Toshihiro Osaki

Vascular endothelial growth factor expression in non-small-cell lung cancer: prognostic significance in squamous cell carcinoma.

BACKGROUND Recently, some studies have focused on the tumor angiogenesis and its prognostic value. We studied the expression of vascular endothelial growth factor, microvessel counts, and serum concentrations of vascular endothelial growth factor to investigate their association with clinicopathologic factors and prognosis in non-small-cell lung cancer. METHODS The expression of vascular endothelial growth factor was determined by an immunohistochemical analysis from 91 paraffin specimens of completely resected non-small-cell lung cancers using anti-growth factor polyclonal antibody. Microvessel staining was performed by immunohistochemical analysis with anti-factor VIII-related antigen polyclonal antibody. Measurement of the serum concentrations of vascular endothelial growth factor used the sandwich enzyme-linked immunosorbent assay technique. RESULTS Expression of vascular endothelial growth factor was detected in 48 of the 91 tumors. The positive ratio was significantly higher in patients with adenocarcinoma than in those with squamous cell carcinoma. The microvessel counts were significantly higher in the patients with nodal metastasis than in those without nodal metastasis. The serum concentrations of vascular endothelial growth factor were also significantly higher in the patients with T3-4 disease than in those with T1-2 disease. The microvessel counts were closely associated with expression of vascular endothelial growth factor. The prognosis of patients with a positive growth factor ratio was significantly worse than that of the patients with a negative ratio (p = 0.002), especially in squamous cell carcinoma. According to a multivariate analysis, only nodal status and expression of vascular endothelial growth factor were found to be independent prognostic factors. CONCLUSIONS The expression of vascular endothelial growth factor was one of the most important prognostic factors in completely resected non-small-cell lung cancer, especially in squamous cell carcinoma.

Prognostic Impact of Micrometastatic Tumor Cells in the Lymph Nodes and Bone Marrow of Patients With Completely Resected Stage I Non–Small-Cell Lung Cancer

PURPOSE This study was designed to substantiate the prognostic impact of occult micrometastatic tumor cells in the lymph nodes (LNs) and bone marrow (BM) in stage I non-small-cell lung cancer (NSCLC) patients using cytokeratin (CK) as a micrometastatic marker and the relationship between the micrometastases in the LNs and BM. PATIENTS AND METHODS A total of 2,432 hilar and mediastinal LNs were removed during surgery from 115 patients with completely resected stage I NSCLC. The LNs were analyzed for micrometastasis using immunohistochemistry with the biclonal anti-CK antibody AE1/AE3. BM aspirates from 115 patients were immunocytochemically stained with the monoclonal anti-CK antibody CK2. RESULTS CK-positive (CK+) cells were detected in 42 (1.7%) of 2,432 LNs, in 32 (27.8%) of 115 patients, and in 32 (27.8%) of 115 BM aspirates. There was no relationship between the frequencies of CK+ cells in the LNs and in the BM. The patients with CK+ cells in the LNs had a poor prognosis by both univariate (P =.008) and multivariate analyses (P =.01), whereas the presence of CK+ cells in the BM did not allow prediction of survival (P =.32). The prognostic impact of LNs micrometastasis was independent even after adjusting for the status of BM micrometastasis. CONCLUSION The detection of lymph nodal micrometastatic tumor cells provides an accurate assessment of tumor staging and has powerful prognostic implications for completely resected stage I NSCLC patients.

Detection of micrometastatic tumor cells in pN0 lymph nodes of patients with completely resected nonsmall cell lung cancer. Impact on recurrence and survival

ObjectiveTo detect occult micrometastatic tumor cells in pN0 lymph nodes of nonsmall cell lung cancer (NSCLC) by a combination of cytokeratin and p53 immunohistochemistry staining, and to evaluate the relation between the micrometastasis in pN0 lymph nodes and the prognosis of patients with completely resected stage 1 NSCLC. Summary Background DataThe average 5-year survival rate for patients with completely resected stage 1 NSCLC is only about 70%; thus, about 30% of these patients have recurrent disease. This suggests that occult micrometastasis may exist at the time of surgery; the rate is clearly underestimated by current clinical staging examinations and conventional histopathologic methods. MethodsA total of 474 hilar and mediastinal lymph nodes were removed during surgery from 49 patients with completely resected stage 1 NSCLC. The lymph nodes analyzed for micrometastasis using immunohistochemical staining with the biclonal anticytokeratin antibody, AE1/AE3. Of these 474 lymph nodes from 49 patients, 263 lymph nodes from 25 patients, whose primary tumors were positive for the p53 protein, were subjected to immunohistochemical staining with the monoclonal anti-p53 protein antibody DO-1. ResultsCells positive for cytokeratin and p53 protein were found in 35 (7.4%) of 474 and 20 (7.6%) of 263 lymph nodes, respectively; 17 (34.7%) of 49 patients had cytokeratin-positive cells and 10 (40.0%) of 25 patients had p53-positive cells in their pN0 lymph nodes. By a combination of cytokeratin and p53 protein immunohistochemical staining, micrometastatic tumor cells were identified in pN0 lymph nodes in 22 (44.9%) of 49 patients. The patients with lymph node micrometastasis identified by a combination of cytokeratin and p53 protein immunohistochemical staining had a poorer prognosis than those without micrometastasis on both univariate and multivariate analyses (overall survival, P = .0003 and 0.013, respectively). ConclusionsThe detection of lymph nodal micrometastasis by cytokeratin and p53 protein immunohistochemical staining will be helpful to predict the recurrence and prognosis of patients with completely resected stage 1 NSCLC.

