Estimating the Risks related to treatment choices
Posted: Fri Jun 27, 2008 9:09 pm
Dealing with cancer is risky.
That is not to say that the risks are beyond understanding. We all take serious risks every day, when we drive our cars. Most fatal accidents happen within thirty miles of home. Grocery shopping can be lethal.
There are prostate cancers that are considered low-risk, and high-risk.
If the cancer has spread to the lymph nodes, or the tumor has grown outside the prostate, it is considered high-risk. I will defer high-risk until, perhaps, another time.
I found an article on WebMD about success rates for the various treatments.
http://www.webmd.com/prostate-cancer/ne ... n-not-best
It, in turn, cited a research article -
2007 Prostate Cancer Symposium, Kissimmee, Fla., Feb. 22-24, 2007. Jay Ciezki, MD, department of radiation oncology, The Cleveland Clinic. Eric Klein, MD, head, urologic oncology, The Cleveland Clinic. Deborah Kuban, MD, professor, radiation oncology, M.D. Anderson Cancer Center, Houston.
The article compared success rates of surgery, external radiation treatments, and radioactive seed treatment for low-risk prostate cancers.
From what I have read, generally, the measure of success for cancer treatments is the five-year horizon. If the patient survives five years without the cancer coming back, then the treatment was successful. Because prostate cancer is slow-growing, this is probably too short. Still, it is a measure of sorts.
Their sample size was refreshingly large, 2,285. 1,053 men had radical prostate surgery, 662 had radioactive seed implants, and 570 had external radiation therapy, mostly the modern IMRT treatment.
From my studies of Statistics, a rough rule of thumb is that for every additional digit of accuracy, you need to increase your sample size by a factor of ten.
In my opinion, results from ten subjects give hardly more than a direction for further investigation. A hundred give a coarse view of the outline of the distribution. A thousand subjects in each group begins to give sufficient detail for reasonable evaluations. We might believe two to two-and-a-half digits of precision, with a thousand subjects.
The Study found that 98% of the patients with surgery survived five years, that 96% of the patients with the seed implants survived five years, and that 94% of the patients that had the external radiation survived five years.
Some ways to look at this: relatively speaking, this is wonderful. There are cancers whose survival rate is considerably less than 50%. This is a fighting chance.
From the other direction, twice as many patients died that had the seed treatment as compared with the patients that had the surgery, and the patients that had the IMRT external radiation had three times the death rate.
For healthy men, both surgery and seed implants are the treatments of choice. The differences in the results are on the edge of being irrelevant. The risk of external radiation treatment appears to be slightly, but significantly, higher, It would be justified if other factors come into play.
That is not to say that the risks are beyond understanding. We all take serious risks every day, when we drive our cars. Most fatal accidents happen within thirty miles of home. Grocery shopping can be lethal.
There are prostate cancers that are considered low-risk, and high-risk.
If the cancer has spread to the lymph nodes, or the tumor has grown outside the prostate, it is considered high-risk. I will defer high-risk until, perhaps, another time.
I found an article on WebMD about success rates for the various treatments.
http://www.webmd.com/prostate-cancer/ne ... n-not-best
It, in turn, cited a research article -
2007 Prostate Cancer Symposium, Kissimmee, Fla., Feb. 22-24, 2007. Jay Ciezki, MD, department of radiation oncology, The Cleveland Clinic. Eric Klein, MD, head, urologic oncology, The Cleveland Clinic. Deborah Kuban, MD, professor, radiation oncology, M.D. Anderson Cancer Center, Houston.
The article compared success rates of surgery, external radiation treatments, and radioactive seed treatment for low-risk prostate cancers.
From what I have read, generally, the measure of success for cancer treatments is the five-year horizon. If the patient survives five years without the cancer coming back, then the treatment was successful. Because prostate cancer is slow-growing, this is probably too short. Still, it is a measure of sorts.
Their sample size was refreshingly large, 2,285. 1,053 men had radical prostate surgery, 662 had radioactive seed implants, and 570 had external radiation therapy, mostly the modern IMRT treatment.
From my studies of Statistics, a rough rule of thumb is that for every additional digit of accuracy, you need to increase your sample size by a factor of ten.
In my opinion, results from ten subjects give hardly more than a direction for further investigation. A hundred give a coarse view of the outline of the distribution. A thousand subjects in each group begins to give sufficient detail for reasonable evaluations. We might believe two to two-and-a-half digits of precision, with a thousand subjects.
The Study found that 98% of the patients with surgery survived five years, that 96% of the patients with the seed implants survived five years, and that 94% of the patients that had the external radiation survived five years.
Some ways to look at this: relatively speaking, this is wonderful. There are cancers whose survival rate is considerably less than 50%. This is a fighting chance.
From the other direction, twice as many patients died that had the seed treatment as compared with the patients that had the surgery, and the patients that had the IMRT external radiation had three times the death rate.
For healthy men, both surgery and seed implants are the treatments of choice. The differences in the results are on the edge of being irrelevant. The risk of external radiation treatment appears to be slightly, but significantly, higher, It would be justified if other factors come into play.