Laparoscopic natural orifice specimen extraction, a minimally invasive surgical technique for mid-rectal cancers: Retrospective single-center analysis and single-surgeon experience of selected patients.

OBJECTIVE: To evaluate the feasibility, safety, and short-term outcomes of middle rectal resection followed by transanal specimen extraction. METHODS: Forty-four patients with small mid-rectal tumors underwent laparoscopic rectal resection followed by transanal specimen extraction. RESULTS: The procedure was successful in all patients without intraoperative conversion or additional access. The mean operation time was 182.7 minutes (range, 130-255 minutes), the mean blood loss was 26.5 mL (range, 5-120 mL), the mean postoperative exhaust time was 31.3 hours (range, 16-60 hours), and the mean length of hospital stay was 9.5 days (range, 8-19 days). One patient developed anastomotic leakage, which was treated by intravenous antibiotics and daily pelvic cavity flushes through the abdominal drainage tube. No infection-related complications or anal incontinence were observed. The mean tumor size was 2.1 cm (range, 1.6-3.2 cm), the mean number of harvested lymph nodes was 16.5 (range, 6-31), and the mean follow-up time was 8.5 months (range, 2-16 months). By the last follow-up, no signs of recurrence had been found in any patient. CONCLUSION: The combination of standard laparoscopic proctectomy and transanal specimen extraction could become a well-established strategy for selected patients.

miRNA-30d serves a critical function in colorectal cancer initiation, progression and invasion via directly targeting the GNA13 gene.

MicroRNAs (miRNAs or miRs) are reported to be dysregulated in the progression and invasion of various human cancer types, including colorectal cancer (CRC). They are also reported to be molecular biomarkers and therapeutic targets in CRC. miRNAs serve functions in a plethora of biological processes, including proliferation, migration, invasion and apoptosis, and several miRNAs have been demonstrated to be involved in CRC carcinogenesis, invasion and metastasis. Aberrant miR-30d expression and its effects have been reported in certain cancer types. However, the function and underlying mechanism of miR-30d in the progression of CRC remains largely unknown. In the current study, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to quantify miR-30d expression in CRC tissues. In vivo and in vitro functional assays indicated that miR-30d inhibits CRC cell proliferation. Target prediction online software packages, miRBase, TargetScan and miRANDA, and luciferase reporter assays were used to confirm the target gene GNA13. Specimens from 45 patients with CRC were analyzed for correlation between the expression of miR-30d and the expression of target gene GNA13, evaluated by RT-qPCR. miR-30d was downregulated in CRC tissues and cell lines. Ectopic expression of miR-30d inhibited cell proliferation and invasion and tumor growth ability. By contrast, inhibition of endogenous miR-30d promoted cell proliferation and tumor growth ability of CRC cells. It was indicated that miR-30d directly targets the 3'-untranslated region of the GNA13 gene. Downregulation of miR-30d led to the activation of cell proliferation in CRC. In addition, miR-30d expression was negatively correlated with the expression of GNA13 in CRC tissues. In conclusion, miR-30d inhibits cancer initiation, proliferation and invasion in colorectal cancer via targeting GNA13.

MicroRNAs in colorectal cancer: role in metastasis and clinical perspectives.

Colorectal cancer (CRC) is the third most common malignancy and the third leading cause of cancer related deaths in the United States. Almost 90% of the patients diagnosed with CRC die due to metastases. MicroRNAs (miRNAs) are evolutionarily conserved molecules that modulate the expression of their target genes post-transcriptionally, and they may participate in various physiological and pathological processes including CRC metastasis by influencing various factors in the human body. Recently, the role miRNAs play throughout the CRC metastatic cascade has gain attention. Many studies have been published to link them with CRC metastasis. In this review, we will briefly discuss metastatic steps in the light of miRNAs, along with their target genes. We will discuss how the aberration in the expression of miRNAs leads to the formation of CRC by effecting the regulation of their target genes. As miRNAs are being exploited for diagnosis, prognosis, and monitoring of cancer and other diseases, their high tissue specificity and critical role in oncogenesis make them new biomarkers for the diagnosis and classification of cancer as well as for predicting patients' outcome. MiRNA signatures have been identified for many human tumors including CRC, and miRNA-based therapies to treat cancer have been emphasized lately. These will also be discussed in this review.