Characterization of Baseline Temperature Characteristics Using Thermography in The Clinical Setting.

BACKGROUND: Thermography is a diagnostic method based on the ability to record infrared radiation emitted by the skin and is unique in its ability to accurately show physiological and/or pathological cutaneous temperature changes in a non-invasive way. This method can be used to indirectly assess changes or impairments in cutaneous perfusion. Significant technological advancements have allowed thermography to be more commonly utilized by clinicians, yet a basic consensus of patient characteristics that may affect temperature recordings is not established. MATERIALS AND METHODS: We evaluated cutaneous temperature in a cohort of outpatients to understand what factors, including tobacco use and other high-risk characteristics, contribute to cutaneous tissue perfusion as measured by thermography. Participants were prospectively enrolled if they were a combustible cigarette smoker, an electronic cigarette (e-cigarette) user, or a never smoker. Standardized thermographic images of the subject's facial profiles, forearms, and calves were taken and demographic characteristics, medical comorbidities, and tobacco product use were assessed. These variables were statistically tested for associations with temperature at each anatomic site. RESULTS: We found that gender had a significant effect on thermographic temperature that differed by anatomic site, and we found a lack of significant difference in thermographic temperature by race. Our regression analysis did not support significant differences in thermographic temperatures across smoking groups, while there was a trend for decreased perfusion in smokers relative to non-smokers and e-cigarette users relative to non-smokers. CONCLUSION: Thermographic imaging is a useful tool for clinical and research use with consideration of sex and other perfusion-affecting characteristics.

Detection of colorectal serrated polyps by stool DNA testing: comparison with fecal immunochemical testing for occult blood (FIT).

OBJECTIVES: Precursors to 1/3 of colorectal cancer (CRC), serrated polyps have been under-detected by screening due to their inconspicuous, non-hemorrhagic, and proximal nature. A new multi-target stool DNA test (multi-target sDNA) shows high sensitivity for both CRC and advanced adenomas. Screen detection of serrated polyps by this approach requires further validation. We sought to assess and compare noninvasive detection of sessile serrated polyps (SSP) ≥ 1 cm by sDNA and an occult blood fecal immunochemical test (FIT). METHODS: In a blinded prospective study, a single stool sample used for both tests was collected from 456 asymptomatic adults prior to screening or surveillance colonoscopy (criterion standard). All 29 patients with SSP ≥ 1 cm were included as cases and all 232 with no neoplastic findings as controls. Buffered stool samples were processed and frozen on receipt; Exact Sciences performed sDNA in batches using optimized analytical methods. The sDNA multi-marker panel targets methylated BMP3 (mBMP3) and NDRG4, mutant KRAS, ß-actin, and hemoglobin. FIT (Polymedco OC-FIT Check) was performed in separate lab ≤ 2 days post defecation and evaluated at cutoffs of 50 (FIT-50) and 100 ng/ml (FIT-100). RESULTS: MEDIAN AGES: cases 61 (range 57-77), controls 62 (52-70), p = NS. Women comprised 59% and 51%, p = NS, respectively. SSP median size was 1.2 cm (1-3 cm), 93% were proximal, and 64% had synchronous diminutive polyps. Among multi-target sDNA markers, mBMP3 proved highly discriminant for detection of SSP ≥ 1 cm (AUC = 0.87, p<0.00001); other DNA markers provided no incremental sensitivity. Hemoglobin alone showed no discrimination (AUC = 0.50, p = NS). At matched specificities, detection of SSP ≥ 1 cm by stool mBMP3 was significantly greater than by FIT-50 (66% vs 10%, p = 0.0003) or FIT-100 (63% vs 0%, p<0.0001). CONCLUSIONS: In a screening and surveillance setting, SSP ≥ 1 cm can be detected noninvasively by stool assay of exfoliated DNA markers, especially mBMP3. FIT appears to have no value in SSP detection.