The evaluation of therapeutic efficacy is necessary to predict the outcome of patients with metastatic colorectal cancer (CRC). In these patients, there is a critical need for predictive chemosensitivity assays and biomarkers to optimize efficacy and minimize toxicity. The introduction of targeted agents has improved the progression-free survival and overall survival of patients with metastatic disease. However, approximately 50% of patients do not show a positive response to chemotherapy and the selection of patients likely to respond to a specific regimen remains challenging. Cell culture-based chemosensitivity tests use autologous viable tumor cells to evaluate susceptibility to specific agents in vitro and predict their direct effects. Adenosine triphosphate-based assays and methyl thiazolyl-diphenyl-tetrazolium bromide-based assays are used widely as sensitivity tests because of their short assay period, technical simplicity, and the requirement of small amount of specimen. Among protein- and gene-based chemosensitivity assays, assessment of KRAS mutation status predicts the response to epidermal growth factor receptor-targeted therapy in CRC patients. The validation of predictive and prognostic markers enables the selection of therapeutic regimens with optimal efficacy and minimal toxicity for each patient, which has been termed personalized treatment. This review summarizes currently available predictive and prognostic chemosensitivity tests for metastatic CRC.
Colorectal adenocarcinomas; Colorectal cancer; Chemotherapy; In vitro assays; Molecular targeted therapy; Individualized therapy
AIM: To investigate alternative or subordinate pathways involved in colorectal tumorigenesis and tumor growth, possibly determining at-risk populations and predicting responses to treatment.
METHODS: Using microarray gene-expression analysis, we analyzed patterns of gene expression relative to canonical molecular changes and clinicopathological features in 84 sporadic colorectal cancer patients, standardized by tumor location. Subsets of differentially expressed genes were confirmed by real-time reverse-transcript polymerase chain reaction (RT-PCR).
RESULTS: The largest number of genes identified as being differentially expressed was by tumor location, and the next largest number by lymphovascular or neural invasion of tumor cells and by mismatch repair (MMR) defects. Amongst biological processes, the immune response was significantly implicated in entire molecular changes observed during colorectal tumorigenesis (P < 0.001). Amongst 47 differentially expressed genes, seven (PISD, NIBP, BAI2, STOML1, MRPL21, MRPL16, and MKKS) were newly found to correlate with tumorigenesis and tumor growth. Most location-associated molecular changes had distinct effects on gene expression, but the effects of the latter were sometimes contradictory.
CONCLUSION: We show that several differentially expressed genes were associated with canonical molecular changes in sporadic colorectal cancers, possibly constituting alternative or subordinate pathways of tumorigenesis. As tumor location was the dominant factor influencing differential gene expression, location-specific analysis may identify location-associated pathways and enhance the accuracy of class prediction.
Colorectal adenocarcinomas; Sporadic; Gene expression; Profiling; Tumorigenesis
The objective of this study was to examine the clincopathologic characteristics and outcomes of familial adenomatous polyposis (FAP) patients with and without desmoid tumors (DTs), including the risk factors for progression of FAP-related DTs.
Materials and Methods
We reviewed the medical records and database of all patients with FAP who were treated between January 1993 and December 2011.
Of 75 FAP patients, 18 (24%) were FAP with DTs. Seventeen of these had intra-abdominal DTs and one had intra- and extra-abdominal DTs. We divided the patients into two groups according to type of resection; the R0 or R1 resection group, referred to as the curative resection group (eight patients), and the R2 resection/palliative operation/medical treatment group, referred to as the palliative resection group (10 patients). Two patients in the curative resection group and two patients in the palliative group had progressed to tumor growth by the follow-up (p=0.800). In univariate analysis, DT diagnosis before or simultaneously with FAP diagnosis (DTs unrelated to surgical trauma) was a significant risk factor for tumor progression at final follow-up.
A multidisciplinary approach to DT treatment is needed, including nonsteroidal antiinflammatory drugs, anti-estrogens, cytotoxic agents, and surgery. However, the role of surgery in resectable and complicated tumors may be limited. DT unrelated to surgical trauma has a relatively poor prognosis.
