Clonal evolution of lung tumors

Lung tumors, particularly squamous cell carcinomas, are believed to develop through a series of morphological abnormalities, driven by underlying somatic genetic changes. One way of studying this process is to analyze candidate somatic genetic changes in samples of squamous metaplasia and bronchial dysplasia of varying degrees of severity as well as tumor from the same patient. This assumes a clonal relationship between these lesions. In this article, we provide evidence that adjacent, physically distinct bronchial abnormalities are clonally related. This has been achieved using a plaque assay technique to detect the same p53 mutation, present throughout a tumor specimen, in a small proportion of cells in an adjacent squamous metaplasia. In addition, we have obtained two dysplasia samples from a tumor-free patient over a 9-month interval. The earlier sample had one p53 mutation, whereas the later sample has to p53 mutations on different alleles. Thus, the pattern of clonal evolution detected in the parallel samples mimics the pattern seen in longitudinal samples and supports the analysis of synchronously collected samples for the study of tumor progression.

Sequential molecular genetic changes in lung cancer development

Epithelial tumours develop through a sequence of pre-invasive lesions of increasing disarray driven by underlying somatic genetic changes. We have studied the occurrence of the two most common somatic genetic changes associated with lung cancer in a series of premalignant bronchial lesions representing different stages in lung tumorigenesis. We present evidence that allele loss on chromosome 3 precedes damage to the p53 gene. Damage to chromosome 3 itself appears to be sequential in that the pattern of allele loss seen in dysplasia is often much more discrete than in invasive tumours. This implies that preneoplastic lesions may be a useful source of material for deletion mapping studies aimed at localising the position of tumour suppressor genes. We illustrate this by the comparison of an interstitial deletion described in this study with a homozygous deletion we have described previously, which has resulted in a better definition of the localisation of a tumour suppressor gene believed to be involved in lung cancer development.

Randomized trial comparing weekly versus 3-week chemotherapy in small-cell lung cancer: a Cancer Research Campaign trial

PURPOSE

A randomized trial of chemotherapy, given on either a 1-week or a 3-week schedule, was performed in small-cell lung cancer (SCLC) patients. The aim was to determine if weekly scheduling produced survival superior to conventional treatment.

PATIENTS AND METHODS

Four hundred thirty-eight patients with SCLC with either limited disease (LD; 276 patients) or good-prognosis extensive disease (ED; 162 patients) were randomized. Weekly chemotherapy was 12 alternating cycles of ifosfamide/doxorubicin and cis-platin/etoposide (PE), while 3-week treatment was six alternating cycles of cyclophosphamide/doxorubicin/vincristine (CAV) and PE. Thoracic irradiation was administered 3 weeks after completion of chemotherapy to LD patients who attained a complete response (CR) or partial response (PR). Patients were well matched for clinical characteristics and prognostic factors.

RESULTS

Overall response was the same in both arms: 82.3% (39.4% CR) with weekly and 81.1% (36.9% CR) with 3-week treatment. The median survival (MS) durations were 10.8 and 10.6 months for weekly and 3-week chemotherapy, respectively. The 2-year survival rates were 11.8% and 11.7% in the weekly and 3-week arms, respectively. Received dose-intensity (DI) was 73.9% of projected for weekly treatment and 92.7% for 3-week treatment. Hematologic toxicity was the major dose-limiting toxicity for the weekly treatment.

CONCLUSION

This trial excludes at 90% power a benefit of greater than 10% for 2-year survival for weekly treatment. The received DI was reduced to a greater extent with weekly treatment, mainly due to hematologic toxicity.

