurrent or a sequential alternating regimen with gefitinib (250 mg) and carboplatin/pemetrexed [area under the curve (AUC) = 6 and 500 mg/m(2); 3-weekly]. The primary end point was progression-free survival (PFS). Secondary end points were overall survival (OS), response, and safety. RESULTS: All 80 patients enrolled were eligible and assessable for efficacy (41 and 39 patients in the concurrent and sequential alternating regimen groups, respectively). Median PFS was 18.3 months for the concurrent regimen and 15.3 months for the sequential alternating regimen [hazard ratio (HR) 0.71 (0.42-1.20), P = 0.20]. Although OS data are immature (16 and 24 death events), median survival times were 41.9 and 30.7 months in the concurrent and sequential alternating regimen groups, respectively [HR 0.51 (0.26-0.99); P = 0.042]. Response rates were similar in both groups (87.8% and 84.6%). Hematological and non-hematological adverse events were common and reversible; interstitial lung disease was neither frequent nor fatal (two cases in each group; 5% of all patients). CONCLUSION: This is the first randomized study to investigate the efficacy of combinational EGFR-TKI and chemotherapy in the EGFR-mutated setting. Both regimens had promising efficacy with predictable toxicities, although concurrent regimens might provide better OS. The concurrent regimen was chosen to compare with gefitinib monotherapy in our ongoing phase III study. CLINICAL TRIALS REGISTRATION: University Hospital Medical Information Network (UMIN) Clinical Trial Registry (UMIN C000002789).

Updated overall survival results from a randomized phase III trial comparing gefitinib with carboplatin-paclitaxel for chemo-naïve non-small cell lung cancer with sensitive EGFR gene mutations (NEJ002).

BACKGROUND: NEJ002 study, comparing gefitinib with carboplatin (CBDCA) and paclitaxel (PTX; Taxol) as the first-line treatment for advanced non-small cell lung cancer (NSCLC) harboring an epidermal growth factor receptor (EGFR) mutation, previously reported superiority of gefitinib over CBDCA/PTX on progression-free survival (PFS). Subsequent analysis was carried out mainly regarding overall survival (OS). MATERIALS AND METHODS: For all 228 patients in NEJ002, survival data were updated in December, 2010. Detailed information regarding subsequent chemotherapy after the protocol treatment was also assessed retrospectively and the impact of some key drugs on OS was evaluated. RESULTS: The median survival time (MST) was 27.7 months for the gefitinib group, and was 26.6 months for the CBDCA/PTX group (HR, 0.887; P=0.483). The OS of patients who received platinum throughout their treatment (n=186) was not statistically different from that of patients who never received platinum (n=40). The MST of patients treated with gefitinib, platinum, and pemetrexed (PEM) or docetaxel (DOC, Taxotere; n=76) was around 3 years. CONCLUSIONS: No significant difference in OS was observed between gefitinib and CBDCA/PTX in the NEJ002 study, probably due to a high crossover use of gefitinib in the CBDCA/PTX group. Considering the many benefits and the risk of missing an opportunity to use the most effective agent for EGFR-mutated NSCLC, the first-line gefitinib is strongly recommended.

Successful histocompatible myoblast transplantation in dystrophin-deficient mdx mouse despite the production of antibodies against dystrophin.

Myoblast transplantation has been considered a potential treatment for some muscular disorders. It has proven very successful, however, only in immunodeficient or immunosuppressed mice. In this study, myoblasts from C57BL10J +/+ mice were transplanted, with no immunosuppressive treatment, in the tibialis anterior of fully histocompatible but dystrophin-deficient C57BL10J mdx/mdx mice. One to 9 months after transplantation, the success of the graft was evaluated by immunohistochemistry. All the transplanted mice (n = 24) developed dystrophin-positive fibers following transplantation. Depending on myoblast cultures, transplantations, and time of analysis, the mice presented 15 to 80% of dystrophin-positive fibers in transplanted muscles. These fibers were correctly oriented and they were either from donor or hybrid origin. The dystrophin-positive fibers remained stable up to 9 months. Possible humoral and cellular immune responses were investigated after grafting. Antibodies directed against dystrophin and/or muscle membrane were developed by 58% of the mice as demonstrated by immunohistochemistry and Western blotting. Despite the presence of these antibodies, dystrophin-positive fibers were still present in grafted muscles 9 months after transplantation. Moreover, the muscles did not show massive infiltration by CD4 cells, CD8 cells, or macrophages, as already described in myoblast allotransplantations. This lack of rejection was attributed to the sequestrated nature of dystrophin after fiber formation. These results indicate that myoblast transplantation leads to fiber formation when immunocompetent but fully histocompatible donors and recipients are used and that dystrophin incompatibility alone is not sufficient to induce an immunological rejection reaction.

