John C. English

Probability of Cancer in Pulmonary Nodules Detected on First Screening CT

BACKGROUND Major issues in the implementation of screening for lung cancer by means of low-dose computed tomography (CT) are the definition of a positive result and the management of lung nodules detected on the scans. We conducted a population-based prospective study to determine factors predicting the probability that lung nodules detected on the first screening low-dose CT scans are malignant or will be found to be malignant on follow-up. METHODS We analyzed data from two cohorts of participants undergoing low-dose CT screening. The development data set included participants in the Pan-Canadian Early Detection of Lung Cancer Study (PanCan). The validation data set included participants involved in chemoprevention trials at the British Columbia Cancer Agency (BCCA), sponsored by the U.S. National Cancer Institute. The final outcomes of all nodules of any size that were detected on baseline low-dose CT scans were tracked. Parsimonious and fuller multivariable logistic-regression models were prepared to estimate the probability of lung cancer. RESULTS In the PanCan data set, 1871 persons had 7008 nodules, of which 102 were malignant, and in the BCCA data set, 1090 persons had 5021 nodules, of which 42 were malignant. Among persons with nodules, the rates of cancer in the two data sets were 5.5% and 3.7%, respectively. Predictors of cancer in the model included older age, female sex, family history of lung cancer, emphysema, larger nodule size, location of the nodule in the upper lobe, part-solid nodule type, lower nodule count, and spiculation. Our final parsimonious and full models showed excellent discrimination and calibration, with areas under the receiver-operating-characteristic curve of more than 0.90, even for nodules that were 10 mm or smaller in the validation set. CONCLUSIONS Predictive tools based on patient and nodule characteristics can be used to accurately estimate the probability that lung nodules detected on baseline screening low-dose CT scans are malignant. (Funded by the Terry Fox Research Institute and others; ClinicalTrials.gov number, NCT00751660.).

P63 expression in lung carcinoma: a tissue microarray study of 408 cases.

p63 is a recently discovered member of the p53 family that has been shown to be important in the development of epithelial tissues. p63 may also play a role in squamous cell carcinomas of the lung, head and neck, and cervix, and its expression is increased in these tumors. The purpose of this study was to investigate the expression of p63 in a broad spectrum of histologic types of lung tumors. A total of 441 cases of primary lung tumors with follow-up data were identified, and the paraffin-embedded tissue blocks were used to construct a duplicate core tissue microarray. After review of the tissue cores, 408 cases, consisting of 123 squamous cell carcinomas, 93 adenocarcinomas, 68 large cell carcinomas, 68 classic carcinoids, 31 atypical carcinoids, 11 large cell neuroendocrine carcinomas, and 14 small cell carcinomas, were adequate for analysis. Immunohistochemistry was performed at 2 different laboratories using monoclonal antibody 4A4 to detect the expression of p63, using different staining protocols. p53 expression was also studied with immunohistochemistry using monoclonal antibody DO-7. Kaplan-Meier curves were plotted to compare the survival of p63-expressing versus nonexpressing tumors. A large proportion of squamous cell carcinomas expressed p63 (96.9%), most showing strong positive nuclear immunoreactivity. Expression in other nonsmall cell lung cancers was also present. Thirty percent of adenocarcinomas and 37% of large cell carcinomas showed p63 expression. In the neuroendocrine tumors, an increasing proportion of tumors stained for p63 as tumor grade increased; 1.9% of classic carcinoids, 30.8% of atypical carcinoids, 50% of large cell neuroendocrine carcinomas, and 76.9% of small cell carcinomas were positive. Approximately half of the positively staining neuroendocrine cases showed strong staining. Expression of p63 was of prognostic significance in neuroendocrine tumors (P < 0.0001), with higher-grade tumors more likely to express p63. Correlation between p63 and p53 expression was not observed (P = 0.18) in nonsmall cell lung cancer; however, a significant correlation between the 2 markers was found in neuroendocrine tumors (P < 0.0001). p63 staining was repeated with a different staining protocol, yielding similar results overall but a lower percentage of positive cases (34.2% vs. 48.4% of tumors positive). In conclusion, p63 expression is consistently expressed in squamous cell carcinoma in the lung, but is also expressed in a subset of adenocarcinomas and large cell carcinomas. Pulmonary neuroendocrine tumors also show p63 staining in some instances, particularly in higher-grade tumors, and the majority of small cell carcinomas are p63-positive. These results suggest that p63 may be involved in oncogenesis in a broader range of tumors than was previously thought.

