Survival is one of the most relevant cancer surveillance and control indicators because survival outcomes in a population reflect mainly two aspects: effectiveness of prevention and efficiency of treatment.
A better organization and more resources available to health services, along with population health education will contribute to make possible the early diagnosis of cancer and therefore a better prognosis. On the other hand, using the most appropriate treatment for each type of cancer, which takes into account the individual characteristics of patients, will improve outcomes, increasing the proportion of patients who can be cured.
Duration of survival is defined as the interval between time of diagnostics and death of patients.
The observed survival rate indicates the proportion of patients who were diagnosed with cancer at a given time and are alive at a certain point in time after diagnosis. All deaths are considered in this calculation regardless of cause, which reflects total mortality in the group of patients, not just that attributable solely to cancer.
However, a more precise idea of the impact of cancer on the population under study is obtained by calculating the relative survival rate, which corrects observed rates, taking into account the risk of patients dying from causes other than cancer. This correction can be made by means of population life-tables that share the same characteristics (sex, age and calendar period of observation). That is why relative survival rates are higher than observed survival, especially in the case of elderly patients.
A third way to analyze survival is age-standardized survival rate, used to compare survival between geographical areas and / or over time.
Cancer survival rates estimated for Spain.
- The table below shows estimated survival rates in Spain, produced from the data obtained by all the Spanish population-based cancer registries that participated in the project EUROCARE-4 (Gerona, Granada, Navarra, Murcia, Basque Country and Tarragona), which includes cancer cases diagnosed from 1995 to 1999. It is a first approach to survival in Spain, though, due to the fact that the data make reference to some specific areas of the country they might not be representative of Spain as a whole.
- In men, five-year relative survival was at 44% for all cancers, except nonmelanoma skin cancer.
- In women, the survival rate (59%) was higher than that in men.
- For the most common cancers, in men the highest relative survival rate was for prostate and bladder cancers; in women, for breast (82%) and corpus uteri (76%) cancers.
- Considering all cancers (not included in the table), cancer survival by site differs greatly, from lip, testis and thyroid cancers (over 95%) to esophagus, liver, pleura, or pancreas cancers (less than 10%).
|Source: EUROCARE-4 (modified). Created by: Granada Cancer Registry, EASP
- There are also significant variations in cancer survival between geographical areas, both across Europe and our country.
- In general, age-standardized survival rates for our country are similar to those estimated for the whole of European population-based cancer registries.
- These geographical variations in cancer survival may be due to several factors: general health status of the population, genetics, stage of disease at diagnosis, health services provision in the area or access to health services by population, etc.., which shows the possible influence of both health and socioeconomic factors.
Cancer Survival rates in Granada
- Granada is the only province in Andalusia with a population-based cancer registry old enough to have estimated survival rates.
- Cancer incidence is higher in males for lung and colorectal cancers and in females for breast and colorectal cancer.
- For these cancers, 5-year relative survival is very low in men as regards lung cancer (6%), varying greatly from breast cancer (78%), while colorectal cancer is in-between (about 50%).