Partial laminin alpha2 chain restoration in alpha2 chain-deficient dy/dy mouse by primary muscle cell culture transplantation.

Laminin-2 is a component of skeletal and cardiac basal lamina expressed in normal mouse and human. Laminin alpha2 chain (LAMA2), however, is absent from muscles of some congenital muscular dystrophy patients and the dystrophia muscularis (dy/dy) mouse model. LAMA2 restoration was investigated following cell transplantation in vivo in dy/dy mouse. Allogeneic primary muscle cell cultures expressing the beta-galactosidase transgene under control of a muscular promoter, or histocompatible primary muscle cell cultures, were transplanted into dy/dy mouse muscles. FK506 immunosuppression was used in noncompatible models. All transplanted animals expressed LAMA2 in these immunologically-controlled models, and the degrees of LAMA2 restoration were shown to depend on the age of the animal at transplantation, on muscle pretreatment, and on duration time after transplantation in some cases. LAMA2 did not always colocalize with new or hybrid muscle fibers formed by the fusion of donor myoblasts. LAMA2 deposition around muscle fibers was often segmental and seemed to radiate from the center to the periphery of the injection site. Allogeneic conditionally immortalized pure myogenic cells expressing the beta-galactosidase transgene were characterized in vitro and in vivo. When injected into FK506-immunosuppressed dy/dy mice, these cells formed new or hybrid muscle fibers but essentially did not express LAMA2 in vivo. These data show that partial LAMA2 restoration is achieved in LAMA2-deficient dy/dy mouse by primary muscle cell culture transplantation. However, not all myoblasts, or myoblasts alone, or the muscle fibers they form are capable of LAMA2 secretion and deposition in vivo.

Simultaneous blockade of AP-1 and phosphatidylinositol 3-kinase pathway in non-small cell lung cancer cells.

c-Jun is a major constituent of AP-1 transcription factor that transduces multiple mitogen growth signals, and it is frequently overexpressed in non-small cell lung cancers (NSCLCs). Earlier, we showed that blocking AP-1 by the overexpression of a c-Jun dominant-negative mutant, TAM67, inhibited NSCLC cell growth. The phosphatidylinositol 3-kinase (PI3K)/Akt signal transduction pathway is important in transformation, proliferation, survival and metastasis of NSCLC cells. In this study, we used NCI-H1299 Tet-on clone cells that express TAM67 under the control of inducible promoter to determine the effects of inhibition of AP-1 and PI3K on cell growth. The PI3K inhibitor, LY294002, produced a dose-dependent inhibition of growth in H1299 cells and that inhibition was enhanced by TAM67. TAM67 increased dephosphorylation of Akt induced by LY294002 and reduced the TPA response element DNA-binding of phosphorylated c-Jun. TAM67 increased G1 cell cycle blockade induced by LY294002, which was partially associated with cyclin A decrease and p27(Kip1) accumulation. Furthermore, TAM67 and LY294002 act, at least additively, to inhibit anchorage-independent growth of the H1299 cells. These results suggest that AP-1 and PI3K/Akt pathways play an essential role in the growth of some NSCLC cells.

Altered p16INK4 and retinoblastoma protein status in non-small cell lung cancer: potential synergistic effect with altered p53 protein on proliferative activity.