Evaluation of immunohistochemical markers in non-small cell lung cancer by unsupervised hierarchical clustering analysis: a tissue microarray study of 284 cases and 18 markers.

This study has investigated a panel of immunomarkers in non‐small cell lung carcinoma (NSCLC). Unsupervised hierarchical clustering analysis was used to investigate the possibility of identifying different subgroups in NSCLC based on their molecular expression profile rather than morphological features. A tissue microarray consisting of 284 cases of NSCLC was constructed. Immunohistochemistry was used to detect the presence of 18 biomarkers including synaptophysin, chromogranin, bombesin, NSE, GFI1, ASH‐1, p53, p63, p21, p27, E2F‐1, cyclin D1, Bcl‐2, TTF‐1, CEA, HER2/neu, cytokeratin 5/6, and pancytokeratin. Univariate analysis of all 18 markers for prognostic significance was performed. Immunohistochemical scoring data for NSCLC were analysed by unsupervised hierarchical clustering analysis. Kaplan–Meier survival curves were plotted for the different cluster groups of lung tumours identified by this method. Analysis of the three different World Health Organization (WHO) subtypes (adenocarcinoma, squamous cell carcinoma, large cell carcinoma) of NSCLC individually showed that different markers were significant in different subtypes. For example, p53 and p63 were significant for squamous cell carcinoma (p = 0.007 and p = 0.03, respectively), whereas cyclin D1 and HER2/neu were significant prognostic markers for adenocarcinoma (p = 0.025 and p = 0.015, respectively). These markers were not significant prognostic predictors for NSCLC as a group. Hierarchical clustering analysis of NSCLC produced four separate cluster groups, although the vast majority of cases were found in two cluster groups, one dominated by squamous cell carcinoma and the other by adenocarcinoma. The clinical outcomes of cases from the four cluster groups were not significantly different. Prognostic indicators vary between different morphological subtypes of NSCLC. Unsupervised hierarchical clustering analysis, based on an extended immunoprofile, identifies two main cluster groups corresponding to adenocarcinoma and squamous cell carcinoma; cases of large cell carcinomas are assigned to one of these two groups based on their molecular phenotype. Copyright

Lung Nodules: CT-guided Placement of Microcoils to Direct Video-assisted Thoracoscopic Surgical Resection

PURPOSE To prospectively assess the safety and effectiveness of computed tomography (CT)-guided placement of fiber-coated microcoils used to guide video-assisted thoracoscopic surgical (VATS) excision of small peripheral lung nodules, with successful excision as the primary outcome and successful CT-guided microcoil placement and procedural complications as secondary outcomes. MATERIALS AND METHODS The institutional review board approved the study protocol. Informed consent was obtained from all 69 enrolled patients (30 men, 39 women; mean age, 60.7 years +/- 10.1 [standard deviation]) with 75 nodules. At CT, one end of an 80-mm long, 0.018-inch-diameter fiber-coated microcoil was placed deep to the small peripheral lung nodule, and the other end was coiled in the pleural space. VATS excision of lung tissue, nodules, and the microcoil was performed with fluoroscopic guidance. RESULTS Seventy-three (97%) 4-24-mm nodules were successfully removed at fluoroscopically guided VATS excision; two nodules could not be removed. CT-guided microcoil placement was successful in all cases; however, two (3%) of 75 coils were displaced at VATS excision. Pneumothorax requiring chest tube placement occurred in two (3%) patients, and asymptomatic hemothorax occurred in one (1%) patient. The microcoil did not impede intraoperative frozen-section histopathologic analysis, which facilitated accurate clinical management in all patients. For 19 (28%) patients, the preoperative treatment plan based on bronchoscopy, needle biopsy, and positron emission tomography findings changed after VATS excision. CONCLUSION Microcoil localization of small peripheral lung nodules enabled fluoroscopically guided VATS resection of 97% of the nodules, with a low rate of intervention (3%) for procedural complications.

