Medical Experts Discuss Cancer Research Findings
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RAY SUAREZ: Intriguing findings in cancer research were announced during the annual meeting of the American Society of Clinical Oncology. Several major studies have garnered attention for shedding light on the prevention of and treatment of numerous cancers.
Some of those findings include a low-fat diet seemed to reduce the risks of recurring breast cancer. In women who followed the diet, they had more than a 20 percent reduction in their rate of recurrence. Colon cancer patients who took aspirin in addition to their standard treatment had a lower risk of recurrence and longer survival rates. And a separate study found that adults who survived childhood cancer have five times the risk of developing other serious illnesses later in life. The conference wrapped up today.
Here to talk us through the findings and others is Dr. David Johnson, president of the society, and director of the Vanderbilt Ingram Cancer Center. Welcome, Doctor. Let’s take a look first at that reduced fat diet. Many studies had been either inconclusive or even pointed to different conclusions in the past. What’s different about this one?
DR. DAVID JOHNSON: This study was conducted in a prospective way, Ray. There were two groups of women included in the study; 40 percent of the women were allocated to a group that received a low-fat diet, which is about 30 grams of diet. To put that into perspective, a normal American diet might have between 40 and 50 grams of fat in the diet or perhaps even a little more if one is eating fast foods, for example. The remaining women were left on a regular or what their normal diet would be.
In addition, all the women included in this study were to receive standard treatment after their surgery for the primary breast cancer. This means that the women all received either chemotherapy or hormonal therapy, drugs such as Tamoxifin which are commonly used after surgery to treat such women.
What the study demonstrated, as you pointed out, is that the women on the low-fat diet had about a 24 percent reduction in their risk of recurrence at an average follow-up of five years.
RAY SUAREZ: Is it possible to tell why, what happens inside the body of participants to give this good result?
DR. DAVID JOHNSON: It’s not yet fully understood why the results are as they are. In fact, it sparked quite a bit of discussion at the meeting itself. There are studies in the medical literature that suggest contrary views about whether fat reduction actually improves outcome or not — whether or not fat intake predisposes a woman to cancer. That’s been known for a number of years, comparing, for example, Japanese women who tend to have a lower fat intake than women in Western countries such as the United States; they also have a lower instance of breast cancer.
When Japanese women migrate to the United States, say, to Hawaii or to the western part of the United States and begin to adopt the same dietary habits that customary diet is used in the United States, it seems that their incidence of breast cancer rises towards the level of that of Euro-descendent women.
RAY SUAREZ: So, quickly, what kind of further work are you going to have to do before you can get some hard-and-fast rule out of this kind of result?
DR. DAVID JOHNSON: Well, I think we’re going to need to know a little bit about some of the biochemical changes that take place in the body with the change in diet. We know that insulin levels, for example, do correlate with the risk of breast cancer. Women that are somewhat overweight tend to have a higher incidence of breast cancer. So we think that there may be some relationship with glucose metabolism, with insulin alone that may be contributing to this.
RAY SUAREZ: And now the study that finds that aspirin can reduce the recurrence of colon cancer. How was this established?
DR. DAVID JOHNSON: Well, this was a very interesting study. If I may, let me give you a little background. We’ve known for quite some time that the use of aspirin or similar type medications such as Ibuprofen, which would be Advil in your drugstore, can reduce the incidence of polyps in the colon. Polyps are a pre-cancerous lesion that if left intact will go on to develop into invasive cancer. Aspirin has been known for some time to reduce the development of polyps into invasive cancer.
This study was slightly different. Individuals who had established cancer, had their cancer removed surgically, they were then treated with the customary therapy which is chemotherapy. And what the study did — this was a study done by Harvard investigators — they looked at patients who were taking aspirin on a regular basis, typically this was a single, regular adult strength aspirin once a day or perhaps every other day.
And what they observed is the cohort of patients that were taking aspirin at that frequency had about a 44 percent reduction in the risk of recurrence, compared to the patients who did not take aspirin on a regular basis. And yet all the patients received the appropriate standard chemotherapy.
RAY SUAREZ: A lot of the reports that came out of the conference, Dr. Johnson, either show surprising new results for drugs that have been developed for other purposes or a new sort of silver-bullet style drugs aimed at treating or preventing one kind of cancer or another. Is pharmacology really the cutting edge of cancer treatment now?