p16INK4 protein (p16) and retinoblastoma protein (pRB), like p53 protein, are important tumor suppressors that regulate the cell cycle. We immunohistochemically examined fresh-frozen specimens of 114 resected non-small cell lung cancers (NSCLCs) for loss of p16 and pRB expression, together with aberrant accumulation of p53 protein and the proliferative activity determined by the Ki-67 index. Three pRB-positive tumors were uninterpretable for p16 status. Of the remaining 111 tumors, 30 (27%) lacked p16 expression, and 10 (9%) lost pRB expression. No tumors showed coincident loss of both proteins, supporting the hypothesis that they function in a single pathway. Of 25 tumors, including 4 p16-negative tumors, examined by Southern blot analysis, only 2 p16-negative tumors were considered to have reduced gene dosage consistent with possible homozygous deletion of the CDKN2 gene encoding p16, suggesting that immunohistochemistry is a sensitive and suitable method to screen for p16 alteration. Loss of p16 expression did not correlate with any clinical factors or p53 status, whereas loss of pRB expression correlated with heavy smoking (P = 0.03 by Fisher's exact test and P = 0.01 by the multivariate logistic regression analysis). Proliferative activity was considerably higher in p53-positive tumors than in p53-negative tumors (P < 0.001). Loss of p16 or pRB expression was associated with a further increase in proliferative activity in the p53-positive tumors (P = 0.009) but not with proliferative activity in the p53-negative tumors. These results suggest that alteration of the p16/pRB pathway is relatively frequently involved in the development and progression of NSCLCs and that its effect on the proliferative activity is potentially synergistic with altered p53 protein.

Inhibition of proliferation by L-myc antisense DNA for the translational initiation site in human small cell lung cancer.

We evaluated the antiproliferative effect of L-myc antisense DNA in NCI-H209, a human small cell lung cancer (SCLC) cell line overexpressing the L-myc gene. The synthetic DNA used in the present study was oligodeoxynucleoside phosphorothioate, which showed rapid incorporation into NCI-H209 cells and localized mainly in the cell nucleus and weakly in the cytoplasm. The exposure of this cell line to L-myc antisense DNA covering the translational initiation site of L-myc proteins inhibited the cell proliferation in a dose-dependent sequence-specific manner. Furthermore, the growth inhibition by this antisense DNA was correlated with the level of L-myc expression in three SCLC cell lines, NCI-H209, NCI-H510, and NCI-H82. In Western blot analysis, expression of the L-myc proteins was down-regulated in the antisense-treated cells compared with control-treated cells in NCI-H209. Together with unique characteristics of the L-myc gene, including: (a) a frequently amplified and overexpressed state in SCLC; and (b) very restricted and low-level expression in human adult tissues, the present data indicate that L-myc is a good candidate for the target gene for antisense DNA therapy based on molecular biological diagnosis in SCLC.

Frequent loss of gelsolin expression in non-small cell lung cancers of heavy smokers.

Most lung and bladder cancers have been shown to be associated with smoking. We have previously demonstrated the frequent loss of gelsolin expression and its tumor suppressor activity in bladder cancer (M. Tanaka et al., Cancer Res., 55: 3228-3232, 1995). Here, we examined gelsolin expression in 12 cultured non-small cell lung cancer (NSCLC) cell lines. Furthermore, we analyzed gelsolin expression in relation to patients' smoking habits in 88 surgically resected NSCLCs to investigate whether gelsolin could be a molecular target for tobacco-induced carcinogenesis of lung cancer. All 12 NSCLC cell lines showed low-to-undetectable expression of the gelsolin gene, compared to that in normal lung tissue, by Northern blot analysis. On the other hand, Southern blot analysis of genomic DNA did not show any gross rearrangements or deletions of the gene in the NSCLC cell lines. Western blot analysis of gelsolin expression showed low-to-undetectable gelsolin expression in all 12 NSCLC cell lines, compared to normal lung tissue. Immunocytochemical analysis of gelsolin expression in NSCLC cell lines showed results that were consistent with those obtained by Western blot analysis, using normal bronchial epithelial cells as a positive control: two cell lines with lower gelsolin expression by Western blot analysis had reduced but positive cytoplasmic immunostaining of gelsolin, compared with primary normal bronchial epithelial cells, whereas no such immunostaining was observed in two cell lines with much lower or undetectable gelsolin expression by Western blot analysis. Therefore, gelsolin expression was analyzed in surgically resected NSCLCs by immunohistochemistry. Reduced or undetectable gelsolin expression was observed in 48 of 88 (55 %) resected NSCLCs. Such altered gelsolin expression significantly correlated with heavy smoking of patients (> or =20 pack-years; P = 0.008 by the chi2 test and P = 0.03 by multivariate logistic regression analysis), whereas there was no significant correlation between gelsolin expression and histological type, pathological tumor-node-metastasis (pTNM) stage, or survival. These findings suggest that the frequent loss of gelsolin expression may be involved in the development of NSCLCs as a potential molecular target of tobacco-induced carcinogenesis.

