Clinical Predictors for KRAS Codon 13 Mutations in Patients With Colorectal Cancer.

GOALS: This study sought to clarify sex differences in KRAS mutations and clinical predictors of KRAS 13 codon mutations. BACKGROUND: Sex differences in KRAS mutations and predictors for KRAS codon 13 mutations in colorectal cancer (CRC) are unclear. STUDY: Between October 2007 and May 2016, 328 patients underwent surgery for CRCs that were analyzed for KRAS mutations at a referral university hospital. Sex differences in the rates and distributions of KRAS mutations, and factors predictive of overall KRAS and KRAS codon 13 mutations were analyzed. RESULTS: KRAS mutations were significantly more common in women than men patients (46.0% vs. 34.4%, P<0.033). However, no sex differences were detected for KRAS mutations by codon subtypes (P=0.592). The Gly13Asp (GGC>GAC) point mutation was identified only within codon 13 in both sexes. For right-sided CRC, KRAS mutations were twice as frequent in men as in women (univariate analysis; P=0.016, multivariate analysis; P=0.019). High-plasma cholesterol level was an independent predictive factor of KRAS codon 13 mutations by univariate (odds ratio, 1.013; 95% confidence interval, 1.003-1.023) and multivariate analysis (odds ratio, 1.011; 95% confidence interval, 1.001-1.021). CONCLUSIONS: Sex differences may affect the presentation of KRAS mutations, as they were more frequently detected in women and in right-sided CRC in men. KRAS codon 13 mutations were significantly associated with high-plasma cholesterol. Further studies are needed on the clinical implications of this finding.

Endoscopic flushing with pronase improves the quantity and quality of gastric biopsy: a prospective study.

BACKGROUND AND STUDY AIMS: Pronase, a proteolytic enzyme, is known to improve mucosal visibility during esophagogastroduodenoscopy (EGD), but little is known about its effects on gastric biopsy. This study assessed whether endoscopic flushing with pronase improves the quality of gastric biopsy. PATIENTS AND METHODS: Consecutive patients who underwent EGD were randomly assigned to either the control group or the pronase group in a prospective setting. The first biopsy of the identified lesion was performed during endoscopy. Endoscopic flushing with either 50 mL of water and dimethylpolysiloxane (DMPS; control group) or 50 mL of water, pronase, sodium bicarbonate, and DMPS (pronase group) was then applied to the lesion. After 5 minutes, the second biopsy was performed 2 - 3 mm away from the first biopsy site. The thickness of mucus, depth of the specimen, overall diagnostic adequacy, anatomical orientation, and crush artifact were measured to assess the quality of the biopsy. RESULTS: Of the 208 patients, 10 were not analyzed due to the absence of an identifiable lesion. Compared with the control group, the pronase group showed significantly decreased thickness of mucus (P < 0.001), increased depth of biopsy (P < 0.001), improved anatomical orientation (P = 0.010), and improved overall diagnostic assessment (P = 0.011) in the second biopsied specimen following endoscopic flushing. The crush artifact and hemorrhage did not differ between the groups. CONCLUSIONS: Endoscopic flushing with pronase not only improved the depth of biopsy but also the anatomical orientation and overall diagnostic adequacy. Pronase can be recommended for flushing during EGD to improve the quantity and quality of biopsy.