May 21, 2002 -- The powerful arthritis drug Celebrex, which is already approved as a treatment to prevent a type of colon cancer, is showing some signs of efficacy against cancer's No. 1 killer: lung cancer.
In a small study of 16 patients with early cancer than had not spread beyond the lungs, patients who took Celebrex along with chemotherapy benefited from the treatment, and the cancer virtually disappeared in five patients, says Nasser K. Altorki, MD, professor of cardiothoracic surgery at Cornell University's Weill Medical College. In eight other patients, tumors shrank, and four more patients had stable disease.
The expected complete clinical response rate -- meaning that tumors are no longer visible by X-ray -- with the chemotherapy alone "is just 1%, so these results were very encouraging."
Altorki presented his findings during the closing day of the American Society of Clinical Oncology meeting in Orlando, Fla.
The American Cancer Society estimates that 170,000 Americans will be diagnosed with lung cancer this year, and 155,000 Americans will die of lung cancer this year. It remains the No. 1 cancer killer in the United States. Patients in this study have the most aggressive type of lung cancer, which is called non-small cell lung cancer.
The patients took 400 mg of Celebrex twice a day, which is twice the recommended dose of the drug, along with standard chemotherapy drugs for six weeks before undergoing surgery to remove part of their lungs. When pathologists examined tissue removed from the lungs, they discovered that about a third of patients had microscopic evidence of tumor death.
After surgery, patients who had tumors about the length of the thumb "only showed microscopic evidence of disease. That is something you rarely see in standard chemotherapy," says Altorki.
But he cautions against too much enthusiasm because as good as these results are, they are very preliminary. He said a larger study that compared chemotherapy plus Celebrex to chemotherapy with a dummy pill is needed to confirm the results.
Michael Gordon, MD, associate dean for research at the University of Arizona in Phoenix, agrees with the need for caution. He tells WebMD that right now many patients with early stage lung cancer don't undergo chemotherapy before surgery to remove the tumor. Adding that treatment along with Celebrex would expose the patients to "several weeks of toxic treatment," which many cancer specialists may consider unnecessary.
But other experts are enthusiastic about the role of drugs like Celebrex, which are called Cox-2 inhibitors. Cox-2 controls production of hormone-like substances called prostaglandins. These substances promote the supply of blood to cells -- including cancer cells -- and may prevent the immune system from attacking cancer cells. Most importantly, says Altorki, prostaglandins control the natural kill switch in cells. In cancer cells the switch is turned off, so "these cells think they can live forever, and they do live forever," he tells WebMD. Celebrex shuts down prostaglandin production, which cuts off the blood supply to the cancer cells and turns the cell's kill switch to the "on" position, promoting cell death.
This theory has captured the imagination of cancer researchers around the world, and right now there are 119 studies examining the effect of drugs like Celebrex and aspirin, which inhibits both Cox-1 and Cox-2.
Bernard Levin, MD, vice president for cancer prevention at the University of Texas M.D. Anderson Cancer Center in Houston, tells WebMD that studies are investigating Cox-2 inhibitors for both prevention and treatment of cancers of the esophagus, bladder, breast, pancreas, and cervix. But he pointed out that although many tumors have high level of Cox-2, "we don't know if inhibiting it will have a benefit."
Altorki says that since he just completed his study last March, "it is too soon to say if there will be a survival benefit from this treatment." -->