Familial adenomatous polyposis; Aggressive fibromatosis; Risk factors
Selecting the best surgical approach for treating complete rectal prolapse involves comparing the operative and functional outcomes of the procedures. The aims of this study were to evaluate and compare the operative and functional outcomes of abdominal and perineal surgical procedures for patients with complete rectal prolapse.
A retrospective study of patients with complete rectal prolapse who had operations at a tertiary referral hospital and a university hospital between March 1990 and May 2011 was conducted. Patients were classified according to the type of operation: abdominal procedure (AP) (n = 64) or perineal procedure (PP) (n = 40). The operative outcomes and functional results were assessed.
The AP group had the younger and more men than the PP group. The AP group had longer operation times than the PP group (165 minutes vs. 70 minutes; P = 0.001) and longer hospital stays (10 days vs. 7 days; P = 0.001), but a lower overall recurrence rate (6.3% vs. 15.0%; P = 0.14). The overall rate of the major complication was similar in the both groups (10.9% vs. 6.8%; P = 0.47). The patients in the AP group complained more frequently of constipation than of incontinence, conversely, in the PP group of incontinence than of constipation.
The two approaches for treating complete rectal prolapse did not differ with regard to postoperative morbidity, but the overall recurrence tended to occur frequently among patients in the PP group. Functional results after each surgical approach need to be considered for the selection of procedure.
Rectal prolapse; Abdomen; Perineum; Procedure
The aim of this study was to analyze oncologic outcomes after transanal local excision (LE) to ensure adequate surveillance of recurrence in order to treat with curative intent.
Between January 2000 and June 2009, 102 patients who underwent transanal LE for rectal adenocarcinoma were retrospectively reviewed.
Of the 102 patients, 53 (52.0%) were male. The mean age was 57 ± 11 years. Postoperative pathologic examination revealed 93 cases (91.2%) of pathologic T stage (pT)1 and 9 cases (8.8%) of pT2. Forty-eight patients (47.1%) underwent adjuvant postoperative radiotherapy. The median follow-up interval was 60 months (range, 3 to 146 months). Seven (6.9%) out of 15 patients who suffered recurrence had locoregional recurrence, three (2.9%) had systemic recurrence and five (4.9%) had both systemic and locoregional recurrence. The latter five patients and two of the three patients with systemic recurrence died because of the disease recurrence. On the other hand, only one of the seven patients with locoregional recurrence died because of disease recurrence.
Systemic recurrence after transanal LE results in fatal consequences. Therefore, not only is it important to identify ideal candidates for LE, but intensive postoperative surveillance is important as well to identify curable recurrence as soon as possible.
Rectal neoplasms; Local excision
The standard treatment for patients with locally advanced rectal cancer is preoperative chemoradiotherapy followed by total mesorectal excision. This approach is supported by randomized trials, but there are still many unanswered questions about the multimodal management of rectal cancer. In surgical terms, these include the optimal time interval between completion of chemoradiotherapy and surgery; adequate distal resection margin and circumferential radial margin; sphincter preservation; laparoscopic surgery; and conservative management, including a 'wait and see' policy and local excision. This review considers these controversial issues in preoperative chemoradiotherapy.
Rectal cancer; Chemoradiotherapy; Surgical procedures
Identification of subgroups of patients who differ in their response to treatment could help to establish which of the best available chemotherapeutic options are best, based on biological activity. In metastatic colorectal cancer (CRC), novel molecular-targeted agents that act on pathways that regulate cell growth, the cell cycle, apoptosis, angiogenesis, and invasion are being developed. Here, we employed an in vitro chemosensitivity assay to evaluate the biological efficacy of conventional monotherapies and combination chemotherapy with targeted drugs.
The chemosensitivities of 12 CRC cell lines to the established regimens FOLFOX (5-fluorouracil [5-FU] + leucovorin + oxaliplatin) and FOLFIRI (5-FU + leucovorin + irinotecan) and to therapy with these regimens in combination with the biologically targeted drugs bevacizumab or cetuximab were comparatively evaluated for their effects on apoptotic and autophagic cell death processes, angiogenesis, and invasion.