Surgical treatment of lung cancer in the octogenarian

The purpose of this study was to investigate the value of surgical treatment for lung cancer in the octogenarian. Thirty-three patients 80 years of age or older (mean age, 82.4; range, 80 to 92 years; 25 men, 8 women) underwent surgical resection in our units between 1974 and 1991. The operative mortality rate was 3%, and the 5-year survival rate was 32%. The relative 5-year survival rate (survival rate of our subjects/that of matched population) was 61%. The mortality and long-term survival rates were similar to those in younger patients. In this study, long-term survival had no significant dependence on stage of disease, histologic tumor type, or complete versus incomplete resection. It was dependent mainly on postoperative complications, in particular, cardiorespiratory complications (cardiac complications, p = 0.0005; respiratory complications, p < 0.05). These data suggest that the octogenarian who suffers from lung cancer deserves the opportunity for a cure and the long-term benefits of surgical treatment, on the condition that no postoperative major cardiorespiratory complications set in.

Micrometastatic p53-positive cells in the lymph nodes of non-small-cell lung cancer: Prognostic significance☆☆☆★★★

OBJECTIVES Approximately one fourth of all patients with stage I non-small-cell lung cancer die of tumor recurrence, despite radical removal of their tumors. We thus tried to detect micrometastasis in the regional lymph nodes indicated to be tumor free by conventional histopathologic methods in patients with non-small-cell lung cancer by using immunohistochemical staining for p53 protein. We also investigated the relation between micrometastatic p53-positive cells in the lymph nodes and the prognosis of the patients. METHODS Samples from 480 regional lymph nodes were taken from 47 patients who underwent pulmonary resection for non-small-cell lung cancer and whose primary lesions were positive for p53 immunohistochemical staining. These samples were fixed in formalin and embedded in paraffin. We used p53 immunohistochemical staining to detect micrometastatic tumor cells in the lymph nodes. RESULTS Cells positive for p53 protein were found in 14 of 31 (45%) patients with a negative pathologic lymph node status and in 26 of 315 (8.3%) lymph nodes in these patients. The proportion of patients with micrometastasis who survived was also significantly lower than the proportion of patients without micrometastasis who survived (p = 0.0001). CONCLUSIONS Immunohistochemical staining for the p53 protein offers a rapid, sensitive, and useful way of detecting for micrometastasis to the regional lymph nodes in patients with non-small-cell lung cancer that is positive for p53 staining. The patients with such micrometastases have a poor prognosis and thus need to be carefully followed up after the initial pulmonary resection.

Micrometastatic tumor cells in the bone marrow of patients with non-small cell lung cancer

BACKGROUND This study was designed to evaluate the incidence and clinical implications of detection of micrometastatic cancer cells in bone marrow aspirates of patients with operable non-small cell lung cancer. The relationship between micrometastatic cells and p53 overexpression in the primary tumor was also assessed. METHODS Thirty-nine patients with stages I through III non-small cell lung cancer who underwent curative resection were entered into this study. Immunohistochemistry with monoclonal antibody to cytokeratin 18 was used to detect tumor cells in bone marrow. Immunostaining of p53 protein in the corresponding primary tumors was also done. RESULTS Cytokeratin 18-positive cells were detected in 15 (39%) of the 39 patients. Overexpression of p53 was associated with positivity of the tumor cells in the bone marrow at borderline significance (14/29 versus 1/10; p = 0.0574). The patients with cytokeratin 18-positive cells in bone marrow demonstrated a significantly earlier recurrence than those without such cells (p = 0.0083, log-rank test). CONCLUSIONS Micrometastatic cancer cells were frequently present in bone marrow of patients with operable non-small cell lung cancer and may be a significant predictor of early recurrence. Further evaluation of this method may be useful in identifying patients with non-small cell lung cancer who are most likely to benefit from adjuvant chemotherapy.

