Cancer antigen 125 (CA125) and the law of unintended consequences
Abstract only e18327 Background: CA125 is a serum tumour marker used to monitor patients with ovarian cancer (OvCa). Its usefulness as a screening tool remains unproven. There is no restriction in its use at our institution, a university teaching hospital. We sought to establish patterns of testing...
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| Published in: | Journal of clinical oncology Vol. 35; no. 15_suppl; p. e18327 |
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| Main Authors: | , , , , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
20-05-2017
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| Online Access: | Get full text |
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| Summary: | Abstract only e18327 Background: CA125 is a serum tumour marker used to monitor patients with ovarian cancer (OvCa). Its usefulness as a screening tool remains unproven. There is no restriction in its use at our institution, a university teaching hospital. We sought to establish patterns of testing during one calendar year (2013), focussing on the economic costs of such unrestricted testing. Methods: A lookback of the CA125 reports issued by the Biochemistry Laboratory was undertaken. The CA125 requests were from physicians within the hospital & from the community. Individual requests for CA125 & those part of tumour marker panel were included & correlated with radiology & histopathology records to identify subsequent investigations (invxs) & diagnoses (dxs). Economic costings were provided by hospital finance department. For the purpose of this study we only included the costs of invxs triggered by out of range CA 125 test results. Results: In 2013, 7,132 CA125 measurements were performed. 871 repeat tests, 40 tests performed on men & 16 tests with inadequate patient identifiers were excluded. Of the remaining 6,205 patient tests; median age was 53yrs (range 13 – 96yrs); median CA125 was 5.5 IU/L (range 0.1 – 22452 IU/L). Out of range tests (>35 IU/L) led to 619 ultrasound scans, 339 CT scans. In total, 20 new cases of OvCa were dx. The crude cost per new dx was €11,459.80. Median time to diagnosis was 4 days (range -2 – 251), median CA125 at dx was 271 (range 8.1 - 9444). Median age at dx was 62 (range 40 – 87). 65% of dx were made during inpatient stays;10% by family physicians;25% by gynaecologists. There was a statistically significant difference in median CA125 in patients diagnosed with OvCa, compared to those who were not dx with a malignant condition (p<0.0001); this was not true of age at dx (p=0.27). Conclusions: This study underlines the lack of efficacy in unrestricted serum CA125 testing & that such testing creates a significant economic burden on hospitals, far in excess of the cost of the CA125 test alone. We plan to implement guidelines in our institution & will reassess this issue following an education programme with local clinicians. [Table: see text] |
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| ISSN: | 0732-183X 1527-7755 |
| DOI: | 10.1200/JCO.2017.35.15_suppl.e18327 |