Texas_Tryhard
Woodpecker
It depends on a case by case basis. As you've put it, cancer is not one disease. Since 2 was my previous number, I'll give three examples this time 
1. Typically it is not the initial cancer but the metastasis that returns. With a lot of cancers, the tumor plus some surrounding tissue is removed, therefor the chance of the same tumor coming back in the same location is relatively low. However, if the cancer has already spread, then it may return to that location, but it is already in other places. If the tumor has metastasized already, there may be no reason to put the patient through a painful and useless surgery to remove a new tumor, as there are tumors elsewhere and that patient is, well, fucked. They may consider chemotherapy to attempt to kill/shrink the metastases and give the patient more time or more quality of life, but often this is an exercise in futility as well.
2. Some tumors (brain) are obviously in sensitive areas that limit tissue removal.
3. A lot of cancers are treated with pre-operative chemo and/or radiation before tumor resection. This often is designed to cause tumor necrosis and shrink the tumor so it can be effectively removed with as little tissue loss as possible, especially in sensitive areas like the brain where removing the minimum amount of tissue is vital to quality of life post-op. However, if the cancer has not been effectively treated, it may return and this new tumor will likely be "chemo-resistant", because the cells that return are the ones that are not negatively affected by chemotherapy. They may also be radioresistant. If there is no effective alternative therapy, then there may be no way to treat the tumor chemotherapeutically again.
1. Typically it is not the initial cancer but the metastasis that returns. With a lot of cancers, the tumor plus some surrounding tissue is removed, therefor the chance of the same tumor coming back in the same location is relatively low. However, if the cancer has already spread, then it may return to that location, but it is already in other places. If the tumor has metastasized already, there may be no reason to put the patient through a painful and useless surgery to remove a new tumor, as there are tumors elsewhere and that patient is, well, fucked. They may consider chemotherapy to attempt to kill/shrink the metastases and give the patient more time or more quality of life, but often this is an exercise in futility as well.
2. Some tumors (brain) are obviously in sensitive areas that limit tissue removal.
3. A lot of cancers are treated with pre-operative chemo and/or radiation before tumor resection. This often is designed to cause tumor necrosis and shrink the tumor so it can be effectively removed with as little tissue loss as possible, especially in sensitive areas like the brain where removing the minimum amount of tissue is vital to quality of life post-op. However, if the cancer has not been effectively treated, it may return and this new tumor will likely be "chemo-resistant", because the cells that return are the ones that are not negatively affected by chemotherapy. They may also be radioresistant. If there is no effective alternative therapy, then there may be no way to treat the tumor chemotherapeutically again.
cardguy said:
