Increase of serum CA19-9 level without an evident lesion on conventional imaging is insufficient for justification of 18FDG-PET examination.
OBJECTIVE
The serum tumor marker carbohydrate associated antigen 19-9 (CA19-9) has been used for screening for cancer, because its increase has been associated with many cancers. We aimed to evaluate the clinical value of positron emission tomography using F-18 fluorodeoxyglucose (18FDG-PET) that was prompted by increases of serum CA19-9 without findings on conventional imaging.


METHODS
Twenty-two patients were retrospectively selected. Eleven were without a history of cancer and eleven had a history of cancer and were treated with curative intent. All 18FDG-PET findings were compared with the findings of histopathology by surgery or biopsy, or clinical follow-up for at least 1 year.


RESULTS
We found only two true positive cases, and eleven cases without a cancer history included 10 true negatives and one false positive.


CONCLUSIONS
Increases in serum CA19-9 are caused by many benign conditions. Increases of CA19-9 without findings on conventional imaging do not justify 18FDG-PET examination, particularly in patients without a cancer history.
Department of Nuclear Medicine and Radiology, Institute of Development, Aging and Cancer, Tohoku University, Aoba-ku, Sendai 980-8575, Japan. kenta@idac.tohoku.ac.jp
Kentaro
K
Inoue
Ken
K
Okada
Yasuyuki
Y
Taki
Ryoi
R
Goto
Shigeo
S
Kinomura
Tomohiro
T
Kaneta
Hiroshi
H
Fukuda
D000328:Adult; D000368:Aged; D018395:CA-19-9 Antigen / Q000097:blood*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D012189:Retrospective Studies
D018395:CA-19-9 Antigen; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18