P53 expression, DNA ploidy and S-phase cell fraction in operable locally advanced non-small-cell lung cancer

Correlation of 4'-[methyl-11C]-thiothymidine PET with Ki-67 immunohistochemistry separately in patients with newly diagnosed and recurrent gliomas

OBJECTIVE

4'-[methyl-11C]-thiothymidine (4DST) uptake on PET was correlated with proliferative activity separately in patients with newly diagnosed and recurrent gliomas.

METHODS

A total of 29 patients, 18 with newly diagnosed gliomas and 11 with recurrent gliomas who underwent 4DST PET/computed tomography (CT) were available for a retrospective analysis of prospectively collected data. The maximum standardized uptake value (SUVmax) of tumor (T) and the mean SUV of normal contralateral hemisphere (N) were calculated, and the tumor-to-normal (T/N) ratio was determined. Proliferative tumor volume (PTV) and total lesion proliferation (TLP) were also calculated. Proliferative activity as indicated by the Ki-67 index was estimated in tissue specimens. Immunohistochemical findings were correlated with 4DST PET parameters.

RESULTS

All gliomas but three newly diagnosed gliomas had 4DST uptake on PET. No significant differences in SUVmax, T/N ratio, PTV, or TLP were observed between the newly diagnosed and recurrent gliomas. In the former, correlations between SUVmax (r = 0.57, P = 0.02), T/N ratio (r = 0.51, P = 0.03), PTV (r = 0.74, P < 0.001), and TLP (r = 0.76, P < 0.001) and the Ki-67 index were found. In the latter, the results did not seem to suggest any correlations between any of the PET parameters and Ki-67 index.

CONCLUSION

Although preliminary, these results suggest that 4DST PET may be useful for the noninvasive evaluation of proliferation in patients with newly diagnosed gliomas. These data in a small recurrent patient population do not support a clear-cut correlation between 4DST uptake and proliferation.

Correlation of 4'-[methyl-11C]-thiothymidine PET with Gd-enhanced and FLAIR MRI in patients with newly diagnosed glioma

PURPOSE

To elucidate the biological association between tumor proliferation, tumor infiltration and neovascularization, we analyzed the association between volumetric information of 4'-[methyl-¹¹C]thiothymidine (4DST) positron emission tomography (PET) and fluid-attenuated inversion recovery (FLAIR) and T1-weighted gadopentetate dimeglumine (Gd)-enhanced magnetic resonance imaging (MRI), in patients with newly diagnosed glioma.

METHODS

A total of 23 patients with newly diagnosed glioma who underwent both 4DST PET/CT and Gd-enhanced MRI before therapy were available for a retrospective analysis of prospectively collected data. The maximum standardized uptake value (SUVmax) for tumor (T) and the mean SUV for normal contralateral hemisphere (N) were calculated, and the tumor-to-normal (T/N) ratio was determined. Proliferative tumor volume (PTV) from 4DST PET and the volume of Gd enhancement (GdV) and hyperintense region on FLAIR (FLAIRV) from MRI were calculated.

RESULTS

All gliomas but 3 diffuse astrocytomas and one anaplastic astrocytoma had 4DST uptake and Gd enhancement on MRI. There was no significant difference between PTV and GdV although the exact edges of the tumor differed in each modality. The FLAIRV was significantly larger than PTV (P < 0.001). Significant correlations between PTV and GdV (ρ = 0.941, P < 0.001) and FLAIRV (ρ = 0.682, P < 0.001) were found.

CONCLUSION

These preliminary results indicate that tumor proliferation assessed by 4DST PET is closely associated with tumor-induced neovascularization determined by Gd-enhanced MRI in patients with newly diagnosed glioma.

Efficacy of cell proliferation imaging with 4DST PET/CT for predicting the prognosis of patients with esophageal cancer: a comparison study with FDG PET/CT

PURPOSE

4'-[Methyl-11C] thiothymidine (4DST) incorporates into DNA directly and is a PET tracer used for cell proliferation imaging. The aim of this study was to evaluate the prediction of prognosis with pretreatment 4DST PET/CT compared to fluorodeoxyglucose (FDG) PET/CT in patients with esophageal cancer.

METHODS

In this prospective study, we analyzed 46 patients (68.2 ± 10.0 years old) with pathologically proven esophageal squamous cell cancer who underwent pretreatment 4DST and FDG PET/CT. The maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and total lesion proliferation (TLP) were measured for FDG and 4DST PET. The study endpoints were progression-free survival (PFS) and overall survival (OS). Patients' clinical backgrounds, including age, histological type, clinical stage, and surgical treatment, were adjusted using the Cox proportional-hazards model.

RESULTS

In the follow-up period (median 18.8 (interquartile range: 10.1-29.0) months), 26 and 19 patients showed disease progression and cancer-related death, respectively. After adjusting for clinical variables, only the 4DST parameters (SUVmax (p = 0.001) and TLP (p = 0.022)) were statistically significant for predicting PFS. FDG MTV (p = 0.031), 4DST SUVmax (p = 0.022), and TLP (p = 0.023) were statistically significant for predicting OS. Of the PET parameters, 4DST SUVmax yielded the highest adjusted hazard ratio for both PFS (4.88, 95% confidence intervals (CI): 1.83-12.97) and OS (4.19, 95% CI: 1.23-14.20).