Coronary angioplasty of chronic total occlusions with bridging collateral vessels: immediate and follow-up outcome from a large single-center experience.

OBJECTIVES: The purpose of the present study was to assess the effect of bridging collateral vessels on the success of coronary angioplasty of chronic total occlusions in the context of state of the art technology and operator skill. BACKGROUND: Coronary angioplasty of chronic total occlusions has been associated with relatively low success rates. Because the presence of bridging collateral vessels in chronic total occlusion has been reported to be the major predictive factor in procedural failure, angioplasty is often not recommended in patients with such vessels. METHODS: Three hundred ninety-seven consecutive patients undergoing coronary angioplasty for chronic total occlusion were classified into two groups. Patients in group I had chronic total occlusion with bridging collateral vessels (97 patients, 109 total occlusions), and patients in group II had chronic total occlusion without such vessels (300 patients, 324 total occlusions). RESULTS: The mean +/- SD duration of occlusion was 46 +/- 66 months (range 2 to 170) in group I and 27 +/- 39 months (range 2 to 112) in group II (p < 0.05, high power value 0.83, group I vs. group II). Angioplasty for single-vessel disease was performed in a smaller proportion of patients in group I than in group II (22% vs. 36%, p < 0.05; power value 0.77). Procedural success was achieved in 82 chronic total occlusions in group I and 270 chronic total occlusions in group II (75% vs. 83%, p = 0.07; power value 0.53). The rates of restenosis and reocclusion were 54% and 16%, respectively, for group I and 56% and 13%, respectively, for group II (p = 0.76, 0.46; power value 0.51, 0.47). Complications were minor with no Q wave infarction or requirement for urgent bypass surgery in either group. Of 81 patients with unsuccessful coronary angioplasty, 1 patient from group I (1%) and 3 patients from group II (1%) required pericardiocentesis because of cardiac tamponade. Guide wire manipulation did not impair the flow of bridging collateral channels in group I. CONCLUSIONS: Coronary angioplasty can open chronic total occlusions, with or without bridging collateral channels, for safe and effective recanalization without major complications.

FK506 immunosuppression to control the immune reactions triggered by first-generation adenovirus-mediated gene transfer.

Despite good initial success in vivo, gene transfer using first-generation replication-defective adenovirus has been reported to lead to transient reporter gene expression and to trigger inflammatory reactions in various organs and animal models. To gain more knowledge on this phenomenon, immune reactions were investigated following in vivo transfection of adult immunocompetent mouse muscle using a delta E1/E3a adenoviral vector encoding a beta-galactosidase (beta-Gal) expression cassette. Cellular and humoral immune reactions, and rejection of beta-Gal-positive muscle fibers, occurred within 3 weeks. The muscles showed massive infiltration by macrophages, natural killer cells, and CD8+ leukocytes. The mRNA levels of granzyme B and interferon-gamma were increased 6 days after vector injection, indicating that the infiltrating lymphocytes were activated. Antibodies were formed against the adenovirus group antigen and the beta-Gal gene product 2 weeks after construct injection. The immunosuppressant FK506, however, blocked the cellular infiltration and the humoral response and allowed strong, stable transgene expression over 1 month. These data emphasize the immune problems related to the use of delta E1/E3a adenoviruses as vectors for gene therapy, and they underline the potential of FK506 as an immunosuppressant adjunct treatment for adenovirus-mediated gene transfer.

Myoblast transplantation in monkeys: control of immune response by FK506.

Myoblasts were grown from monkey muscle biopsies and infected in vitro with a defective retroviral vector containing a cytoplasmic beta-galactosidase (beta-gal) gene. These myoblasts were then transplanted to 14 different monkeys, 6 of which were immunosuppressed with FK506. Without immunosuppression, only a few myoblasts and myotubes expressing beta-gal were observed 1 week after the transplantation, but no cells expressing beta-gal were observed after 4 weeks. This result was attributed to immune responses since infiltration by CD4+ or CD8+ lymphocytes was abundant 1 week after transplantation but not after 4 weeks. The expression of interleukin 6 (IL-6), interleukin 2 (IL-2), granulocyte/macrophage colony stimulating factor (GM-CSF), transforming growth factor-beta (TGF-beta) and granzyme B mRNAs was increased in the myoblast-injected muscle indicating that the infiltrating lymphocytes were activated. Moreover, antibodies against the donor myoblasts were detected in 3 out of 6 cases. When the monkeys were immunosuppressed with FK506, muscle fibers expressing beta-galactosidase (beta-gal) were present 1, 4 and 12 weeks after the transplantation. There was neither significant infiltration by CD4 or CD8 lymphocytes, nor antibodies detected. The mRNA expression of most cytokines was significantly reduced as compared to the nonimmunosuppressed monkeys. These results indicate that FK506 is effective in controlling short-term immune reactions following myoblast transplantation in monkeys and suggest that it may prove useful for myoblast transplantation in Duchenne Muscular Dystrophy patients.

