A pilot study performed by Epigenomics showing the ability of two biomarkers to detect lung cancer from bronchial lavage specimens may embolden the company to develop a diagnostic test for the condition, the firm announced last week.
A bronchial lavage, a washout of the alveolar compartment of the lung, is routinely taken during bronchoscopies performed to diagnose lung cancer.
Pathologists analyze the lavage fluid under a microscope to identify cancerous tumor cells. However, according to physicians Epigenomics has spoken to, this microscopic analysis is often inaccurate and fails to either confirm or exclude lung cancer.
“A molecular diagnostic test that sensitively and objectively detects the presence of tumor cells in [lavage fluid] could potentially improve clinical decision-making for patients with suspected lung cancer,” the company said in a statement announcing the completion of the pilot study.
In the study of 84 lavage fluid samples, a panel of two biomarkers, proprietary to Epigenomics, detected 79 percent of lung cancer specimens at 95 percent specificity.
Any lung cancer test developed by Epigenomics to analyze bronchial lavage samples would be positioned as a diagnostic to follow X-ray or CT scans, and after a nodule is found, the company said.
Epigenomics conducted the pilot study, which is not yet published, in collaboration with Christian Witt and Bernd Schmidt at the Charité Universitätsmedizin Berlin. According to Achim Plum, Epigenomics’ senior VP of corporate development, more detailed study results will be presented at the International Lung Cancer Conference in Liverpool, UK, next month.
The company is currently conducting a larger study in lung cancer patients to further confirm the biomarkers and assay. Following this study, Epigenomics will provide more information about the development and commercialization strategy for a potential diagnostic for this indication.
The Pilot Study
Although at this time the company cannot specifically discuss the biomarkers at play in this study, Plum told Pharmacogenomics Reporter last week that in tissue samples the genes of interest are methylated in the majority of lung cancers.
“This methylation is highly specific for cancer compared to normal lung tissue,” Plum noted. When the two markers are combined “they show some level of complementation, which made us panel them in the bronchial lavage study.”
“The medical experts we work with in our lung cancer program strongly believe that a test for lung cancer on bronchial lavage that is more sensitive and more objective than cytology alone could support decision-making in lung cancer diagnosis.”
The biomarkers were uncovered as part of Epigenomics' biomarker-discovery program, which used the company’s internally developed differential methylation-hybridization technology. This technology has been validated in tumor specimens prior to the current study in bronchial lavage specimens.
Additionally, the assay procedure used in the pilot study relies on sample prep solutions such as the EpiTect kit for bisulfite conversion, which is marketed by Qiagen and is licensed to Epigenomics.
Although detailed results from the pilot study are not yet disclosed, according to Epigenomics, the study yielded two false-positive results among 45 patients with benign lung disease.
Plum noted that moving forward, the company will analyze more closely the selection of biomarkers and the technical performance of the assays. “Further optimization will depend on the exact clinical question we eventually intend to address,” Plum stressed.
The company intends to hold off on outlining a development or commercialization strategy for a potential lung cancer diagnostic until further validation studies are completed, and until it gains a better understanding of the feasibility of detecting lung cancer from bronchial lavage specimens, and of the economics associated with such a product.
Although the development of this test is still in preliminary stages, the company has determined that physicians need a lung cancer test based on bronchial lavage fluid that more accurately detects the presence of cancer.
“The medical experts we work with in our lung cancer program strongly believe that a test for lung cancer on bronchial lavage that is more sensitive and more objective than cytology alone could potentially support decision-making in lung cancer diagnosis,” Plum said.
According to Epigenomics, based in Seattle and Berlin, more than 200,000 bronchoscopies are performed in Germany each year, approximately 95 percent of which are due to a suspected tumor. Currently, the main methods of detecting lung cancer are through CT scans and bronchoscopy. When these methods yield inconclusive results, a bronchial lavage is performed and samples are analyzed by a pathologist.
However, for many, cytological analysis of bronchial lavage samples is neither accurate nor confirmatory when it comes to lung cancer detection. “Cancer cells are not detected in about half of the cancer patients [and] … are not really helpful in deciding on whether or not to do a biopsy, a procedure that is associated with a considerable risk to the patients,” said Plum.
A diagnostic test developed by Epigenomics for this indication would be conducted only if nodules cannot be assessed via bronchoscopy, at which point doctors can perform a bronchial lavage and analyze the samples through cytological analysis or with the diagnostic test, or both. A biopsy would be performed on patients for whom the test did not rule out cancer.
In addition to conducting a larger study using bronchial lavage samples to confirm the findings from the pilot study, Epigenomics is currently also running a large clinical study to further validate a biomarker panel for the early detection of lung cancer in blood plasma. This study contains a “significant number” of early-stage lung cancer patients who are of particular relevance for a potential screening application.
Based on the outcome of this study, Epigenomics will “evaluate the potential development or partnering of a bronchial lavage diagnostic product,” the company said in a statement.
“We expect to present data from this study in blood plasma in due course,” Plum said.
According to the National Cancer Institute, lung cancer, including small cell and non-small cell, is the second-most common cancer in men after prostate cancer and in women after breast cancer. Lung cancer accounts for approximately 15 percent of all new cancers in the US. During 2008, the NCI estimates there will be 215,020 new cases of lung cancer.