David A. Ahlquist

Next-generation stool DNA testing: expanding the scope.

Stool DNA testing has emerged as a noninvasive approach to colorectal cancer screening. As with fecal occult blood testing, stool DNA testing offers userfriendly features of noninvasiveness, avoidance of unpleasant purgative bowel preparation, and the potential for markedly increased access via off-site sample collection and shipping. Added advantages of stool DNA testing include sampling of a single stool rather than multiple stools per screen, no diet or medication restriction, and possibly reduced screen frequency because of its capacity to detect precursor lesions. Various technical challenges that compromised first-generation stool DNA tests have been rigorously addressed with more recent laboratory methodologies. Advances in technology promise to strengthen assay performance of stool DNA testing and allow expanded and new clinical applications. Next generation stool DNA tests have the potential to improve the effectiveness of colorectal cancer screening, open the door to screening of gastrointestinal (GI) neoplasms above the colon, and spawn other novel uses.

Does performance status influence the outcome of Nd:YAG laser therapy of proximal esophageal tumors?

The value of endoscopic palliative therapy for malignant obstruction in the proximal esophagus has been questioned. To assess the importance of pre-treatment performance status on treatment outcome, we reviewed the records of patients with tumors of the proximal esophagus undergoing endoscopic laser therapy between January 1986 and December 1988. As compared with 10 patients having a good performance status, eight patients with a poor performance status had a lower frequency of obtaining complete functional relief of dysphagia (14% versus 71%), an increased rate of complications (50% versus 0%), and a shorter median survival time (24 days versus 161 days). We conclude that performance status should be considered in determining the appropriateness of laser therapy in patients with proximal esophageal cancer.

PD71-03 NOVEL DNA METHYLATION MARKERS FOR ACCURATE PROGNOSTIC ASSESSMENT OF PROSTATE CANCER: DISCOVERY AND EARLY VALIDATION

INTRODUCTION AND OBJECTIVES: The prostate health index (PHI) is superior to PSA and other PSA-derivatives for the detection of prostate cancer (PCa). We sought to explore the utility of PHI density for the detection of clinically-significant PCa in a contemporary cohort of men presenting for diagnostic workup of PCa. METHODS: The study cohort includedpatientswith elevatedPSA (>2 ng/mL) and negative digital rectal examination who underwent PHI testing and prostate biopsy at our institution in 2015. Serummarkers were prospectively measured per standard clinical pathway. PHI was calculated as [([-2]proPSA/free PSA) x (PSA)], and density calculations were performed using prostate volume as determined on transrectal ultrasound. Logistic regression was used to assess the ability of serum markers to predict clinically-significant PCa, defined as any Gleason score 7 cancer or Gleason score 6 cancer in >2 cores or >50% of any positive core. RESULTS: Of 118 men with PHI testing who underwent biopsy, 47 (39.8%) were found to have clinically-significant PCa on biopsy. The median PHI density was 0.70 (IQR 0.43-1.21); it was 0.53 (IQR 0.360.75) in men with negative biopsy or clinically-insignificant PCa and 1.21 (IQR 0.74-1.88) in men with clinically-significant PCa (p<0.001). Clinically-significant PCa was detected in 3.6% of men in the first quartile of PHI density (<0.43), 36.7% of men in the interquartile range (0.43-1.21) of PHI density, and 80.0% of men with PHI density >1.21 (p<0.001). Using a threshold of 0.43, PHI density was 97.9% sensitive and 38.0% specific for clinically-significant PCa, and 100% sensitive for Gleason score 7 disease. Compared to PSA (AUC 0.52), PSAD (AUC 0.70), % free PSA (AUC 0.75), and PHI (AUC 0.76), PHI density demonstrated the highest discriminative ability for clinically-significant PCa (AUC 0.84). CONCLUSIONS: Based on this prospective single-center experience, PHI density could be used to avoid 38% of unnecessary biopsies while failing to detect only 2% of clinically-significant cancers.