据估计，如果在早期阶段检测到的肺癌的80％以上，可以治愈。不幸的是，只有15％的肺癌在此阶段被诊断，使得对于肺癌的20％的所有阶段的五年存活率。使肺癌所有阶段的五年生存率仅仅为20％。在早期阶段能够检查出肺癌，而且肺癌没有转移也是至关重要的。当肿瘤生长到3cm或更多时，人的生存机会减少很多。 如果癌症扩散到肺外部的身体其他区域，存活率仅为5％，而如果早期检测到癌症，则为70％。CT肺筛查能够检测到小至2或3 mm的肺结节。通过定性恶性肿瘤，当它们仍然很小时，可以在疾病传播到身体的其他区域之前通过手术除去。
It is estimated that over 80 percent of lung cancers could be cured if detected at an early stage. Unfortunately, only 15 percent of lung cancers are caught at this stage, making the five-year survival rate for all stages of lung cancer 20%. Catching lung cancer in an early stage while it is still localized to the lung is essential. A person’s chance of survival decreases when the tumor grows to be 3 cm or more. If the cancer spreads to areas of the body outside the lungs, the survival rate is only 5 percent, compared with 70 percent if the cancer is detected early. CT lung screening is capable of detecting lung nodules as small as 2 or 3 mm. By catching malignant tumors when they are still small, they can be surgically removed before disease spreads to other areas of the body.
Who Should Have Lung Screening?
The U.S. Preventive Services Task Force, National Comprehensive Cancer Network, American College of Chest Physicians, American Society of Clinical Oncology, American Cancer Society, American Thoracic Society, and the American College of Radiology recommend lung screening for individuals between 55 and 77 who have any of the following risk factors:
· History of lung cancer
· 30 pack-year or more smoking history (one pack of cigarettes per day for 30 years, two packs of cigarettes per day for 15 years, etc.)
· Past history of 30 pack-year smoking (less than 15 years ago)
· Exposure to other cancer-causing agents (eg, asbestos and radon)
Follow-up screening is recommended every once a year for patients who remain at high risk. It is important for patients to be aware that having a negative scan (no nodules or cancer) does not mean that lung cancer will not develop in the future if they remain at high risk for the disease.
Women and Lung Cancer
In 1987, lung cancer surpassed breast cancer as the leading cause of cancer deaths in women. Although the number of lung cancer deaths in men has plateaued, the number of lung cancer deaths among women continues to increase. The American Lung Association’s Lung Force seeks to unite women to stand together against lung cancer and for lung health.
How Accurate is Lung Screening?
最近的研究显示，CT肺筛查在检测肺癌方面比标准肺筛选方法（即，胸部X射线，痰细胞学）更灵敏。与标准胸部X线不同，CT肺筛查采用肺的横截面图像。 这允许放射科医生从上到下看肺。 胸部X射线只显示从前面和侧面的肺的视图。 使用3D成像，CT肺筛查可以测量肿瘤在所有方向的生长，而标准X射线只能在其最宽点测量肿瘤，从而阻止了放射科医师跟踪肿瘤体积的变化。
Recent studies show that CT lung screening is more sensitive than standard lung screening methods (ie, chest X-ray, sputum cytology) in detecting lung cancer. Unlike standard chest X-rays, CT lung screening takes cross-sectional images of the lungs. This allows the radiologist to see the lungs from top to bottom. Chest X-rays only show views of the lungs from the front and sides. With 3D imaging, CT lung screening can measure the growth of tumors in all directions whereas standard x-rays can only measure tumors at their widest point, preventing the radiologist from tracking changes in the volume of the tumor.
Does the Procedure Involve Radiation?
CT lung screening does involve exposure to radiation in the form of X-rays, but the benefit of an accurate diagnosis far outweighs the risk. The effective radiation dose from this procedure is about 1 to 1.5 mSv, which is less than the average person receives from background radiation in six months.