By Ed Weiner
The Search for Breaking News
News anchors Edward R. Murrow and Peter Jennings both died quickly of the same disease. How much has changed in lung cancer treatment in 40 years?
By Ed Weiner
Surgery, or resection, “is the most effective treatment for essentially every cancer,” adds medical oncologist Bruce E. Johnson, the director of the Lowe Center for Thoracic Oncology at the Dana-Farber Cancer Institute and Harvard Medical School in Boston. Unfortunately, though, with lung cancer “only about 15 percent to 20 percent of people will show up with local disease that can get resected.”
As for radiation, Detterbeck says it “would have been used, but not very successfully. A problem with cobalt was that a lot of the radiation was deposited fairly superficially. People got skin burns, and yet the amount the tumor got, only several inches deeper, wasn’t all that great.” Indeed, Murrow’s chest was burned brown from his treatments. (The type of cobalt radiation therapy that Murrow experienced is no longer used in modern Western medicine.)
Making matters worse, the only way to obtain an image of the tumor was with a plain chest X-ray. If a tumor was blocked by other chest structures, and thus not clearly visible on the X-ray, “the doctors would draw an outline on the chest X-ray where they thought the tumor was,” Detterbeck says, “then they would add an inch or so on either side, and that’s how they planned out their radiation course.”
Today, many treatment plans include a new technology called three-dimensional conformal radiation therapy, says James D. Cox, a radiation oncologist at the University of Texas M. D. Anderson Cancer Center in Houston. With this therapy, a tumor is imaged in slices or layers, using either a CT or PET scan. Then a computer program puts the images together for a more precise determination of the size, shape and position of a tumor, which allows pinpoint radiation targeting. More radiation goes to the tumor, and less to the non-cancerous lung tissue surrounding it.
Pairing radiation with chemotherapy also makes a difference today. “With chemotherapy concurrent with radiation, with an advanced tumor still confined to the chest”—that is, in stage III lung cancer—”we’re currently seeing one patient in five living five years or more,” says Cox. “With radiation therapy alone, it’s about 5 percent.” Going from one out of 20 patients living five years to one out of five is progress, he says, but “there’s still a heck of a way to go.” Johnson adds that these statistics are not affected much when surgery is added to the mix.
Chemotherapy is thought to be the primary medical treatment used for Peter Jennings’ cancer—presumed to be a stage IV, non-small cell lung cancer. Today, the standard chemotherapy regimen normally includes the agents Platinol (cisplatin) or Paraplatin (carboplatin), in combination with a drug such as Gemzar (gemcitabine), Navelbine (vinorelbine), Taxol (paclitaxel) or Taxotere (docetaxel). Since Murrow’s time, multiple generations of chemo combinations have been developed. “Through the 1980s and ‘90s,” Johnson says, “we began seeing that getting chemotherapy to people with advanced lung cancer prolonged their lives. And it delayed the onset of symptoms. That’s the good news. The bad news is that [prolonged survival] is somewhere between two and four months.”
More recent studies have tested the use of chemotherapy in association with targeted agents, such as Avastin (bevacizumab), Iressa (gefitinib) and Tarceva (erlotinib), which are directed against specific parts of the tumor’s growth-related pathways. One trial suggests that Avastin, which interferes with a tumor’s blood supply, can add another couple of months to median survival when combined with chemotherapy, says Johnson. Tarceva has led to a two-month improvement in median survival in a trial of patients who had stopped traditional chemotherapy. Moreover, there seems to be a very small subset of patients whose lung tumors shrink drastically when they take Tarceva, extending their lives for two or three years. Researchers have found that these people have excess copies of a protein, called epidermal growth factor receptor, on their tumors’ cells, and there are studies under way to see if a screening process can be developed to identify similar patients. For now, though, scientists can only say that Tarceva is more likely to have this positive result in nonsmokers than smokers, in women than men, and in Asian patients than non-Asian patients.
There has been progress, too, in the way standard chemotherapy drugs are administered: Instead of a regimen given over a long period of time, it’s now broken up into so-called first-line, second-line and even third-line regimens. A short course knocks back the cancer. Should it reappear, then a second, different short-course regimen is used to regain stability; and then another. “Intermittent treatment with chemotherapy can often keep people going for a long time even if [their cancer] is not curable,” says Detterbeck.