CONCLUSION

Higher accumulation of 4DST in the primary tumor may lead to shorter OS and PFS. 4DST PET/CT is useful for predicting prognosis and may outperform FDG PET/CT.

4'-[methyl-11C]-thiothymidine as a proliferation imaging tracer for detection of colorectal cancer: comparison with 18F-FDG

OBJECTIVE

The novel radiotracer, 4'-[methyl-¹¹C]-thiothymidine (¹¹C-4DST), was developed based on the DNA incorporation method as a cell proliferation marker. This study investigated the feasibility of ¹¹C-4DST positron emission tomography/computed tomography (PET/CT) for detection of colorectal cancer, as compared with 2-deoxy-2-¹⁸F-fluoro-D-glucose (¹⁸F-FDG) PET/CT, and to correlate the two radiotracers with proliferative activity.

METHODS

A total of 18 patients with newly diagnosed colorectal cancer underwent both ¹¹C-4DST and ¹⁸F-FDG PET/CT. Tumor lesions were identified as areas of focally increased uptake, exceeding that of adjacent normal tissue. For semiquantitative analysis, the maximal standardized uptake value (SUV_max) was calculated. Proliferative activity as quantified by the Ki-67 index was estimated in tumor specimens.

RESULTS

In all 18 patients, colorectal cancers were detected by both ¹¹C-4DST and ¹⁸F-FDG PET/CT. The median (± SD) SUV_max for ¹¹C-4DST (6.02 ± 2.55) was significantly lower than that for ¹⁸F-FDG (13.91 ± 7.62) (P < 0.001). ¹¹C-4DST SUV_max and ¹⁸F-FDG SUV_max showed a significant correlation (r = 0.69, P = 0.002). ¹¹C-4DST SUV_max and Ki-67 index were weakly correlated (r = 0.50, P = 0.04). ¹⁸F-FDG SUV_max and Ki-67 index were not significantly correlated (r = 0.44, P = 0.06).

CONCLUSIONS

Despite a significantly lower uptake of ¹¹C-4DST than that of ¹⁸F-FDG, detection of colorectal cancer was also feasible with ¹¹C-4DST PET/CT. ¹¹C-4DST PET/CT might have a role in the noninvasive assessment of proliferation in colorectal cancer.

Evaluation of [18F]FDG/[18F]FLT/[18F]FMISO-based micro-positron emission tomography in detection of liver metastasis in human colorectal cancer

INTRODUCTION

Positron emission tomography (PET) is extensively used in clinical oncology for tumor detection. This study aimed to explore the application of the radiotracers [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG), 3'-deoxy-3'- [¹⁸F]fluorothymidine ([¹⁸F]FLT), and [¹⁸F]fluoromisonidazole ([¹⁸F]FMISO) in the diagnosis and monitoring of hepatic metastasis in human colorectal cancer (CRC).

METHODS

A mouse model of human CRC with hepatic metastasis was established by intrasplenic implantation of human CRC cell lines LoVo or HCT8. Metastatic potential of these two cell lines was evaluated by wound healing assay in vitro and survival analysis. Uptake of radiotracers between LoVo and HCT8 cells and uptake of radiotracers in the resulting mouse tumor models were examined by in vivo and in vitro experiments. Uptake of each radiotracer in hepatic metastatic lesions was quantified and expressed as standard uptake value (SUV). Protein expression of multiple tumor biomarkers was determined in metastatic lesions. The correlation between tracer uptake and tumor marker expression was evaluated using linear regression.

RESULTS

LoVo cells exhibited a stronger metastatic potential and a higher radiotracer uptake ability than HCT8 cells, as evidenced by significantly greater wound closure percentage, shorter survival, higher incidence of liver metastases, and higher cellular radiotracer levels in LoVo cells or LoVo cell-xenografted mice. SUV values of [¹⁸F]FLT and [¹⁸F]FMISO, but not [¹⁸F]FDG, in LoVo cell-derived metastatic lesions were significantly greater than those in HCT8 lesions. Mechanistically, the expression of MACC1, HIF-1α, and GLUT-1(metastasis associated in colon cancer 1, MACC1; hypoxia-inducible factor 1-alpha, HIF-1α; and glucose transporter 1, GLUT-1, respectively) in LoVo cell-derived metastatic lesions was more effectively induced than in HCT8-derived ones. A linear regression analysis demonstrated significant positive correlations between [¹⁸F]FLT/[¹⁸F]FMISO uptake and tumor biomarker expression in metastatic tissues.

CONCLUSIONS

[¹⁸F]FLT and [¹⁸F]FMISO-based PET imaging may serve as a promising method for early detection and monitoring of hepatic metastasis in patients with CRC.

