New Technologies Offer Tests that Diagnose and Predict Cancer

Irregular molecules in the lining of the mouth, the saliva, the fallopian tube, or the bladder can identify early stage cancer. Scientists hope to apply basic knowledge to medical practice by developing tests that diagnose, predict, or monitor cancer risks without invasive tissue sampling.

Because smoking exposes both the lungs and oral cavity to tobacco carcinogens, scientists hypothesized that cells lining the mouth undergo molecular alterations similar to those in other parts of the airway and therefore could be used as surrogate tissue to assess molecular damage to the lungs, according to Li Mao, M.D., professor of thoracic/head and neck medical oncology and of systems biology at the M.D. Anderson Cancer Center (Houston, TX, USA).

Prof. Mao and colleagues, analyzing lung and mouth tissue samples from 125 chronic smokers enrolled in a cancer prevention trial, found similar molecular changes in both types of tissue. "Our study provides the first systematic evidence that readily accessible tissue from the mouth can be used to monitor molecular events in inaccessible tissue like the lungs, offering a convenient biomonitoring method to provide insight into the molecular events that take place in lungs of chronic smokers,” Prof. Mao said. "An oral brush is easy to obtain and noninvasive; it allows us to test for lung damage without having to do a bronchoscopy.”

The DNA in saliva may indicate early signs of head and neck squamous cell carcinoma (HNSCC), according to scientists from the Henry Ford Hospital in Detroit (MI, USA). Currently, most cases of HNSCC are diagnosed in advanced stages when prognosis is poor, according to Seema Sethi, M.D., from the department of otolaryngology-head and neck surgery at the hospital.

Dr. Sethi and her colleagues took saliva samples from 27 patients with HNSCC and 10 healthy control participants, and extracted DNA from the samples. Using a multiplex ligation-dependent probe amplification assay, the scientists examined 82 genes with known associations to HNSCC. The data were analyzed to determine whether genetic alterations distinguished subjects with HNSCC from healthy controls. Eleven genes showed a high individual predictive ability for HNSCC.

The fallopian tube fimbria rather than ovarian surface cells may be the site of origin for over 50% of sporadic and hereditary serous carcinoma, the most aggressive form of ovarian cancer. This fact could enable earlier detection, better treatment, and potential prevention of the most lethal gynecologic malignancy in Western countries.

"With the correct cell-of-origin in hand, we can now look for differences between the benign cells and the tumor that arises from them and develop early detection biomarkers. We can identify aberrations in signaling pathway and genetic alterations in serous cancers compared with the fallopian tube secretory epithelial cells [FTSECs], and propose new targeted therapies to tackle these pathways,” said Keren Levanon, M.D., Ph.D., a postdoctoral fellow at the Dana-Farber Cancer Institute in Boston (MA, USA).

A new, comprehensive noninvasive diagnostic tool for bladder cancer suggests a potential therapeutic target for the disease, according to scientists from the Spanish National Cancer Research Center (CNIO; Madrid, Spain).

Marta Sánchez-Carbayo, Ph.D., and colleagues, used protein arrays with more than 12,000 proteins to examine serum samples from 18 patients with bladder cancer and six control participants. The control group included patients with other neoplasia, benign urologic diseases, and healthy individuals. A panel of 171 autoantibodies in patients with bladder cancer was identified that were differentially expressed from the control group. These bladder cancer tumor-specific antigens (TPAs) included proteins linked to cell proliferation, signal transduction, apoptosis (programmed cell death), DNA binding, and transcription factors.

These findings were presented at the annual meeting of the American Association for Cancer Research, which was held on April 12-16, 2008, in San Diego (CA, USA).


Related Links:
M.D. Anderson Cancer Center
Henry Ford Hospital
Dana-Farber Cancer Institute