When diagnosed with mesothelioma or any cancer, the first thing most people want to know is their overall chance of recovery and survival. They may also be interested in knowing how they can use this information to choose from available treatment options. While it is extremely important to understand survival statistics, it can be confusing sometimes. Using survival statistics, doctors can also make a prognosis and evaluate treatment options.
Five-year relative survival rates
Generally given as rates, survival statistics describe the percentage of individuals (diagnosed with a particular type of cancer and stage) who will be alive for a specific period of time after the diagnosis is made. Survival rates can be expressed for any time duration. Cancer statistics are generally expressed as a five-year relative survival rate, which describes the percentage of cancer patients who will survive for five years after cancer is detected (excluding individuals whose deaths that may be caused due to other diseases). For instance, the five-year survival rate for cervical cancer is 72%. This implies that 72% of women diagnosed with cervical cancer will be alive 5 years after cancer is detected.
Survival statistics are generally calculated for specific stages of cancer (cancer stage describes the presence and extent of the cancer’s spread) since these statistics vary based on stage. For instance, the five-year relative survival rate, as relevant to early-stage bladder cancer (as of 2008), is 95%. However, the five-year relative survival rate for individuals diagnosed with advanced stages of cancer is 16%. Survival statistics that cover all the different stages of cancer are called an overall rate. For example, the overall five-year relative survival rate, as applicable to cases of prostate cancer (irrespective of stage), is 98%.
Survival statistics: disease-free and progression-free
For calculating five-year relative survival rates, all those individuals are included who may still be living for five years after cancer is detected. These include patients who may be in remission (brief or permanent absence of cancer), or those who may still be receiving treatment. More specific survival statistics, for example, disease-free and progression-free survival statistics, are generally used to evaluate cancer treatments.
- Disease-free survival rates describe only that percentage of patients who may have achieved a complete remission after the completion of treatment.
- Progression-free survival rates refer to the percentage of patients with no new tumor growth or cancer spread for the duration of and after treatment.
These include individuals whose disease may have either responded partially or completely to treatment, or those with a stable disease (the cancer still exists, but has stopped advancing).
Survival statistics and the theory of “cure”
In the medical world, a disease is said to have been cured when it is treated successfully and does not reoccur. It is difficult to apply the concept of “cure” to cancer because in specific cases, some cancer cells can remain undetected. These cells can cause the cancer to return after a certain period of time (called relapse or recurrence). Most types of cancers are categorized as “cured” if there is no relapse or recurrence of cancer five years after cancer is detected. However, a relapse can occur even after five years.
When cancer is diagnosed, one of the most common questions people ask is whether or not the cancer can be successfully treated. This is referred to as a prognosis – the expected course of cancer, its potential outcome and the patient’s chances of recovery. To make a prognosis, doctors usually rely on survival statistics. For instance, it can be said that an individual diagnosed with testicular cancer has a favorable prognosis because the overall five-year relative survival rate is 95%.
As with survival statistics, a prognosis is based on the cancer’s stage at the time of diagnosis – how early the diagnosis has been made and the cancer’s spread, if any. For instance, if an early diagnosis is achieved, the five-year survival rate, as relevant to colorectal cancer, is more than 90%. For colorectal cancer patients in advanced stages of the disease (cancer that has spread to other areas of the body), the five-year relative survival rate is around 10%.
Important Points to remember
- Statistics only provide an estimate of trends prevalent amongst large population groups. They are not indicative of what actually may happen to an individual.
- Survival statistics, as relevant to different stages of cancer, age groups, or time durations, can vary significantly. People need to talk to their doctor about the most appropriate statistics, as relevant to their specific medical condition.
- As with most other types of medical information, ask your doctor to provide a clarification in case cancer-related statistics appear unclear to you.
Evaluating treatment choices
Five-year relative survival rates allow doctors to evaluate and compare available treatment options. While an individual who is still living five years after diagnosis cannot be described as being completely “cured”, the five-year relative survival statistic does indicate that the disease is responding properly to treatment. It also shows that the treatment is helping extend the cancer patient’s life. Using survival statistics, doctors can determine which treatment protocol will prove most beneficial for cancer patients, and whether the associated benefits of a treatment will outweigh its potential risks (for example, discomforting side effects).
Important points to remember
Since five-year survival statistics relate to patients who may have received treatment at least five years earlier, they may not be indicative of the latest, more advanced treatment options.
While survival statistics provide valuable information for evaluating treatment options, they should only be used as a specific component of a comprehensive treatment plan devised by a doctor who is well aware of the patient’s individual condition.