Prognostic significance of CDC25C in lung adenocarcinoma: An analysis of TCGA data

OBJECTIVE

Cell division cycle 25C (CDC25C) is involved in the regulation of the G2/M phase transition and is associated with various cancers, including non-small cell lung cancer. We evaluated its prognostic value in lung adenocarcinoma (LUAD) based on data from The Cancer Genome Atlas (TCGA).

METHODS

Kruskal-Wallis test, Wilcoxon signed-rank test, and logistic regression were used to evaluate relationships between clinical-pathologic features and CDC25C expression. Cox regression analyses and the Kaplan-Meier method were used to evaluate factors contributing to prognosis. Gene set enrichment analysis (GSEA) was performed.

RESULTS

High CDC25C expression in LUAD was associated with a high tumor extent (odds ratio (OR) = 2.23 (1.52-3.29), P < 0.001), regional lymph node invasion (OR = 2.18 (1.48-3.22), P < 0.001), OR = advanced stage (OR = 2.47 (1.72-3.59), P < 0.001), and poor status (OR = 1.87 (1.19-2.96), P = 0.007). A univariate analysis showed that high CDC25C expression is associated with a short overall survival (OS) (HR: 1.873; 95% CI: 1.385-2.535; P < 0.001) and poor progression-free survival (HR: 1.503; 95% CI: 1.173-1.926; P = 0.0012). In a multivariate analysis, high CDC25C expression was associated with poor OS (HR = 2.193; CI: 1.394-3.452, P = 0.001). GSEA showed the enrichment of cell cycle, apoptosis, p53-dependent G1 DNA damage response, S-phase, mitotic M-M G1 phases, and FA-mediated cell death in the CDC25C high-expression phenotype.

CONCLUSIONS

CDC25C predicts poor prognosis in LUAD and may function in cell cycle regulation and FAS-mediated apoptosis.

18F-FDG and 11C-4DST PET/CT for evaluating response to platinum-based doublet chemotherapy in advanced non-small cell lung cancer: a prospective study

Background

4′-[Methyl-¹¹C] thiothymidine (4DST) PET/CT provides DNA synthesis imaging, which represented a higher correlation with the proliferation in advanced non-small cell lung cancer (NSCLC) than that from imaging with FDG. The aim of this prospective study was to evaluate the potential of 4DST in early therapy monitoring for advanced NSCLC, and to compare the results with those from CT and FDG PET/CT.

Results

Patients who had been pathologically diagnosed with advanced NSCLC and were scheduled to receive platinum-doublet chemotherapy (PT-DC) were eligible. PET/CT imaging with 4DST and with FDG, and CT were performed at baseline and after 2 cycles of PT-DC (interim). Patients were evaluated semi-quantitatively after the 2 cycles of PT-DC using several PET parameters, response evaluation criteria in solid tumors (RECIST) 1.1 based on CT measurements, European Organization for Research and Treatment of Cancer (EORTC) criteria and PET Response Criteria in Solid Tumors (PERCIST) 1.0 based on PET/CT measurements. Baseline measurement data and metabolic response were compared between patients with progression-free survival (PFS) > 4 months and ≤ 4 months, and PFS and overall survival (OS) were compared between patients with and without metabolic response measured with each of the different parameters, using Kaplan-Meier statistics and log-rank testing. A total of 22 patients were included in this study. For predicting PFS > 4 months and ≤ 4 months, metabolic tumor volume (MTV) of baseline 4DST showed the highest area under the curve (0.73), positive predictive value (80.0%), negative predictive value (66.7%), and accuracy (72.7%) among baseline measurement data and metabolic responses from 4DST PET/CT, FDG PET/CT, and CT. Kaplan-Meier curves and log-rank tests for PFS with MTV of baseline FDG and baseline 4DST, and for OS with MTV of baseline FDG and baseline TLG, and MTV of baseline 4DST revealed significant results.

Conclusions

MTV of baseline 4DST PET/CT along with MTV of baseline FDG PET/CT represent promising predictors of PFS, and MTV of baseline 4DST PET/CT along with MTV and TLG of baseline FDG PET/CT are possible predictors of OS in patients with advanced NSCLC.

Correlation of 4'-[methyl-11C]-thiothymidine uptake with human equilibrative nucleoside transporter-1 and thymidine kinase-1 expressions in patients with newly diagnosed gliomas

OBJECTIVE

We examined expressions of human equilibrative nucleoside transporter-1 (hENT1) and thymidine kinase-1 (TK1), the key enzyme in 4'-[methyl-¹¹C]-thiothymidine (4DST) phosphorylation, to elucidate the mechanism of 4DST uptake in patients with newly diagnosed gliomas.

METHODS

A total of 19 patients with newly diagnosed gliomas were examined with 4DST PET. Tumor lesions were identified as areas of focally increased uptake, exceeding that of normal brain background. For semi-quantitative analysis, tumor-to-contralateral normal brain tissue (T/N) ratio was determined by dividing the maximal standardized uptake value (SUV) for tumor by that of the mean SUV for reference tissue. The expressions of hENT1, TK1 and Ki-67 in tumor specimens were examined by immunohistochemistry and compared with 4DST T/N ratio.

