Incidence is the number of new cases of disease that occur within a defined population during a specified time period, usually a year. Age (5-year age bands) and sex-specific rates are calculated and rates are expressed as per 100,000 persons per year.
\[\mathsf{\text{Incidence rate} = \left({\text{Number of new cases in a year (source: HMRN)} \over \text{Mid-year population estimate (source: ONS)}}\right) \times 100,000}\]
Sex rate ratio
The sex rate ratio (male:female) is the annual incidence of males divided by the annual incidence of females.
Estimated cases per year
Annual estimated cases are generated by applying HMRN's age and sex-specific annual incidence rates to equivalent population data. Estimates for the UK and its constituent countries (England, Wales, Northern Ireland and Scotland) are made using 2016 mid-year data obtained from Office for National Statistics. Worldwide estimates are calculated using UN World Population Data and are calculated for countries with populations of at least 1.5 million. UK estimates in the worldwide page may differ from those elsewhere due to the difference in population estimates from the different sources but are provided for comparability.
All estimated annual numbers are shown to the nearest 10 cases. Due to rounding totals may differ from the sum of male and female estimates.
Age-standardised rates
Direct age-standardisation is used to allow comparisons to be made between HMRN’s annual incidence rates and those of other populations with different age and sex structures. HMRN's age and sex-specific annual incidence rates are applied to the equivalent 2013 European Standard Population strata. The age-standardised rate is then calculated by dividing the total number of cancers that would have occured in the standard population if it had experienced the same incidence rates as HMRN, by the total standard population.
Rates standardised to the World Standard Population 1966, the World Standard Population (2000-2025) and the US Standard Population 2000 are shown on the 'Age-standardised rates' page.
Survival is often expressed as the proportion of patients still alive at a specified time after their condition was diagnosed, for example 1 or 5 years. Net survival is a technique which enables the background population mortality to be taken into account and provides an estimate of survival if patients could only die from causes related to their cancer. Here it is calculated using the Stata programme stns, which implements the Pohar Perme estimator, and English life tables obtained from the Office for National Statistics.
Survival estimates cannot be reliably estimated when the number of deaths is small. Where this occurs, these are marked as 'undefined' in the downloadable data.
Prevalence measures the number (or proportion) of people with a condition at a specific time. Cancer prevalence estimates generally include all people who have ever had the disease, regardless of whether or not they have been cured.
HMRN uses limited-duration prevalence, which is defined as the number of people alive on a certain day who were diagnosed with the disease at any point during a specified time period. The time periods used on this website are 1 year, 3 years, 5 years and 10 years before the index date (currently 31/12/2019). These time periods are relevant to different stages in the patient pathway. For example, for potentially curable conditions, 1 and 3-year prevalence gives an indication of the number of patients undergoing intensive treatment and/or monitoring; whereas 10-year prevalence contains people on treatment, those living with cancer, and those who have been cured.
Estimated UK prevalence
The expected number of prevalent UK cases is estimated by applying HMRN's age and sex-specific prevalence rates to equivalent UK population age and sex strata.