Cancer of unknown primary incidence statistics

Coronavirus (COVID-19)

We have created a central resources hub for Health Professionals which hosts all of our CRUK resources and further materials to help with managing the pandemic. We are updating the information as guidance changes. There is also a page specifically for patients on our about cancer hub.

Health Professional COVID-19 and Cancer Hub

Cases

New cases of cancer of unknown primary, 2015-2017, UK.

 

Proportion of all cases

Percentage cancer of unknown primary is of total cancer cases, 2015-2017, UK

 

Age

Peak rate of cancer of unknown primary cases, 2015-2017, UK

Trend over time

Change in cancer of unknown primary incidence rates since the early 1990s, UK

 

Cancer of unknown primary is the 15th most common cancer in the UK, accounting for 2% of all new cancer cases (2017).[1-4]

In females in the UK, cancer of unknown primary is the 11th most common cancer (2% of all new female cancer cases). In males in the UK, it is the 14th most common cancer (2% of all new male cancer cases).

52% of cancer of unknown primary cases in the UK are in females, and 48% are in males.

Cancer of unknown primary incidence rates (European age-standardised (AS) rates Open a glossary item) for persons are significantly higher than the UK average in Scotland and Wales, significantly lower than the UK average in Northern Ireland, and similar to the UK average in England.

Cancer Of Unknown Primary (C77-C80), Number of New Cases, Crude and European Age-Standardised (AS) Incidence Rates per 100,000 Population, UK, 2017

  England Scotland Wales Northern Ireland UK
Female Cases 3,578 438 228 83 4,327
Crude Rate 12.7 15.7 14.4 8.7 12.9
AS Rate 12.3 14.9 12.8 9.3 12.5
AS Rate - 95% LCL 11.9 13.5 11.1 7.3 12.1
AS Rate - 95% UCL 12.7 16.3 14.4 11.3 12.8
Male Cases 3,314 348 266 86 4,014
Crude Rate 12.1 13.2 17.3 9.3 12.3
AS Rate 14.5 15.8 18.6 13.0 14.8
AS Rate - 95% LCL 14.0 14.2 16.4 10.2 14.3
AS Rate - 95% UCL 15.0 17.5 20.8 15.7 15.2
Persons Cases 6,892 786 494 169 8,341
Crude Rate 12.4 14.5 15.8 9.0 12.6
AS Rate 13.3 15.3 15.3 10.9 13.5
AS Rate - 95% LCL 13.0 14.3 13.9 9.2 13.2
AS Rate - 95% UCL 13.6 16.4 16.6 12.5 13.8

95% LCL and 95% UCL are the 95% lower and upper confidence limits Open a glossary item  around the AS Rate Open a glossary item 
 

For cancer of unknown primary, there are few established risk factors therefore differences between countries largely reflect differences in diagnosis and data recording.

References

  1. Data were provided by the National Cancer Registration and Analysis Service (part of Public Health England), on request through the Office for Data Release, November 2019. Similar data can be found here: https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/conditionsanddiseases/bulletins/cancerregistrationstatisticsengland/previousReleases
  2. Data were provided by ISD Scotland on request, April 2019. Similar data can be found here: http://www.isdscotland.org/Health-Topics/Cancer/Publications.
  3. Data were provided by the Welsh Cancer Intelligence and Surveillance Unit, Health Intelligence Division, Public Health Wales on request, December 2019. Similar data can be found here: http://www.wcisu.wales.nhs.uk.
  4. Data were provided by the Northern Ireland Cancer Registry on request, May 2019. Similar data can be found here: http://www.qub.ac.uk/research-centres/nicr/.

About this data

Data is for UK, 2017, ICD-10 C77-C80.

Last reviewed:

Cancer of unknown primary incidence is strongly related to age, with the highest incidence rates being in older people. In the UK in 2015-2017, on average each year almost 6 in 10 new cases (56%) were in people aged 75 and over.[1-4]

Age-specific incidence rates rise steadily from around age 40-44 and more steeply from around age 65-69.The highest rates are in in the 90+ age group for females and males.