Peripheral Lung Nodules: Fluoroscopically Guided Video-Assisted Thoracoscopic Resection After Computed Tomography-Guided Localization Using Platinum Microcoils

Objectives:We sought to test the safety and efficacy of fluoroscopically guided, video-assisted, thoracoscopic resection after computed tomography (CT)-guided localization using platinum microcoils. Summary Background Data:Video-assisted thoracoscopic (VATS) resection of small pulmonary nodules >5 mm deep to the visceral pleura fails to locate the nodule and requires conversion to open thoracotomy in two thirds of cases. Therefore, we developed a new technique for intraoperative localization of these nodules using CT-guided placement of platinum microcoils. This study tests the safety and efficacy of this technique in a Phase I human study. Methods:Twelve patients with undiagnosed growing pulmonary nodules <20 mm were marked preoperatively using percutaneously placed CT-guided platinum microcoils. The coil was deployed adjacent to the nodule with the distal end of the coil placed deep to the nodule and the superficial end coiled on the pleural surface. The nodule and coil were excised using endostaplers guided by VATS and fluoroscopy. Histopathologic diagnosis was performed immediately after resection. Results:CT-guided microcoil localization was successful in all patients. A small hemothorax and a pneumothorax requiring a chest tube occurred in 2 patients. Mean distance from visceral pleura to the deep edge of the nodule was 30.9 ± 15.4 mm. VATS resection of the nodules (size = 11.8 ± 3.2mm) was successful in all patients. Mean microcoil localization, fluoroscopy, and operative times were 42 ± 14, 3.1 ± 2.0, and 67 ± 27 minutes. A diagnosis of primary nonsmall cell bronchogenic carcinoma was made in 6 patients who then received a completion lobectomy. Six patients (hamartoma: 2, reactive lymph node: 1, bronchoalveolar cell carcinoma: 2, metastatic sarcoma: 1) did not receive further resections. Conclusions:Preoperative localization of pulmonary nodules using percutaneous CT-guided platinum microcoil insertion combined with operative fluoroscopic visualization is a safe, effective technique that increases the success rate of VATS excision.

Development and validation of human airway analysis algorithm using multidetector row CT

There is currently no accurate method to measure airway dimensions on multidetector row computed tomography (multi-slice CT). We developed CT image analysis software to measure airway lumenal area (Ai) and airway wall area (Aaw) and compared these with quantitative morphology of excised human lungs as the gold standard. Airways identified on the CT images (1.25 mm collimation) were matched to airways identified on the lungs cut surface and Ai and Aaw were measured using custom software. The measured morphological airway lumen ranged from 1.0 to 6.4 mm in diameter. Airway dimensions obtained from CT data correlated with morphologic measurements (r = 0.96 for Ai and r = 0.91 for Aaw). However the CT systematically underestimated Ai and overestimated Aaw; average error (100 x (CT-morphology) / morphology) was -55% for Ai and +90% for Aaw. We used the morphology data to correct the CT measurements and reduced the average error to +23% for Ai and +7% for Aaw. This algorithm can be used to assess the structure and function of human airways.

Penicillin to Prevent Recurrent Leg Cellulitis

BACKGROUND Cellulitis of the leg is a common bacterial infection of the skin and underlying tissue. We compared prophylactic low-dose penicillin with placebo for the prevention of recurrent cellulitis. METHODS We conducted a double-blind, randomized, controlled trial involving patients with two or more episodes of cellulitis of the leg who were recruited in 28 hospitals in the United Kingdom and Ireland. Randomization was performed according to a computer-generated code, and study medications (penicillin [250 mg twice a day] or placebo for 12 months) were dispensed by a central pharmacy. The primary outcome was the time to a first recurrence. Participants were followed for up to 3 years. Because the risk of recurrence was not constant over the 3-year period, the primary hypothesis was tested during prophylaxis only. RESULTS A total of 274 patients were recruited. Baseline characteristics were similar in the two groups. The median time to a first recurrence of cellulitis was 626 days in the penicillin group and 532 days in the placebo group. During the prophylaxis phase, 30 of 136 participants in the penicillin group (22%) had a recurrence, as compared with 51 of 138 participants in the placebo group (37%) (hazard ratio, 0.55; 95% confidence interval [CI], 0.35 to 0.86; P=0.01), yielding a number needed to treat to prevent one recurrent cellulitis episode of 5 (95% CI, 4 to 9). During the no-intervention follow-up period, there was no difference between groups in the rate of a first recurrence (27% in both groups). Overall, participants in the penicillin group had fewer repeat episodes than those in the placebo group (119 vs. 164, P=0.02 for trend). There was no significant between-group difference in the number of participants with adverse events (37 in the penicillin group and 48 in the placebo group, P=0.50). CONCLUSIONS In patients with recurrent cellulitis of the leg, penicillin was effective in preventing subsequent attacks during prophylaxis, but the protective effect diminished progressively once drug therapy was stopped. (Funded by Action Medical Research; PATCH I Controlled-Trials.com number, ISRCTN34716921.).

