WEBVTT 1 00:00:00.510 --> 00:00:01.800 Hi, everyone. 2 00:00:01.800 --> 00:00:03.900 This will be the last video 3 00:00:03.900 --> 00:00:07.710 in our lecture series about lung cancer, 4 00:00:07.710 --> 00:00:10.770 and in this lecture we'll discuss survival and protection. 5 00:00:10.770 --> 00:00:13.500 So we only have one goal in this presentation 6 00:00:13.500 --> 00:00:14.490 and that is to describe 7 00:00:14.490 --> 00:00:17.553 lung cancer prevention, control, and therapy. 8 00:00:19.200 --> 00:00:21.210 So this figure from your textbook 9 00:00:21.210 --> 00:00:23.880 shows the trend in five-year lung cancer survival, 10 00:00:23.880 --> 00:00:25.260 and fortunately, we see that 11 00:00:25.260 --> 00:00:28.680 the survival percentage has increased, albeit slightly, 12 00:00:28.680 --> 00:00:32.523 from 1960 to 63 to 2004 to 2005, 13 00:00:33.480 --> 00:00:35.760 and this is despite intensive medical efforts 14 00:00:35.760 --> 00:00:38.130 involving surgical resection, chemotherapy, 15 00:00:38.130 --> 00:00:39.393 and radiation therapy. 16 00:00:40.320 --> 00:00:42.000 The primary reason for the failure 17 00:00:42.000 --> 00:00:43.650 of treatment protocols to improve survival 18 00:00:43.650 --> 00:00:46.530 is the lack of early detection of lung tumors. 19 00:00:46.530 --> 00:00:49.620 Standard chest x-rays and most other imaging techniques 20 00:00:49.620 --> 00:00:51.990 have shown little value in detecting lung tumors 21 00:00:51.990 --> 00:00:55.500 prior to the invasion of the blood, lymphatic system, 22 00:00:55.500 --> 00:01:00.000 contiguous tissues, and more distant sites of the body. 23 00:01:00.000 --> 00:01:02.940 The imaging technique spiral computerized tomography 24 00:01:02.940 --> 00:01:05.400 has been demonstrated to accurately identify 25 00:01:05.400 --> 00:01:08.100 preneoplastic lesions of the lung in one center 26 00:01:08.100 --> 00:01:09.423 but not others. 27 00:01:11.760 --> 00:01:13.440 The primary prevention of lung cancer 28 00:01:13.440 --> 00:01:14.760 depends to a large extent 29 00:01:14.760 --> 00:01:16.380 on the prevention of cigarette smoking 30 00:01:16.380 --> 00:01:18.480 among adolescents and young adults. 31 00:01:18.480 --> 00:01:20.880 In the U.S., anti-smoking programs and laws 32 00:01:20.880 --> 00:01:21.810 have led to reduced 33 00:01:21.810 --> 00:01:25.350 prevalence rates of smoking in adolescents from 30% to 40% 34 00:01:25.350 --> 00:01:30.350 to 20% to 25% in the U.S. over the past 20 years. 35 00:01:30.390 --> 00:01:32.340 Despite international public health efforts, 36 00:01:32.340 --> 00:01:35.640 a huge segment of the world population, nearly a third, 37 00:01:35.640 --> 00:01:37.560 continues to smoke. 38 00:01:37.560 --> 00:01:39.720 As a consequence of this addictive habit, 39 00:01:39.720 --> 00:01:42.120 5.4 million people are dying annually 40 00:01:42.120 --> 00:01:43.500 from tobacco-related diseases 41 00:01:43.500 --> 00:01:46.560 like lung cancer, heart disease, and stroke, 42 00:01:46.560 --> 00:01:48.390 chronic obstructive pulmonary disease 43 00:01:48.390 --> 00:01:49.923 and other forms of cancer. 44 00:01:50.760 --> 00:01:54.600 In 1988, British scientists reported the results 45 00:01:54.600 --> 00:01:56.910 of a randomized prospective study 46 00:01:56.910 --> 00:02:01.910 of daily aspirin use among 5,139 British physicians. 47 00:02:01.980 --> 00:02:03.540 This study was designed to determine 48 00:02:03.540 --> 00:02:06.000 if 500 milligrams of aspirin daily 49 00:02:06.000 --> 00:02:08.700 would reduce rates of stroke, myocardial infraction, 50 00:02:08.700 --> 00:02:10.800 and other conditions. 51 00:02:10.800 --> 00:02:14.070 In this study, 3,429 of the enrolled subjects 52 00:02:14.070 --> 00:02:16.020 were randomly assigned to receive aspirin 53 00:02:16.020 --> 00:02:18.900 and 1,710 were randomly assigned 54 00:02:18.900 --> 00:02:21.990 to avoid taking any aspirin or aspirin products. 