Seung Kook Sohn

Comparative study of transrectal ultrasonography, pelvic computerized tomography, and magnetic resonance imaging in preoperative staging of rectal cancer.

PURPOSE: The preoperative assessment of rectal cancer wall invasion and regional lymph node metastasis is essential for the planning of optimal therapy. This study was done to determine the accuracy and clinical usefulness of transrectal ultrasonography, pelvic computed tomography, and magnetic resonance imaging in preoperative staging. METHODS: A total of 89 patients with rectal cancer were examined with transrectal ultrasonography (n=89), pelvic computed tomography (n=69), and magnetic resonance imaging with endorectal coil (n=73). The results obtained by these diagnostic modalities were compared with the histopathologic staging of specimens. RESULTS: In staging depth of invasion, the overall accuracy was 81.1 percent (72/89) by transrectal ultrasonography, 65.2 percent (45/69) by computed tomography, and 81 percent (59/73) by magnetic resonance imaging. Overstaging was 10 percent (9/89) by transrectal ultrasonography, 17.4 percent (12/69) by computed tomography, and 11 percent (8/73) by magnetic resonance imaging; and understaging was 8 of 89 (8.9 percent) by transrectal ultrasonography, 12 of 69 (17.4 percent) by computed tomography, and 6 of 73 (8 percent) by magnetic resonance imaging. In staging lymph node metastasis, the overall accuracy rate was 54 of 85 (63.5 percent) in transrectal ultrasonography, 39 of 69 (56.5 percent) in computed tomography, and 46 of 73 (63 percent) in magnetic resonance imaging. The sensitivity was 24 of 45 (53.3 percent) in transrectal ultrasonography, 14 of 25 (56 percent) in computed tomography, and 33 of 42 (78.5 percent) in magnetic resonance imaging; and specificity was 30 of 40 (75.0 percent) in transrectal ultrasonography, 25 of 44 (56.8 percent) in computed tomography, and 13 of 31 (41.9 percent) in magnetic resonance imaging. The accuracy in detection of positive lateral pelvic lymph nodes under magnetic resonance imaging (n=8) was 12.5 percent. The accuracy in detection of posterior vaginal wall invasion was 100 percent in transrectal ultrasonography (n=7) and 100 percent in magnetic resonance imaging (n=3), but 28.5 percent in computed tomography (n=7). CONCLUSIONS: Both transrectal ultrasonography and magnetic resonance imaging with endorectal coil exhibited similar accuracy and were superior to conventional computed tomography in preoperative assessment of depth of invasion and adjacent organ invasion. Because transrectal ultrasonography is a safer and more cost-effective modality than magnetic resonance imaging, transrectal ultrasonography is an appropriate method for preoperative staging of rectal cancer. Further efforts will be needed to provide a better staging of lymph node involvement.

Assessment of Sexual and Voiding Function After Total Mesorectal Excision With Pelvic Autonomic Nerve Preservation in Males With Rectal Cancer

