Jung-A Yun

The role of palliative resection for asymptomatic primary tumor in patients with unresectable stage IV colorectal cancer.

BACKGROUND: The prognostic role of surgical resection of primary tumors is not well established in patients with asymptomatic unresectable stage IV colorectal cancer. OBJECTIVE: The aims of this study were to reveal the prognostic role of surgical resection of primary tumors and to define prognostic factors affecting long-term oncological outcomes in patients with asymptomatic unresectable synchronous metastases. DESIGN: This study was a retrospective analysis of prospectively collected data. PATIENTS: Between 2000 and 2008, a total of 416 patients with asymptomatic unresectable stage IV colorectal cancer were analyzed with propensity score matching. MAIN OUTCOME MEASURES: Prematching baseline characteristics were compared by bivariate analysis, and 113 pairs were selected after 1:1 matching with propensity scores estimated from logistic regression. The primary end point was overall survival. RESULTS: Among 416 patients, 218 (52.4%) underwent palliative resection of the primary tumor. Before propensity score matching, palliative resection resulted in a better survival rate than nonresection in univariate analysis (p < 0.001), but not in multivariate analysis (p = 0.08). After matching, the 5-year overall survival rate was significantly lower for patients with peritoneal metastasis and clinical M1b stage tumors in univariate analysis (p = 0.004 and p = 0.02). However, neither peritoneal metastasis nor clinical M1b stage showed any prognostic significance in multivariate analysis. The overall 5-year survival rate of the postmatching group was 4.9% and 3.5% in the palliative resection and nonresection groups. Consequently, palliative resection was not associated with a significant increase in survival compared with nonresection (p = 0.27). A subgroup analysis performed according to the site of metastasis also did not show any significant survival benefit of palliative resection after matching. LIMITATIONS: Selection bias and potential confounders were limitations of this study. CONCLUSIONS: Resection of the primary tumor in patients with asymptomatic unresectable stage IV colorectal cancer was not associated with an improvement in overall survival after propensity score matching.

Oncologic Outcomes of Single-incision Laparoscopic Surgery Compared With Conventional Laparoscopy for Colon Cancer.

Objective:The aim of this study is to document perioperative results and mid-term oncologic outcomes of single-incision laparoscopic (SIL) colectomy compared to conventional laparoscopic (CL) colectomy. Background:SIL surgery is an advance in minimally invasive operative techniques and is widely accepted for various types of surgery. Methods:We prospectively collected data from 767 patients who underwent radical colectomy (250 SIL colectomy and 517 CL colectomy) between 2010 and 2011 due to primary colon cancer and retrospectively analyzed these patients with propensity score matching. Results:Before matching, patients with CL surgery had a significantly higher percentage of comorbidities (49.2% vs 57.8%, P = 0.024). Tumor location significantly differed between 2 groups: SIL surgery was performed more frequently in patients with right colon cancer. After propensity score matching, each group included 239 patients, and there was no difference between the SIL and CL surgery groups. Estimated blood loss was more in the patients with SIL colectomy, but the rate itself of intraoperative complications was not statistically different (P = 0.662). The median follow-up period was 37 months. There were 20 recurrences in the SIL surgery group (8.4%), including 3 locoregional recurrences and 18 (7.5%) in the CL surgery group. Disease-free survival at 48 months did not differ significantly between the SIL and CL surgery groups (89.8% vs 89.9%, P = 0.548). Conclusions:SIL colectomy for colon cancer shows probably higher, but an acceptable complication rate and can provide resection and oncologic outcomes equal to those of CL colectomy.

Loss of E-Cadherin Expression Is Associated with a Poor Prognosis in Stage III Colorectal Cancer

Purpose: The epithelial-mesenchymal transition (EMT) is known to be associated with tumor progression, invasion and metastasis in colorectal cancer (CRC). Materials and Methods: Tissue samples obtained from 409 patients with stage III CRC treated from 2006 to 2007 were examined by immunohistochemistry to reveal the expression levels of E-cadherin, fibronectin, vimentin and α-smooth muscle actin (SMA). Results: Among the 409 patients, 402 cases (98.3%) showed positive E-cadherin expression. Positive E-cadherin expression was associated with well or moderately differentiated cell types and a stable microsatellite status. In multivariate analysis, a preoperative carcinoembryonic antigen level >5 ng/ml (p = 0.021), advanced N stage (p = 0.017), positive vascular invasion (p = 0.048), positive perineural invasion (p = 0.002) and negative E-cadherin expression (p = 0.002, relative risk = 5.098, 95% CI = 1.801-14.430) were poor prognostic factors affecting disease-free survival. The declining E-cadherin expression was associated with a poor outcome in terms of overall survival in univariate (p = 0.016) but not in multivariate analyses (p = 0.303, relative risk = 1.984, 95% CI = 0.539-7.296). Fibronectin, vimentin and α-SMA were of no prognostic value in this study. Conclusion: The expression pattern of EMT markers in stage III CRC suggests that declining E-cadherin expression is a possible immunohistochemical predictor of patient prognosis.

Local recurrence after curative resection for rectal carcinoma: The role of surgical resection.

