• Journal of Digestive Cancer Research
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• v.5 no.1
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• pp.32-36
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• 2017

In unresectable stage IV colorectal cancer, the role of palliative surgery is not defined clearly. The palliative surgery can be categorized into two surgeries; first, palliative primary tumor resection; second, palliative metastatectomy. Several retrospective studies reported initial palliative systemic chemotherapy in unresectable stage IV colorectal cancer did not increase primary tumor related complications such as obstruction, perforation and hemorrhage, so they insisted that primary tumor resection in asymptomatic stage IV colorectal cancer should be preserved. However, in terms of overall survival and cancer-specific or progression-free survival, several retrospective studies, especially using population-based big data, reported favored survivals in palliative primary tumor resection group. And also several studies reported that palliative metastatectomy such as liver resection without resection of lung metastasis showed better overall survivals. But those results from those studies came from retrospective studies and are likely to be affected by selection bias. Prospective randomized studies are needed to define the benefit of palliative primary tumor resection and metastatectomy in unresectable stage IV colorectal cancer. However, based on the updated evidences, the dogma that palliative primary tumor resection should be preserved in asymptomatic unresectable stage IV colorectal cancer should be questioned.

• Radiation Oncology Journal
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• v.27 no.2
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• pp.78-83
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• 2009

Purpose: To examine the effect of suboptimal chemotherapy in patients undergoing preoperative chemoradiotherapy for the treatment of rectal cancer. Materials and Methods: The medical records of 43 patients who received preoperative concurrent chemoradiotherapy, followed by radical surgery for the treatment of pathologically proven adenocarcinoma of the rectum from April 2003 to April 2006 were retrospectively reviewed. The delivered radiation dose ranged from 41.4 to 50.4 Gy. The standard group consisted of patients receiving two cycles of a 5-FU bolus injection for three days on the first and fifth week of radiotherapy or twice daily with capecitabine. The standard group included six patients for each regimen. The non-standard group consisted of patients receiving one cycle of 5-FU bolus injection for three days on the first week of radiotherapy. The non-standard group included 31 patients. Radical surgery was performed at a median of 58 days after the end of radiotherapy. A low anterior resection was performed in 36 patients, whereas an abdominoperineal resection was performed in 7 patients. Results: No significant difference was observed between the groups with respect to pathologic responses ranging from grades 3 to 5 (83.3% vs. 67.7%, p=0.456), downstaging (75.0% vs. 67.7%, p=0.727), and a radial resection margin greater than 2 mm (66.7% vs. 83.9%, p=0.237). The sphincter-saving surgery rate in low-lying rectal cancers was lower in the non-standard group (100% vs. 75%, p=0.068). There was no grade 3 or higher toxicity observed in all patients. Conclusion: Considering that the sphincter-saving surgery rate in low-lying rectal cancer was marginally lower for patients treated with non-standard, suboptimal chemotherapy, and that toxicity higher than grade 2 was not observed in the both groups, suboptimal chemotherapy should be avoided in this setting.

• Radiation Oncology Journal
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• v.20 no.3
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• pp.215-220
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• 2002

Purpose : Preoperative radiotherapy has been used to induce tumor regression and allow complete resection of rectal cancer with a sphincter preservation surgery. This study was performed to determine the effectiveness of preoperative radiotherapy for $T_2,\;T_3$ distal rectal carcinoma. Materials and Methods : From November 1995 to June 1997, fifteen patients with invasive distal rectal cancer were treated with preoperative radiotherapy followed by sphincter preservation surgery. Classification by preoperative T stage consisted of 7 $T_2$ and 8 $T_3$ tumors. Radiation therapy was delivered with 6 MV and 15 MV linear accelerator, at 1.8 Gy fractions for 5 days per week. Total radiation doses were 45 Gy to 50.4 Gy (median : 50.4 Gy). Sphincter preservation surgery was peformed $4\~6$ weeks after the completion of radiotherapy. Median follow-up was 22 months (range : $16\~37\;months$). Results : One patient $(6.7\%)$ had a complete pathologic response. Comparing the stage at the diagnostic workup with the pathologic stage, tumor downstaging of T stages occurred in 11 of 15 patients $(73.3\%)$ and $N_1$ stages occurred in 2 of 5 patients $(40\%)$. No patient developed progressive disease undergoing treatment. Two patients suffered local recurrence at 7 and 20 months, and one a distant metastasis at 30 months. No grade 3 or 4 toxicity was observed. Conclusion : Our experience suggests that preoperative radiotherapy followed by sphincter preservation surgery is well tolerated, and can significantly reduce the tumor burden for $T_2\;T_3$ distal rectal cancer.