Laparoscopic correction of vesicoureteral reflux in the pig

Extravesical detrusorrhaphy is a modification of the Lich-Gregoir antireflux procedure that incorporates ureteral advancement into the repair. We report on our use of laparoscopic detrusorrhaphy to correct vesicoureteral reflux in an animal model. Reflux was created by transurethral incision of the roof of each ureteral orifice. In phase 1 of this study, laparoscopic repair was performed 1 week later in 3 pigs and an open technique was done in the remainder. In phase 2 laparoscopic repair was done in 3 pigs 3 weeks after inducing vesicoureteral reflux. All phase 1 repairs successfully corrected reflux but 1 ureter in the laparoscopic group developed obstruction. All phase 2 repairs were successful, which was determined by preoperative and postoperative cystography, and a postoperative excretory urogram. Average time was 2 hours 21 minutes for laparoscopic repair and 1 hour 10 minutes for the open procedure. Complications included bladder perforation and ureteral obstruction in 1 case each with no postoperative deaths. These preliminary results indicate that laparoscopic detrusorrhaphy is a feasible procedure in a porcine model.

Phase II study of fotemustine in untreated inoperable non-small-cell lung cancer

A total of 43 patients with advanced, previously untreated non-small-cell lung cancer (NSCLC) were treated with a novel nitrosourea, fotemustine, given at 100 mg/m2 on days 1 and 8. Maintenance treatment consisted of a single injection of 100 mg/m2 given every 21 days. 37 patients were evaluable for response. Of these, 5 patients had a partial response (13.5%; 95% confidence interval, 6%-28%). Toxicity comprised mainly anaemia and thrombocytopenia. Other toxicities were mild. This phase II study confirms that fotemustine is a moderately active and well-tolerated drug in NSCLC.

p53 and chromosome 3 abnormalities, characteristic of malignant lung tumours, are detectable in preinvasive lesions of the bronchus

Bronchial epithelial dysplasia is believed to precede invasive squamous cell carcinoma of the lung. Six paired dysplasia and tumour samples were distinguished histologically in sections of formalin-fixed paraffin-embedded lung tissue from patients with lung cancer. Additionally, samples of dysplastic bronchial epithelium were obtained from patients without lung tumours. Microdissection of the unstained sections provided dysplastic and tumour samples from which DNA was prepared for comparison with the patients' constitutional genotype, using polymerase chain reaction-based restriction fragment length polymorphism analysis. All six samples of tumour and the paired adjacent samples of bronchial dysplasia showed loss of heterozygosity (LOH) at loci on the short arm of chromosome 3. Five of the six cases showed involvement of the p53 gene as assessed by LOH at the AccII site within the gene, and by immunoreactivity to CM-1, an antibody which recognizes the mutated form of the p53 protein in paraffin-embedded material. Of the dysplastic samples, obtained from patients without invasive tumours, all three showed LOH at 3p; one sample showed LOH at the AccII polymorphic locus within the p53 gene, and another sample, uninformative at this locus, stained positively with this antibody. These results indicate that somatic genetic changes are present in preinvasive lesions in the bronchus.

Clinical value of the measurement of Mycobacterium tuberculosis specific antibody in pulmonary tuberculosis

BACKGROUND

A serological test that could help to diagnose tuberculosis, especially smear negative disease, would contribute to patient management.

METHODS

Levels of antibody to distinct antigens of Mycobacterium tuberculosis were assessed for their value in the diagnosis and management of pulmonary tuberculosis. Serum was taken from 52 patients who were smear positive, from 27 patients who were smear negative but with evidence of active tuberculosis (sputum culture positive in 16, response to antituberculosis chemotherapy in 11), from 11 patients with old healed tuberculosis (pre-antibiotic era), and from 39 healthy subjects vaccinated with BCG.

RESULTS

In smear positive tuberculosis an enzyme linked immunosorbent assay using a single 38 kDa antigen gave a diagnostic sensitivity of 80% with a 100% specificity. In smear negative pulmonary tuberculosis, however, combination of the 19 kDa antigen, lipoarabinomannan (ML 34 epitope), and hsp 65 (TB 78 epitope) was needed to achieve a sensitivity of 64% with a specificity of 95%. Recurrent and extensive radiographic disease with a poor prognosis was associated with high anti-38 kDa and low anti-14 kDa antibody levels in patients with active disease. Patients with less pulmonary cavitation had high anti-19 kDa titres. Bacteriological relapse during treatment was indicated by a rise in anti-14 kDa (TB68 epitope) antibodies. Four patients with non-tuberculous mycobacterial infection showed no anti-38 kDa antibody.