RESULTS

All but two gliomas showed focally increased 4DST uptake. All gliomas showed hENT1 staining, except one grade II glioma, which was also not visualized on 4DST PET. A significant correlation was observed between T/N ratio and hENT1 score (ρ = 0.90, p < 0.001). All gliomas showed TK1 staining, except two gliomas which were also not visualized on 4DST PET. There was a significant correlation between T/N ratio and TK1 score (ρ = 0.92, p < 0.001). There was a significant correlation between T/N ratio and Ki-67 index (ρ = 0.50, p < 0.03).

CONCLUSION

Results of this preliminary study indicate that expressions of hENT1 and TK1 appear to be important determinants of 4DST uptake in newly diagnosed gliomas.

A pilot study of 4'-[methyl-11C]-thiothymidine PET/CT for detection of regional lymph node metastasis in non-small cell lung cancer

Background

4′-[methyl-¹¹C]-thiothymidine (4DST) is a novel positron emission tomography (PET) tracer to assess proliferation of malignancy. The diagnostic abilities of 4DST and 2-deoxy-2-¹⁸ F-fluoro-d-glucose (FDG) for detecting regional lymph node (LN) metastases of non-small cell lung cancer (NSCLC) were prospectively compared. In addition, the relationship between the PET result and the patient's prognosis was evaluated.

Methods

A total of 31 patients with NSCLC underwent 4DST PET/computed tomography (CT) and FDG PET/CT. The PET/CT images were evaluated qualitatively and quantitatively for focal uptake of each PET tracer, according to the staging system of the American Joint Committee on Cancer. Surgical and histological results provided the reference standards. Patients were followed for up to two years to assess disease-free survival.

Results

On a per-lesion basis, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for LN staging were 82%, 72%, 32%, 96%, and 73%, respectively, for 4DST, and 29%, 86%, 25%, 88%, and 78%, respectively, for FDG. The sensitivity of 4DST was significantly higher than that of FDG (P < 0.001). The disease-free survival rate with positive 4DST uptake in nodal lesions was 0.35, which was considerably lower than the rate of 0.83 with negative findings (P = 0.04). Among the factors tested, nodal staging by 4DST was the most influential prognostic factor (P = 0.05) in predicting the presence of a previously existing spread lesion or of a recurrence over the course of 2 years.

Conclusion

4DST PET/CT is sensitive for detecting mediastinal lymph node metastasis in NSCLC, but its low specificity is a limitation. However, it may be helpful in predicting the prognosis of NSCLC.

4'-[Methyl-11C]-thiothymidine PET/CT for proliferation imaging in non-small cell lung cancer

A new tracer, 4'-[methyl-(11)C]-thiothymidine ((11)C-4DST), has been developed as an in vivo cell proliferation marker based on the DNA incorporation method. This study evaluated the potential of (11)C-4DST PET/CT for imaging proliferation in non-small cell lung cancer (NSCLC), compared with (18)F-FDG PET/CT.

METHODS

Eighteen patients with lung lesions were examined by PET/CT using (11)C-4DST and (18)F-FDG. We constructed decay-corrected time-activity curves of 9 major regions as the mean standardized uptake value. We then compared the maximum standardized uptake value (SUVmax) of lung tumors on both (11)C-4DST and (18)F-FDG PET/CT with the Ki-67 index of cellular proliferation and with CD31-positive vessels as a marker of angiogenesis in surgical pathology.

RESULTS

NSCLC was pathologically confirmed in 19 lesions of 18 patients. Physiologic accumulation of (11)C-4DST was high in liver, kidney, and bone marrow and low in aorta, brain, lung, and myocardium. Biodistribution of (11)C-4DST was almost stable by 20 min after injection of (11)C-4DST. Mean (11)C-4DST SUVmax for lung cancer was 2.9 ± 1.0 (range, 1.5-4.7), significantly different from mean (18)F-FDG SUVmax, which was 6.2 ± 4.5 (range, 0.9-17.3; P < 0.001). The correlation coefficient between SUVmax and Ki-67 index was higher with (11)C-4DST (r = 0.82) than with (18)F-FDG (r = 0.71). The correlation coefficient between SUVmax and CD31 was low with both (11)C-4DST (r = 0.21) and (18)F-FDG (r = 0.21), showing no significant difference between the tracers.

CONCLUSION

A higher correlation with proliferation of lung tumors was seen for (11)C-4DST than for (18)F-FDG. (11)C-4DST PET/CT may allow noninvasive imaging of DNA synthesis in NSCLC.

Detection of gastric cancer using 18F-FLT PET: comparison with 18F-FDG PET

PURPOSE

We prospectively investigated the feasibility of 3'-deoxy-3'-(18)F-fluorothymidine (FLT) positron emission tomography (PET) for the detection of gastric cancer, in comparison with 2-deoxy-2-(18)F-fluoro-D-glucose (FDG) PET, and determined the degree of correlation between the two radiotracers and proliferative activity as indicated by Ki-67 index.