Each of the chemotherapeutic regimens promoted apoptotic cell death and invasion. All drug regimens caused significantly greater apoptotic cell death with activation of caspase-3 in SW480 cells compared to other cells, effects that were associated with a remarkable reduction in matrix metalloproteinase-9 activity. The FOLFOX regimen more effectively promoted apoptotic cell death, angiogenesis, and invasion than the FOLFIRI regimen. Combination therapy with FOLFOX/FOLFIRI regimen and bevacizumab produced a moderate angiogenesis-blocking effect in most cell lines.
The results validate our in vitro chemosensitivity assay, and suggest that it may be applied to help determine adequate regimens in individual CRC patients based on the biological characteristics of their tumors.
Colorectal neoplasms; Chemotherapy; Pharmacological biomarkers
The objective of the current study was to identify the clinicopathological risk factors affecting recurrence after a curative resection for stage I colorectal cancer.
We retrospectively studied 434 patients who underwent a curative resection for stage I colorectal cancer between January 1999 and December 2004. Postoperative oral chemotherapy was performed in 189 patients (45.3%). The following prognostic factors were correlated with recurrence: age, gender, preoperative carcinoembryonic antigen level, location of tumor, T stage, size of tumor, histologic differentiation, growth pattern, and lymphovascular invasion. The median follow-up duration was 65 months.
The overall recurrence rate was 4.6% (20/434). The median time to recurrence was 33 months. Two-thirds of the recurrence occurred more than two years after surgery. Risk factors associated with recurrence were rectal cancer (P = 0.009), T2 stage (P = 0.010), and infiltrative growth pattern (P = 0.020). A Cox proportional hazards regression analysis demonstrated that the infiltrative growth pattern was an independent predictor for recurrence. Tumor cell budding was observed in all pathologic reviews with recurrence.
Long-term follow-up is necessary for stage I colorectal patients with high risk factors like rectal cancer, T2 stage, and infiltrative growth pattern.
Colorectal neoplasms; Recurrence; Risk factors
To evaluate the comparative therapeutic efficacy of radiofrequency ablation (RFA) and hepatic resection for the treatment of colorectal liver metastasis (CRLM).
Between 1996 and 2008, 177 patients underwent RFA, 278 underwent hepatic resection and 27 underwent combination therapy for CRLM. Comparative analysis of clinical outcomes was performed including number of liver metastases, tumor size, and time of CRLM.
Based on multivariate analysis, overall survival (OS) correlated with the number of liver metastases and the use of combined chemotherapy (P < 0.001, respectively). Disease-free survival (DFS) also correlated with the number of liver metastases (P < 0.001). In the 226 patients with solitary CRLM < 3 cm, OS and DFS rates did not differ between the RFA group and the resection group (P = 0.962 and P = 0.980). In the 70 patients with solitary CRLM ≥ 3 cm, DFS was significantly lower in the RFA group as compared with the resection group (P = 0.015).
The results indicate that RFA may be a safe alternative treatment for solitary CRLM less than 3 cm, with outcomes equivalent to those achieved with hepatic resection. A randomized controlled study comparing RFA and resection for patients with single small metastasis would help to determine the most efficient treatment modalities for CRLM.
Radiofrequency ablation; Hepatectomy; Colorectal neoplasms; Liver metastasis
Hereditary colorectal cancer develops through a series of well-defined genetic and histological changes. However, elucidation of the canonical pathway based on hereditary colorectal cancer has not provided a clear explanation of the molecular mechanisms of sporadic colorectal cancer. To identify the alterative pathways involved in sporadic colorectal tumorigenesis, we performed gene expression analysis in patients with sporadic colorectal tumors. A comparison analysis of gene expression profiles revealed a pattern of upregulation of small proline rich repeat protein 3 (SPRR3) in tumor samples. SPRR3 has previously been reported to be downregulated in esophageal cancer. However, in the present study, we observed that SPRR3 was strongly upregulated in 31 of 35 samples of sporadic colorectal tumors (88%). We also determined that overexpression of SPRR3 not only accelerates colorectal cancer cell proliferation but also is associated with lymphovascular invasion in colorectal cancer. Moreover, AKT was activated and p53 levels were decreased in cells that overexpressed SPRR3. In contrast to the pattern seen in esophageal cancer, these results suggest that increased expression of SPRR3 is involved in colorectal tumorigenesis.