AbstractLocal recurrence of rectal cancer is difficult to treat, may cause severe and disabling symptoms, and usually has a fatal outcome. The aim of this study was to document the clinical nature of locally recurrent rectal cancer and to determine the effect of surgical resection on long-term survival.A retrospective review was conducted of the prospectively collected medical records of 2485 patients with primary rectal adenocarcinoma who underwent radical resection between September 1994 and December 2008.In total, 147 (5.9%) patients exhibited local recurrence. The most common type of local recurrence was lateral recurrence, whereas anastomotic recurrence was the most common type in patients without preoperative concurrent chemoradiotherapy (CCRT). Tumor location with respect to the anal verge significantly affected the local recurrence rate (P < 0.001), whereas preoperative CCRT did not affect the local recurrence rate (P = 0.433). Predictive factors for surgical resection of recurrent rectal cancer included less advanced tumor stage (P = 0.017, RR = 3.840, 95% CI = 1.271–11.597), axial recurrence (P < 0.001, RR = 5.772, 95% CI = 2.281–14.609), and isolated local recurrence (P = 0.006, RR = 8.679, 95% CI = 1.846–40.815). Overall survival after diagnosis of local recurrence was negatively influenced by advanced pathologic tumor stage (P = 0.040, RR = 1.867, 95% CI = 1.028–3.389), positive CRM (P = 0.001, RR = 12.939, 95% CI = 2.906–57.604), combined distant metastases (P = 0.001, RR = 2.086, 95% CI = 1.352–3.218), and nonsurgical resection of recurrent tumor (P < 0.001, RR = 4.865, 95% CI = 2.586–9.153).In conclusion, the clinical outcomes of local recurrence after curative resection of rectal cancer are diverse. Surgical resection of locally recurrent rectal cancer should be considered as an initial treatment, especially in patients with less advanced tumors and axial recurrence.

Prognostic significance of perineural invasion in stage IIA colon cancer

Perineural invasion (PNI) may influence the prognosis of colon cancer, but little is known about its predictive value. The aim of this study was to reveal the role of PNI in predicting prognosis after curative resection of colon cancer, especially T3N0.

Low-Level Microsatellite Instability as a Potential Prognostic Factor in Sporadic Colorectal Cancer.

AbstractAlthough microsatellite instability-high (MSI-H) colorectal cancers (CRCs) have been shown to exhibit a distinct phenotype, the clinical value of MSI-low (MSI-L) in CRC remains unclear. We designed this study to examine the clinicopathologic characteristics and oncologic implications associated with MSI-L CRCs.We retrospectively reviewed data of CRC patients from 3 tertiary referral hospitals in Korea, who underwent surgical resection between January 2003 and December 2009 and had available MSI testing results. MSI testing was performed using the pentaplex Bethesda panel. Clinicopathologic features and oncologic outcomes were compared between MSI-L and microsatellite stable (MSS) CRCs; prognostic factors for survival were also examined.Of the 3019 patients reviewed, 2621 (86.8%) were MSS, and 200 (6.6%) were MSI-L; the remaining 198 (6.6%) were MSI-H. MSI-L and MSS CRCs were comparable in terms of their clinicopathologic features, with the exception of proximal tumor location (MSI-L 30.0% vs MSS 22.1%, P = 0.024) and tumor size (MSI-L 5.2 ± 2.6 cm vs MSS 4.6 ± 2.1 cm, P = 0.001). No differences were detected in either 3-year disease-free survival (MSI-L 87.2% vs MSS 82.6%, P = 0.121) or 5-year overall survival (OS) (MSI-L 74.2% vs MSS 78.3%, P = 0.131) by univariable analysis. However, MSI-L was an independent prognostic factor for poor OS by Cox regression analysis (hazard ratio 1.358, 95% confidence interval 1.014–1.819, P = 0.040).MSI-L may be an independent prognostic factor for OS in sporadic CRCs despite their clinicopathologic similarity to MSS. Further studies investigating the significance of MSI-L in the genesis and prognosis of CRCs are needed.

Risk factors for the requirement of surgical or endoscopic interventions during chemotherapy in patients with uncomplicated colorectal cancer and unresectable synchronous metastases

The purpose of this study was to determine the risk factors for requirement of surgical or endoscopic interventions for complications caused by the primary tumor during chemotherapy in patients with unresectable metastatic colorectal cancer.

Oncologic outcome after cessation or dose reduction of capecitabine in patients with colon cancer.

Purpose Oral capecitabine has been used as adjuvant therapy for colorectal cancer patients since the 1990s. Patient-initiated cessation or reduced use of capecitabine occurs widely for various reasons, yet the consequences of these actions are unclear. The present study sought to clarify treatment outcomes in such patients. Methods The study included 173 patients who had been diagnosed with stage II or III colon cancer according to the pathologic report after radical surgery at Samsung Medical Center from May 2005 to June 2007 and who had received capecitabine as adjuvant therapy. The patients were divided into groups according to whether the dose was reduced (I, dose maintenance; II, dose reduction) or stopped (A, cycle completion; B, cycle cessation). Recurrence and disease-free survival rates between the two groups each were analyzed. Results Of the 173 patients, 128 (74.6%) experienced complications, most frequently hand-foot syndrome (n = 114). Reduction (n = 35) or cessation (n = 18) of medication was most commonly due to complications. Concerning reduced dosage, both groups displayed no statistically significant differences in recurrence rate and 3-year disease-free survival rate. Concerning discontinued medication use, the cycle completion group showed an improved recurrence rate (P = 0.048) and 3-year disease-free survival rate (P = 0.028). Conclusion The results demonstrate that maintaining compliance with capecitabine as an adjuvant treatment for colon cancer to preventing complications positively affects patient prognosis.

Clinical manifestations and risk factors of anastomotic leakage after low anterior resection for rectal cancer

Anastomotic leakage is a common complication that can be associated with catastrophic consequences. However, the risk factors and incidence of anastomotic leakage vary considerably among clinical studies because of the lack of a standardized definition, clinical course and appropriate treatment options. The aim of this study was to identify and classify the clinical manifestations and treatment of anastomotic leakage and analyse the possible risk factors after low anterior resection.