• Radiation Oncology Journal
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• v.26 no.1
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• pp.56-64
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• 2008

Purpose: Cathepsin D(CD) is a lysosomal acid proteinase that is related to malignant progression, invasion, and a poor prognosis in several tumors. The aim of this study was to evaluate the prognostic clinical significance of CD and p53 expression in pretreatment biopsy specimens from patients with locally advanced rectal cancer who were treated with preoperative chemoradiation. Materials and Methods: Eighty-nine patients with locally advanced rectal cancer(cT3/T4 or N+) were included in this study. Preoperative chemoradiation consisted of a dose of 50.4 Gy of pelvic radiation and two concurrent cycles of administration of 5-fluorouracil and leucovorin. Surgery was performed six weeks after chemoradiation. CD and p53 expression in pretreatment formalin-fixed paraffin-embedded tumor biopsy specimens were assessed by immunohistochemical staining using a CD and p53 monoclonal antibodies. The threshold value for a positive stain in tumor tissue and stromal cells was 1+ intensity in 10% of the tumors or stromal cells, respectively. Results: Positive CD expression was found in 57(64%) of the tumors and 32(35%) of the stromal cell specimens. There was no association with CD expression of the tumor or stromal cells and patient characteristics. There was a correlation between tumor CD expression with stromal cell CD expression(p=0.01). Overexpression of p53 was not a significant prognostic factor. The 5-year overall survival(OS) and disease-free survival(DFS) rates were not different between tumor CD-negative and positive patient biopsy samples(69% vs. 65%, 60% vs. 61%, respectively). The 5-year OS rates in the tumor-negative/stromal cell-negative, tumor-negative/stromal cell-positive, tumor-positive/stromal cell-negative and tumor-positive/stromal cell-positive biopsy samples were 75%, 28%, 62%, and 73%, respectively. Stromal cell staining only without positive tumor staining demonstrated the worst overall survival prognosis for patients(p=0.013). Conclusion: Overexpression of p53 in rectal biopy tissue was not associated with prognostic significance. In the pretreatment biopsy specimens, an exclusive increase in CD expression in stromal cells without tumor expression was related to poor overall survival in patients with locally advanced rectal cancer treated with preoperative chemoradiation.

• Radiation Oncology Journal
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• v.29 no.1
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• pp.11-19
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• 2011

Purpose: To evaluate the pathological and clinical effects of preoperative chemoradiation (CCRT) in cases of locally advanced rectal cancer and to determine the predictive factors for tumor downstaging. Materials and Methods: From March 2004 to August 2008, 33 patients with locally advanced rectal cancer were treated with preoperative CCRT. Twenty-eight patients (84.8%) were treated using a concomitant boost technique while five (15.2%) patients were treated using a cone down boost technique. All patients received 50.4 Gy of irradiation and concurrent chemotherapy with 5-fluorouracil. The median follow-up duration was 24.2 months (range, 9.8 to 64.7 months). Results: Thirty-one (93.9%) patients underwent surgery. Twenty-four patients (72.7%) underwent anal sphincter-preserving surgery. The 3-year disease free survival (DFS) and overall survival rates were 63.4% and 78.8%, respectively. Post-operative factors were more important for DFS. Pathologic N stage, margin status, and pathologic differentiation were significant prognostic factors (p=0.001, 0.029, 0.030). Tumor size and lymphovascular invasion were also associated with marginal significance (p=0.081, 0.073). However, only pre-treatment T stage was a significant pre-operative factor (p=0.018). The complete pathological response rate was 9.1 %. T-downstaging was observed in ten (30.3%) patients, whereas N-downstaging was found in 24 (72.7%) patients. Pre-treatment T stage and the interval between CCRT and operation were the predictive factors for downstaging in a univariate analysis (p=0.029, 0.027). Pre-treatment carcinoembryogenic antigen was also associated with marginal significance (p=0.068). Conclusion: The survival of rectal cancer patients can be better determined based on post-operative findings. Therefore, pre-operative CCRT for downstaging of the tumor seems to be important. Pre-treatment T stage and the interval between CCRT and operation can be used to predict downstaging.

• Parasites, Hosts and Diseases
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• v.26 no.2
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• pp.137-140
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• 1988

Female and male nematodes isolated from an eye of a 36-year old Korean man in August 1987 were identified as Thelagia callipaeda. This is the 17th record of human thelaBiasis in Korea. The internal structures of both female and male were described.