Integrative Genomic Analyses Identify BRF2 as a Novel Lineage-Specific Oncogene in Lung Squamous Cell Carcinoma

William Lockwood and colleagues show that the focal amplification of a gene, BRF2, on Chromosome 8p12 plays a key role in squamous cell carcinoma of the lung.

Establishment in Severe Combined Immunodeficiency Mice of Subrenal Capsule Xenografts and Transplantable Tumor Lines from a Variety of Primary Human Lung Cancers: Potential Models for Studying Tumor Progression–Related Changes

Purpose: Lung cancer is a biologically diverse disease and relevant models reflecting its diversity would facilitate the improvement of existing therapies. With a view to establishing such models, we developed and evaluated xenografts of a variety of human lung cancers. Experimental Design: Using nonobese diabetic/severe combined immunodeficiency mice, subrenal capsule xenografts were generated from primary lung cancer tissue, including moderately and poorly differentiated squamous cell carcinoma, adenocarcinoma, adenosquamous carcinoma, small cell carcinoma, large cell undifferentiated carcinoma, and carcinosarcoma. After 4 to 12 weeks, xenografts were harvested for serial transplantation and comparison with the original tissue via histologic, chromosomal, and cytogenetic analyses. Results: Xenografts were successfully established. H&E staining showed that xenografts retained major histologic features of the original cancers. Immunohistochemistry and fluorescence in situ hybridization confirmed the human origin of the tumor cells and development in xenografts of murine supportive stroma. Four transplantable lines were developed from rapidly growing tumors (>5 generations), i.e., a small cell lung carcinoma, large cell undifferentiated carcinoma, pulmonary carcinosarcoma, and squamous cell carcinoma. Analyses including spectral karyotyping, comparative genomic hybridization, and fluorescence in situ hybridization, revealed that the xenografts were genetically similar to the original tumors, showing chromosomal abnormalities consistent with karyotypic changes reported for lung cancer. Conclusions: The subrenal capsule xenograft approach essentially provides a living tumor bank derived from patient material and a means for isolating and expanding specific cell populations. The transplantable tumor lines seem to provide good models for studying various aspects of tumor progression and a platform for developing novel therapeutic regimens, with the possibility of patient-tailored therapies.

ASAP1, a Gene at 8q24, Is Associated with Prostate Cancer Metastasis

Metastatic prostate cancer is a terminal disease, and the development of reliable prognostic tools and more effective therapy is critically important for improved disease survival and management. This study was aimed at identifying genes that are differentially expressed in metastatic and nonmetastatic prostate cancer cells and, as such, could be critical in the development of metastasis. Long-SAGE analysis was used to compare a transplantable human metastatic prostate cancer subline, PCa1-met, with a nonmetastatic counterpart, PCa2. Both sublines were developed from a patients prostate cancer specimen via subrenal capsule grafting and subsequent orthotopic implantation into SCID mice. Among various differentially expressed genes identified, ASAP1, an 8q24 gene encoding an ADP-ribosylation factor GTPase-activating protein not previously associated with prostate cancer, was up-regulated in the metastatic subline as confirmed by quantitative real-time PCR. Immunohistochemistry of xenograft sections showed that cytoplasmic ASAP1 protein staining was absent or weak in benign tissue, significantly stronger in nonmetastatic PCa2 tissue, and strongest in PCa1-met tissue. In clinical specimens, ASAP1 protein staining was elevated in 80% of primary prostate cancers and substantially higher in metastatic lesions compared with benign prostate tissue. Moreover, additional ASAP1 gene copies were detected in 58% of the primary prostate cancer specimens. Small interfering RNA-induced reduction of ASAP1 protein expression markedly suppressed in vitro PC-3 cell migration (approximately 50%) and Matrigel invasion (approximately 67%). This study suggests that the ASAP1 gene plays a role in prostate cancer metastasis and may represent a therapeutic target and/or biomarker for metastatic disease.