Smoking with Recurrent Lung Cancer
My father (53 years old) was diagnosed with non-small cell lung cancer nearly a year ago. He responded to first-line treatment of chemotherapy and radiation therapy but his tumor recently began growing again. He is now receiving docetaxel. My father's oncologist said that smoking did not cause his cancer, even though he smoked for 43 years! Now he thinks that it is okay to smoke since his cancer was not caused by smoking. He believes that smoking will not make it worse! Is this true? I have tried everything to get him to stop smoking. Can it actually make the tumor grow?
Barbara Campling, MD, Medical Oncologist, responds:
Most cases of lung cancer are caused by many years of smoking. Your father has smoked for most of his life, and this is likely the major factor in causing his lung cancer. I am not sure why your father's oncologist thought that this was not the case. When non-small cell lung cancer occurs in never-smokers (a minority of cases), it is usually a particular subtype called adenocarcinoma. Nevertheless, the majority of cases of adenocarcinoma arising in the lung still occur in smokers. Was you father's tumor possibly an adenocarcinoma?
Your father initially responded well to chemotherapy and radiation therapy, but now a year later, the tumor is growing again, and he is being started on another chemotherapy drug, docetaxel. This particular drug has been shown to be modestly effective as second line treatment for non-small cell lung cancer. He is continuing to smoke, and this is causing you some distress. About half of patients with smoking-related lung cancer have actually stopped smoking prior to diagnosis. For reasons we do not fully understand, some patients find it easy to quit at that time. However, those patients who have not stopped may find it very difficult to quit. Studies in lung cancer, as well as other smoking-related cancers such as head and neck cancer, have shown that those patients who have stopped smoking prior to diagnosis have a better clinical outcome than those who continue to smoke. They live longer, respond better to chemotherapy and radiation therapy, and tolerate the side effects of treatment better. Does this mean that if we could get those patients who continue to smoke to stop, they would do better? We do not know for sure, because these studies were not designed to address that question. There is also some evidence from laboratory studies that nicotine in tobacco smoke, while it does not directly cause cancers, can promote the growth of lung tumors.
Despite continuing to smoke, your father has already responded well to therapy. Should he try to stop smoking at this point? If he is not motivated to quit himself, then all your efforts to persuade him to quit will be to no avail. Smoking is a very powerful addiction, and smoking cessation is a tremendously difficult process. In his weakened state, it may be next to impossible for him to quit. Although it is good for you to encourage him to quit, you may just have to accept that he will continue smoking despite your wishes and the impact that it has on his disease course. Furthermore, withdrawal from nicotine can be quite unpleasant, adding to the already unpleasant symptoms from his cancer. He has recurrent lung cancer, which is highly unlikely to be cured with any form of treatment. The goals of therapy should be to make him as comfortable as possible so that he can enjoy what remaining time he has with his family.