Incidence rates are significantly lower in females than males in a number of (mainly older) age groups.The gap is widest at age 60 to 64, when the age-specific incidence rate is 1.3 times lower in females than males.

Cancer of unknown primary (C77-C80), Average Number of New Cases per Year and Age-Specific Incidence Rates per 100,000 Population, UK, 2015-2017

For cancer of unknown primary, like most cancer types, incidence increases with age. This largely reflects cell DNA damage accumulating over time. Damage can result from biological processes or from exposure to risk factors. A drop or plateau in incidence in the oldest age groups often indicates reduced diagnostic activity perhaps due to general ill health.

References

  1. Data were provided by the National Cancer Registration and Analysis Service (part of Public Health England), on request through the Office for Data Release, November 2019. Similar data can be found here: https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/conditionsanddiseases/bulletins/cancerregistrationstatisticsengland/previousReleases
  2. Data were provided by ISD Scotland on request, April 2019. Similar data can be found here: http://www.isdscotland.org/Health-Topics/Cancer/Publications.
  3. Data were provided by the Welsh Cancer Intelligence and Surveillance Unit, Health Intelligence Division, Public Health Wales on request, December 2019. Similar data can be found here: http://www.wcisu.wales.nhs.uk.
  4. Data were provided by the Northern Ireland Cancer Registry on request, May 2019. Similar data can be found here: http://www.qub.ac.uk/research-centres/nicr/.

About this data

Data is for UK, 2015-2017, C77-C80.

Last reviewed:

Cancer of Unknown Primary European age-standardised (AS) Open a glossary item incidence rates for females and males combined decreased by 55% in the UK between 1993-1995 and 2015-2017.[1-4] The decrease was larger in males than in females.

For females, cancer of unknown primary AS incidence rates in the UK decreased by 53% between 1993-1995 and 2015-2017. For males, cancer of unknown primary AS incidence rates in the UK decreased by 59% between 1993-1995 and 2015-2017.

Over the last decade in the UK (between 2005-2007 and 2015-2017), cancer of unknown primary AS incidence rates for females and males combined decreased by 35%. In females AS incidence rates decreased by 35%, and in males rates decreased by 35%.

Cancer of Unknown Primary (ICD-10 C77-C80), European Age-Standardised Incidence Rates, UK, 1993-2017

Cancer of unknown primary incidence rates have decreased overall in most broad age groups in females and males combined in the UK since the early 1990s, but remained stable in some.[1-4] Rates in 0-24s have remained stable, in 25-49s have decreased by 49%, in 50-59s have decreased by 58%, in 60-69s have decreased by 63%, in 70-79s have decreased by 61%, and in 80+s have decreased by 45%.

Cancer of Unknown Primary (ICD-10 C77-C80), European Age-Standardised Incidence Rates, By Age, UK, 1993-2017

CUP incidence trends reflect improvements in data collection and diagnostic capabilities which mean identification of primary site is possible for more cancer cases, hence fewer cases are registered as CUP. CUP data were not consistently collected until the 1990s, meaning trends starting before this time are not reliable.

References

  1. Data were provided by the National Cancer Registration and Analysis Service (part of Public Health England), on request through the Office for Data Release, August 2018. Similar data can be found here: https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/conditionsanddiseases/bulletins/cancerregistrationstatisticsengland/previousReleases
  2. Data were provided by ISD Scotland on request, April 2018. Similar data can be found here: http://www.isdscotland.org/Health-Topics/Cancer/Publications.
  3. Data were provided by the Welsh Cancer Intelligence and Surveillance Unit, Health Intelligence Division, Public Health Wales on request, February 2019. Similar data can be found here: http://www.wcisu.wales.nhs.uk.
  4. Data were provided by the Northern Ireland Cancer Registry on request, April 2018. Similar data can be found here: http://www.qub.ac.uk/research-centres/nicr/.

About this data

Data is for UK, 1993-2017, ICD-10 C77-C80.

