Ki-ras mutations and the carcinoembryonic antigen level in fine needle aspirates of the pancreas.
OBJECTIVE
To evaluate the sensitivity and specificity of the carcinoembryonic antigen (CEA) immunoassay and Ki-ras genotyping as adjuncts to the cytologic diagnosis of pancreatic fine needle aspirates (FNAs).


METHODS
A retrospective study of 30 patients with pancreatic masses evaluated with CEA immunoassay and gel or hybridization analysis of allele-specific polymerase chain reaction for mutant Ki-ras (codons 12 and 13). DNA was isolated from fixed, paraffin-embedded samples. Diagnoses were correlated with cytologic evaluations and patient outcome.


RESULTS
Diagnoses included 17 pancreatic carcinomas, 3 other malignancies and 10 benign lesions. Sixty-five percent of all FNAs had mutated Ki-ras, and 42% of samples with altered Ki-ras had multiple mutations. Replicate FNA samplings in five of six patients had concordant genotypes. Sensitivities for diagnosis were as follows: cytology alone, 76%; CEA alone, 82%; Ki-ras alone, 82%; cytology plus CEA, 100%; cytology plus Ki-ras, 94%. Although specificities for Ki-ras (30%) and CEA (50%) individually were low, elevated CEA level and mutated Ki-ras in a sample with negative cytology strongly indicated false negative cytology.


CONCLUSIONS
The addition of either or both the CEA assay and Ki-ras mutation analysis enhances the sensitivity of the cytologic diagnosis of pancreatic carcinoma by FNA.
Pinto
M M
MM
Department of Pathology, Bridgeport Hospital, Connecticut 06610, USA.
Emanuel
J R
JR
Chaturvedi
V
V
Costa
J
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D002272:Carcinoembryonic Antigen / Q000032:analysis*; D003536:Cystadenocarcinoma / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D005260:Female; D011905:Genes, ras / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D017354:Point Mutation; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
D002272:Carcinoembryonic Antigen