GWEN IFILL: Next: the latest developments in the treatment of cancer.
Ray Suarez has that.
RAY SUAREZ: Researchers reported progress in the treatment of breast, skin, lung, and ovarian cancers at a major cancer conference this weekend.
For a summary of some of the top findings from the annual meeting of the American Society of Clinical Oncology, we turn to the group’s president, George Sledge. He is a breast cancer specialist and a professor of oncology at the Indiana University Cancer Center, and joins us from Chicago.
Dr. Sledge, let’s begin with lung cancer, a big killer, and investigations into the effectiveness of a drug called crizotinib. What do the results show?
DR. GEORGE SLEDGE, president, American Society of Clinical Oncology: Well, this is a fascinating result, Ray.
In the past, we have treated patients with non-small-cell lung cancer with combinations of chemotherapy. And these combinations benefit some patients, but not most. Now investigators have been able to detect a gene mutation for what’s called a fusion gene in a fairly small number of lung cancer patients, about 5 percent.
But when you treat the patients with a drug that blocks this particular gene product, you get stupendous results. Somewhere around 70 percent of patients will have an active response to the drug. And we know that these responses last for prolonged periods of time. This is a real sea change for this type of lung cancer.
RAY SUAREZ: So, you mentioned this is true of a small number of patients. How would you figure out who to treat in this way before commencing with that treatment?
DR. GEORGE SLEDGE: Well, you can take a piece of the patient’s tumor tissue and do specific testing for this gene product. And in doing so, it will tell you very rapidly whether or not someone is likely or not likely to benefit.
This is part of the general trend towards individualized medicine, matching the right patient to the right drug.
RAY SUAREZ: Let’s move on to melanoma, another very serious form of cancer, especially when it leaves the concentrated area of the skin. What does new research show there?
DR. GEORGE SLEDGE: Well, here we have another very interesting finding from a large phase three trial that was performed that compared a more standard therapy to the use of a new drug that mobilizes the body’s immune system.
This — this mobilization of the immune system has been shown in this study to significantly prolong the survival of patients with advanced disease. This is particularly exciting because this has been a disease where, for nearly a generation, we have had no real advances.
So, in contrast to the earlier lung cancer study, this may be a case where we’re seeing a more general benefit for a population of patients with melanoma.
RAY SUAREZ: Now, I understand, from this test, you found that you could induce patients to live 10 months, instead of six-and-a-half months, yielding an extra three-and-a-half months of life, on average.
DR. GEORGE SLEDGE: That’s correct.
RAY SUAREZ: Now, I don’t want to minimize that, but is that really that significant a result, and why?
DR. GEORGE SLEDGE: Well, it’s a significant result, because this is a fairly advanced population of patients with melanoma. Of course, most patients with melanoma present with earlier stages of the disease. And the risk there is that they will eventually develop a metastasis or distant spread.
So, when we see this high level of activity, and, indeed, the first improvement in survival in a generation for this population of patients, doctors immediately think about moving this to an earlier stage of the disease, where perhaps we might have an increase in the cure rate for patients with melanoma.
RAY SUAREZ: So, you will have to do another research protocol to find out if — in fact, if you start the treatment earlier, it will yield even better results?
DR. GEORGE SLEDGE: That’s absolutely correct. This will undoubtedly lead to new trials in earlier stages of patients.
RAY SUAREZ: OK, moving on to ovarian cancer, there has been big news about the results of a test of long-term use of the drug Avastin.
DR. GEORGE SLEDGE: That’s correct.
So, Avastin is a drug that blocks new blood vessel growth. And it’s been used in a number of different human tumors. We know that it shows benefits in colorectal cancer and in breast cancer and a variety of other cancers. This was the first real test of this drug in patients with advanced ovarian cancer.
And, in this trial, patients either received standard therapy with chemotherapy or received chemotherapy plus Avastin. And the combination of the blood vessel drug with the standard chemotherapy drugs prolonged the time to which patients had progression of their disease.
RAY SUAREZ: So, by establishing that long-term use is safe, you have accomplished something pretty significant. But Avastin is a very expensive drug. And using it even longer means you are talking about perhaps hundreds of thousands of dollars per individual patient.
DR. GEORGE SLEDGE: Yes.
I think cost is a real issue here, Ray.
And I think the challenge to us in the oncology community is to find out exactly which patients are likely to benefit from the addition of Avastin, so that we can narrow the focus of our treatment for patients with ovarian cancer and other cancers.
And, of course, there is a great deal of research going on right now to find exactly that.
RAY SUAREZ: Well, finally, you are a breast cancer specialist. How did anybody think, oh, let’s try a drug extracted from sea sponges?
DR. GEORGE SLEDGE: Well, the National Cancer Institute and a number of the pharmaceutical companies over the years have done exactly this. So, one of the standard drugs we have used for many years in breast cancer comes from a fungus. Another one comes from tree bark. So, being from a sea sponge isn’t that much of a reach for breast cancer doctors.
RAY SUAREZ: And the results?
DR. GEORGE SLEDGE: The results were that, in patients with fairly heavily pre-treated advanced breast cancer, the addition of this drug, compared to the doctor’s choice of the best approach, resulted in improvement in survival of several months for this population of patients.
And I think, as with some of the earlier trials we discussed, this means that we will be moving this drug into an earlier stage of the disease to see whether or not it might up the cure rate, rather than just simply prolong survival by a few months, as important as that is.
RAY SUAREZ: Dr. George Sledge of the meeting — the annual meeting of the American Society of Clinical Oncology, thanks for joining us.
DR. GEORGE SLEDGE: Thank you, Ray.