Factors associated with reclassification of hyperplastic polyps after pathological reassessment from screening and surveillance colonoscopies.

INTRODUCTION: A substantial interobserver variation in the differential diagnosis of hyperplastic polyps (HPs) and sessile or traditional serrated adenomas (SSAs/TSAs) has been described. METHODS: The aim of this study is to determine the magnitude of reclassification of HPs and associated factors after pathological reassessment of specimens from screening and surveillance colonoscopies, and to estimate its consequences for follow-up recommendations. RESULTS: Among 1694 screening and surveillance colonoscopies, a total of 536 polyps were initially diagnosed as HPs and remained unchanged in 88.5% (n = 474), whereas 7.6 (n = 41) and 1.1% (n = 6) were reclassified as SSA and TSA, respectively. Compared to definite HPs, SSAs were found more frequently in men than in women (82.9 vs. 61.2%, p < 0.05), and in individuals ≥65.0 years (51.2 vs. 31.6%, p = 0.05). Also, more SSAs were >5 mm in size (36.6 vs. 6.3%, p < 0.05) and were localized in the proximal colon (31.7 vs. 11.8%, p < 0.05). In a mixed model analysis, age ≥65.0 years (OR 4.13, 95% CI 1.22-14.2), snare polypectomy (OR 23.6, 95% CI 4.86-115), and coincident advanced adenomas (OR 7.56, 95% CI 1.31-43.5) were significantly (p < 0.05) associated with reclassification to SSAs. Only 0.53% of patients had received false recommendations for follow-up visits based on the incorrect HP diagnosis. A c.1799T>A, p.V600E BRAF mutation was detected in 21.9 % (n = 9) of reclassified SSAs. CONCLUSION: Considering these factors may be helpful in serrated lesions that are difficult to allocate. Incorrect recommendations regarding control colonoscopy intervals due to misdiagnosed HPs can explain only a small fraction of interval colorectal cancers.

SRC inhibition represents a potential therapeutic strategy in liposarcoma.

Liposarcomas (LS) are the most common malignant mesenchymal tumors, with an overall long-term mortality rate of 60%. LS comprise three major subtypes, i.e., well-differentiated/dedifferentiated liposarcoma (WDLS/DDLS), myxoid/round cell liposarcoma (MLS) and pleomorphic liposarcoma (PLS). Aiming at the preclinical identification of novel therapeutic options, we here investigate the functional significance of SRC in primary human LS and in LS-derived cell lines. Immunohistochemical and Western blot analyses reveal relevant levels of activated p-(Tyr416)-SRC in LS of the different subtypes with particular activation in MLS and PLS. Dysregulation of the SRC modifiers CSK and PTP1B was excluded as major reason for the activation of the kinase. Consistent siRNA-mediated knockdown of SRC or inhibition by the SRC inhibitor Dasatinib led to decreased proliferation of LS cell lines of the different subtypes, with MLS cells reacting particularly sensitive in MTT assays. Flow cytometric analyses revealed that this effect was due to a significant decrease in mitotic activity and an induction of apoptosis. SRC inhibition by Dasatinib resulted in dephosphorylation of SRC itself, its interacting partners FAK and IGF-IR as well as its downstream target AKT. Consistent with a particular role of SRC in cell motility, Dasatinib reduced the migratory and invasive potential of MLS cells in Boyden chamber and Matrigel chamber assays. In summary, we provide evidence that SRC activation plays an important role in LS biology and therefore represents a potential therapeutic target, particularly in MLS and PLS.