55 00:02:21.990 --> 00:02:23.670 After six years of follow up, 56 00:02:23.670 --> 00:02:25.770 the observed death rate from lung cancer 57 00:02:25.770 --> 00:02:28.650 was 7.4 per 10,000 person years 58 00:02:28.650 --> 00:02:30.240 in the group treated with aspirin 59 00:02:30.240 --> 00:02:34.683 and 11.6 per 10,000 person years in the control group, 60 00:02:35.790 --> 00:02:40.710 meaning that there was a relative mortality of 0.64 61 00:02:40.710 --> 00:02:44.730 in the group using aspirin compared to the group without. 62 00:02:44.730 --> 00:02:47.070 Many subsequent investigations have also observed 63 00:02:47.070 --> 00:02:49.320 significant protective effects of aspirin 64 00:02:49.320 --> 00:02:53.100 and other NSAIDs against the development of lung cancer. 65 00:02:53.100 --> 00:02:54.780 For example, an early case control study 66 00:02:54.780 --> 00:02:56.430 of lung cancer and NSAIDs 67 00:02:56.430 --> 00:02:58.710 observed a risk reduction of 60% 68 00:02:58.710 --> 00:03:01.170 with the use of selective COX-2 inhibitors 69 00:03:01.170 --> 00:03:02.850 and comparable risk reductions 70 00:03:02.850 --> 00:03:05.640 with regular use of ibuprofen or aspirin. 71 00:03:05.640 --> 00:03:07.410 Notably, the comparison group in the study 72 00:03:07.410 --> 00:03:09.420 consisted of controls that smoked 73 00:03:09.420 --> 00:03:11.700 but did not have lung cancer. 74 00:03:11.700 --> 00:03:15.210 In a meta-analysis of 18 studies of lung cancer and NSAIDs, 75 00:03:15.210 --> 00:03:16.920 the combined relative risk estimate 76 00:03:16.920 --> 00:03:21.120 for regular NSAID users was 0.72 77 00:03:21.120 --> 00:03:24.333 with no evidence of heterogeneity among studies. 78 00:03:27.720 --> 00:03:29.310 We also see that smoking cessation 79 00:03:29.310 --> 00:03:31.890 has major and immediate health benefits for men and women 80 00:03:31.890 --> 00:03:33.720 regardless of all ages. 81 00:03:33.720 --> 00:03:35.370 Though there's typically a small weight gain 82 00:03:35.370 --> 00:03:36.360 with smoking cessation 83 00:03:36.360 --> 00:03:38.580 with some adverse psychological impact, 84 00:03:38.580 --> 00:03:40.410 the health benefits of smoking cessation 85 00:03:40.410 --> 00:03:42.990 far exceed any risks. 86 00:03:42.990 --> 00:03:45.120 On average, former smokers live longer 87 00:03:45.120 --> 00:03:46.350 than continuing smokers, 88 00:03:46.350 --> 00:03:47.400 and the benefits of quitting 89 00:03:47.400 --> 00:03:50.160 extend to those who quit at older ages. 90 00:03:50.160 --> 00:03:52.800 For example, persons who quit smoking before age 50 91 00:03:52.800 --> 00:03:55.890 have one half the risk of dying in the next 15 years 92 00:03:55.890 --> 00:03:57.440 compared to continuing smokers. 93 00:03:58.290 --> 00:04:00.570 Furthermore, women who stop smoking before 94 00:04:00.570 --> 00:04:01.740 or early during pregnancy 95 00:04:01.740 --> 00:04:04.890 reduce their risk of having a low birth weight baby. 96 00:04:04.890 --> 00:04:07.230 Smoking cessation reduces the risk of heart attack 97 00:04:07.230 --> 00:04:10.050 and stroke by 50% within the first year after quitting 98 00:04:10.050 --> 00:04:12.870 and rapidly improves pulmonary function in patients 99 00:04:12.870 --> 00:04:16.140 with established chronic obstructive pulmonary disease. 100 00:04:16.140 --> 00:04:19.020 Sustained smoking cessation produces a gradual decrease 101 00:04:19.020 --> 00:04:20.520 in the risk of developing lung cancer 102 00:04:20.520 --> 00:04:23.700 as well as other tobacco-related cancers. 103 00:04:23.700 --> 00:04:26.310 Paradoxically, there is a slight increase 104 00:04:26.310 --> 00:04:28.140 in the risk of lung cancer diagnosis 105 00:04:28.140 --> 00:04:30.930 within the first few years after quitting smoking, 106 00:04:30.930 --> 00:04:32.190 which is apparently related 107 00:04:32.190 --> 00:04:33.960 to the modified growth characteristics 108 00:04:33.960 --> 00:04:37.293 of existing lung tumors that enhances their detection.