Yoon Ah Park

Prognostic impact of p300 expression in patients with colorectal cancer

This study evaluated the expression of p300 in colorectal cancer, its relationship with clinicopathological characteristics, and its potential prognostic significance.

Risk Factors of Permanent Stomas in Patients with Rectal Cancer after Low Anterior Resection with Temporary Stomas

Purpose The aim of this study was to identify risk factors influencing permanent stomas after low anterior resection with temporary stomas for rectal cancer. Materials and Methods A total of 2528 consecutive rectal cancer patients who had undergone low anterior resection were retrospectively reviewed. Risk factors for permanent stomas were evaluated among these patients. Results Among 2528 cases of rectal cancer, a total of 231 patients had a temporary diverting stoma. Among these cases, 217 (93.9%) received a stoma reversal. The median period between primary surgery and stoma reversal was 7.5 months. The temporary and permanent stoma groups consisted of 203 and 28 patients, respectively. Multivariate analysis showed that independent risk factors for permanent stomas were anastomotic-related complications (p=0.001) and local recurrence (p=0.001). The 5-year overall survival for the temporary and permanent stoma groups were 87.0% and 70.5%, respectively (p<0.001). Conclusion Rectal cancer patients who have temporary stomas after low anterior resection with local recurrence and anastomotic-related complications may be at increased risk for permanent stoma.

Negative impact of pretreatment anemia on local control after neoadjuvant chemoradiotherapy and surgery for rectal cancer

Purpose Although anemia is considered to be a contributor to intra-tumoral hypoxia and tumor resistance to ionizing radiation in cancer patients, the impact of pretreatment anemia on local control after neoadjuvant concurrent chemoradiotherapy (NACRT) and surgery for rectal cancer remains unclear. Materials and Methods We reviewed the records of 247 patients with locally advanced rectal cancer who were treated with NACRT followed by curative-intent surgery. Results The patients with anemia before NACRT (36.0%, 89/247) achieved less pathologic complete response (pCR) than those without anemia (p = 0.012). The patients with pretreatment anemia had worse 3-year local control than those without pretreatment anemia (86.0% vs. 95.7%, p = 0.005). Multivariate analysis showed that pretreatment anemia (p = 0.035), pathologic tumor and nodal stage (p = 0.020 and 0.032, respectively) were independently significant factors for local control. Conclusion Pretreatment anemia had negative impacts on pCR and local control among patients who underwent NACRT and surgery for rectal cancer. Strategies maintaining hemoglobin level within normal range could potentially be used to improve local control in rectal cancer patients.

Diagnostic accuracy and prognostic impact of restaging by magnetic resonance imaging after preoperative chemoradiotherapy in patients with rectal cancer

BACKGROUND The prognostic role of restaging rectal magnetic resonance imaging (MRI) in patients with preoperative CRT has not been established. The goal of this study was to evaluate the diagnostic accuracy and prognostic role of radiological staging by rectal MRI after preoperative chemoradiation (CRT) in patients with rectal cancer. METHODS A total of 231 consecutive patients with rectal cancer who underwent preoperative CRT and radical resection from January 2008 to December 2009 were prospectively enrolled. The diagnostic accuracy and prognostic significance of post-CRT radiological staging by MRI was evaluated. RESULTS The sensitivity, specificity, positive predictive value, and negative predictive value of radiological diagnosis of good responders (ypTNM stage 0-I) were 32%, 90%, 65%, and 69%, respectively. The overall accuracy of MRI restating for good responders was 68%. The 5-year disease-free survival rates of patients with radiological and pathological TNM stage 0, stage I, and stage II-III were 100%, 94%, and 76%, respectively (P=0.037), and 97%, 87%, and 73%, respectively (P=0.007). On multivariate analysis, post-CRT radiological staging by MRI was an independent prognostic factor for disease-free survival. CONCLUSION Radiological staging by MRI after preoperative CRT may be an independent predictor of survival in patients with rectal cancer.