• Radiation Oncology Journal
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• v.15 no.1
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• pp.49-56
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• 1997

Purpose : To evaluate the pathologic effects of preoperative radiotherapy o the resectable distal rectal cancer, we analyzed the results of postoperative pathologic findings for the patients with preoperative radiotherapy ant surgery Materials and Methods: From July 1995 to April 1996, we treated sixteen patients of resectable rectal cancer with preoperative radiation therapy and curative surgery At diagnosis, Thomas Jefferson (TJ) system was used for the clinical stage of the Patients. We treated the patients with conventional radiation therapy of 4500~5000cGy before surgery. The surgery was carried out 4 weeks after completion of radiation therapy. Modified Astler Coller (MAC) system was used for the postoperative pathologic stage. We analyzed the pathologic stages and findings according to preoperative clinical stage and compared with those of the control group in similar clinical stages. Result : All patients were treated with sphincter preservation surgery after Preoperative radiation therapy. Pathoiogic complete response (CR) was shown in 1 case $(6.3\%)$. We compared the results between preoperative radiation therapy group (Preop.RT group) and surgery only group (control group). In TJ stage II, among nine patients of Preop.RT group, 8 patients $(88.9\%)$ were in MAC stage 8 except 1 CR patient, but among 17 patients of control group. 11 patients$(64.7\%)$ were in MAC stage B and 6 Patients $(35.3\%)$ in MAC stage C. In TJ stage III, among 7 patients of Preop.RT group, 4 patients $(57.1\%)$ were in MAC stage B and 3 patients$(42.9\%)$ in MAC stage C. Among 14 Patients of control group, 4 patients $(28.6\%)$ were in MAC stage B and 10 Patients $(71.4\%)$ in MAC stage C. Above results showed that postoperative Pathologic stage was decreased in Preop.RT group with statistical significance (P=0.049). The postoperative Pathologic findings (blood vessel invasion. Iymphatic vessel invasion, perineural invasion) were decreased in the Preop.RT group compared with those of control group. But statistical significance was found only in Iymphatic vessel invasion (p=0.019). Conclusion : The Postoperative pathologic stages and adverse Prognostic pathologic findings were decreased in preoperative radiation therapy group. The Iymphatic vessel invasion and MAC stage C findings were abruptly decreased in Preoperative radiation therapy group. The preoperative radiation therapy was found to be effective in resectable rectal cancer. The patients group in our study was very small and long term follow up was not done. Therefore, further study about this issues is needed.

• Radiation Oncology Journal
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• v.16 no.3
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• pp.303-310
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• 1998

Purpose : To evaluate the results of the treatment of locally advanced but resectable rectal cancers and to analyze prognostic factors. especially with the emphasis on the treatment time factor. Materials and Methods : There were 71 patients with rectal cancer who had been treated by curative surgical procedure and postoperative radiotherapy from August 1989 to December 1993. The minimum follow up period was 24 months and the median follow-up was 35 months Radiation therapy had been given by 6 MV linear accelerator by parallel opposing or four-box portals. Whole pelvis was treated up to 5040 cGy in most cases. Systemic chemotherapy had been given in 94$\%$ of the patients, mostly with 5-FU/ACNU regimen. Assessment for the overall and disease-free survival rates were done by life-table method and prognostic factors by Log-Rank tests. Results : Five-year overall survival, disease-free survival were 58.8$\%$ and 57$\%$, respectively. Two-year local control rate was 76.6$\%$. Stage according to Modified Astler-Coller (MAC) system, over 4 positive lymph nodes, over 6weeks interval between definitive surgery and adjuvant radiotherapy and over 7 days of interruption during radiotherapy period were statistically significant, or borderline significant prognostic factors. Conclusion : The treatment results of patients with rectal cancers are comparable to those of other large institutes. The treatment results for the patients with bowel wall penetration and/or positive regional lymph nodes were still discouraging for their high local recurrence rate for the patients with MAC 'c' stage diseases and high distant metastases rate even for the patients with node-negative diseases. Maybe more effective regimen of chemotherapy would be needed with proper route and schedule. To maximize postoperative adjuvant treatment. radiotherapy should be started at least within 6 weeks after surgery and preferably as soon as wound healing is completed. Interruption of treatment during radiotherapy course affects disease-free survival badly, especially if exceeds 7 days. So, the total treatment period trout definitive surgery to the completion of radiotherapy should be kept as minimal as possiable.

