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Prognosis and survival for lung cancer
If you have lung cancer, you may have questions about your prognosis. A prognosis is the doctor’s best estimate of how cancer will affect someone and how it will respond to treatment. Prognosis and survival depend on many factors. Only a doctor familiar with your medical history, the type and stage and other features of your cancer, the treatments chosen and the response to treatment can put all of this information together with survival statistics to arrive at a prognosis.
A prognostic factor is an aspect of the cancer or a characteristic of the person (such as their overall health) that the doctor will consider when making a prognosis. A predictive factor influences how a cancer will respond to a certain treatment. Prognostic and predictive factors are often discussed together. They both play a part in deciding on a treatment plan and a prognosis.
The following are prognostic and predictive factors for lung cancer.
The stage of lung cancer is the most important prognostic factor. Early stages of lung cancer have a better prognosis than later stages.
- Non–small cell lung cancer stages 0 or 1 generally have a more favourable prognosis than stages 2, 3 or 4.
- Limited stage small cell lung cancers have a much better prognosis than extensive stage cancers.
Number and type of metastases
People who have only one metastasis from lung cancer have a more favourable prognosis than those who have multiple metastatic tumours. A single metastasis to the brain may have a more favourable prognosis than multiple metastases in another part of the body.
- Non–small cell lung cancer that has spread to the adrenal glands has a more favourable prognosis than cancer that has spread to the brain or liver.
- Small cell lung cancer that has spread to the brain has a less favourable prognosis than cancer that has spread only to the bones or mediastinum.
People who have lost more than 5% of their body weight before treatment starts have a less favourable prognosis than people who haven’t lost much weight.
Performance status measures how well a person can do their daily activities and everyday tasks. People with a higher performance status score have a better prognosis than people who have a lower performance status score.
Women with lung cancer have a slightly better prognosis than men who are diagnosed with the same cancer.
People who have lung problems have a less favourable prognosis. Lung problems can include the following:
- collapsed lung
- lung infection (pneumonia)
- buildup of fluid around the lung (pleural effusion)
During diagnosis, several tests are done on the lung cancer tissue to see if there are certain changes (mutations) to the genes of the cancer cells. These markers can predict how well a non–small cell lung cancer may respond to specific treatments.
- Epidermal growth factor receptor (EGFR)–positive tumours have too many EGFR receptors. These cancers will respond to drugs that block the receptors.
- Anaplastic lymphoma kinase (ALK) is a gene that is mutated in a very small number of non–small cell lung cancers. ALK-positive tumours respond to drugs that block the signals from the ALK mutation.
- BRAF is a gene that controls cell signals and growth. BRAF V600 mutations are found in a very small number of non–small cell lung cancers. BRAF V600 positive tumours respond to drugs that stop the signals from the BRAF V600 mutation.
A standard measure of a person’s ability to perform ordinary tasks and carry out daily activities.
The Karnofsky performance status scale is used to assess a person’s prognosis, to monitor changes in a person’s ability to function or decide if a person is suitable for a clinical trial. The person’s performance status is given a score out of 100. The higher the score, the better able a person is to carry out daily activities.
Also called Karnofsky performance scale or Karnofsky scale.
Great progress has been made
Some cancers, such as thyroid and testicular, have survival rates of over 90%. Other cancers, such as pancreatic, brain and esophageal, continue to have very low survival rates.