Diagnostic significance of IgG, C3, and C9 at the limb muscle motor end-plate in minimal myasthenia gravis.

We detected deposits of IgG, C3, and C9 (immune complexes) at the limb muscle motor end-plates (biceps brachii muscle) in 16 of 19 patients who exhibited only ocular signs and symptoms of myasthenia gravis that were improved by intravenous injections of edrophonium chloride. Circulating anti-acetylcholine receptor (anti-AChR) antibodies were negative in 6 of the 16 patients, but the motor end-plate fine structure in the postsynaptic regions was abnormal in all 16. Single-fiber EMG revealed no abnormalities in 8 of 13 patients studied. Our results indicate that the detection of immune complexes at the limb muscle end-plate provides a highly sensitive and confirmative method for diagnosing patients with minimal or atypical myasthenia gravis who have no detectable anti-AChR antibodies in their serum.

Cyclophosphamide immunosuppression does not permit successful myoblast allotransplantation in mouse.

Cyclophosphamide immunosuppression does not permit successful myoblast allotransplantation in mouse. Myoblast transplantation is a potential treatment for Duchenne muscular dystrophy. In one clinical trial, Duchenne patients were immunosuppressed with cyclophosphamide. We report here that myoblasts from transgenic mice expressing the beta-galactosidase reporter gene transplanted in mdx mice failed to form new muscle fibres when cyclophosphamide (2 or 10 mg kg-1 per day) was used for immunosuppression. At the lowest dose of cyclophosphamide (2 mg kg-1 per day), some mdx recipient mice formed antibodies against donor myoblasts; however, no humoral immune reaction was observed at the highest dose (10 mg kg-1 per day). The failure of transplantation under cyclophosphamide treatment was attributed to the low immunosuppressive activity at a low dose and to the toxic action of a high dose of this drug. These results could explain the lack of success of myoblast transplantation in a previous clinical trial.

Successive injections in mdx mice of myoblasts grown with bFGF.

We studied the effects of single and repeated sets of injections in the same muscle of mdx mice of myoblasts grown with or without a high concentration 100 ng ml-1 of basic fibroblast growth factor (bFGF). The injected myoblasts were obtained from non-dystrophic transgenic mice expressing the beta-galactosidase gene under the control of a muscle-specific promoter. In these experiments, the host muscle was not irradiated to prevent muscle regeneration by host myoblasts. The host muscle was not damaged before myoblast transplantation with notexin, marcaïne or cold to trigger a regeneration-degeneration cycle. Without such pretreatments, the first set of injections of myoblasts grown without bFGF produced only 8% beta-galactosidase-positive and dystrophin-positive muscle fibers 1 month after transplantation. The percentage of muscle fibers containing the donor reporter gene increased, however, to 26% following a second set of injections in the same muscle. The percentage of muscle fibers expressing the donor reporter gene was significantly higher when the myoblasts were grown with a high dose of bFGF. Indeed the first set of injections produced 34% beta-gal-positive fibers while a second set of injections raised this percentage to 54%. In all cases, the percentage of dystrophin-positive fibers was similar to that of beta-gal-positive fibers. Therefore a high percentage of muscle fibers of donor origin can be obtained without preliminary damaging treatments of the mdx muscle when myoblasts grown with bFGF are injected several times. The effects of bFGF is not produced by increasing the percentage of myoblasts in a primary muscle culture since improvement of myoblast transplantation was obtained with a pure myoblast clone even with a lower concentration (10 ng ml-1) of bFGF.

Increased granzyme B mRNA after alloincompatible myoblast transplantation.