METHODS

A total of 21 patients with newly diagnosed advanced gastric cancer were examined with FLT PET and FDG PET. Tumour lesions were identified as areas of focally increased uptake, exceeding that of surrounding normal tissue. For semiquantitative analysis, the maximal standardized uptake value (SUV) was calculated.

RESULTS

For detection of advanced gastric cancer, the sensitivities of FLT PET and FDG PET were 95.2% and 95.0%, respectively. The mean (+/-SD) SUV for FLT (7.0 +/- 3.3) was significantly lower than that for FDG (9.4 +/- 6.3 p < 0.05). The mean FLT SUV and FDG SUV in nonintestinal tumours were higher than in intestinal tumours, although the difference was not statistically significant. The mean (+/-SD) FLT SUV in poorly differentiated tumours (8.5 +/- 3.5) was significantly higher than that in well and moderately differentiated tumours (5.3 +/- 2.1; p < 0.04). The mean FDG SUV in poorly differentiated tumours was higher than in well and moderately differentiated tumours, although the difference was not statistically significant. There was no significant correlation between Ki-67 index and either FLT SUV or FDG SUV.

CONCLUSION

FLT PET showed as high a sensitivity as FDG PET for the detection of gastric cancer, although uptake of FLT in gastric cancer was significantly lower than that of FDG.

Comparison of (18)F-FLT PET and (18)F-FDG PET for preoperative staging in non-small cell lung cancer

PURPOSE

The nucleoside analog 3'-deoxy-3'-(18)F-fluorothymidine (FLT) has been introduced for imaging cell proliferation with positron emission tomography (PET). We prospectively compared the diagnostic efficacy of FLT PET with that of 2-deoxy-2-(18)F-fluoro-D-glucose (FDG) PET for the preoperative nodal and distant metastatic staging of non-small cell lung cancer (NSCLC).

METHODS

A total of 34 patients with NSCLC underwent FLT PET and FDG PET. PET imaging was performed at 60 min after each radiotracer injection. The PET images were evaluated qualitatively for regions of focally increased metabolism. For visualized primary tumors, the maximum standardized uptake value (SUV) was calculated. Nodal stages were determined by using the American Joint Committee on Cancer staging system and surgical and histologic findings reference standards.

RESULTS

For the depiction of primary tumor, sensitivity of FLT PET was 67%, compared with 94% for FDG PET (P = 0.005). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for lymph node staging on a per-patient basis were 57, 93, 67, 89, and 85%, respectively, with FLT PET and 57, 78, 36, 91, and 74%, respectively, with FDG PET (P > 0.1 for all comparisons). Two of the three distant metastases were detected with FLT and FDG PET.

CONCLUSION

In NSCLC, FLT PET showed better (although not statistically significant) specificity, positive predictive value and accuracy for N staging on a per-patient basis than FDG PET. However, FDG PET was found to have higher sensitivity for depiction of primary tumor than FLT PET.

Correlation of 18F-FLT and 18F-FDG uptake on PET with Ki-67 immunohistochemistry in non-small cell lung cancer

PURPOSE

The nucleoside analogue 3'-deoxy-3'-(18)F-fluorothymidine (FLT) has recently been introduced for imaging cell proliferation with positron emission tomography (PET). We prospectively evaluated whether FLT uptake reflects proliferative activity as indicated by the Ki-67 index in non-small cell lung cancer (NSCLC), in comparison with 2-deoxy-2-(18)F-fluoro-D-glucose (FDG).

METHODS

A total of 18 patients with newly diagnosed NSCLC were examined with both FLT PET and FDG PET. PET imaging was performed at 60 min after each radiotracer injection. Tumour lesions were identified as areas of focally increased uptake, exceeding background uptake in the lungs. For semi-quantitative analysis, the maximum standardised uptake value (SUV) was calculated. Proliferative activity as indicated by the Ki-67 index was estimated in tissue specimens. Immunohistochemical findings were correlated with SUVs.

RESULTS

The sensitivity of FLT and FDG PET for the detection of lung cancer was 72% and 89%, respectively. Four of the five false-negative FLT PET findings occurred in bronchiolo-alveolar carcinoma. The mean FLT SUV was significantly lower than the mean FDG SUV. A significant correlation was observed between FLT SUV and Ki-67 index (r = 0.77; p < 0.0002) and for FDG SUV (r = 0.81; p < 0.0001).

CONCLUSION

The results of this preliminary study suggest that, compared with FDG, FLT may be less sensitive for primary staging in patients with NSCLC. Although FLT uptake correlated significantly with proliferative activity in NSCLC, the correlation was not better than that for FDG uptake.

