Trial Information

A Randomized Phase IIb Trial of Pulmicort Turbuhaler (Budesonide) in People With Dysplasia of the Bronchial Epithelium

Lung cancer is the most common cause of cancer death worldwide: the mortality rate of lung
cancer exceeds that of colon, breast, and prostate cancers combined. Former heavy smokers
retain an elevated risk for lung cancer even years after they stop smoking. Given the large
number of current and former smokers and the increasing incidence of lung cancers among
women, lung cancer will remain a major health issue for the next several decades.

One potential strategy to inhibit the development of invasive cancer in those who are at
risk of developing lung cancer is to use chemopreventive agents that can regress existing
intraepithelial neoplastic lesions, prevent the progression of these lesions to cancer, or
prevent the development of new lesions.

We performed a randomized, double-blind, placebo-controlled, phase IIb clinical trial to
determine the efficacy and safety of inhaled budesonide (Pulmicort Turbuhaler) as a
chemopreventive agent in smokers with premalignant lesions in their bronchial epithelia. The
primary end point was change in the histopathologic grade on repeat biopsy of the same sites
at the end of 6 months. The secondary end points of this study aimed to gather additional
insight into the potential effects of budesonide on the central bronchial epithelial lung
compartment, on the peripheral lung that could not be directly assessed through
bronchoscopic biopsy, and on drug effect biomarkers that reflect the ability of inhaled
budesonide to reach its target. Thus, the balance between proliferation and apoptosis was
examined through immunohistochemical analysis of the expression of the proliferative marker
MIB-1 and the antiapoptotic protein BclII. Expression of the tumor suppressor p53, which
functions to maintain the integrity of the human genome, is a major determinant of cell
survival, is frequently mutated in lung cancer, and was assessed in bronchial biopsies.
Examination of peripheral pulmonary nodules via spiral computed tomography (CT) was
performed to assess, for the first time, the potential usefulness of spiral CT in response
to chemopreventive interventions. Finally, prostaglandin E2 (PGE2), a prostaglandin derived
from arachidonic acid metabolism whose synthesis is inhibited by glucocorticoids, was
measured in the bronchoalveolar lavage fluid.

Study subjects were recruited using television programs, radio broadcasts, and local
newspapers between June 1, 2000, and November 1, 2001. Eligibility included age > 40 years,
smoking history of 30 pack-years, and normal organ function. Sputum samples were obtained
using simultaneous high-frequency chest wall oscillation with a ThAIRapy Vest (Advanced
Respiratory, Inc., St. Paul, MN) and inhalation of 3% hypertonic saline from an ultrasonic
nebulizer for 12 minutes. The subjects were instructed to cough intermittently during the
induction procedure and for at least 2 hours afterward to produce sputum samples. The sputum
samples were fixed in 50% etomidate, cytospun onto glass slides, and stained with
Feulgen-thionin. The DNA content, the size, shape, and DNA distribution of at least 3000
epithelial cell nuclei per sample were measured using automated high-resolution image
cytometry (Cyto-Savant system; Perceptronix Medical, Inc., Vancouver, British Columbia,
Canada; refs. 13 , 14 ). Cells were classified as either epithelial, inflammatory, or
pyknotic based on these features, and an experienced cytotechnologist confirmed the
automated classifications. Diploid DNA had a DNA index of 1.0. Atypia was defined as the
presence of more than or equal to five cells having a DNA index > 1.2. This criterion was
based on a retrospective analysis of 1885 apparently healthy volunteer smokers who underwent
sputum quantitative cytometry as part of the Lung Health Study at the British Columbia
Cancer Agency since 1990. Participants were followed by repeat chest X-ray and
autofluorescence bronchoscopy if they were in a National Cancer Institute-sponsored
chemoprevention trial or through the British Columbia Cancer Registry and the Medical
Services Plan Hospital Registry. Using the threshold of more than or equal to five cells
with a DNA index > 1.2, the sensitivity of detecting lung cancer in the initial screening or
on follow-up was 94%, with a specificity of 38% after a mean follow-up of 3.2 years. This
threshold was adopted in the current study to identify smokers with the highest risk for
lung cancer for bronchoscopy.

Autofluorescence bronchoscopy was performed in subjects with sputum atypia who agreed to
undergo bronchoscopy to localize areas of dysplasia using the LIFE-Lung device (Xillix
Technologies Corp., Richmond, British Columbia, Canada). Biopsy samples were taken from
areas with abnormal fluorescence that were at least 1.2 mm in size, as well as from at least
two control areas of normal fluorescence. The median number of biopsy samples obtained per
subject was 6 (range, 4–14 samples). Bronchoalveolar lavage was performed using standard
techniques. The collected fluid (30 mL per participant) was immediately placed at 4°C, and a
differential cell count was obtained within 1 hour of collection. The fluid was separated
from the cells by centrifugation and frozen at –160°C for subsequent PGE2 assays.

The biopsy samples were fixed in buffered formalin, embedded in paraffin, and serially
sectioned. H&E-stained sections were systematically reviewed by two pathologists who were
blinded to intervention assignments (J. leRiche, A. Gazdar). All biopsy samples were
classified into one of the following seven groups (normal, basal cell hyperplasia,
metaplasia, mild/moderate/severe dysplasia, or carcinoma in situ) according to WHO criteria.
Because individual biopsies frequently contained more than one histologic cell type, the
diagnosis was based on the most advanced histology present.

The two pathologists resolved minor (i.e., one grade) differences in sample classification
by telephone consultation. If the histopathology diagnosis differed by two or more grades,
both pathologists reviewed the slides again and, if necessary, reached a consensus diagnosis
after verbal communication by phone or e-mail.

One hundred fifty-one subjects (27% of subjects who underwent bronchoscopy) had one or more
sites of bronchial dysplasia with a surface diameter > 1.2 mm (i.e., greater than the size
of a bronchial biopsy using standard biopsy forceps). Only subjects with dysplastic lesions
> 1.2 mm were enrolled onto the chemoprevention trial to minimize the effect of mechanical
removal of these lesions by the biopsy procedure.

Participants were randomly assigned to receive either budesonide (Pulmicort Turbuhaler;
AstraZeneca, Lund, Sweden) at a dose of 800 µg twice daily by inhalation or placebo for 6
months. The placebo turbuhalers were identical to the ones containing the active drug.
Randomization was stratified according to smoking status (current versus former) and gender.
All study personnel were blinded to the study codes, as was confirmed by independent review.

The participants were interviewed monthly for compliance and drug-related adverse events.
Compliance was determined from a drug diary and from estimation of the number of doses
remaining in the turbuhaler. Toxicity was monitored according to the National Cancer
Institute Common Toxicity Criteria, version 2.0.10 Dose modification was performed for any
grade 2 toxicity or for evidence of cortisol suppression (ante meridiem (AM) plasma cortisol
< 140 nmol/L/L). For grade 3 or 4 toxicity, therapy was discontinued until toxicity resolved
to grade 1 or less. At that time, the use of the study drug was resumed with a 75% dose
reduction.

All participants underwent a second fluorescence bronchoscopy with bronchoalveolar lavage
after 6 months on study medication and biopsies were obtained from the same sites biopsied
at baseline. Biopsy samples were also taken from new areas that displayed abnormal
fluorescence. The bronchoscopist was blinded to the intervention assignment.

Current smokers were encouraged to stop smoking and were invited to take part in the Fresh
Start Program at the British Columbia Cancer Agency. The Clinical Investigations Committees
of the British Columbia Cancer Agency and the University of British Columbia approved this
study. Written informed consent was obtained from all participants.