This current study examined the clinicopathologic characteristics of patients with splenic flexure (SF) colon cancer and the association with the surgical outcomes to find the optimal procedure to treat this malady.
Materials and Methods
A total of 167 operated patients with SF colon cancer were consecutively recruited between 1993 and 2003. The clinicopathological, operative and survival data was reviewed and analyzed.
For the SF colon cancer patients, the proportion of males was higher than that for the right-sided colon patients or the sigmoid-descending junction & sigmoid (SD & S) colon patients (p≤0.05, respectively) and the age at the time of diagnosis was younger (p≤0.05). Obstruction was more frequent in the patients with SF colon cancer than that for the patients with colon cancer at other sites (p≤0.001). The incidence of mucinous adenocarcinoma for the SF patients was similar to that for the patients with right-sided colon cancer, but it was higher than that for the patients with SD & S colon cancer (11.4% vs. 6.5%, p=0.248 or 2.5%, respectively, p=0.001). Disease-free and overall survival did not differ between the patients who underwent a left hemicolectomy and extended surgery such as combined splenectomy or subtotal colectomy. Multivariate analysis showed that old age (≥60 years) and a N1-2 and M1 status were the independent risk factors for overall survival.
The SF colon cancers exhibited exclusively different characteristics as compared to colon cancers at other site colon cancers. It appears that left hemicolectomy was generally sufficient for a satisfactory oncological outcome, obviating concurrent splenectomy.
Colonic neoplasms; Left colic flexure; Colectomy; Splenectomy
Integrative genetic changes were examined in relation to tumor growth and progression of sporadic colorectal cancers. Ninety-two sporadic colorectal cancer patients and 12 human colorectal cancer cell lines were evaluated. Genetic changes in representative steps of colorectal tumorigenesis were determined. Biological characteristics, i.e., clinicopathologic parameters, expression of invasion-associated molecules, and in vitro invasion and migration, in association with these changes were further analyzed. Adenomatous polyposis coli (APC) and/or Wnt-activated alterations occurred in 66% patients, whereas mismatch repair (MMR) defects and/or RAF-mediated alterations were identified in 47% patients. The crossover rate between these two alterations was 26%. Differential mRNA expression of ARK5 was closely associated with that of MMP2, MMP9, and S100A4 (P≤0.044-0.001). Additionally, enhanced ARK5 mRNA expression was more frequent in tumors displaying RAF-mediated alterations and crossover pathways (P=0.01 and 0.03, respectively). Upregulation of CEA mRNA was more common in the advanced stages (P=0.034), while VEGF expression was greater in poorly differentiated or mucinous tumors (P=0.042). The high expressions of MMP2 and MMP9 were closely associated with invasion and migration of colorectal tumors and cell lines. Our results conclusively show that specific pathways of colorectal tumorigenesis are closely associated with characteristic tumor growth and invasion.
Colorectal Neoplasms; Sporadic; Tumorigenesis; Molecular; Growth; Invasion
To determine whether family history of cancer may be a risk factor for the mutator phenotype in colorectal cancer, we recruited 143 consecutive colorectal cancer patients with a family history of accompanying cancers not meeting the Amsterdam criteria. Microsatellite instability (MSI) at 5 markers, hMLH1-promoter methylation, and expression of mismatch repair (MMR) proteins (hMLH1, hMSH2, hMSH6, hMPS1, and hPMS2) were determined. Among the relatives of familial colorectal cancer patients, colorectal cancer was the most common tumor type. Of the proband colorectal cancers, 26 (18.2%) showed high-level MSI (MSI-H); 47 additional tumors with mutator phenotype (32.9%) were identified by hMLH1-promoter methylation and/or loss of MMR protein expression. Mutator phenotype was associated with right-sided colon cancer and the type of accompanying cancer. Family history, which was differentially quantified according to the degree of relatives and the type of accompanying cancers, effectively discriminated MSI-H from microsatellite stable (MSS) and low-level microsatellite instability (MSI-L) and mutator phenotypes. Our findings indicate that familial colorectal cancer may be associated with multiple occurrences of colorectal or accompanying cancers and that family history could be correlated with microsatellite instability.
