Broadly speaking, bronchogenic carcinoma is the technical term for lung cancer, referring to the cancerous tumours typical of the disease. It is the cancer most likely to lead to death, accounting for about 20% of the cancer mortality rate. However, bronchogenic carcinoma is not homogeneous. It is roughly split into two types depending on how the tumours look under a microscope - small-cell lung cancers (SCLC) and non-small cell lung cancers (NSCLC).
SCLC predominantly affects smokers, yet only accounts for 10-15% of diagnoses. Nonetheless, it is more aggressive, spreads quicker, and with a more negative prognosis than other types. NSCLC are far more common, and can be further subdivided into three more categories. Adenocarcinoma is related to glands, and the associated tumours are comparatively smaller than other lung cancers. It seems to affect (non-smoking) women and those of Asian descent more than other demographics, with tumours usually appearing in the outer areas of the lungs. In contrast, squamous cell carcinomas grow in more central areas, often clustering to form large cavities. It has been consistently linked to smoking, and with relatively poor prognoses for sufferers. Finally, large-cell carcinomas are the rarest NSCLS, and - as the name suggests - form quite large structures. Though it only accounts for 10% of all bronchogenic carcinomas, it is very aggressive. This list of lung cancer types is by no means exhaustive, as there are more subtle differences between who it affects and how it presents which lead to more detailed diagnosis.
Likewise, they do not all present the same symptoms. Indeed, sometimes a person may experience no symptoms, leading to a very late diagnosis and poor survival rate. Sometimes the tumours cause an obstruction to the bronchus, leading to coughing, wheezing, and/or chest pain. Alternatively, it can begin to spill over into or squash other organs, causing further complications by metastases: the spreading of the tumours to other areas of the body. Treatment usually involves chemotherapy, radiotherapy, and surgery, but again this can vary depending on exact diagnosis and the developmental stage of the cancer.
There are a number of risk factors associated with the development of bronchogenic carcinomas. Gender is one; lung cancer is the leading type of cancer in men, whilst only the 6th most common type amongst women. Inhaling or exposing yourself to a variety of chemicals also increases risk. For instance, particulate matter in air pollution, paint fumes, and asbestos have all being reliably named as contributory factors. As previously mentioned, lung cancer is strongly linked to smoking, with as many as 86% of cases in the UK being directly related. Shockingly, a small percentage of these are due to the inhalation of second-hand smoke from sharing an environment with smokers. Lung cancers due to smoking are the most lethal, and smoking for a longer period of your life is associated with a poorer outcome than smoking a higher quantity but over fewer years.
Bronchogenic carcinomas are the molecular beginnings of lung cancer, but interventions do not need to be all that scientific. Choosing to quit smoking can massively reduce your risk, and being mindful of other environmental pollutants will help the right people get the correct support and checks. As with all cancers, finding it early gives a person the best chance of treating and overcoming the disease, so if you are concerned, consult your doctor as soon as possible.