• Radiation Oncology Journal
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• v.18 no.3
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• pp.194-199
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• 2000

Purpose : Then determining the lower margin of post-operative pelvic radiation therapy field according to the traditional method (recommended by Gunderson), the organs located in the low pelvic cavity and the perineum are vulnerable to unnecessary radiation. This study evaluated the effect of individualized determination of the lower margin at 2 cm to 3 cm below the anastomotic site on the failure patterns. Materials and Methods . Authors included ぉ patients with modified Astler-Coiler (MAC) stages from B2 through C3, who received low anterior resection and post-operative pelvic radiation therapy from Sept. 1994 to May 1998 at Samsung Medical Center, Sungkyunkwan University. The numbers of male and female patients were 44 and 44, and the median age was 57 years (range: 32-81 years). Three field technique (posterior-anterior and bilateral portals) by 6, 10, 15 MV X-rays was used to deliver 4,500 cGy to the whole pelvis followed by Sn cGy's small field boost to the tumor bed over 5.5 weeks. Sixteen patients received radiation therapy by traditional field margin determination, and the lower margin was set either at the low margin of the obturator foramen or at 2 cm to 3 cm below the anastomotic site, whichever is lower. In 72 patients, the lower margin was set at 2 cm to 3 cm below the anastomotic site, irrespectively of the obturator foramen, by which the reduction of radiation volume was possible in 55 patients ($76\%$). Authors evaluated and compared survival, local control, and disease-free survival rates of these two groups. Results : The median follow-up period was 27 months (range : 7-58 months). MAC stages B2 in 32($36\%$), B3 in 2 ($2\%$), Cl in 2 ($2\%$), C2 in 50 ($57\%$), and C3 in 2 ($2\%$) Patients, respectively. The entire patients' overall survival rates at 2 and 4 years were $94\%$ and $68\%$, respectively, and disease-free survival rates at 2 and 4 years were $86\%$ and $58\%$, respectively. The first failure sites were local only in 4, distant only in 14, and combined local and distant in 1 patient, respectively. There was no significant difference with respect to local control and disease-free survival rates ( p=0.42, p=0.68) between two groups of different lower margin determination policies. Conclusion : The new concept in the individualized determination of the lower margin depending on the anastomotic site has led to the equivalent local control and disease-free survival rates, and is expected to contribute to the reduction of unnecessary radiation-related morbidity by reduction of radiation volume, compared with the traditional method of lower margin determination.

• Radiation Oncology Journal
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• v.23 no.1
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• pp.22-31
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• 2005

Purpose : To conduct a nationwide survey on the principals in radiotherapy for rectal cancer, and produce a database of Korean Patterns of Care Study. Materials and Methods : We developed web-based Patterns of Care Study system and a national survey was conducted using random sampling based on power allocation methods. Eligible patients were who had postoperative radiotherapy for rectal cancer without gross residual tumor after surgical resection and without previous history of other cancer and radiotherapy to pelvis. Data of patients were Inputted to the web based PCS system by each investigators in 19 institutions. Results : Informations on 309 patients with rectal cancer who received radiotherapy between 1998 and 1999 were collected. Male to female ratio was 59 : 41, and the most common location of tumor was lower rectum ($46\%$). Preoperative CEA was checked in $79\%$ of cases and its value was higher than 6 ng/ml in $32\%$. Pathologic stage were I in $1.5\%$, II in $32\%$, III in $53\%$, and IV in $1.6\%$. Low anterior resection was the most common type of surgery and complete resection was peformed in $95\%$ of cases. Distal resection margin was less than 2 cm in $30\%$, and number of lymph node dissected was less than 12 in $31\%$. Chemotherapy was peformed in $91\%$ and most common regimen was 5-FU and leucovorine ($59\%$). The most common type of field arrangement used for the initial pelvic field was the four field box (Posterior-Right-Left) technique ($65.0\%$), and there was no AP-PA parallel opposing field used. Patient position was prone in $81.2\%$, and the boost field was used in $61.8\%$. To displace bowel outward, pressure modulating devices or bladder filling was used in $40.1\%$. Radiation dose was prescribed to isocenter in $45.3\%$ and to isodose line in 123 cases ($39.8\%$). Percent delivered dose over $90\%$ was achieved in $92.9\%$. Conclusion : We could find the Patterns of Care for the radiotherapy in Korean rectal cancer patients was similar to that of US national survey. The type of surgery and the regimen of chemotherapy were variable according to institutions and the variations of radiation dose and field arrangement were within acceptable range.