Induction of chromosomal gene mutations in Escherichia coli by direct incorporation of oxidatively damaged nucleotides. New evaluation method for mutagenesis by damaged DNA precursors in vivo

We have developed a new strategy for the evaluation of the mutagenicity of a damaged DNA precursor (deoxyribonucleoside 5′-triphosphate) in Escherichia coli. 8-Hydroxydeoxyguanosine triphosphate (8-OH-dGTP) and 2-hydroxydeoxyadenosine triphosphate (2-OH-dATP) were chosen for this study because they appear to be formed abundantly by reactive oxygen species in cells. We introduced the oxidatively damaged nucleotides into competent E. coli and selected mutants of the chromosomal lacI gene. Both damaged nucleotides inducedlacI gene mutations in a dose-dependent manner, whereas unmodified dATP and dGTP did not appear to elicit the mutations. The addition of 50 nmol of 8-OH-dGTP and 2-OH-dATP into anE. coli suspension induced 12- and 9-fold more substitution mutations than the spontaneous event, respectively. The 8-OH-dGTP induced A·T → C·G transversions, and the 2-OH-dATP elicited G·C → T·A transversions. These results indicate that the two oxidatively damaged nucleotides are mutagenic in vivo and suggest that 8-OH-dGTP and 2-OH-dATP were incorporated opposite A and G residues, respectively, in the E. coli DNA. This new method enables the evaluation and comparison of the mutagenic potentials of damaged DNA precursors in vivo.

Detection of CYP1A1 gene polymorphism using designed RFLP and distributions of CYP1A1 genotypes in Japanese.

Isoleucine (Ile)-valine (Val) polymorphism, which is caused by a point mutation from A to G in exon 7, is reported to be associated with an elevated risk of lung cancer among Japanese. Because CYP1A1 catalyzes bioactivation of environmental procarcinogens, such as benzo[a]pyrene, it is very important to study the clinical meaning of Ile-Val polymorphism using an epidemiological study. In an epidemiological study, easy, economical, rapid and reliable identification of the CYP1A1 genotype is necessary. The present study shows that the new method, designed restriction fragment length polymorphism (designed RFLP), can detect Ile-Val polymorphism of CYP1A1 The Ile-Val polymorphism detected using this new method was consistent with that found by the allele-specific PCR amplifications (ASA) method in six cases tested. This new method detected Ile-Va1 polymorphism of CYP1A1 using 240 healthy Japanese who lived in the northern Kyusyu region. The frequency of the genotypes was as follows: Ile/Ile, 159 (66.2%); Ile/Val, 65 (27.1%); Val/Val, 16 (6.7%). The frequency of the Ile gene was 0.798 and that of the Val gene, 0.202. There was no difference in Ile-Val polymorphism based on sex or age. Racial differences influenced the distribution of this polymorphism, but Japanese regional differences did not. Since this new method, designed RFLP, is rapid, reliable and suitable for large-scale screening of polymorphisms, it may be used routinely to detect Ile-Val polymorphism of CYP1A1 Furthermore, it will help to evaluate the relationship between CYP1A1 polymorphism and individual sensitivity to xenobiotics that may affect the incidence of lung cancer.

Prognostic value of the immunohistochemical detection of p16INK4 expression in nonsmall cell lung carcinoma

The product of the p16INK4/CDKN2/MTS1 (p16) controls the transition from the G1 phase to the S‐phase in the cell cycle by inhibiting the phosphorylation of the retinoblastoma gene product. A lack of p16 expression has been reported in various cancer cell lines and tumors; however, there have been only a few reports on the prognostic significance of p16 alteration. The authors studied p16 expression in nonsmall cell lung carcinoma (NSCLC) and also examined its correlation with clinicopathologic features and prognosis.

Prognostic Impact of Telomerase Activity in Non-Small Cell Lung Cancers

OBJECTIVE To evaluate the clinical significance of telomerase activity, particularly in terms of prognostic impact, in non-small cell lung cancer (NSCLC). SUMMARY BACKGROUND DATA Telomerase activity has been found in various tissues. The activation of telomerase is considered necessary for the immortalization of human tumor cells, including NSCLC. METHODS The authors studied 103 NSCLC specimens using a polymerase chain reaction based on a telomeric repeat amplification protocol assay. RESULTS Telomerase activity was detected in 85 (82.5%) of 103 NSCLC specimens but in none of the paired normal lung tissue specimens. More cases of positive telomerase activity were observed in the group with advanced disease and in the group with poorly differentiated tumors. Such factors as the mean age at surgery, sex, smoking, histologic type, and size of tumor extension did not correlate with the telomerase activity. The Kaplan-Meier survival curves in all patients with NSCLC demonstrated that patients with telomerase-positive tumors survived for a significantly shorter period than those with a telomerase-negative tumor (p = 0.0058). According to a multivariate analysis, telomerase activity was identified as an independent prognostic factor (RR = 8.62, p = 0.035). CONCLUSIONS Telomerase activity was one of the most important prognostic factors in patients with NSCLC, and its potential prognostic implication was independent of tumor stage.