What Is Squamous Cell Carcinoma?
As indicated by the name, squamous cell carcinomas start to grow in squamous cells throughout the body. These thin, flat cells line the surface of the skin as well as various organs, including those in the respiratory and digestive systems. Squamous cell lung cancer begins in the tissues that line the air passages of the lungs. This type of cancer in the lungs tends to be centrally located along the bronchi that connect the trachea to the lungs. About 80% to 85% of lung cancers are non-small cell cancers, and about 30% of those cancers are squamous cell carcinomas.
Symptoms of Squamous Cell Lung Carcinoma
In its earliest stages, squamous cell lung carcinoma often doesn’t cause any obvious symptoms. Adding to the challenge, many of the symptoms that do gradually appear, such as fatigue and wheezing, are often attributed to other illnesses or conditions. Although lung cancer may not be the cause, you should talk to your doctor if you experience frequent infections of the respiratory tract, a nagging cough that doesn't go away or blood in your sputum. Shortness of breath, unexplained weight loss and pain in your upper back, chest or shoulder when breathing are also possible symptoms that should be investigated.
Some lung cancer tumors secrete hormones that cause paraneoplastic syndromes to develop. This is more common with small cell lung cancer, but it can also happen with non-small cell cancers like squamous cell lung cancer. Depending on the exact syndrome, paraneoplastic syndromes cause many different kinds of symptoms that appear to be related to other organs but are more noticeable in general. Examples include muscle weakness, vomiting, stomach cramps and dizziness.
Because squamous cell lung cancer affects the larger airways in the lungs, it often causes symptoms earlier than other lung cancers. This can help patients and doctors detect the cancer at an earlier stage, but a high number of lung cancer cases still aren’t diagnosed until after the cancer has spread to the lymph nodes or other organs.
Diagnosing Squamous Cell Lung Cancer
When doctors first suspect something could be wrong with the lungs, they rely on various imaging tests, such as x-rays, MRIs, CAT scans and PET scans, to provide a closer look at the lungs. Blood work can also be helpful to rule out other diseases that could be causing symptoms. If anomalies are detected in imaging tests, the definitive diagnosis typically comes after a biopsy is conducted on a tissue sample taken from the lung. Biopsy tests determine if cancer is present and identify the type of cancer.
If squamous cell lung cancer is detected, your doctor will perform more tests to determine if the cancer has spread to the lymph nodes or other organs. This information is essential to determining the stage of the cancer and the most successful treatment plan.
Staging of Squamous Cell Lung Cancer
Determining the stage, also known as the progression, of lung cancer is a critical part of developing an effective course of treatment. Non-small cell lung cancers have six primary stages: Occult, Stage 0, Stage I, Stage II, Stage III and Stage IV. Additionally, Stages I through IV have numerous levels within each stage.
In the simplest of terms, cancer cells are detected in the Occult stage, but a tumor is too small to be found. Stage 0 tumors are located on the surface and haven’t invaded deeper tissues. Stage I tumors remain contained in one lung, while Stage II tumors have spread to the lining of the lungs or lymph nodes near the lung. Stage III tumors have spread to lymph nodes in different parts of the body or tissues near the lungs. In Stage IV, the cancer has spread to the other lung and metastasized to other organs throughout the body, such as the bones, liver and brain.