AbstractPURPOSE: Total mesorectal excision with pelvic autonomic nerve preservation has been reported to be an optimal surgery for rectal cancer. It minimizes local recurrence and sexual and urinary dysfunction. The aim of this study was to assess the safety of total mesorectal excision with pelvic autonomic nerve preservation in terms of voiding and sexual function in males with rectal cancer. METHODS: We performed urine flowmetry using Urodyn® and a standard questionnaire using the International Index of Erectile Function and the International Prostate Symptom Score before and after surgery in 68 males with rectal cancer. RESULTS: Significant differences in mean maximal urinary flow rate and voided volume were seen before and after surgery (18.9 ± 5.7 vs. 13.7 ± 7.0, 240 ± 91.9 vs. 143 ± 78; P < 0.05, P < 0.05, respectively), but no differences in residual volume before and after surgery were apparent (4.4 ± 2.6 vs. 8.1 ± 4.4; P > 0.05). The total International Prostate Symptom Score was increased after surgery from 6.2 ± 5.8 to 9.8 ± 5.9 (P < 0.05). There were no changes of score for one of each of seven International Prostate Symptom Score items in 49 patients (73.5 percent) to 61 patients (89.7 percent). Five International Index of Erectile Function domain scores (erectile function, intercourse satisfaction, orgasmic function, sexual desire, and overall satisfaction) were significantly decreased after surgery (18.2 ± 9.3 vs. 13.5 ± 9, 8.4 ± 4.2 vs. 4.4 ± 2.9, 5.8 ± 2.9 vs. 4.4 ± 2.9, 6.1 ± 2.4 vs. 4.8 ± 2, 6.1 ± 2.2 vs. 4.5 ± 2.3, respectively; P < 0.05). Erection was possible in 55 patients (80.9 percent); penetration ability was possible in 51 patients (75 percent). Complete inability for erection and intercourse was observed in three patients (5.5 percent). Retrograde ejaculation was noted in 9 patients (13.2 percent). International Index of Erectile Function domains such as sexual desire and overall satisfaction were greatly decreased in 39 patients (57.4 percent) and 43 patients (63.2 percent), respectively. Multiple regression analysis of factors affecting postoperative sexual dysfunction showed that age older than 60 years (sexual desire, P = 0.019), within six months (erectile function, P = 0.04; intercourse satisfaction, P = 0.011; orgasmic function, P = 0.03), lower rectal cancer (erectile function, P = 0.02; intercourse satisfaction, P = 0.036; orgasmic function, P = 0.027) were significant factors adversely affecting sexual function. CONCLUSION: Total mesorectal excision with pelvic autonomic nerve preservation showed relative safety in preserving sexual and voiding function. The International Prostate Symptom Score and International Index of Erectile Function questionnaires were useful in assessing urinary and sexual function.

Comparative study of resection and radiofrequency ablation in the treatment of solitary colorectal liver metastases

BACKGROUND We compared outcomes in patients with solitary colorectal liver metastases treated by either hepatic resection (HR) or radiofrequency ablation (RFA). METHODS A retrospective analysis from a prospective database was performed on 67 consecutive patients with solitary colorectal liver metastases treated by either HR or RFA. RESULTS Forty-two patients underwent HR and 25 patients underwent RFA. The 5-year overall and local recurrence-free survival rates after HR (50.1% and 89.7%, respectively) were higher than after RFA (25.5% and 69.7%, respectively) (P = .0263 and .028, respectively). In small tumors less than 3 cm (n = 38), the 5-year survival rates between HR and RFA were similar, including overall (56.1% vs 55.4%, P = .451) and local recurrence-free (95.7% vs 85.6%, P = .304) survival rates. On multivariate analysis, tumor size, metastases treatment, and primary node status were significant prognostic factors. CONCLUSIONS HR had better outcomes than RFA for recurrence and survival after treatment of solitary colorectal liver metastases. However, in tumors smaller than 3 cm, RFA can be recommended as an alternative treatment to patients who are not candidates for surgery because the liver metastases is poorly located anatomically, the functional hepatic reserve after a resection would be insufficient, the patients comorbidity inhibits a major surgery, or extrahepatic metastases are present.

Oncologic outcomes after neoadjuvant chemoradiation followed by curative resection with tumor-specific mesorectal excision for fixed locally advanced rectal cancer: Impact of postirradiated pathologic downstaging on local recurrence and survival

