Voss, Jesse S.

BACKGROUNDPatients diagnosed with primary sclerosing cholangitis (PSC) and dominant strictures often undergo endoscopic retrograde cholangiopancreatography with brush cytology to exclude or confirm the development of malignancy. Equivocal (atypical or suspicious) routine cytologic results may confound patient management decisions, especially in the absence of a mass on imaging. The objective of the current study was to identify independent predictors of malignancy in patients with PSC with an equivocal cytology diagnosis.METHODSPatients with PSC underwent brush cytology for routine cytology and fluorescence in situ hybridization (FISH) during endoscopy as per standard care. FISH slides were classified as polysomy if at least 5 cells displayed a gain of ≥ 2 probes. A retrospective search identified 102 patients without a mass lesion noted on initial imaging studies, an equivocal routine cytology, and ≥ 2 years of follow‐up.RESULTSOf 102 patients, 30 (29%) with an equivocal cytology result developed cancer within 2 years. Serum carbohydrate antigen 19‐9 (CA 19‐9) levels ≥ 129 U/mL (hazard ratio [HR] 3.19; P = .001) and polysomy (HR 8.70; P < .001) were each found to be predictive of cancer. Of 10 patients who had elevated CA 19‐9 levels and polysomy, all went on to develop cancer (9 within 2 years). Although only 10 patients were included in this subset, the combination of elevated CA 19‐9 and polysomy was found to be predictive of cancer (HR 10.92; P < .001).CONCLUSIONSPolysomy by FISH identified those patients most likely to have or develop malignancy in the challenging clinical scenario of PSC with no mass at baseline and equivocal cytology. The combination of an elevated serum CA 19‐9 level with polysomy is highly suspicious for the presence of malignancy. Cancer (Cancer Cytopathol) 2013;121:708–717. © 2013 American Cancer Society.

Abstract Rationale Bronchoscopically collected cytology specimens are commonly used to obtain a diagnosis of cancer in patients with pulmonary lesions. However, the sensitivity of cytology is suboptimal, especially for peripheral lesions less than 2 cm in diameter. Objectives We assessed the performance of a testing algorithm using cytology and fluorescence in situ hybridization (FISH) as part of clinical practice. Methods Bronchial brushing specimens (n = 343) were obtained from patients undergoing bronchoscopy for indeterminate pulmonary lesions. Routine cytology was performed and specimens without a positive diagnosis (n = 294) were analyzed by FISH, using residual brushing material. Pathology-confirmed lung cancer or clinical/radiographic evidence of disease was considered diagnostic of malignancy. Measurements and Main Results Routine cytology had a sensitivity and specificity of 41% (23 of 56) and 100% (45 of 45) for central lesions and 20% (26 of 133) and 100% (109 of 109) for peripheral nodules, respectively. FISH detected an additional 32% of lung cancers (18 central and 43 peripheral) not detectable by cytology alone, while producing false positive diagnoses in 22% (10 of 45) and 6% (6 of 109) benign central and peripheral lesions, respectively. In peripheral nodules, FISH detected (relative to routine cytology) an additional 44% (15 of 34) and 28% (25 of 91) of lung cancers less than 2 cm and 2 cm or more in size, respectively. A positive FISH result had a likelihood ratio of 1.45 and 5.87 for central and peripheral lesions and 3.44 and 15.38 for peripheral nodules less than 2 cm and 2 cm or more in size, respectively. Conclusions FISH testing significantly increases the detection of lung cancer over routine cytology alone. It is especially useful for peripheral nodules.