Familial Colorectal Cancer; Family History; Mutator Phenotype; Ncrosatellite Instability
Lymph node involvement is the most important prognostic factor of rectal cancer. Cancer originating from sites other than the rectum rarely metastasizes to the mesorectal lymph node. We report a rectal cancer patient with a synchronous metastatic prostatic carcinoma to the mesorectal lymph node.
Mesorectal; Lymph node; Prostatic carcinoma
The aim of this study was to evaluate the responsiveness to CPT-11 with respect to hMLH1 and hMSH2 protein expressions in primary colorectal tumors.
Materials and Methods
91 patients with colorectal cancer treated having undergone surgery and postoperative CPT-11-based adjuvant chemotherapy, between 1997 and 2002, were prospectively recruited. Tumor samples were immunohistochemically analyzed for the expressions of hMLH1, hMSH2, p53 and CEA proteins.
Of the 91 tumors, 6 (6.6%) and 4 (4.4%) showed loss of hMLH1 and hMSH2 protein expressions, respectively. The response rate of patients with tumors not expressing either hMLH1 or hMSH2 was higher than that of those expressing either of these proteins (p=0.026). Patients with tumors not expressing hMLH1 showed a significantly better response to CPT-11 (p=0.04). The responsiveness was not associated with the expressions of hMSH2, p53 or CEA. There were no correlations between drug toxicity and the expressions of hMLH1, hMSH2 or p53. The overall survival was better in patients responsive to CPT-11-based chemotherapy compared to non-responders.
The immunohistochemical determination of loss of hMLH1 and hMSH2 expressions may be used in determining the responsiveness to CPT-11-based chemotherapy. Our results suggest that hMLH1 protein expression may be a predictor for CPT-11 responsiveness in patients with colorectal cancer.
Colorectal neoplasm; CPT-11; Response; hMLH1; hMSH2
A diverting stoma is known to reduce the consequences of distal anastomotic failure following colorectal surgery. The aim of this study was to evaluate the efficacy of a diverting stoma after an ultra-low anterior resection (uLAR) for rectal cancer.
Between 2000 and 2007, 836 patients who underwent an uLAR were divided into two groups, depending on the fecal diversion: 246 received fecal diversion, and 590 had no diversion. Patient- and disease-related variables were compared between the two groups.
Thirty-two of the 836 patients (3.8%) had immediate anastomosis-related complications and required reoperation. Anastomosis leakage comprised 72% of the complications (23/32). The overall immediate complication rate was significantly lower in patients with a diverting stoma (0.8%, 2/246) compared to those without a diverting stoma (5.1%, 30/590; P = 0.005). The fecal diversion group had lower tumor location, lower anastomosis level, and more preoperative chemo-radiation therapy (P < 0.001). In total, 12% of patients in the diverting stoma group had complications either in making or reversing the stoma (30/246).
The diverting stoma decreased the rate of immediate anastomosis-related complications. However, the rate of complications associated with the diverting stoma was non-negligible, so strict criteria should be applied when deciding whether to use a diverting stoma.
Rectal neoplasms; Ileostomy; Colorectal surgery
Autophagy has paradoxical and complex functions in cancer development, and autophagy-related genes (ATG) are key regulators in autophagy. Until now, more than 30 different ATG proteins have been identified in yeast, and their mammalian counterparts also have been reported. Although the roles of a few ATG proteins in cancer have been characterized, the role of ATG10 is almost completely unknown.
To investigate the clinicopathological role of ATG10 in colorectal cancer, we analyzed ATG10 expression in colorectal cancer tissues and cell lines. Protein expression analysis showed that ATG10 is highly increased in colorectal cancer (tissue - 18/37 cases, 48%; cell line –8/12 cell lines, 66%). Immunohistochemical analysis with clinicopathological features indicated a strong association of the up-regulation of ATG10 with tumor lymph node metastasis (p = 0.005) and invasion (p<0.001). Moreover, both 5-year disease free survival and overall survival rates of patients bearing tumors that did not express ATG10 were significantly higher than those of patients bearing ATG10-expressing tumors (p = 0.012).
Increased expression of ATG10 in colorectal cancer is associated with lymphovascular invasion and lymph node metastasis indicating that ATG10 may be a potential prognostic maker in colorectal cancer.
To assess the incidence and factors predictive of early postoperative complications in Korean patients who undergo surgery for Crohn's disease (CD).