Mismatch repair system and p53 expression in patients with T1 and T2 colorectal cancer: predictive role of lymph node metastasis and survival.

The aim of this study was to evaluate the predictive role of the mismatch repair (MMR) system and p53 expression for lymph node metastasis and long‐term survival in patients with T1 and T2 colorectal cancer.

Contributing factors on lymph node yield after surgery for mid-low rectal cancer.

Purpose The purpose of the present study was to evaluate the contributing factors to the lymph node status as well as to define the impact of preoperative concurrent chemoradiotherapy (CCRT) on the number of lymph nodes retrieved in mid-low rectal cancer. Materials and Methods We retrospectively analyzed 277 patients who underwent curative surgical resection for mid-low rectal cancer between 1998 and 2007. Eighty-two patients received long course preoperative CCRT followed by surgery. Results A mean of 13.12±9.28 lymph nodes was retrieved. In a univariate analysis, distance from the anal verge, pT stage, pN stage, lymphovascular invasion, preoperative CCRT had significant influence on the number of lymph nodes retrieved. In a multivariate model, patients in the CCRT group had fewer retrieved lymph nodes than the non-CCRT group (p<0.001). Both univariate and multivariate analyses showed that the ypN0 group had fewer retrieved lymph nodes than the ypN1-2 group (p=0.027) in the CCRT group. Conclusion Preoperative CCRT was an independent risk factor for failure to harvest an appropriate number of lymph nodes, and node-negative patients who received CCRT had fewer lymph nodes harvested.

Prognostic factors in sporadic colon cancer with high-level microsatellite instability

BACKGROUND The microsatellite instability-high (MSI-H) phenotype of colon cancer has a good prognosis and limited response to chemotherapy. We aimed to investigate prognostic factors and oncologic outcomes in patients with MSI-H sporadic colon cancer. METHODS A total of 329 patients with MSI-H sporadic colon cancer who underwent radical surgery from January 2004 to December 2012 at a single institution were included. We analyzed prognostic factors and oncologic outcomes according to chemotherapy in these patients compared with patients with MSI-low/microsatellite stable colon cancer. RESULTS Among the 329 patients, 174 were male and 155 were female. The median age was 59 years. The population consisted of 220 patients with stage II, 97 with stage III, and 12 with stage IV disease. Old age and advanced stage were independent poor prognostic factors of overall survival (OS; P = .014 and P = .040, respectively) and advanced stage and presence of perineural invasion were independent poor prognostic factors of disease-free survival (DFS; P = .004 and P = .001, respectively). In addition, a greater number of poor prognostic factors were associated with worse survival (P < .001). Patients with stage II disease showed no differences in OS and DFS according to receiving or not receiving chemotherapy (P = .140 and P = .694, respectively). CONCLUSION Old age, advanced stage, and presence of perineural invasion were independent and poor prognostic factors in patients with MSI-H sporadic colon cancer. Survival rates of MSI-H colon cancer patients with stage II disease were not improved by adjuvant chemotherapy.

Immunohistochemical Detection of p53 Expression in Patients with Preoperative Chemoradiation for Rectal Cancer: Association with Prognosis

Purpose The expression of p53 in patients with rectal cancer who underwent preoperative chemoradiationand and its potential prognostic significance were evaluated. Materials and Methods p53 expression was examined using immunohistochemistry in pathologic specimens from 210 rectal cancer patients with preoperative chemoradiotherapy and radical surgery. All patients were classified into two groups according to the p53 expression: low p53 (<50% nuclear staining) and high p53 (≥50%) groups. Results p53 expression was significantly associated with tumor location from the anal verge (p=0.036). In univariate analysis, p53 expression was not associated with disease-free survival (p=0.118) or local recurrence-free survival (p=0.089). Multivariate analysis showed that tumor distance from the anal verge (p=0.006), ypN category (p=0.011), and perineural invasion (p=0.048) were independent predictors of disease-free survival; tumor distance from the anal verge was the only independent predictor of local recurrence-free survival. When the p53 groups were subdivided according to ypTNM category, disease-free survival differed significantly in patients with ypN+ disease (p=0.027) only. Conclusion Expression of p53 in pathologic specimens as measured by immunohistochemical methods may have a significant prognostic impact on survival in patients with ypN+ rectal cancer with preoperative chemoradiotherapy. However, it was not an independent predictor of recurrence or survival.

