Disorders of the Gastrointestinal System, 2nd Edition
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Numbers or letters after T, N, and M provide more details about each factor. Higher numbers mean the cancer is more advanced. ● The T category can be assigned a letter or a number. ○ TX means there’s no information about the primary tumor, or it can’t be measured. ○ T0 means there is no evidence of a primary tumor. ○ Tis means that the cancer cells are only growing in the layer of cells where they started. It may be known as cancer in situ or precancer . ○ A number after the T (such as T1, T2, T3, or T4) might describe the tumor size and/or amount of spread into nearby structures. The higher the T number, the larger the tumor and/or the more it has grown into nearby tissues. ● The N category can be assigned a letter or a number. ○ NX means there’s no information about the nearby lymph nodes, or they can’t be assessed. ○ N0 means nearby lymph nodes do not contain cancer. ○ A number after the N (such as N1, N2, or N3) might describe the size, location, and/or the number of nearby lymph nodes affected by cancer. The higher the N number, the greater the cancer has spread to nearby lymph nodes. ● The M category is assigned a number. ○ M0 means that no distant cancer spread has been found. ○ M1 means that cancer has been found to have spread to distant organs or tissues.
The treatment course depends on the cancer stage and other factors, such as the patient’s age, overall physical strength, general health, and ability to tolerate the prescribed treatment. Treat- ment may include radiation therapy, sur- gery, chemotherapy, immunotherapy, or a combination of these initiatives (OCF, 2022). The five-year survival rate is based on cancer staging, patient age, the over- all level of health, how cancer responds to treatment, and other factors. DISORDERS OF THE ESOPHAGUS The esophagus is a long muscular tube composed of four layers and connects the hypopharynx to the stomach (National Cancer Institute [NCI], 2022). The layers of the esophagus are the mucosal layer, the submucosal layer, the muscular layer (a thick muscular band that rhythmical- ly contracts to propel food to the stom- ach), and the adventitial layer. The upper esophageal sphincter (UES) rests at the pharynx and upper esophagus. It blocks air from entering the stomach and food from regurgitating into the airway. The lower esophageal sphincter (LES), locat- ed at the bottom of the esophagus, pre- vents the reflux of stomach contents back into the esophagus (Bajwa et al., 2022). Esophageal cancers Esophageal cancers are aggressive malignancies with a high mortality rate. Esophageal cancer accounts for 1% of all cancers diagnosed in the U.S. and has a five-year survival rate of approximate - ly 20%. It is estimated that more than 20,000 new esophageal cancer cases are diagnosed annually, and it is three to four times more likely to be diagnosed in men than in women (ACS, 2022a). The most common esophageal cancers are squa- mous cell carcinoma and adenocarcino- ma (NCI, 2022).
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