How is lung cancer diagnosed?
The majority of lung cancer cases are discovered too late for effective therapy.
At the time of diagnosis, lung cancer had already spread (metastasized) in more than half of patients.
Early diagnosis is difficult because many of the common symptoms of lung cancer
are similar to those of smokers' lung (chronic obstructive pulmonary disease or COPD).
In addition to this, most lung cancer patients will also have COPD because
both conditions are mainly caused by smoking. However, only 1 or 2 per cent of COPD patients will go on to develop
lung cancer .
The first investigation is a chest X-ray. For a lung tumor to be seen on a standard X-ray, it must have
a diameter of at least one centimeter. However, the initial malignant cell has split (or doubled) 36 times
by the time a tumor reaches this size. It is obvious thatlung cancer is a disease that is typically identified
late in its normal course because death typically happens after 40 such cell divisions.
Additional exams and certain straightforward blood tests could also be performed..
The best test for tumors in the major bronchi (air passageways) in the center of the chest is bronchoscopy,
which involves direct examination of the inside of the breathing tubes with a tiny fiber-optic device under
Depending on the site of the cancer, a biopsy will be obtained either by a bronchoscopy or a needle biopsy.
Needle biopsy is better for cancers near the periphery of the lungs (ie closer to the ribs than the centre of
the chest), beyond the reach of the bronchoscope.
Sputum, the substance that is coughed up from the respiratory system, is typically also tested for cancer
cells, which can eliminate the need for a biopsy..
A CT scan provides more information about how much the tumour may have spread.
Based on how a pathologist observes the tumors when they are inspected under a microscope, there are three primary
forms of lung cancer :
- small cell carcinoma
- squamous cell carcinoma
These conditions (such as non-small cell cancer) respond better to surgery or radiation (X-ray treatment).
Therefore, a tiny tissue sample (biopsy) is required for the pathologist to evaluate. This will demonstrate
the sort of cell that is implicated and prove that the cancer diagnosis was made correctly.