Cytofluorimetric Evaluation of DNA Ploidy in Lung Cancer: A Bronchoscopic Study

The study of the biological characteristics of lung cancer is gaining more and more interest both because of their potential role as prognostic indicators and for therapeutic reasons. The DNA content estimated by flow cytometry in surgical samples of non-small cell lung cancer (NSCLC) has already been demonstrated to be correlated with survival in these patients. From July 1990 to February 1992 we analyzed the DNA distribution of bronchoscopic biopsies from 88 patients with lung cancer (18 small cell lung cancer, SCLC, and 68 NSCLC, two unspecified histology). Twenty-eight tumors (34.6%) had a diploid DNA distribution, while 53 were aneuploid (65.4%). A correlation was found between DNA ploidy and survival. Evaluation of the DNA content in bronchoscopic samples in a large series of patients could determine the role of this analysis prior to surgery in NSCLC and its value as a marker with respect to prognosis and response to therapy in SCLC.

Stratification of the biologic aggressiveness of non-small cell lung cancer using DNA flow cytometry and immunohistochemistry for the retinoblastoma protein

DNA ploidy pattern and S-phase fraction (SPF) measured by flow cytometry and expression of the retinoblastoma gene product (pRB) estimated by immunohistochemistry were correlated with outcome in 114 patients who received a curative operation for primary non-small cell lung cancer (NSCLC). One hundred ten tumors yielded an adequate DNA histogram, and all tumors exhibited an assessable immunohistochemical stain. DNA diploidy was detected in 31 tumors and DNA aneuploidy in 79 tumors. The mean SPF was 14.1 +/- 6.4%. Eighty tumors were positively stained, and 34 tumors were negative for pRB. Multivariate analysis clarified that both TNM staging and DNA ploidy were prognostic factors after surgery. In 39 recurrent cases, the SPF value was inversely correlated with disease-free interval. With only supportive care after recurrence, high SPF tumors and pRB-negative tumors progressed rapidly, whereas active treatment yielded an equivalent effect on recurrent tumors regardless of the SPF or pRB expression. DNA ploidy is related to the risk of recurrence, while SPF is related to tumor growth rate and the impact of active treatment on recurrence. The utility of pRB expression was limited. The combination of DNA ploidy and SPF allows practical stratification of the biologic aggressiveness of NSCLC.

[18F]FLT PET for diagnosis and staging of thoracic tumours

The nucleoside analogue 3'-deoxy-3'-[18F]fluorothymidine (FLT) has been introduced for imaging of tumour cell proliferation by positron emission tomography (PET). This study evaluated the use of FLT in patients with thoracic tumours prior to treatment. Whole-body FLT PET was performed in 16 patients with 18 tumours [17 thoracic tumours (nine non-small cell lung cancers, five oesophageal carcinomas, two sarcomas, one Hodgkin's lymphoma) and one renal carcinoma] before treatment. Fluorine-18 fluorodeoxyglucose (FDG) PET was performed for comparison except in those patients with oesophageal carcinoma. For semi-quantitative analysis, the average and maximum standardised uptake values (avgSUV and maxSUV, respectively) (FLT, 114+/-20 min p.i.; FDG, 87+/-8 min p.i.; 50% isocontour region of interest) was calculated. All 17 thoracic tumours and 19/20 metastases revealed significant FLT accumulation, resulting in easy delineation from surrounding tissue. The additional small grade 1 renal carcinoma was not detected with either FLT or FDG. In most lung tumours (avgSUV 1.5-8.2) and metastases, FLT showed intense uptake. However, one of two spinal bone metastases was missed owing to the high physiological FLT uptake in the surrounding bone marrow. Oesophageal carcinoma primaries (avgSUV 2.7-10.0) and occasional metastases showed particularly favourable tumour/non-tumour contrast. Compared with FDG, tumour uptake of FLT was lower (avgSUV, P=0.0006; maxSUV, P=0.0001), with a significant linear correlation (avgSUV, r2=0.45; maxSUV, r2=0.49) between FLT and FDG. It is concluded that FLT PET accurately visualises thoracic tumour lesions. In the liver and the bone marrow, high physiological FLT uptake hampers detection of metastases. On the other hand, FLT may be favourable for imaging of brain metastases owing to the low physiological uptake.

Ability of bivariate cytokeratin and deoxyribonucleic acid flow cytometry to determine the biologic aggressiveness of resectable non-small cell lung cancer

OBJECTIVE

The purpose of this study was to clarify the significance of bivariate cytokeratin and DNA flow cytometry for analysis of the biologic aggressiveness of resectable non-small cell lung cancer.

METHODS

In 92 patients who underwent curative operations, the DNA ploidy status and S-phase fractions of the cancer cell populations inside the tumors were analyzed by a cytokeratin gating technique with paraffin-embedded specimens and were correlated with the surgical results.

