Dr. Edward S. Kim from the Levine Cancer Institute in Charlotte, NC discusses the feasibility of molecular marker testing and targeted therapy in the adjuvant or post-operative setting.
Let’s put this in context: right now, when someone is diagnosed with lung cancer, that’s a very unfortunate situation. The majority of times, that tumor is going to be in a locally advanced, or metastatic, or spread situation where only therapy will try to slow it down. Certainly, we have great therapies now, and I’ve personally had patients who lived for years when they can take the appropriate therapy.
There are about 30% of patients out there who are diagnosed with early stage lung cancer, meaning surgery can be done, and as we get more screening with CT scans, we’re hopeful to diagnose more people earlier, rather than later.
In the setting of having a surgery done for lung cancer, the first step is to be evaluated by a surgeon, make sure you are fit to have a surgery — sometimes it’s a part of the lung, sometimes it’s more of the lung, so the rest of your lung has to be healthy enough to support the breathing requirements and the oxygen requirements your body needs. If that goes okay after a complete staging, then you undergo the surgery. In some cases, you’re done — nothing else is needed. In other cases, we have to give additional chemotherapy, or adjuvant chemotherapy, for three to four cycles after the surgery, and in some cases, not only after the surgery, but also the chemotherapy, we have to do four weeks of radiation. But, in all of those settings, we are considering the patient cured of their disease — we have delivered curative intent therapy. Again, that’s opposed to the advanced stage where we deliver chemotherapy or biologic therapy that is not meant to be curative intent, but it is meant to try and prolong the control of the disease as long as possible.
So now the question is: we have these fancy biologic drugs that are targeting certain mutations such as EGFR or ALK in the metastatic setting — can we use some of these principles in the early stage, or post-operative setting?
The answer right now, again in 2015, is no. We are not routinely testing surgical samples after surgery to see if there is a marker such as EGFR mutation or ALK translocation because we don’t know if that tissue that has that marker, and the drug — we have several drugs that target EGFR mutation and several drugs that target ALK translocation — whether they are effective in a patient who has had their tumor removed. Again, in the advanced setting where there is disease and we know we can’t cure it, we know these drugs are very effective when the marker is present to prolong the disease and help patients have better qualities of life and live longer.
In the early stage setting, the tumor has been removed, and we’re not sure that taking a pill for one year or six months has any benefit to helping prolong survival. However, there are clinical research studies that are looking at this. One of them is called ALCHEMIST, it’s being run through the NCI, and they are doing exactly this: testing for the markers, and if the marker is positive, placing that patient on the appropriate targeted therapy. The therapies are usually for about a year, sometimes two years, and we won’t get results of a study like this for years down the road, because again, when patients are diagnosed in the early stage setting, they live much longer, and we hope we don’t see their tumors come back. We want to see the effectiveness of the treatment, so it will take quite a bit of time to see the results of these studies, but at least they are underway and they are being conducted, and hopefully, in about five or six years, we will have some results.