We retrospectively assessed 350 patients (246 males, 104 females; mean age, 30 ± 9 years) who underwent surgery for primary or recurrent CD at Asan Medical Center between January 1991 and May 2010. The incidence and predictive factors of early postoperative complications were analyzed by both univariate and multivariate analyses.
Of the 350 patients, 81 patients (23.1%) developed postoperative complications, the most common being septic complications (54 patients), including 19 cases of wound infection. Thirty patients (8.6%) required re-operations, and only one patient died. Multivariate analysis showed that four factors were independently associated with a high risk of early postoperative complications; preoperative moderate to severe anemia (hematocrit concentration <30%; odds ratio [OR], 3.1; 95% confidence interval [CI], 1.6 to 5.9), hypoalbuminemia (serum albumin level <3.0 g/dL; OR, 2.6; 95% CI, 1.4 to 4.7), emergency surgery (OR, 4.0; 95% CI, 1.5 to 10.6), and covering stoma (OR, 2.6; 95% CI, 1.3 to 5.4). Correction of preoperative moderate to severe anemia and hypoalbuminemia decreased the incidence of postoperative complications. Mean hospital stay was significantly longer in patients with than without postoperative complications (31.3 ± 27.2 days vs. 10.3 ± 3.8 days, P < 0.001).
Preoperative anemia, low albumin level, emergency surgery, and covering stoma significantly increased the risk of early postoperative complications in patients with CD. Correcting preoperatively deficient nutritional factors may reduce postoperative morbidities.
Crohn disease; Surgery; Korea; Risk factors; Postoperative complications
To evaluate the safety and effectiveness of a 20-mm diameter dual-design expandable colorectal stent for malignant colorectal obstruction.
Materials and Methods
The study series included 34 patients with malignant colorectal obstruction who underwent implantation of a 20-mm dual-design expandable colorectal stent in our department between March 2009 and June 2010. The 20-mm dual-design expandable colorectal stent was placed by using a 3.8-mm delivery system that had 28-mm diameter proximal and distal ends. Among the 34 patients, stent placement for palliation was performed in 20 patients, while stent placement for bridge to surgery was performed in 14 patients.
A 97% (33 of 34) success rate was achieved for the stent placement. The perforation rate in the bridge to surgery group was 7% (1 of 14), compared to 0% (0 of 19) in palliative group. Migration occurred in one of 33 patients (3%) at 30 days after stent placement.
The placement of a 20-mm diameter dual-design stent appears to be clinically safe and effective for the management of colorectal obstruction, with low perforation and migration rates.
Colorectal cancer; Stent; Dual-design; Expandable
The aim of this study was to evaluate outcomes of a total colectomy with ileorectal anastomosis in patients with slow transit constipation.
A retrospective review of 37 consecutive patients with slow transit constipation who underwent a total colectomy between 1994 and 2008 was undertaken. Preoperative and postoperative Wexner's constipation scores were collected and used to evaluate the outcomes after surgical treatment. Also patients' postoperative satisfaction scores were collected using a 4-point scale.
The 37 patients consisted of 31 women and 6 men, with a median age of 41 years (range, 17 to 71 years). Pre- and post-operative Wexner's scores were collected from 33 patients (89.1%), and the mean preoperative Wexner's score was 19.3 (range, 11 to 24), which decreased to an average post-operative score of 2.3 (range, 0 to 8). Neither intraoperative complications nor postoperative mortalities were noted. Five patients (13.5%) had early postoperative complications, and the most common complication was postoperative ileus (10.8%). Seven patients (18.9%) had late postoperative complications, and postoperative ileus (10.8%) was also the most common. Twenty seven of 33 patients were satisfied with their surgical outcome (81.8%).
A total colectomy with ileorectal anastomosis might be an effective surgical procedure with acceptable morbidity to treat medically intractable slow transit constipation.
