Squamous cell lung cancer

Non-small-cell lung carcinoma (NSCLC) is any type of epithelial lung cancer other than small cell lung carcinoma (SCLC). NSCLC accounts for about 85% of all lung cancers. As a class, NSCLCs are relatively insensitive to chemotherapy, compared to small cell carcinoma. When possible, they are primarily treated by surgical resection with curative intent, although chemotherapy has been used increasingly both pre-operatively (neoadjuvant chemotherapy) and post-operatively (adjuvant chemotherapy). Non-small-cell lung carcinoma (NSCLC) is any type of epithelial lung cancer other than small cell lung carcinoma (SCLC). NSCLC accounts for about 85% of all lung cancers. As a class, NSCLCs are relatively insensitive to chemotherapy, compared to small cell carcinoma. When possible, they are primarily treated by surgical resection with curative intent, although chemotherapy has been used increasingly both pre-operatively (neoadjuvant chemotherapy) and post-operatively (adjuvant chemotherapy). The most common types of NSCLC are squamous cell carcinoma, large cell carcinoma, and adenocarcinoma, but there are several other types that occur less frequently. A few of the less common types are pleomorphic, carcinoid tumor, salivary gland carcinoma, and unclassified carcinoma. All types can occur in unusual histologic variants and as mixed cell-type combinations. Non-squamous cell carcinoma almost occupy the half of NSCLC. In the tissue classification, the central type contains about one-ninth. Sometimes the phrase 'not otherwise specified', or NOS is used generically, usually when a more specific diagnosis cannot be made. This is most often the case when a pathologist examines a small amount of malignant cells or tissue in a cytology or biopsy specimen. Lung cancer in never-smokers is almost universally NSCLC, with a sizeable majority being adenocarcinoma. On relatively rare occasions, malignant lung tumors are found to contain components of both SCLC and NSCLC. In these cases, the tumors are classified as combined small cell lung carcinoma (c-SCLC), and are (usually) treated like 'pure' SCLC. Adenocarcinoma of the lung is currently the most common type of lung cancer in 'never smokers' (lifelong non-smokers). Adenocarcinomas account for approximately 40% of lung cancers. Historically, adenocarcinoma was more often seen peripherally in the lungs than small cell lung cancer and squamous cell lung cancer, both of which tended to be more often centrally located. However, recent studies suggest that the 'ratio of centrally-to-peripherally occurring' lesions may be converging toward unity for both adenocarcinoma and squamous cell carcinoma. Squamous cell carcinoma (SCC) of the lung is more common in men than in women. It is closely correlated with a history of tobacco smoking, more so than most other types of lung cancer. According to the Nurses' Health Study, the relative risk of SCC is approximately 5.5, both among those with a previous duration of smoking of 1 to 20 years, and those with 20 to 30 years, compared to never-smokers. The relative risk increases to approximately 16 with a previous smoking duration of 30 to 40 years, and approximately 22 with more than 40 years. Large cell lung carcinoma (LCLC) is a heterogeneous group of undifferentiated malignant neoplasms originating from transformed epithelial cells in the lung. LCLC's have typically comprised around 10% of all NSCLC in the past, although newer diagnostic techniques seem to be reducing the incidence of diagnosis of 'classic' LCLC in favor of more poorly differentiated squamous cell carcinomas and adenocarcinomas. LCLC is, in effect, a 'diagnosis of exclusion', in that the tumor cells lack light microscopic characteristics that would classify the neoplasm as a small-cell carcinoma, squamous-cell carcinoma, adenocarcinoma, or other more specific histologic type of lung cancer. LCLC is differentiated from small cell lung carcinoma (SCLC) primarily by the larger size of the anaplastic cells, a higher cytoplasmic-to-nuclear size ratio, and a lack of 'salt-and-pepper' chromatin. Many of the symptoms of NSCLC can be signs of other diseases, but having chronic or overlapping symptoms may be a signal of the presence of the disease. Some symptoms are indicators of less advanced cases while some may signal that the cancer has spread. Some of the symptoms of less advanced cancer include chronic cough, coughing up blood, chest pain, hoarseness, shortness of breath, wheezing, chest pain, weight loss, and loss of appetite. A few more symptoms associated with the early progression of the disease are feeling weak, being very tired, having trouble swallowing, swelling in the face or neck, and continuous or recurring infections like bronchitis or pneumonia. Signs of more advanced cases include bone pain, nervous system changes (headache, weakness, dizziness, balance problems, seizures), jaundice, lumps near the surface of the body, numbness of extremities due to Pancoast Syndrome, and nausea, vomiting and constipation brought on by hypercalcemia. Some more of the symptoms that indicate further progression of the cancer include shortness of breath, superior vena cava syndrome, trouble swallowing, large amounts of mucus, weakness, fatigue, and hoarseness.