Objective:The purpose of this study was to determine the oncologic outcomes and clinical factors affecting survival in patients who underwent neoadjuvant chemoradiotherapy following tumor specific mesorectal excision for locally advanced, fixed rectal cancer. Summary Background Data:Neoadjuvant chemoradiation therapy has resulted in significant tumor downstaging, which enhances curative resection and subsequently improves local disease control for rectal cancer. However, oncologic outcomes, according to clinical factors, have not yet been fully understood in locally advanced and fixed rectal cancer. Methods:A total of 114 patients who had undergone neoadjuvant chemoradiation for advanced rectal cancer (T3 or T4 and node positive) were investigated retrospectively. Chemotherapy was administered intravenously with 5-FU and leucovorin during weeks 1 and 5 of radiotherapy. The total radiation dose was 5040 cGY in 25 fractions delivered over 5 weeks. Tumor-specific mesorectal excision was done 4 to 6 weeks after the completion of neoadjuvant chemoradiation. Survival and recurrence rates, according to the pathologic stage, were evaluated. Moreover, factors affecting survival were investigated. Results:The 5-year survival rates according to pathologic stage were: 100% in pathologic complete remission (n = 10), 80% in stage I (n = 23), 56.8% in stage II (n = 34), and 42.3% in stage III (n = 47) (P = 0.0000). Local, systemic, and combined recurrence rates were 11.4%, 22.8%, and 3.5%, respectively. Multivariate analysis showed that the pathologic N stage and operation method were the independent factors affecting survival rate. Conclusion:Pathologic complete remission showed excellent oncologic outcomes, and the pathologic N stage was the most important factor for oncologic outcomes.

Accuracy of endorectal ultrasonography and computed tomography for restaging rectal cancer after preoperative chemoradiation

BACKGROUND Preoperative restaging of irradiated rectal cancer is essential for the planning of optimal therapy. The aim of this study was to compare the accuracy of endorectal ultrasonography (ERUS) and CT in restaging rectal cancer after preoperative chemoradiation and to evaluate the factors affecting the accuracy of ERUS. STUDY DESIGN Eighty-three patients with initial, locally advanced rectal cancer were prospectively evaluated by ERUS (n=60) and CT (n=80) after preoperative chemoradiation and just before surgery. All patients then underwent subsequent surgical resection and complete pathologic staging. RESULTS In restaging the depth of invasion, the overall accuracy was 38.3% (23 of 60) by ERUS and 46.3% (37 of 80) by CT. Overstaging was more common than understaging with both imaging modalities. Accuracy for restaging lymph node metastasis was 72.6% (37 of 51) by ERUS and 70.4% (50 of 71) by CT. The predictive value of node-negative cases by ERUS was somewhat lower than that of CT (81.1% versus 85.4%, respectively). Complete pathology-proved remission was not correctly predicted in any of the 11 patients by any imaging modalities. Pathologic T and N staging correlated with the staging accuracy of ERUS (p=0.028 and p=0.001, respectively). CONCLUSIONS ERUS and CT may allow good prediction of node-negative rectal cancers, although they are inaccurate modalities for predicting treatment response on the rectal wall. New methods of interpretation and diagnostic criteria for ERUS and CT are essential for increasing the accuracy of cancer prediction in at-risk patients.

Prognostic Effect of Perioperative Change of Serum Carcinoembryonic Antigen Level: A Useful Tool for Detection of Systemic Recurrence in Rectal Cancer

BackgroundThe prognosis of patients even with the same stage of rectal cancer varies widely. We analyzed the capability of perioperative change of serum carcinoembryonic antigen (CEA) level for predicting recurrence and survival in rectal cancer patients.MethodsWe reviewed 631 patients who underwent potentially curative resection for stage II or III rectal cancer. Patients were categorized into three groups according to their serum CEA concentrations on the seventh day before and on the seventh day after surgery: group A, normal CEA level (≤5 ng/mL) in both periods; group B, increased preoperative and normal postoperative CEA; and group C, continuously increased CEA in both periods. The prognostic relevance of the CEA group was investigated by analyses of recurrence patterns and survival.ResultsStage III patients showed higher systemic recurrence (P = .001) and worse 5-year survival rates (P < .0001) for group C than for groups A and B. On multivariate analysis, the CEA group was a significant predictor for recurrence (P < .001; relative risk, 2.740; 95% confidence interval, 1.677–4.476) and survival (P = .001; relative risk, 2.174; 95% confidence interval, 1.556–3.308).ConclusionsThe perioperative serum CEA change was a useful prognostic indicator to predict for systemic recurrence and survival in stage III rectal cancer patients.