Colonic inertia; Colectomy; Treatment outcome; Postoperative complication
To determine the role of methylation in colorectal cancer patients with a family history, we enrolled 25 colorectal cancer patients with a family history of colorectal cancer but without a mutation in the hMLH1 and hMSH2 genes. Thirty patients with sporadic colorectal cancer were included as control. The methylation status of COX2, MGMT, hMLH1, TIMP3, p16, and MINT2 in normal mucosa and tumor were assessed using methylation-specific PCR. In patients with a family history, the methylation frequency ranged from 4.0% for TIMP3 to 44.4% for MGMT, whereas, in patients with sporadic colorectal cancer, it ranged from 6.7% for TIMP3 to 50.0% for p16. Nine of the 25 patients with family history (36.0%) were classified as methylation-prone, and nine of the 30 patients with sporadic cancers (30.0%) were as methylation-prone, making their methylation indices 0.19 and 0.16, respectively (p=0.522). As for the individual genes, the methylation rate of MGMT was higher in colorectal cancer patients with family history (44.0% vs. 13.0%, p=0.016), whereas the methylation rate of p16 was higher in sporadic colorectal cancers (50.0% vs. 8.7%, p=0.046). While CpG island methylation of tumor suppressor genes may play a role in colorectal carcinogenesis, the genes involved may be different between tumors of patients with and without a family history of colorectal cancer.
Colorectal Neoplasms; Familial; Carcinogenesis; Methylation; Microsatellite Instability
Granulocytic sarcoma is an extramedullary tumor composed of immature granulocytic cells. These tumors usually occur simultaneously with or follow after the onset of acute myeloid leukemia (AML) or other myeloproliferative disorders. Rarely, it is the first manifestation of AML which appears several months before the onset of leukemia. We report a case of a 48-year-old man presenting with symptoms of small bowel obstruction. Laparotomy and open biopsy were performed. Immunohistochemical studies showed that the neoplastic cells were of myeloid lineage positive for myeloperoxidase and leukocyte common antigen, but negative for CD3, 20, 56, 79a, and cytokeratin. Initially, there was no evidence of blood or bone marrow involvement suggesting acute leukemia or other myeloproliferative disorders. The findings were consistent with the diagnostic findings of solitary granulocytic sarcoma (preleukemic). However, one month later, bone marrow biopsy revealed 57% myeloblasts. Sequentially, the patient developed FAB M2 acute myeloid leukemia. Induction chemotherapy including cytarabine and idarubicine was done which led to complete remission. Allograft bone marrow transplantation was performed later, and there is no evidence of recurrence till present.
Granulocytic sarcoma; Acute myeloid leukemia; Small bowel obstruction
Colonic hamartomas are rare polypoid lesions. We report an unusual case of multiple colonic hamartomatous polyps, including a giant hamartoma, unrelated to hereditary or familial polyposis syndromes, in a 48-year-old man. The diameter of the largest polyp was 9.5 cm, and endoscopy revealed that the lesion caused colonic obstruction. The clinical, endoscopic and histological aspects of this case are discussed.
Hamartoma; giant hamartoma
Capecitabine is an oral fluoropyrimidine carbamate and it is known as an effective radiosensitizer. Capecitabine and its metabolite reach their peak concentration in the plasma at 1~2 hours after a single oral administration of capecitabine and the levels fall rapidly thereafter. To verify the radiosensitizing effect of capecitabine that is based on such pharmacokinetic characteristics, we performed a retrospective analysis on the optimal timing of capecitabine administration with performing preoperative chemoradiation for locally advanced rectal cancer.
Materials and Methods
Among 171 patients who were treated with preoperative radiotherapy and concurrent capecitabine administration for rectal cancer, 56 patients were administered capecitabine at 1~2 hours before radiotherapy (group A), and at other time in the other 115 patients (group B). Total mesorectal excision was done at 4 to 6 weeks after the completion of chemoradiation. The radiosensitizing effect of capecitabine was evaluated on the basis of the pathological response.
Complete pathological regression of the primary tumor was observed in 12 patients (21.4%) for group A and in 11 patients (9.6%) for group B (p=0.031). Residual disease less than 0.5 cm (a good response) was observed in 19 patients (33.9%) for group A and in 23 patients (20.0%) for group B (p=0.038). On multivariate analysis, the capecitabine ingestion time showed marginal significance.
When performing preoperative chemoradiation for locally advanced rectal cancer, the radiosensitizing effect of capecitabine was enhanced when it was administered 1 hour before radiotherapy.
Rectal neoplasms; Combined modality therapy; Capecitabine