RESUMEN
INTRODUCTION: There are limited findings available on KIT-negative GIST-like (KNGL) population. Also, KIT expression may be post-transcriptionally regulated by miRNA221 and miRNA222. Hence, the aim of this study is to characterize KNGL population, by differential gene expression, and to analyze miRNA221/222 expression and their prognostic value in KNGL patients. METHODS: KIT, PDGFRA, DOG1, IGF1R, MIR221 and MIR222 expression levels were determined by qRT-PCR. We also analyzed KIT and PDGFRA mutations, DOG1 expression, by immunohistochemistry, along with clinical and pathological data. Disease-free survival (DFS) and overall survival (OS) differences were calculated using Log-rank test. RESULTS: Hierarchical cluster analyses from gene expression data identified two groups: group I had KIT, DOG1 and PDGFRA overexpression and IGF1R underexpression and group II had overexpression of IGF1R and low expression of KIT, DOG1 and PDGFRA. Group II had a significant worse OS (p = 0.013) in all the series, and showed a tendency for worse OS (p = 0.11), when analyzed only the localized cases. MiRNA222 expression was significantly lower in a control subset of KIT-positive GIST (p < 0.001). OS was significantly worse in KNGL cases with higher expression of MIR221 (p = 0.028) or MIR222 (p = 0.014). CONCLUSIONS: We identified two distinct KNGL subsets, with a different prognostic value. Increased levels of miRNA221/222, which are associated with worse OS, could explain the absence of KIT protein expression of most KNGL tumors.
RESUMEN
INTRODUCTION: Neoadjuvant chemo-radiotherapy is the treatment of choice for rectal cancer in order to reduce local recurrence. Patients with a pathological complete response (PCR) have a better prognosis. The aim of this study was to determine the influence of PCR on the oncological outcomes in our patients. METHODS: All patients with stage ii/iii rectal cancer treated with neoadjuvant chemo-radiotherapy and radical resection between 2007 and 2011 were identified from a prospective database, and grouped based on whether they achieved PCR or not (non-PCR). Clinical, histological and oncological outcome data were compared. RESULTS: A total of 162 patients were included (62% men), with a mean age of 65 years. In terms of pre-operative TNM staging, 82 patients (50%) were T2, 75 (46%) were T3, and 5 (3%) were T4. Forty-two patients (25%) were N1, and 87 (53%) were N2. Low anterior resection and abdominoperineal resection were performed in 125 (77%) and 25 (15%) patients. Forty-three patients (26.5%) had postoperative morbidity. PCR was achieved in 19 patients (11.7%). After a median follow-up of 26 months, there are no recurrences in the PCR group, and in the non-PCR group, local recurrence was 1.4% (P=.78), and distant metastasis was 8.4% (P=.21). Overall survival (P=.39) and survival free of diseases (P=.23) were better in the PCR group, but the differences were not significant. CONCLUSION: Patients with pathological complete response have better oncological outcome.