DR. DAVID JOHNSON: Well, I think our knowledge of cancer biology has improved to a considerable degree in the last five to 10 years, allowing us to target our therapy in a more sensible way.
For example, a drug that’s currently already available, known as Avastin, which was approved by the FDA a year or two ago for the treatment of colon cancer, at this year’s meeting we learned that that same drug, which chokes off the blood supply, if you will, to a tumor, also is effective in the treatment of advanced lung cancer, one of the most — actually, the most deadly of cancers, and also was very useful in prolonging survival in women with advanced breast cancer.
So now we have a drug that works by limiting blood supply to tumors in all of the big three tumors: Lung cancer, colon cancer and breast cancer. Learning how tumors behave and how they survive and then attacking those vulnerable points is what targeted therapy is all about.
RAY SUAREZ: One study that got a lot of other attention this week was a new analysis of cancer care and disparities in treatment. To tell us more about that one, we’re joined by Dr. Ezekiel Emanuel, head of the society’s Task Force on Quality Cancer Care and chair of clinical bioethics at the National Institutes of Health. What did your study show about the quality of cancer care in the United States?
DR. EZEKIEL EMANUEL: Well, we’ve looked for the last five years; the society has contracted with Harvard and Rand to examine the quality of breast cancer and colorectal cancer. And basically we showed that compared to a standard quality measures, 86 percent of the time women with breast cancer got the right treatment and 78 percent of the time people with colorectal cancer got the right treatment.
Importantly, compared to previous studies that had looked at the quality of care for primary care and other diseases like heart disease or stroke these are much better numbers. The society is sort of gratified by that. Oncologists are doing the right things by and large. But we’re also disappointed that they’re not 100 percent of the time. When someone has a deadly illness, you really want everything to go smoothly and accurately.
RAY SUAREZ: Were there variations in different regions of the country or different types of cancers, where you saw real differences in how well people report that they’re being treated?
DR. EZEKIEL EMANUEL: Absolutely. This wasn’t just how people report they’re being treated but we also actually looked at the medical record and how things were going in the patient’s record of the treatment. And what you see actually is on certain things doctors do very, very well. For example, on assessing lymph nodes in the case of breast cancer or getting patients on to Tamoxifin, one of the hormonal treatments for breast cancer.
On other things we do less well: asking patient about preferences, where there’s a choice to be made between mastectomy and breast conserving therapy or in surveillance afterwards. We’re very good about ordering the mammogram, less good about telling patients with colorectal cancer that their family members really need to be screened for colorectal cancer.
So we did find variations in the different quality measures. And a lot of the quality measures about giving treatment were very good. The ones about eliciting patient preferences and telling them about follow-up were less than optimal.
RAY SUAREZ: So we get piles of reports out of a conference like this, a lot of great research being done. How does research turn into practice? Does anything that you learn in your study change the way you practice oncology? Will Dr. Johnson and you and other oncologists start to give people aspirin when there’s an opportunity to give them aspirin after colon cancer treatment or prescribe low-fat diets? How do we get from a paper report to what happens in a doctor’s office?
DR. EZEKIEL EMANUEL: That’s a fascinating question. In some cases it will I think be very effective. I think probably this aspirin case you’re going to see a lot of action. It’s relatively easy to do. It’s a recommendation and there are multiple reasons not just colorectal cancer for people to take aspirin preventing and reducing heart disease.
In other cases it’s very haphazard. And we aren’t perfect at translating for everyone in the country results, path-breaking news into better services. And one of the things that the American Society of Clinical Oncology is concerned about is really measuring the quality of care on a consistent, regular basis.
One of the rationales for starting this study five years ago was really could we set up a quality monitoring system and how complicated would it be to actually regularly monitor all the patients getting cancer care? That’s an enormous task. And actually one of the measures of this study was the fact that that really is a very complicated and costly process, which we as a country aren’t doing regularly now, and I think we really have to if we want to bring the quality up for everyone in the country.
Let me just give you an example. On average, every patient who gets treated for cancer has about four doctors that they have to go to. That’s a complicated process involving a lot of coordination of care. And we know that the ball can be dropped in a lot of different places. And we need to do better about assessing across all the doctors, making sure they have all the relevant information to do optimal treatment.
RAY SUAREZ: Dr. Emanuel, Dr. Johnson, gentlemen, thank you both.
DR. EZEKIEL EMANUEL: Thank you.
DR. DAVID JOHNSON: Thank you.