Prognosis of any disease means the estimate of the likely course and outcome of the disease. Prognosis of cancers usually means the estimate of success with treatment and chances of recovery.
Factors that affect prognosis of cancer
There are several factors that affect the prognosis of a cancer. Some of these include:
- Type of cancer - some cancers generally have a good prognosis while others are known to be aggressive and come with a high fatality rate
- Location of cancer
- Stage of the cancer – at early stages the prognosis of a cancer is good while at later stages and when the cancer has spread to other organs, the prognosis is usually poor
- Cancer’s grade – a poorly differentiated cancer or a high grade cancer usually carries a poor prognosis
- Patient’s age and general health condition at the beginning of therapy usually determines prognosis to some extent. Newborns and frail elderly individuals usually have a lower chance of surviving the cancer for long and have a poor prognosis.
- Responses to treatment – some cancers are genetically programmed in such a way that they fail to respond to therapy. These carry a poor prognosis.
How is prognosis depicted and explained to the patient?
After considering the factors that affect prognosis the estimated five year survival is calculated for an individual patient. This included all factors like available treatment options, other health problems that can affect successful treatment of the disease. The estimation is determined from information researchers have collected over many years about hundreds or even thousands of people with the same type of cancer.
Some common numbers that are used to determine prognosis include cancer specific survival, relative survival, overall survival, disease-free survival etc. Cancer-specific survival calculates the percentage of patients with a specific type and stage of cancer who have survived their cancer during a certain period of time (1 year, 2 years, 5 years, etc.) after diagnosis. This also called disease-specific survival.
Relative survival is a comparison of survival of patients diagnosed with cancer to survival of people in the general population who are the same age, race, and sex and who do not have that cancer.
Overall survival is the percentage of patients with a specific type and stage of cancer who are still alive during a certain period of time after diagnosis.
Disease-free survival is the percentage of patients who have no evidence of cancer during a certain period of time after treatment. This is also termed progression free survival or recurrence free survival. Usually the common period of time used for these statistics is 5 years.
Why is knowledge of the prognosis important?
Most cancer patients want to know their prognosis. It is easier for many to cope with the diagnosis if they know the possible prognosis of their condition. This also helps patients and their loved ones make decisions regarding possible modalities of treatment, palliative care, and personal matters, such as financial matters and inheritance.
Knowledge of prognosis is the patient’s prerogative. He or she might want to know it or might refuse to know the prognosis of their cancer as they may find it frightening or confusing.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)