I'm Dr. Greg Kalemkerian. I'm a Professor of Medicine and a Medical Oncologist at the University of Michigan. Today we're going to talk about lung cancer. The initial lecture is the lung cancer problem, and during this lecture, we'll review the incidence and mortality rates of lung cancer, and we'll try to understand the causes of the overall poor prognosis associated with lung cancer. Lung cancer is the most common cancer and the most common cause of cancer-related death throughout the world. In the United States, lung cancer is the leading cause of cancer death in both men and women. More Americans will die from lung cancer each year than from colon cancer, breast cancer, pancreatic cancer and prostate cancer combined. We'll start off with a pre-lecture question. Lung cancer is the leading cause of cancer-related mortality in the United States and worldwide, which of the following accounts for the high mortality rate associated with lung cancer? A, the high prevalence of tobacco use in patients with lung cancer, B, the high frequency of advanced disease at diagnosis, C, the relatively low stage-specific survival rates, or D, A and B, or E, A, B and C? We'll cover the answer to this question at the end of the lecture. According to the World Health Organization in 2010, lung cancer was the seventh leading cause of death throughout the world. As you can see, the numbers 1, 2, 4, and 7, leading causes of death are all smoking-related diseases, and lung cancer is highly smoking related with about 90% of patients being either current or former cigarette smokers. As you can see from this slide, lung cancer is also the leading cancer-related cause of death with almost twice as many deaths per year as gastric cancer, the second leading cause. On this slide, we will see that lung cancer is the second most common cause of cancer in both men and women in the United States behind prostate cancer in men and behind breast cancer in women. But as far as deaths go, lung cancer is the leading cause of cancer-related death in both men and women. So, this slide presents the mortality rates for men in the United States since 1930, and we see that over time, the mortality rate rose dramatically for lung cancer, which is the red top line on this graph, and peaked in 1995, which was about 20 years after the first Surgeon's General report on the link between tobacco smoking and lung cancer. So, the rate has since been going down at a fairly steady rate in men. In women however, the mortality rate from lung cancer rose more slowly due to a delayed pick up of smoking amongst women, and we see that women began smoking in mass in the 1940s during World War Two, and we see that 20 years later, the rate of lung cancer or the mortality of lung cancer in women began its steady rise. It did not peak until just a few years ago, and now we are seeing a slight decline in more recent years. This slide indicates the incidence of new cases of cancer in blue, and the number of deaths from each cancer listed across the bottom in orange, and we see that lung cancer has a much higher death rate per number of cases than the other leading causes of cancer in the United States, namely; breast, prostate and colon cancer. So, this indicates the high mortality rate associated with lung cancer. One of the reasons for this high mortality rate is that unlike the other common cancers, lung cancer tends to present at a more advanced stage of disease. Here, we can see the grey bars indicate early stage stage one disease, and that most people with breast cancer, prostate cancer, and colon cancer present with either stage one or stage two disease. However, for lung cancer, the ratio is flipped in that the majority of people present with stage three or four more advanced disease at stage at which the overall survival is much lower. This table presents the stages of lung cancer going down in rows. And across the rows, we see the incidence, the general treatment scheme and the five-year survival rates. We see that for stage one non-small cell lung cancer, the survival even with people who have stage one disease is rather low at about 60 to 70%. For patients with stage two disease, the survival does drop down fairly significantly, so that even with this relatively early potentially curative stage, only about 50% of people are cured. As we get into the higher stages of disease where the majority of people present, we see that the survival rates drop off dramatically down to 15% to 25% for stage three and less than 5% of people at stage four who lived beyond five years. When we compare the five-year survival rates of a variety of different cancers, we see that lung cancer ranks down near the bottom of the list with very slight improvements over the last 30 to 40 years. So, going back to the question that we asked at the top of the lecture, lung cancer is the leading cause of cancer-related mortality in the United States and worldwide. Which of the following accounts for the high mortality rate associated with lung cancer? A, the high prevalence of tobacco use, B, high frequency of advanced disease, C, relatively low stage-specific survival rates, D, A and B, or E, A, B and C? We see that the correct answer is E, because all of the three answers that were given in A, B, and C are all correct as we have just discussed in this lecture. So, what do we take home from this? We've learned that lung cancer is the number one cause of cancer-related death in both the United States and in the world, that most patients present with stage three or four advanced disease, that stage-specific survival is relatively low when compared to other common cancers, and that smoking causes co-morbidities that limit survival in this population as well. Well, thank you for your time.
