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Video transcript
Voiceover: There are several different types of lung cancer, and to determine the type a patient has, cancer cells need to be taken from either fluid around the lungs, or from a lung tissue sample known as a biopsy or from a sputum sample. Then this sample is taken back to the lab, where the cells are looked at under a microscope, and a diagnosis is made based on some characteristics of the cell. There are two main categories of lung cancer, one being small cell lung cancer, and the other non-small cell lung cancer. Maybe you can already tell that these two main categories have to do with the actual size of the cell. For small cell lung cancer, this is a tiny cell, so I like to think of it as a baby cell. A baby doesn't have much distance from its head to i's toes, right? Well, a small cell, then, doesn't have much distance from one side to the other. That means its nucleus and cell wall are close to each other. Also like a baby, this particular type of cell is not fully developed. Small cell lung cancer typically occurs in females. Let me draw her here with a pink bow, and give her a cigarette, because this occurs in females with a long history of smoking. A thing to keep in mind about this type of lung cancer, is that it divides quickly, and spreads rapidly throughout the body. In fact, by the time it's diagnosed, it's usually in numerous locations in the body. The way I remember this is that a small cell lung cancer is associated with heavy smoking. So let me draw a female with some extra cigarettes. If she's rapidly smoking, she has a greater risk of developing the rapidly dividing and rapidly spreading type of lung cancer. This accounts for about 15% of all lung cancers. But what about the other 85%? Eighty-five percent of the time, it's a non-small cell lung cancer diagnosis. Now, these are big, mature cells, and there's lots of mature cells in the respiratory tract. So this category has subcategories, depending on which type of mature cell has become cancerous. Here, I'm going to draw a big cell, lots of distance from the nucleus to the cell wall. This mature cell has the function of secreting mucin. So let me write that here. Mucin is responsible for keeping the lungs moist. If this cell becomes cancerous, it's called an adenocarcinoma. Adeno meaning coming from a gland, and glands produce mucin. This occurs 40% of the time in all non-small cell lung cancers. This is going to affect women, so again here's my bow. But I'm not going to include a cigarette this time, because it actually affects both smokers and nonsmokers. For this next subcategory, I need to draw two cells. They're still large, but they're a little flatter this time, and they're kind of stapled together by these proteins that make up a desmasome. It helps the cells create a barrier between the airways and the rest of the body. Keratin is also in the cells. This is a lot like the keratin you find in our hair and serves a protective function. If these cells become cancerous, it's called a squamous cell carcinoma. This occurs about 30% of the time, and in males this time, so let me give him a blue hat. Males who have a history of smoking. Of all the non-small cell lung cancers, this one has the greatest link to smoking. Okay, let's move this canvas up and talk about another sub-type. Here's a nice large, round cell, and actually, it doesn't have much more defining characteristics than that, so it's simply called a large cell carcinoma, and it occurs in male smokers. Oh, I almost forgot. Large cell carcinomas occur in 10% of all non-small cell lung cancers. Finally, there's this flask-shaped cell that has added space here, some nerves, and when it receives signals from these nerves, it releases hormones. If one of these cells becomes cancerous, The cancer is called a carcinoid. This happens about 5% of the time. Interestingly, males and females have an equal risk of developing carcinoid cancers, and there's really no direct link to smoking. Now I hope you can see that there's many different types of lung cancers, and it's important to know what type a patient has, because it affects things like treatment options and prognosis.