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.