Cancer of unknown primary incidence statistics

Cases

New cases of cancer of unknown primary, 2013, UK

 

Proportion of all cases

Percentage cancer of unknown primary is of total cancer cases, 2013, UK

 

Age

Age that almost 6 in 10 of cancer of unknown primary cases are diagnosed, 2011-2013, UK

 

Trend since 1990s

Cancer of unknown primary incidence rates have decreased since the early 1990s, UK

 

Cancer of unknown primary (CUP) accounts for 3% of all new cases of cancer in the UK (2013). It accounts for 2% of the male total and 3% of the female total.[1-4]

In 2013, there were 9,274 new cases of CUP in the UK: 4,372 (47%) in males and 4,902 (53%) in females, giving a male:female ratio of around 9:10.[1-4] The crude incidence rate Open a glossary item shows that there are 14 new cases of CUP for every 100,000 males in the UK, and 15 for every 100,000 females.

Differences in registration practice may have a bearing on comparisons between countries in the UK.[4] The European age-standardised incidence rates Open a glossary item (AS rates) for females are significantly higher in Wales compared with England.[1-4] There are no other significant differences in rates between the constituent countries of the UK.

Cancer of Unknown Primary (C77-C80), Number of New Cases, Crude and European Age-Standardised (AS) Incidence Rates per 100,000 Population, UK, 2013

England Wales Scotland Northern Ireland UK
Male Cases 3,636 258 375 103 4,372
Crude Rate 13.7 17.0 14.5 11.5 13.9
AS Rate 17.4 19.5 18.4 16.9 17.5
AS Rate - 95% LCL 16.8 17.1 16.5 13.6 17.0
AS Rate - 95% UCL 17.9 21.8 20.2 20.2 18.1
Female Cases 4,021 306 460 115 4,902
Crude Rate 14.7 19.5 16.8 12.3 15.0
AS Rate 14.6 17.9 16.5 13.9 15.0
AS Rate - 95% LCL 14.2 15.9 15.0 11.3 14.5
AS Rate - 95% UCL 15.1 19.9 18.0 16.4 15.4
Persons Cases 7,657 564 835 218 9,274
Crude Rate 14.2 18.3 15.7 11.9 14.5
AS Rate 15.8 18.5 17.3 15.1 16.1
AS Rate - 95% LCL 15.5 17.0 16.1 13.1 15.8
AS Rate - 95% UCL 16.2 20.0 18.5 17.1 16.4

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

ASR calculated with ESP2013. Not comparable with ASRs calculated with ESP1976.

References

  1. Data were provided by the Office for National Statistics on request, July 2015. 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 2015. 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, February 2015. 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, March 2015. Similar data can be found here: http://www.qub.ac.uk/research-centres/nicr/
Last reviewed:

CUP incidence is strongly related to age with, the highest incidence rates being in older males and females. In the UK in 2011-2013, on average each year almost 6 in 10 (56%) cases were diagnosed in people aged 75 and over.[1-4]

Age-specific incidence rates rise gradually from around age 35-39, then more sharply from around age 65-69, with the highest rates in the 90+ age group. Incidence rates are generally higher for males than for females aged 45-49 and over (the gap is not significant at younger ages or at age 55-59). This gap is widest at the ages of 65-69, when the male:female incidence ratio of age-specific rates (to account for the different proportions of males to females in each age group) is around 13:10.[1-4]

Cancer of Unknown Primary (C77-C80), Average Number of New Cases per Year and Age-Specific Incidence Rates, UK, 2011-2013

References

  1. Data were provided by the Office for National Statistics on request, July 2015. 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 2015. 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, February 2015. 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, March 2015. Similar data can be found here: http://www.qub.ac.uk/research-centres/nicr/
Last reviewed:

Cancer of unknown primary (CUP) incidence rates have decreased by 35% in the UK since the mid-1990s.[1-4] This includes a slightly larger overall increase for males than for females.

Over the last decade (between 2002-2004 and 2011-2013), CUP European age-standardised (AS) Open a glossary item incidence rates have decreased by 38% in males and 34% in females.

Cancer of Unknown Primary (C77-C80), European Age-Standardised Incidence Rates, UK, 1993-2013

ASR calculated with ESP2013. Not comparable with ASRs calculated with ESP1976.

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.[5,6] CUP data were not consistently collected until the 1990s, meaning trends starting before this time are not reliable.

CUP incidence rates have decreased overall for all of the broad age groups in the UK since the mid-1990s; however, this includes an increase followed by a decrease in most age groups.[1-4] The largest decreases have been in people aged 60-69 and those aged 70-79, in whom European AS incidence rates have decreased by 57% and 54% respectively, between 1993-1995 and 2011-2013.

Cancer of Unknown Primary (C77-C80), European Age-Standardised Incidence Rates, by Age, UK, 1993-2013

ASR calculated with ESP2013. Not comparable with ASRs calculated with ESP1976.

References

  1. Data were provided by the Office for National Statistics on request, July 2015. 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 2015. 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, February 2015. 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, March 2015. Similar data can be found here: http://www.qub.ac.uk/research-centres/nicr/
  5. National Cancer Intelligence Network (NCIN) and Cancer Research UK. Cancer of Unknown Primary. London: NCIN; 2012.
  6. Hemminiki K, Liu H, Hemminiki A, et al. Power and limits of modern cancer diagnostics: cancer of unknown primary Ann Onc 2012; 23(3): 760-64.
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]

Cancer of Unknown Primary (C77-C80), Percentage Distribution of Cases Diagnosed By Anatomical Site, UK, 2010-2012

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/.
Last reviewed:

The lifetime risk of developing cancer of unknown primary is 1 in 66 for men and 1 in 62 for women, in 2012 in the UK.[1]

The lifetime risk for CUP has been calculated on the assumption that the possibility of having more than one diagnosis of CUP over the course of a lifetime is very low (‘Current Probability’ method).[2]

References

  1. Lifetime risk estimates calculated by the Statistical Information Team at Cancer Research UK. Based on data provided by the Office of National Statistics, ISD Scotland, the Welsh Cancer Intelligence and Surveillance Unit and the Northern Ireland Cancer Registry, on request, December 2013 to July 2014.
  2. Esteve J, Benhamou E and Raymond L. Descriptive epidemiology. IARC Scientific Publications No.128, Lyon, International Agency for Research on Cancer, pp 67-68 1994.
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]

Last reviewed:

Cancer Statistics Explained

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

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