Approximately 80 percent of people with lung
cancer have non-small cell lung cancer. Depending on the type of cancer
cell present, non-small cell cancer is in turn divided into several
subtypes. Squamous cell carcinoma begins in thin, flat surface cells
that line the respiratory tract, and is the most common type.
Adenocarcinoma forms in cells that have a secretory or glandular
function. Adenosquamous carcinoma begins in flattened cells that also
have secretory properties. In sarcomatoid carcinoma, cells look
markedly abnormal under the microscope. Carcinoid tumors grow slowly,
and release hormones when stimulated by the nervous system. Cells in
salivary glands in larger airways can also become cancerous.
Cancer cells in non-small cell lung cancer
can produce hormones or hormone-like substances to cause certain
conditions called paraneoplastic syndromes. These conditions include
high blood calcium levels, abnormal clotting, overgrowth of certain
bones and those in the fingertips in particular, and abnormal breast
growth in men.
People with non-small cell lung cancer tend
to be diagnosed later in the course of their disease, making these a
difficult group of cancers to treat. The type of cancer, its location
and stage, the presence of symptoms, and the patient’s overall
condition and ability to withstand treatment all affect the ultimate
outcome. Symptoms include breathlessness, chest pain, coughing up of
blood, fatigue, fever and weight loss. A diagnosis is typically made by
imaging, a lung biopsy, and blood tests.
Early non-small cell lung cancer can be
treated by surgery. Once it spreads to surrounding chest tissues and to
lymph nodes, chemotherapy and radiotherapy are frequently employed.
Newer forms of treatment include laser therapy, photodynamic therapy,
and biotherapy. The five-year survival rate for early non-small cell
lung cancer is close to 50 percent; five-year survival drops to about
two percent in the most advanced cases. A number of clinical trials are
underway to find better treatment options. The National Cancer
Institute website provides information on such trials.