CONCLUSION

Antigen or epitope specific serology may help in the diagnosis, assessment of prognosis, and monitoring of chemotherapy in patients with pulmonary tuberculosis.

Epithelial differentiation in the absence of extracellular matrix

To investigate the regulation of epithelial differentiation, normal human epidermal keratinocytes were cultured floating on the surface of culture medium without attachment to a solid substrate. Keratinocytes spread out on the surface of the medium, proliferated and differentiated either into several flat lacy sheets 1 to 3 cells thick (on medium containing 0.15 mM calcium) or formed one single aggregate of cells from 5 to 15 cells in thickness on medium containing 1.15 mM calcium. The cell aggregates demonstrated a pattern of ordered epithelial differentiation. Levels of progressive differentiation resembling the structure of normal human epidermis were identified by light microscopy, immunohistochemistry, and electron microscopy. Differentiation proceeded from cells at the air side toward cells at the medium side with basal appearing cells on the air side and keratinocytes expressing filaggrin and involucrin on the side toward the medium. These results demonstrate that organized epithelial differentiation can occur in the absence of extracellular matrix. In contrast with other air-liquid interface cultures, epithelial differentiation in the absence of extracellular matrix progresses from air towards medium.

Intensive weekly chemotherapy for good-prognosis patients with small-cell lung cancer

A weekly, intensive chemotherapy regimen has been used to treat 70 patients with small-cell lung cancer (SCLC). Forty-five patients had limited disease (LD) and 25 extensive disease (ED) with good prognostic features. The regimen consisted of cisplatin 50 mg/m2 intravenously (IV) day 1 and etoposide 75 mg/m2 IV days 1 and 2, alternating weekly with ifosfamide 2 g/m2 IV day 8 and doxorubicin 25 mg/m2 IV day 8, for a total of 12 weeks. Dose modifications were made according to defined hematologic criteria. Responding patients with limited disease subsequently received mediastinal radiotherapy. Overall response to chemotherapy was 91% with a complete response (CR) rate of 50%. Forty-five patients with limited disease (LD) achieved an overall response rate of 91% with a CR rate of 51%, and 25 patients with extensive disease (ED) achieved an overall response rate of 92% with a CR rate of 48%. Median survival for the whole group was 54 weeks (LD, 58 weeks; ED, 42 weeks). Hematologic toxicity was predictable, without the wide fluctuations in WBC count seen in conventional 3-weekly regimens. In all, one quarter of treatment courses were delayed, most frequently because of leukopenia. Dose reductions were required in 63% of cases. The average delivered dose intensity was calculated and shown to be 73% of projected. Nonhematologic toxicity was mild with nausea and vomiting being the most common. This weekly schedule of chemotherapy has proved to be active and well tolerated and is currently being compared with conventional 3-weekly chemotherapy in a randomized study.

Mitomycin, ifosfamide and cisplatin in non-small-cell lung cancer

Chemotherapy with mitomycin C, ifosfamide and cisplatin (MIC) is reported to produce responses of 56% and 69% in inoperable non-small-cell lung cancer (NSCLC). We evaluated the regimen in 45 similar patients who received up to six courses of 6 mg/m2 mitomycin C, 3 g/m2 ifosfamide, and 50 mg/m2 cisplatin every 3 weeks. In all, 18 patients had limited disease (LD) and 27 had extensive disease (ED). A total of 18 patients responded (40%), 9/18 with LD and 9/27 with ED; there were 4 complete responders. The median duration of response was 25 weeks, and median survival was 32 weeks (range, 2-96 weeks). Toxicity was moderate. Nausea and vomiting were controlled with i.v. dexamethasone and high-dose metoclopramide. Other toxicities included myelosuppression and alopecia. This study confirms that MIC is one of the most active regimens for treatment of NSCLC, with acceptable toxicity.

