Lung Cancer Rates on the Decline

The rates of new lung cancer cases in the United States dropped among men in 35 states and among women in 6 states between 1999 and 2008 Among women, lung cancer incidence decreased nationwide between 2006 and 2008, after increasing steadily for decades.

The decrease in lung cancer cases corresponds closely with smoking patterns across the nation. In the West, where smoking prevalence is lower among men and women than in other regions, lung cancer incidence is decreasing faster. Studies show declines in lung cancer rates can be seen as soon as five years after smoking rates decline.

The report also noted that states that make greater investments in effective tobacco control strategies see larger reductions in smoking; and the longer they invest, the greater the savings in smoking–related health care costs. Such strategies include higher tobacco prices, hard–hitting media campaigns, 100 percent smoke-free policies, and easily accessible quitting treatments and services for those who want to quit.

“Although lung cancer among men and women has decreased over the past few years,” said CDC Director Thomas R. Frieden, M.D., M.P.H. “too many people continue to get sick and die from lung cancers, most of which are caused by smoking.  The more we invest in proven tobacco control efforts, the fewer people will die from lung cancer.”

Lung cancer is the most commonly diagnosed cancer that affects both men and women, and is the leading cause of cancer death in the United States. Cigarette smoking and exposure to secondhand smoke cause most lung cancer deaths in the United States. To further reduce lung cancer incidence, intensified efforts to reduce smoking are needed.

For this report, researchers analyzed lung cancer data from CDC′s National Program of Cancer Registries and the National Cancer Institute′s Surveillance, Epidemiology, and End Results Program. They estimated smoking behavior by state using the CDC′s Behavioral Risk Factor Surveillance System.

Study findings include:

  • Among men, lung cancer rates continued to decrease nationwide.
  • From 1999 to 2008 lung cancer rates among men decreased in 35 states and remained stable in nine states (change could not be assessed in six states and the District of Columbia).
  • States with the lowest lung cancer incidence among men were clustered in the West.
  • After increasing for years, lung cancer rates among women decreased nationwide between 2006 and 2008.
  • Lung cancer rates decreased between 1999 and 2008 among women in California, Florida, Nevada, Oregon, Texas, and Washington.
  • Lung cancer rates among women remained stable in 24 states, and increased slightly in 14 states (change could not be assessed in six states and the District of Columbia).

Source: CDC

Low Dose CT Benefits Lung Cancer Detection

The National Cancer Institute (NCI) is today releasing initial results from a large-scale test of screening methods to reduce deaths from lung cancer by detecting cancers at relatively early stages. The report shows twenty percent fewer lung cancer deaths seen among those who were screened with low-dose spiral CT than with chest X-ray.

The National Lung Screening Trial (NLST), a randomized national trial involving more than 53,000 current and former heavy smokers ages 55 to 74, compared the effects of two screening procedures for lung cancer — low-dose helical computed tomography (CT) and standard chest X-ray — on lung cancer mortality and found 20 percent fewer lung cancer deaths among trial participants screened with low-dose helical CT. The NLST was sponsored by NCI, a part of the National Institutes of Health, and conducted by the American College of Radiology Imaging Network (ACRIN) and the Lung Screening Study group. A paper describing the design and protocol of the NLST, “The National Lung Screening Trial. [Read more…]

Genetic Markers Identify Probability of Lung Cancers Recurrence

Genetic alterations in tumors and tissue taken from early-stage lung cancer patients are clear pointers to which cancers might recur. Researchers say the findings could change the approach to treating even the smallest lung cancers—the size of a pea—which are known to recur within five years in 30 to 40 percent of patients.

"This is DNA forensics for cancer," says Malcolm Brock, M.D., associate professor of surgery at Johns Hopkins. "While there may be no trace of cancer that we can spot after surgery with a microscope, the DNA evidence from these tumors may have been left at the scene, especially in lymph nodes."

The research team from Johns Hopkins Kimmel Cancer Center identified methyl groups that connect with the DNA structure of a gene. The development of cancers signals cells to switch certain genes on or off, and methylation is a common phenomenon in this process. Disruption to these signals may create abnormal proteins that lead to cancer or its recurrence.