RESULTS

Ninety tumors yielded assessable DNA histograms. DNA diploidy was detected in 25 tumors with a mean S-phase fraction of 14.3% +/- 4.7%, and DNA aneuploidy was detected in 65 tumors with a mean S-phase fraction of 15.1% +/- 7.1%. The 5-year overall and recurrence-free survivals were 73.3% and 70.3%, respectively. Multivariate analysis showed that only TNM staging was a prognostic factor after surgery. There was a negative correlation between the logarithms of S-phase fraction and the disease-free interval for 22 patients with proven recurrence (P =.006). The tumors with high S-phase fractions recurred more rapidly than did those with low S-phase fractions.

CONCLUSION

In a bivariate analysis of cytokeratin and DNA flow cytometry in resectable non-small cell lung cancer, the S-phase fraction appeared to be correlated with the disease-free interval. However, DNA ploidy and S-phase fraction were not predictive of either recurrence or survival after operation. Thus DNA flow cytometry may be of limited use for the analysis of the biologic aggressiveness of lung cancer.

Aneuploidy and prognosis of non-small-cell lung cancer: a meta-analysis of published data

In lung cancer, DNA content abnormalities have been described as a heterogeneous spectrum of impaired tumour cell DNA histogram patterns. They are merged into the common term of aneuploidy and probably reflect a high genotypic instability. In non-small-cell lung cancer, the negative effect of aneuploidy has been a subject of controversy inasmuch as studies aimed at determining the survival-DNA content relationship have reported conflicting results. We made a meta-analysis of published studies aimed at determining the prognostic effect of aneuploidy in surgically resected non-small-cell lung cancer. 35 trials have been identified in the literature. A comprehensive collection of data has been constructed taking into account the following parameters: quality of specimen, DNA content assessment method, aneuploidy definition, histology and stage grouping, quality of surgical resection and demographic characteristics of the analysed population. Among the 4033 assessable patients, 2626 suffered from non-small-cell lung cancer with aneuploid DNA content (overall frequency of aneuploidy: 0.65; 95% CI: (0.64-0.67)). The DerSimonian and Laird method was used to estimate the size effects and the Peto and Yusuf method was used in order to generate the odds ratios (OR) of reduction in risk of death for patients affected by a nearly diploid (non-aneuploid) non-small-cell lung cancer. Survivals following surgical resection, from 1 to 5 years, were chosen as the end-points of our meta-analysis. Patients suffering from a nearly diploid tumour benefited from a significant reduction in risk of death at 1, 2, 3 and 4 years with respective OR: 0.51, 0.51, 0.45 and 0.67 (P< 10(-4)for each end-point). 5 years after resection, the reduction of death was of lesser magnitude: OR: 0.87 (P = 0.08). The test for overall statistical heterogeneity was conventionally significant (P< 0.01) for all 5 end-points, however. None of the recorded characteristics of the studies could explain this phenomenon precluding a subset analysis. Therefore, the DerSimonian and Laird method was applied inasmuch as this method allows a correction for heterogeneity. This method demonstrated an increase in survival at 1, 2, 3, 4 and 5 years for patients with diploid tumours with respective size effects of 0.11, 0.15, 0.20, 0.20 and 0.21 (value taking into account the correction for heterogeneity;P< 10(-4)for each end-point). Patients who benefit from a surgical resection for non-small-cell lung cancer with aneuploid DNA content prove to have a higher risk of death. This negative prognostic factor decreases the probability of survival by 11% at one year, a negative effect deteriorating up to 21% at 5 years following surgery.

Clinical importance of correlations between p53 immunoreactivity and clinicopathological parameters in lung carcinoma

Many studies have revealed the frequency of p53 abnormalities in lung cancer. However, clinico-pathological studies of p53 abnormalities have yielded conflicting results. We examined the p53 immunoreactivity and studied the correlations of p53 status and clinicopathological parameters in 76 primary lung cancers. By using DO-7 antibody, different degrees of p53 immunoreactivity was detected in 8 of 30 small cell lung cancer (SCLC, 26.6%) and 22 of 46 non-small cell lung cancer (NSCLC, 47.8%), 6 of 19 adenocarcinoma, 16 of 27 epidermoid carcinoma cases. In the whole group, no correlation was detected between the p53 status and the histological types of tumor, local tumor invasion, nodal status, and distant metastasis and patient characteristics, such as age, gender or smoking habit. P53 status was also found to have no effect on survival. However, in the NSCLC group, there was a significantly higher p53 immunoreactivity in well- and moderately-differentiated tumors (p<0.05). Patients with p53 immunoreactivity had a poor therapeutic response in the whole group. We concluded that, although p53 immunreactivity may be found in NSCLC, this does not correlate with clinicopathological parameters except therapeutic response. In SCLC p53 immunreactivity can be negligible.

Prognostic value of nucleolar protein p120 in patients with resected lung adenocarcinoma

PURPOSE

In this study we investigated the prognostic significance of proliferation-associated nucleolar protein p120 in primary resected lung adenocarcinoma because it reflects tumor growth fractions in vitro.

PATIENTS AND METHODS

Expression levels of p120 in tumors were assessed by immunohistochemistry in 74 patients who underwent radical resection. With clinical follow-up data, the prognostic significance of p120 calculated by labeling indices was evaluated using the Cox proportional hazards model.