Last reviewed:

The largest proportion of cancer of unknown primary cases occur in the respiratory and digestive organs, with much a smaller proportion in the lymph nodes Open a glossary item (2010-2012).[1-4]

The proportion of cases in each part of the body is similar between males and females.[1-4]

A large proportion of cases did not have the specific site of unknown primary recorded in cancer registry data, or overlapped more than one part.[1-4]

Cases and percentages may not sum due to rounding

References

  1. Data were provided by the Office for National Statistics on request, July 2014. Similar data can be found here: http://www.ons.gov.uk/ons/rel/vsob1/cancer-statistics-registrations--england--series-mb1-/index.html.
  2. Data were provided by ISD Scotland on request, April 2014. Similar data can be found here: http://www.isdscotland.org/Health-Topics/Cancer/Publications/index.asp.
  3. Data were provided by the Welsh Cancer Intelligence and Surveillance Unit on request, April 2014. Similar data can be found here: http://www.wales.nhs.uk/sites3/page.cfm?orgid=242&pid=59080.
  4. Data were provided by the Northern Ireland Cancer Registry on request, June 2014. Similar data can be found here: http://www.qub.ac.uk/research-centres/nicr/CancerInformation/.

About this data

Data is for UK, 2010-2012, ICD-10 C77-C80.

Last reviewed:

There is evidence for an association between cancer of unkown primary (CUP) incidence and deprivation for both males and females in England.[1]  England-wide data for 2006-2010 show European age-standardised Open a glossary item incidence rates are 67% higher for males living in the most deprived areas compared with the least deprived, and 60% higher for females.[1]

Cancer of Unknown Primary (C77-C80), European Age-Standardised Incidence Rates by Deprivation Quintile, England, 2006-2010

The estimated deprivation gradient in CUP incidence between people living in the most and least deprived areas in England has narrowed for males in the period 1996-2010, but has not changed for females.[1] It has been estimated that there would have been around 1,600 fewer cancer cases each year in England during 2006-2010 if all people experienced the same incidence rates as the least deprived.[1]

References

  1. Cancer Research UK and National Cancer Intelligence Network. Cancer by deprivation in England: Incidence, 1996-2010, Mortality, 1997-2011. London: NCIN; 2014.

About this data

Data is for UK, 2006-2010, ICD-10 C77-C80

Deprivation gradient statistics were calculated using incidence data for 2006-2010. The deprivation quintiles were calculated using the Income domain scores from the Index of Multiple Deprivation (IMD) from the following years: 2004, 2007 and 2010. Full details on the data and methodology can be found in the Cancer by Deprivation in England NCIN report.

Last reviewed:

An estimated 12,500 people who had been diagnosed with cancer of unknown primary (CUP) between 1991 and 2010 were alive in the UK at the end of 2010.[1]

References

  1. Macmillan Cancer Support and National Cancer Registration and Analysis Service. Cancer Prevalence UK Data Tables. London: NCRAS; 2015.

About this data

Data is for: Great Britain (1991-2010) and Northern Ireland (1993-2010), ICD-10 C77, C78, C79, C80

Last reviewed:

Cancer stats explained

See information and explanations on terminology used for statistics and reporting of cancer, and the methods used to calculate some of our statistics.

Citation

You are welcome to reuse this Cancer Research UK content for your own work.
Credit us as authors by referencing Cancer Research UK as the primary source. Suggested styles are:

Web content: Cancer Research UK, full URL of the page, Accessed [month] [year].
Publications: Cancer Research UK ([year of publication]), Name of publication, Cancer Research UK.
Graphics (when reused unaltered): Credit: Cancer Research UK.
Graphics (when recreated with differences): Based on a graphic created by Cancer Research UK.

When Cancer Research UK material is used for commercial reasons, we encourage a donation to our life-saving research.
Send a cheque payable to Cancer Research UK to: Cancer Research UK, 2 Redman Place, London, E20 1JQ or

Donate online

We’re now on twitter.
Join the conversation and follow @CRUKHCPs for news, updates and opinion.

@CRUKHCPs

Acknowledgements

We are grateful to the many organisations across the UK which collect, analyse, and share the data which we use, and to the patients and public who consent for their data to be used. Find out more about the sources which are essential for our statistics.