Lung Tumor Grows, but Must Chemo Change?
Hello. This is Mark Kris from Memorial Sloan-Kettering Cancer Center in New York, talking once again about disease from progression. I would like to talk in my next 2 commentaries about a very common situation that we need to deal with in medical oncology. That is the definition of "progression of disease," a concept that has not been looked at critically and is deserving of our attention and a few minutes of thought.
Many of us look to the RECIST criteria that are used for clinical trials to decide whether an agent is effective or not. Those criteria include about a 20% increase in the size of the lesion. Please remember that criteria developed for clinical trials were never developed for clinical use. You must be careful not to jump to the conclusion that that 20% change is a reason to change your therapy in a patient.
There is general agreement that when unequivocal new lesions or a new disease site appears, or when a tumor or mass grows to the point that it causes a new symptom, that is the time (with standard chemotherapy) to stop that treatment and recommend the best alternative or some means of palliation if the symptoms are severe.
However, what about situations in which there are no new lesions, new symptoms, or serious symptoms that inhibit lifestyle, but indeed, the tumor has grown by that 20% in its greatest diameter? Please remember that the RECIST criterion is a 20% change above the smallest tumor. If you are a slave to those RECIST criteria for designing the care of your patients, consider an 8-cm tumor that shrank to 2 cm (a good partial remission). All that tumor would need to do is grow to 2.4 cm, and that patient would suffer progression by RECIST criteria.
We can't jump to the conclusion that this degree of growth is the signal to change therapy, so what do you do? I am now addressing the situation with a traditional -- intravenous -- cytotoxic chemotherapy. The first thing you have to do is be very certain that the patient is not symptomatic. Sometimes our "listening button" is not pressed and sometimes the symptoms that are important for the patient are subtle and require some extra attention and extra quizzing. That is the first step -- to make sure that there isn't a symptom.
The second thing is to make sure that progression has really occurred. Please remember that there is variability in a CT scan. I have talked before about the study by my colleague, Jeff Oxnard, in which we looked at the reproducibility of a CT scan for changes less than 20% and particularly for smaller tumors where there is greater variability. You need to be careful and make sure that the cancer has grown and that you are not just looking at the variability of the CT scan.
The third thing you have to do as an oncologist is to very critically assess the tolerability of that regimen. Before you decide to continue a regimen and particularly with the issue of whether disease progression has occurred, you need to be very careful in assessing that the regimen is tolerable. Part of that assessment is carefully talking with and listening to the patient. We need to make sure that from the patient's standpoint, the side effects of therapy clearly are an advantage to the patient before treatment is started and maintained. Also, the side effects of the treatment are ones that the patient feels are acceptable and do not disrupt the life that the patient chooses to lead.
If all of these criteria are correct -- there is minimal growth of a lesion without symptoms and the side effects of the treatment are tolerable from both the physician's and the patient's point of view -- it does sometimes make sense, even in the face of some small degree of lesion progression, to keep patients on that drug. When you do that, it's very important to reassess, to reexamine, and to reimage, and to do so at probably a shorter interval just to make sure that you are not seeing a more rapidly advancing disease.
In some but not all tumors, growth prompts a change in therapy. It is very important to put the entire clinical situation together and make the best decision for that patient.
Hello. This is Mark Kris from Memorial Sloan-Kettering Cancer Center in New York, talking once again about disease from progression. I would like to talk in my next 2 commentaries about a very common situation that we need to deal with in medical oncology. That is the definition of "progression of disease," a concept that has not been looked at critically and is deserving of our attention and a few minutes of thought.
Many of us look to the RECIST criteria that are used for clinical trials to decide whether an agent is effective or not. Those criteria include about a 20% increase in the size of the lesion. Please remember that criteria developed for clinical trials were never developed for clinical use. You must be careful not to jump to the conclusion that that 20% change is a reason to change your therapy in a patient.
There is general agreement that when unequivocal new lesions or a new disease site appears, or when a tumor or mass grows to the point that it causes a new symptom, that is the time (with standard chemotherapy) to stop that treatment and recommend the best alternative or some means of palliation if the symptoms are severe.
However, what about situations in which there are no new lesions, new symptoms, or serious symptoms that inhibit lifestyle, but indeed, the tumor has grown by that 20% in its greatest diameter? Please remember that the RECIST criterion is a 20% change above the smallest tumor. If you are a slave to those RECIST criteria for designing the care of your patients, consider an 8-cm tumor that shrank to 2 cm (a good partial remission). All that tumor would need to do is grow to 2.4 cm, and that patient would suffer progression by RECIST criteria.
We can't jump to the conclusion that this degree of growth is the signal to change therapy, so what do you do? I am now addressing the situation with a traditional -- intravenous -- cytotoxic chemotherapy. The first thing you have to do is be very certain that the patient is not symptomatic. Sometimes our "listening button" is not pressed and sometimes the symptoms that are important for the patient are subtle and require some extra attention and extra quizzing. That is the first step -- to make sure that there isn't a symptom.
The second thing is to make sure that progression has really occurred. Please remember that there is variability in a CT scan. I have talked before about the study by my colleague, Jeff Oxnard, in which we looked at the reproducibility of a CT scan for changes less than 20% and particularly for smaller tumors where there is greater variability. You need to be careful and make sure that the cancer has grown and that you are not just looking at the variability of the CT scan.
The third thing you have to do as an oncologist is to very critically assess the tolerability of that regimen. Before you decide to continue a regimen and particularly with the issue of whether disease progression has occurred, you need to be very careful in assessing that the regimen is tolerable. Part of that assessment is carefully talking with and listening to the patient. We need to make sure that from the patient's standpoint, the side effects of therapy clearly are an advantage to the patient before treatment is started and maintained. Also, the side effects of the treatment are ones that the patient feels are acceptable and do not disrupt the life that the patient chooses to lead.
If all of these criteria are correct -- there is minimal growth of a lesion without symptoms and the side effects of the treatment are tolerable from both the physician's and the patient's point of view -- it does sometimes make sense, even in the face of some small degree of lesion progression, to keep patients on that drug. When you do that, it's very important to reassess, to reexamine, and to reimage, and to do so at probably a shorter interval just to make sure that you are not seeing a more rapidly advancing disease.
In some but not all tumors, growth prompts a change in therapy. It is very important to put the entire clinical situation together and make the best decision for that patient.
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