Normal C57BL/10SnJ myoblasts were transplanted into the tibialis anterior of C57BL/10SnJ, C57BL/ScSn mdx, or BALB/c mice. These transplantations allowed us to investigate the immune response not only against MHC but also against dystrophin introduced in the dystrophic muscles by such transplantations. Recently, our group reported following myoblast transplantations cellular infiltration of the host muscle by class II MHC cells, macrophages, and lymphocytes expressing CD4 or CD8 and IL-2 receptors. In the present study, activation of these infiltrating lymphocytes was investigated by measuring the expression of granzyme B mRNA. We used reverse-transcriptase polymerase chain reaction to detect granzyme B mRNA at various intervals after myoblast transplantations. To standardize the results, the mRNA were reverse transcribed using an oligo (dt) so that beta-actin mRNA could also be amplified from the same cDNA preparation. Granzyme B mRNA was increased for at least 3 weeks after MHC alloincompatible grafts. The absence of increased granzyme B expression after allocompatible transplantation in mdx mice suggests that dystrophin is not sufficiently immunogenic to induce short term acute rejection. These results indicate that lymphocytes infiltrated in muscles injected with histoincompatible myoblasts are activated and sustain the requirement for an adequate immunosuppression after such transplantations.

Vascular cell adhesion molecule-1-mediated matrix metalloproteinase-2 induction in peripheral blood T cells is up-regulated in patients with HTLV-I-associated myelopathy.

We investigated whether matrix metalloproteinase-2 (MMP-2) is induced in peripheral blood T cells after their contact with tumor necrosis factor-alpha (TNF-alpha)-stimulated glioblastoma cell line (T98G), expressing vascular cell adhesion molecule-1 (VCAM-1), in patients with HTLV-I-associated myelopathy (HAM) compared to control patients with other neurological disorders (OND). Gelatin zymography revealed that the incremental ratio of gelatinolytic activity of MMP-2 in culture supernatants derived from T cells cocultured with TNF-alpha-stimulated T98G to that of supernatants derived from cultures of T cells alone was significantly higher in HAM patients than in control patients with OND. Immunoblot analysis of immunoprecipitates of culture supernatant showed that increased gelatinolytic activity of MMP-2 was due to increased production of MMP-2 protein in T cells. Increased gelatinolytic activity of MMP-2 in T cells of HAM patients was blocked by pretreatment of TNF-alpha-stimulated T98G with anti-VCAM-1 antibody before coculture with T cells, indicating that MMP-2 induction was VCAM-1-mediated. Although no significant differences were noted in the percentage of VLA-4-positive cells in cultured T cells between HAM patients and control patients with OND, our results indicate that VCAM-1-mediated MMP-2 induction is up-regulated in T cells of HAM patients.

Surgical treatment of pulmonary metastases from uterine cervical cancer. Operation method by lung tumor size.

Between 1959 and 1986, 32 patients with pulmonary metastatic tumors from squamous cell carcinoma of the uterine cervix underwent pulmonary resection. The method of pulmonary resection was correlated with the pathology of the metastases. In 20 patients with pulmonary metastatic lesions 3 cm in diameter or larger, secondary lymph node involvement was observed in 65% and microscopic satellite lesions around the main metastatic lesion were seen in 50%. On the other hand, in none of 12 patients having metastatic lesions smaller than 3 cm was there accompanying lymph node involvement, and microscopic satellite lesions were observed in only one patient among them. Consequently, we concluded that wedge resection with a disease-free margin of 2 cm or a little more from the tumor edge was appropriate for lesions smaller than 3 cm in diameter, and lobectomy with lymph node dissection was necessary for lesions 3 cm in diameter or more.

Abnormal p53 expression in human lung cancer is associated with histologic subtypes and patient smoking history.

Among the most common mutations in human lung cancer are those affecting the p53 gene. The expression of p53 in the nucleus is considered an immunohistochemical reflection of the nuclear accumulation of mutant p53 protein, which is coded by the p53 gene with missense mutation and has a prolonged half-life. In the present study, p53 expression detected by means of immunohistochemistry occurred frequently in human lung cancer and was associated with histologic subtypes. The alteration in the p53 gene was found to be a relatively early genetic event in the development and progression of lung cancer and to be maintained in the process of metastasis: abnormal p53 expression was found in both the early and late clinical stages, and identical p53 expression was detected consistently among primary and metastatic lesions from the same patients. Furthermore, an observed association between abnormal p53 expression and the patients' smoking history suggests that the p53 gene could be a common target of tobacco-associated carcinogenesis in lung cancer.