Paul
04-22-2004, 03:06 PM
Lola,
Ok Lola, I'm not buying the mild to major brain damage stuff. Your questions are poignant and well thought out. In addition, I know for a fact that the women of this board quite sharp.
I understand your frustration with respect to all of the unanswered medical questions. I too feel anxiety with respect to those things I can't control and don't understand. I think such anxiety is fairly typical and normal. I can assure you that with respect to the questions posed in your 2nd post, I have no definitive answers.
I copied your questions below and any thoughts I have are set forth below.
Q#1: Now, I do understand that because we are living longer now the cancer cells are moving to our brain. I wonder if somehow the her-2 cells are figuring out that they are safe there.
-- Based on stats, the most frequent locations of breast cancer metastasis are bone (#1), lung (#2), liver (#3), and brain (#4). Metastatic cancer occurs when the original (primary) tumor spreads to organs in other parts of the body. Some cancer cells break off from the tumor, travel through the blood stream or lymphatic system to another part of the body and invade and then the cells begin to multiply. And before traveling to distant sites in the body, cancer cells may also spread to the lymph nodes near the tumor.
I agree that the frequency of brain mets is increasing because Stage IV women are living much longer. In addition, many helpful cancer drugs can not penetrate the blood-brain barrier (BBB) and get to the brain. There are methods to disrupt the BBB but research continues (e.g., small molecule drugs, immunoliposomes, etc). Interestingly, radiation is one way to penetrate the BBB. In theory, whole brain radiation treatment may actually breach the BBB and allow certain drugs such as herceptin to "seep" in.
In any event, cancer cells located in the general blood circulation are capable of getting to the brain via that circulation.
Q#2: I wonder why someone would not respond to herceptin at all.
--I don't think we know the answer to this one. In fact, the exact biological action of herceptin is not known with certainty; therefore, it makes sense that we do not know why some people do not respond to it. Some of the lack of response was caused by inexact IHC testing to determine HER-2 status. That is, many women who took herceptin in the past, if tested by FISH, would not test positive. The remainder, I believe, is attributable to what we do not know about the exact activity of the HER-2 receptor inside and outside the cell.
Q#3: After a period of time on herceptin, why would someone have a relapse in the body organs? It seems to me if it works, it works all the time.
--This is the issue you raised earlier. It relates to the concept of so-called "herceptin resistance." Again, we do not know what causes it but it does exist with respect to some women. Two (of many) theories being researched relate to other things present (or alternatively, absent) in the body that curtail the action of herceptin. One such item is insulin-like growth factor (IGF) (see Eric's March 24 post on the Articles of Interest Message board re "counter" IGF being used with herceptin). Another potential avenue is cyclin-dependent kinase inhibitor, p27.
To make it easier to understand, the body must produce growth factor to allow our bodies to heal from cuts. This same growth factor may prevent cell death caused by herceptin. Certain growth factors cause cell death. An absence of those factors could allow cancer to continue. In essence, the body has many checks and balances for various functions that we do not fully understand yet. Certain checks and balances may offset the effect of herceptin.
Q#4: Is it possible that Chemo killed all the "master cells" and it is the best kept secret? Is there anyway to see a master cell on a PEt or something like that?
--Lola, the master cell theory I stated earlier is just that -- a theory. Again, we do not fully understand the exact action behind cancer metastasis. For example, this past week, a group of researchers believe that they have identified a protein which, if overexpressed, makes the cancer cell more likely to cause problems in the lung.
If the master cell theory is true, it seems possible that treatment could kill the master cells if we knew how to identify and locate such cells with targeted treatments. At this time, the master cell theory is just a theory and PET scans can not detect so-called "master cells."
I not sure the added information helped Lola. You are asking all the right questions. If we could answer all four of the questions you pose, we would be well on our way to beating cancer.
Ok Lola, I'm not buying the mild to major brain damage stuff. Your questions are poignant and well thought out. In addition, I know for a fact that the women of this board quite sharp.
I understand your frustration with respect to all of the unanswered medical questions. I too feel anxiety with respect to those things I can't control and don't understand. I think such anxiety is fairly typical and normal. I can assure you that with respect to the questions posed in your 2nd post, I have no definitive answers.
I copied your questions below and any thoughts I have are set forth below.
Q#1: Now, I do understand that because we are living longer now the cancer cells are moving to our brain. I wonder if somehow the her-2 cells are figuring out that they are safe there.
-- Based on stats, the most frequent locations of breast cancer metastasis are bone (#1), lung (#2), liver (#3), and brain (#4). Metastatic cancer occurs when the original (primary) tumor spreads to organs in other parts of the body. Some cancer cells break off from the tumor, travel through the blood stream or lymphatic system to another part of the body and invade and then the cells begin to multiply. And before traveling to distant sites in the body, cancer cells may also spread to the lymph nodes near the tumor.
I agree that the frequency of brain mets is increasing because Stage IV women are living much longer. In addition, many helpful cancer drugs can not penetrate the blood-brain barrier (BBB) and get to the brain. There are methods to disrupt the BBB but research continues (e.g., small molecule drugs, immunoliposomes, etc). Interestingly, radiation is one way to penetrate the BBB. In theory, whole brain radiation treatment may actually breach the BBB and allow certain drugs such as herceptin to "seep" in.
In any event, cancer cells located in the general blood circulation are capable of getting to the brain via that circulation.
Q#2: I wonder why someone would not respond to herceptin at all.
--I don't think we know the answer to this one. In fact, the exact biological action of herceptin is not known with certainty; therefore, it makes sense that we do not know why some people do not respond to it. Some of the lack of response was caused by inexact IHC testing to determine HER-2 status. That is, many women who took herceptin in the past, if tested by FISH, would not test positive. The remainder, I believe, is attributable to what we do not know about the exact activity of the HER-2 receptor inside and outside the cell.
Q#3: After a period of time on herceptin, why would someone have a relapse in the body organs? It seems to me if it works, it works all the time.
--This is the issue you raised earlier. It relates to the concept of so-called "herceptin resistance." Again, we do not know what causes it but it does exist with respect to some women. Two (of many) theories being researched relate to other things present (or alternatively, absent) in the body that curtail the action of herceptin. One such item is insulin-like growth factor (IGF) (see Eric's March 24 post on the Articles of Interest Message board re "counter" IGF being used with herceptin). Another potential avenue is cyclin-dependent kinase inhibitor, p27.
To make it easier to understand, the body must produce growth factor to allow our bodies to heal from cuts. This same growth factor may prevent cell death caused by herceptin. Certain growth factors cause cell death. An absence of those factors could allow cancer to continue. In essence, the body has many checks and balances for various functions that we do not fully understand yet. Certain checks and balances may offset the effect of herceptin.
Q#4: Is it possible that Chemo killed all the "master cells" and it is the best kept secret? Is there anyway to see a master cell on a PEt or something like that?
--Lola, the master cell theory I stated earlier is just that -- a theory. Again, we do not fully understand the exact action behind cancer metastasis. For example, this past week, a group of researchers believe that they have identified a protein which, if overexpressed, makes the cancer cell more likely to cause problems in the lung.
If the master cell theory is true, it seems possible that treatment could kill the master cells if we knew how to identify and locate such cells with targeted treatments. At this time, the master cell theory is just a theory and PET scans can not detect so-called "master cells."
I not sure the added information helped Lola. You are asking all the right questions. If we could answer all four of the questions you pose, we would be well on our way to beating cancer.