Regional lung microvascular permeability using dual isotope scintigraphy

We have extended the dual isotope probe technique of Basran et al. for the measurement of pulmonary microvascular permeability (PMVP) to include gamma camera data acquisition and functional imaging of the plasma protein accumulation index (PPA) throughout the lung fields. The study group consisted of 11 patients with possible increased PMVP following the drainage of a pleural effusion or the evacuation of air from a pneumothorax, and 11 control patients. The PPA was calculated (1) for probe data, (2) on a pixel by pixel basis for the camera data, the results being stored in a functional image and (3) for four pixel x four pixel regions of interest positioned over the lung fields using the functional image and raw data as a guide. Functional images of the control group showed uniformly low PPAs throughout the lung fields. Nine of the eleven patients in the effusion/pneumothorax group showed discrete areas of increased PPA on the functional images. In the effusion/pneumothorax group, the re-expanded lung four pixel x four pixel ROI PPA values were significantly higher than the nonexpanded lung ROI values (p less than 0.001). The re-expanded lung ROI values were also significantly higher than the mean of the left and right lung ROIs in the control group (p less than 0.01). Five of the eleven patients in the effusion/pneumothorax group had probe PPAs that differed significantly from zero. We believe that probe positioning problems in the absence of sufficient clinical guidelines were largely responsible for there being no overall significant difference in the probe PPAs between the two study groups.

Systemic autoimmune disease and concurrent nematode infection in a dog

Systemic lupus erythematosus was diagnosed in a dog with concurrent nematode infection. The clinical signs of disease were unusually severe and included multiple neurologic deficits, polyarthritis, and weight loss. The dog was thrombocytopenic, and serotest results included positive lupus erythematosus test, positive rheumatoid factor test, positive antinuclear antibody test, hypergammaglobulinemia, and high platelet-associated IgG concentration. After treatment of hookworm, whipworm, and heartworm infections concurrently with corticosteroid and empiric treatment, the dog's condition improved. However, 10 days later, cyclophosphamide administration was necessary for continued immunosuppression. The dog was euthanatized because of progressive deterioration and development of canine coronavirus diarrhea. Serotest data generated from the dog's serum obtained at the time of referral suggested that autoantibodies and circulating immune complexes may have included IgE isotypes.

Humoral response to defined epitopes of tubercle bacilli in adult pulmonary and child tuberculosis

In order to investigate the humoral response to tuberculosis in different categories of patients, serum antibody levels to six epitopes of Mycobacterium tuberculosis in adult pulmonary and child tuberculosis were determined. Serum antibody titres were determined by competitive inhibition with radio-labelled murine monoclonal antibodies in 67 adults and 85 children with tuberculosis and in 79 age-matched controls. BCG vaccination (n = 39) and self-healed tuberculosis (n = 11) in adults gave rise to higher antibody titres to TB68, TB23 and TB72 epitopes (all p less than 0.003) when compared to non-vaccinated controls (n = 18). TB68 titres were higher (p = 0.006) in self-healed than in vaccinated adults. Adult sputum-negative patients (n = 15) had higher titres to TB71 (p = 0.015) and ML34 (p = 0.02) epitopes compared to BCG-vaccinated healthy controls, while sputum-positive patients (n = 41) had higher titres to all epitopes tested (all p less than 10(-4]. The diagnostic sensitivity, with a 95% specificity, was best with the combination of probes TB23, TB68, TB72 for sputum-positive (85%) and TB78, ML34 (53%) for sputum-negative patients. Antibody titres in children with tuberculosis were lower than in adult patients; diagnostic sensitivity in histologically or microbiologically proven cases (n = 18) was only 44%, while that in mediastinal lymph-adenitis (n = 67) was 13.5%. This study suggests that the magnitude and specificity of the humoral response to tubercle bacilli varies with site and severity of infection; the implications for pathogenesis or protective immunity are discussed.