RESULTS

p120 protein was clearly detected in nucleoli of adenocarcinoma cells. Its expression levels widely varied in each sample from 8.5% to 67. 2%, with a mean +/- SD of 35.2% +/- 15.1%. No significant correlation was found between expression levels of p120 and clinicopathologic factors. However, the expression levels of p120 were negatively correlated with the tumor doubling time calculated with retrospective chest roentgenograms. Using a cutoff value of 35% in the labeling index of p120, patients with high expression of p120 experienced early recurrence and shorter survival compared with those who had low expression of p120. Multivariate analysis showed that p120 served as an independent, as well as the strongest, prognostic factor for resected lung adenocarcinoma.

CONCLUSION

This report provides the first evidence that expression levels of p120 in tumor tissues can be used as an independent and powerful prognostic marker for resected lung adenocarcinoma.

Phase III comparison of twice-daily split-course irradiation versus once-daily irradiation for patients with limited stage small-cell lung carcinoma

PURPOSE

Because small-cell lung cancer is a rapidly proliferating tumor, it was hypothesized that it may be more responsive to thoracic irradiation (TI) given twice-daily than once-daily. This hypothesis was tested in a phase III trial.

PATIENTS AND METHODS

Patients with limited-stage small-cell lung cancer were entered onto a phase III trial, and all patients initially received three cycles of etoposide (130 mg/m(2) x 3) and cisplatin (30 mg/m(2) x 3). Subsequently, patients who did not have progression to a distant site (other than brain) were randomized to twice-daily thoracic irradiation (TDTI) versus once-daily thoracic irradiation (ODTI) given concomitantly with two additional cycles of etoposide (100 mg/m(2) x 3) and cisplatin (30 mg/m(2) x 3). The irradiation doses were TDTI, 48 Gy in 32 fractions, with a 2.5-week break after the initial 24 Gy, and ODTI, 50.4 Gy in 28 fractions. After thoracic irradiation, the patients received a sixth cycle of etoposide/cisplatin, followed by prophylactic cranial irradiation (30 Gy/15 fractions) if they had a complete response.

RESULTS

Of 311 assessable patients enrolled in the trial, 262 underwent randomization to TDTI or ODTI. There were no differences between the two treatments with respect to local-only progression rates, overall progression rates, or overall survival. The patients who received TDTI had greater esophagitis (> or = grade 3) than those who received ODTI (12.3% v 5.3%; P =.05). Although patients received thoracic irradiation encompassing the postchemotherapy volumes, only seven of 90 local failures were out of the portal of irradiation.

CONCLUSION

When TI is delayed until the fourth cycle of chemotherapy, TDTI does not result in improvement in local control or survival compared with ODTI.

Cell proliferation indexes: a biomarker in solid tumors

Clinical studies have shown that carcinogenesis is linked to the development of proliferative abnormalities. Proliferative activity has been found to have prognostic significance in a variety of human tumors. Because proliferative abnormalities can precede the occurrence of morphological abnormalities, their measurement could also serve as useful biomarkers for chemoprevention trials. The variety of techniques for measuring cell proliferation in routine sections include mitosis counting, AgNORs, DNA precursor uptake (bromodeoxyuridine), and immunohistochemical detection of cell cycle proteins (PCNA, Ki-67/MIB-1). It is essential that the virtues and limitations of these methods be examined to ensure collection of meaningful clinical data.

Relationship between TA01 and TA02 polypeptides associated with lung adenocarcinoma and histocytological features

TA01 (molecular weight 35.0 kDa, isoelectric point 5.45) and TA02 (molecular weight 35.0 kDa, isoelectric point 5.29) polypeptides were detected using two-dimensional polyacrylamide gel electrophoresis (2-DE). A previous study has shown that these polypeptides are distributed in primary adenocarcinomas and some large-cell carcinomas of the lung. However, various expression levels of TA01 and TA02 polypeptides were demonstrated in adenocarcinoma, while large-cell carcinoma expressed low levels. To evaluate the relationship between the expression of TA01 and TA02 polypeptides and the histocytological features of primary adenocarcinoma of the lung, these two polypeptides were analysed by 2-DE combined with a non-enzymatic sample preparation technique, and their expression levels were compared with the histocytological features of primary lung adenocarcinoma. Out of 57 primary lung adenocarcinoma cases, 46 cases (80.7%) and 52 cases (91.2%) expressed TA01 and TA02 polypeptides respectively. Furthermore, the expression levels of TA01 and TA02 polypeptides correlated with the degree of cellular atypia, structural atypia and histocytological differentiation of primary lung adenocarcinoma. On the other hand, these two polypeptides were not detected in adenocarcinoma of the lung, metastatic from the colon and mammary glands. High expression of TA01 and TA02 polypeptides reflected the differentiation of primary adenocarcinoma in the lung. These two polypeptides are valuable in determining the histocytological differentiation of primary lung adenocarcinoma as well as in distinguishing between primary and metastatic adenocarcinoma of the lung.