The incidence of non-ovarian cancers in women with elevated CA125 levels in General Practice


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Garth Funston1,Willie Hamilton2,Gary Abel2,Emma Crosbie3,Brian Rous4,Fiona Walter5

1Department of Public Health and Primary Care, University of Cambridge,2University of Exeter,3Gynaecological Oncology Research Group, Division of Cancer Sciences, University of Manchester,4National Cancer Registration and Analysis Service, Public Health England,5Department of Public Health and Primary Care, University of Cambridge, Cambridge

Abstract

Background

The serum biomarker Cancer Antigen 125 (CA125) is recommended as an investigation for ovarian cancer in symptomatic women presenting in UK General Practice (GP). However, the symptoms of ovarian cancer are non-specific and CA125 can be elevated in a number of other cancers. We determined the incidence of non-ovarian cancers in women with raised CA125 levels in English GP.

Method

Women with a CA125 recorded in the UK Clinical Practice Research Datalink between the 1st of May 2011 to the 31st of December 2014 were included. Cancer registry data was used to identify non-ovarian cancers diagnosed in the 12 months following testing. Non-melanoma skin cancers were excluded. We determined the incidence of non-ovarian cancers in women >50 and <50 years with normal (<35U/ml) and abnormal (>35U/ml) CA125 levels.

Results

1,160 (3.7%) of the 31,086 women >50 years old and 161 (0.8%) of the 19,694 women <50 years old who underwent CA125 testing were diagnosed with a non-ovarian cancer. 17.3% of women aged >50 with a raised CA125 were diagnosed with a non-ovarian cancer compared to 2.8% with a normal CA125. 2.7% of women aged <50 with a raised CA125 were diagnosed with non-ovarian cancer compared to 0.7% with a normal CA125. Most cancers in which CA125 was elevated were from sites in the chest, abdomen and pelvis. CA125 was raised in 46 women (49%) diagnosed with pancreatic cancer, 49 women (47%) diagnosed with lung cancer and 48 women (36%) diagnosed with uterine cancer.

Conclusion

Women aged 50 years or more with elevated CA125 levels in primary care frequently have non-ovarian rather than ovarian cancer. When managing symptomatic women with elevated CA125 levels clinicians should take this into account and consider performing appropriate investigations for these cancers in order to avoid diagnostic delay, particularly if ovarian cancer has been excluded.