Laparoscopic modified mesocolic excision with central vascular ligation in right-sided colon cancer shows better short- and long-term outcomes compared with the open approach in propensity score analysis

BackgroundThe introduction of complete mesocolic excision (CME) with central vessel ligation (CVL) for right-sided colon cancer has improved oncologic outcomes. However, there is controversy over the oncologic safety of laparoscopic CME with CVL. This study compared short-term and long-term oncologic outcomes between laparoscopic and open modified CME (mCME) with CVL in patients with right-sided colon cancer.MethodsWe enrolled 1239 patients who underwent open mCME with CVL and 1010 patients treated by a laparoscopic approach for right-side colon cancer between 2000 and 2013 and used 1:1 propensity score matching to adjust for potential baseline confounders between two groups.ResultsAfter propensity score matching, 683 patients who underwent open mCME with CVL were compared with 683 patients treated with a laparoscopic approach. There were no significant differences between these groups in age, sex, ASA score, TNM stage, tumor size, lymphovascular invasion, and perineural invasion. Comparison of open and laparoscopic mCME groups showed no significant difference in postoperative morbidity (21.4 vs. 18.3%, p = 0.175) and mortality (0.1 vs. 0%, p = 1.000). The laparoscopic mCME group showed shorter length of hospital stay. The 5-year overall survival rate was 83.7% in the open group and 94.7% in the laparoscopic group (p < 0.001). The laparoscopic group also showed a significantly better 5-year disease-free survival rate (82.7 vs. 88.7%, p = 0.009) and 5-year disease-specific survival rate (83.7 vs. 94.7%, p < 0.001).ConclusionLaparoscopic modified mesocolic excision with central vascular ligation is a safe and feasible approach with better short-term recovery profiles and potential oncologic benefits than the open approach for right-sided colon cancer.

Transanal Endoscopic and Transabdominal Robotic Total Mesorectal Excision for Mid-to-Low Rectal Cancer: Comparison of Short-term Postoperative and Oncologic Outcomes by Using a Case-Matched Analysis

Purpose This study aimed to compare short-term postoperative and oncologic outcomes of a transanal endoscopic total mesorectal excision (TME) to those of a transabdominal robotic TME. Methods A total of 62 patients with rectal cancer underwent transanal (n = 26) or robotic (n = 36) TME between June 2013 and December 2014. After case-matching by tumor location and TNM stage, 45 patients were included for analysis. The median follow-up period was 21.3 months. Operative, histopathologic and postoperative outcomes and recurrences were analyzed. Results Patients younger than 60 years of age were more frequently observed in the robotic TME group (75.0% vs. 47.6%, P = 0.059), but tumor location, cT and cN category, and preoperative chemoradiotherapy were not different between the 2 groups. Estimated blood loss was greater in the transanal group (283 mL vs. 155 mL, P = 0.061); however, the operation time and the rate of a diverting ileostomy and subsequent ileostomy repair were not different between the groups. The proximal resection margin was longer in the transanal TME group (20.8 cm ± 16.0 cm, P = 0.030), but the distal resection margins, involvements of the circumferential resection margin, TME quality, numbers of retrieved lymph nodes, postoperative complications, including anastomotic leak and voiding difficulty, and recurrence rates for the 2 groups were not statistically different. Conclusion Transanal endoscopic and transabdominal robotic TME showed similar histopathologic and postoperative outcomes with the exception of the estimated blood loss and the proximal resection margin for a select group of patients.