In the study, Brock and his team checked more than 700 surgical samples from 167 early stage non-small lung cancer patients, looking for specific methylation patterns linked o cancer. For 51 patients, whose cancers recurred within 40 months, tumor and lymph node tissue was compared with samples from the remaining 116 patients whose cancer did no recur. The scientists tested all the samples for methylation on seven genes linked to the development of lung cancer. Four of them—p16, H-cadherin, APC and RASSF1A—showed the highest amounts of methylation in patients who had a recurrence of the cancer.

For many of the genes, the study revealed a twofold difference in methyl marks between recurrent cancers and those that did not return.

"The DNA evidence we see for many of the recurring cases suggests it may be wise if our work is confirmed to reclassify such cancers as advanced disease instead of early stage," says Brock.

Higher than normal methylation, combining two genes known as p16 and H-cadherin located in both tumor tissue and a lymph node remote from the tumor area, meant that cancers returned faster than average in 11 patients. For 8 of them this methylation pattern had cancers returning within a year; for the remaining 3 it took 30 months for the cancers to recur.

When analyzing the results to quantify the odds on a patient’s cancer returning, they noted a 5 to 25-fold in risk depending on the particular methylation pattern. While the small sample size meant that some of the gene markers lacked statistical significance, they believed that odds predictions were valid for p16 and H-cadherin.

Kimmel Cancer Center medical oncologist James Herman, M.D. says if these results are confirmed, it may lead doctors to consider treating high-risk patients more aggressively with chemotherapy after surgery. He also believes that therapies which target these gene patterns by stripping off methyl groups hold promise as well. "These marks of aggressive disease also are themselves targets for therapy."

The study appeared in the March 13 issue of the New England Journal of Medicine.

Lung Cancer Patient Response to Treatment May Be Predicted by Biomarkers

Researchers at UCLA’s Jonsson Center, led by Dr. Steven Dubinett, have discovered biomarkers capable of predicting the response to a combination treatment by Celebrex and Tarceva by patients with advanced non-small cell lung cancer.

It is believed that these findings may help oncologists avoid prescribing conventional treatments that don’t work, in favor of drugs to which they know patients will respond.

In 2008 more than 213,000 Americans will be diagnosed with lung cancer, and of these some 160,000 will die. If further studies confirm the findings of this first study, said Dr. Steven Dubinett, a professor of pulmonary and critical care medicine and senior author, this personalized drug therapy would offer a much-needed alternative therapy. "We need good predictors of response to targeted therapy in lung cancer so individual patients receive the specific therapy that targets the particular molecular abnormalities of their tumors," he said.

The Phase 1 dose-escalation study of the drug combination surveyed a group of patients for whom all other treatments had been unsuccessful. The tumors in 50% of the patients decreased by more than 30%, or had tumors that did not grow—described as stable disease.

When the UCLA team analyzed tumor, blood and urine samples to find out why some patients did so well, they found several biomarkers that could help identify patients likely to respond to the combination Celebrex and Tarceva therapy. The answer appeared to be in the levels of certain proteins in the patients’ blood: Dubinett said that changes in these proteins may help explain the potential benefit of Celebrex in making the tumor cells more vulnerable to Tarceva.

Cycloxygenase-2 (COX-2) is an enzyme that makes cancer cells resistant to death, and causes resistance to drugs like Tarceva, allowing the cancer to grow.

Dr. Dubinett and his team found that if they inhibited the COX-2 pathway, they could restore the sensitivity of lung cancer tumor cells to Tarceva. The samples from Phase 1 patients showed that patients with low levels of MMP9 before treatment responded best to the combination therapy.

If these findings are confirmed in larger studies, in the future that protein biomarker could be used to place patients into groups with patients having low blood levels of MMP9 receiving the Celebrex and Tarceva therapy and responding. A larger, multi-site Phase 11 study of 10 patients is now under way, to confirm if there is a connection between tumors that express the proteins named in the Phase 1 study and a response to combination treatment.

"This study cold determine whether these biomarkers can be used in the future before treatment to select the patients likely to respond," said Dr. Dubinett.

The findings of the study were published in the February 1, 2008 issue of the Journal of Thoracic Oncology.

Source: University of California Los Angeles (UCLA), Health Sciences