The Influence of the Number of Retrieved Lymph Nodes on Staging and Survival in Patients With Stage II and III Rectal Cancer Undergoing Tumor-Specific Mesorectal Excision

Objective:This study was designed to determine whether the number of lymph nodes retrieved influence staging and survival in patients with stage II and III rectal cancer that undergo tumor-specific mesorectal excision. Summary Background Data:The prognostic impact of the retrieved nodes has been emphasized in patients with colorectal cancer, but few studies have focused on patients with rectal cancer. Methods:A total of 900 patients who underwent tumor-specific mesorectal excision with curative intent and adjuvant chemoradiation therapy for stage II and III rectal cancer from January 1989 to December 2006 were analyzed. Results:Cancer-specific survival (CSS) of stage II patients with less than 15 nodes (25th percentile) was not different from stage III patients, but CSS was better in stage II patients with more than 15 nodes. When using cutoff values of the 25th and 50th percentiles (22 and 31 nodes), recurrence-free survival (RFS) was statistically different among subgroups of stage II and III patients. In multivariate analysis, stage II disease with less than 15 nodes retrieved was an adverse factor for CSS and RFS. In Kaplan-Meier survival analysis, using cutoff values, the difference for CSS was not significant with 22 and more nodes and the difference for RFS was not observed with 23 and more nodes. Conclusions:The number of lymph nodes retrieved is closely associated with survival and recurrence in patients with stage II rectal cancer and, for more accurate prognostic stratification, at least 22 and 23 nodes seem to be necessary, respectively, for CSS and for RFS.

Factors associated with anastomotic recurrence after total mesorectal excision in rectal cancer patients

In patients undergoing total mesorectal excision (TME), the clinical variables most relevant to anastomotic recurrence have not been identified. We evaluated factors associated with anastomotic recurrence in patients undergoing TME and the impact of a reduced distal margin on anastomotic recurrence.

A Diverting Stoma Is Not Necessary when Performing a Handsewn Coloanal Anastomosis for Lower Rectal Cancer

PurposeAlthough a temporary diverting stoma is a frequent surgical procedure for the protection of anastomosis in a sphincter-preserving operation for lower rectal cancer, its impact on anastomotic leakage is not conclusive. This study was designed to evaluate anastomotic complications after ultralow anterior resection and handsewn coloanal anastomosis without a diverting stoma for lower rectal cancer patients.MethodsBetween January 1995 and December 2005, 96 patients were treated by ultralow anterior resection and handsewn coloanal anastomosis for lower rectal cancer. Fifty-one patients received preoperative concurrent chemoradiation, whereas 45 had no preoperative treatment. No diverting stoma was created in any of these cases. The anastomotic complications were evaluated between the groups.ResultsSix of 96 patients (6.1 percent) developed anastomotic complications: three anastomotic stenoses, one partial anastomotic dehiscence, one retrorectal abscess, and one rectovaginal fistula. All of the complications occurred in the preoperative radiation group, whereas none from the nonradiation group had an anastomotic complication (P = 0.017). The patients with stenosis and partial dehiscence were managed conservatively. The patient with retrorectal abscess was treated with debridement, irrigation and drainage, and seton procedure with a transanal approach. The patient with rectovaginal fistula underwent a second coloanal anastomosis.ConclusionsThe anastomotic complication rate was low even without a diverting stoma. This study suggests that a diverting stoma is not necessary when performing a handsewn coloanal anastomosis for lower rectal cancer however, an effort should be made for healthy anastomotic healing in patients with rectal cancer who are preoperatively radiated.

The prognostic impact of the number of lymph nodes retrieved after neoadjuvant chemoradiotherapy with mesorectal excision for rectal cancer

We aimed to assess factors associated with the number of nodes retrieved and the impact of the number of lymph nodes in rectal cancer patients who underwent neoadjuvant chemoradiation with radical surgery.