They see a lung nodule and suspect cancer. Why is a biopsy n

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They see a lung nodule and suspect cancer. Why is a biopsy needed? The Tissue is the Issue

April 5th, 2013 - by Dr. Jack West

http://expertblog.lungevity.org/2013/04 ... the-issue/

It’s pretty common for people to learn that they have a “nodule”, “mass”, or just “lesion” or “abnormality” on their chest x-ray or CT scan and presume that this means they have lung cancer. Often, the report from the imaging study will mention that the finding is suspicious for lung cancer or, in medical terminology often used on these reports, “bronchogenic carcinoma”. However, it’s important for physicians, patients, and their caregivers to all remember that the diagnosis of a lung cancer or any other cancer is really not made until a biopsy shows cancer under the microscope. People may be wary about undergoing a biopsy, whether because they fear the risk of complications or just the delay before moving on to the important step of developing a plan for what to do, but the biopsy is a critical step. Why?

The key reason is that it’s very possible for something to look like cancer but be something else, whether a different cancer, or infection, inflammation, etc., even if a PET scan is done and there’s evidence of increased metabolic activity in a pattern that suggests cancer. Even in very current studies of patients who undergo surgery for a small and resectable presumed lung cancer, about 18% of patients are found after surgery to not have cancer after all, and these were patients who had a lobe of their lung removed on the presumption they had cancer. Many and probably even most oncologists have been part of or at least are aware of cases in which a patient was treated with chemo and/or other anti-cancer therapies, only to learn later that the abnormal areas were actually infection or sarcoidosis or some other finding that can look for all the world like cancer.

Even if it is cancer, it’s not uncommon at all to be unsure based on the appearance on films whether it’s actually a small cell lung cancer, non-small cell lung cancer, lymphoma, or metastatic lung lesions from a cancer that started in another part of the body. Yet all of these answers lead to a different set of recommendations for how the cancer should be managed, which chemo agents to pursue, etc.

Finally, cancer care has recently shifted to a new world of molecular oncology where many of our treatments are becoming guided by specific molecular markers that are detected by looking at the tumor tissue itself. There is an ever-growing interest in the potential value of re-biopsying patients as they demonstrate progression on a prior treatment. More and more clinical trials with exciting targeted therapies are requiring biopsy material to look for molecular features that may identify a subgroup of patients more or less likely to benefit from the novel treatment in question. The direction of cancer management is only moving more into the direction of being guided by molecular marker results, for many different cancers, and that will require plenty of biopsy material, ideally from recent sampling.

This isn’t to say that a biopsy is completely risk-free. Any time you stick a needle into something, there’s some risk for bleeding, infection, pain, and for lung lesions, a risk for collapse of the lung. There is also a very tiny risk of track seeding (somewhere in the range of 1 in 1000) – having tumor cells track along where the needle is withdrawn after a biopsy for a lung cancer. Unfortunately, no intervention is completely risk-free, and we are left needing to make judgments about whether what we are considering has more benefits than anticipated risks. In nearly all cases of a suspected cancer, though, the anticipated benefits of knowing what you’re actually dealing with far outweigh the very small risks of the biopsy procedure.