Long-term results of adipose-derived stem cell therapy for the treatment of Crohn's fistula

A previous phase II clinical trial of adipose-derived stem cell (ASC) therapy for fistulae associated with Crohn's disease, a devastating condition with a high recurrence rate, demonstrated safety and therapeutic potential with a 1-year sustained response. In the present study, 41 of the 43 phase II trial patients were followed for an additional year, regardless of response in the initial year. At 24 months, complete healing was observed in 21 of 26 patients (80.8%) in modified per protocol analysis and 27 of 36 patients (75.0%) in modified intention-to-treat analysis. No adverse events related to ASC administration were observed. Furthermore, complete closure after initial treatment was well-sustained. These results strongly suggest that autologous ASCs may be a novel treatment option for Crohn's fistulae.

Ratio of metastatic lymph nodes is more important for rectal cancer patients treated with preoperative chemoradiotherapy

AIM: To evaluate the predictive value of the lymph node (LN) ratio (LNR, number of metastatic LNs/ examined LNs) for recurrence in patients with rectal cancer and to compare its applicability according to preoperative chemoradiotherapy (PCRT).

METHODS: From 2000 to 2009, 967 patients with metastatic LNs after curative resection for locally advanced rectal cancer were identified. Patients were categorized according to PCRT (PCRT vs No PCRT). The cut-off LNR was determined based on the pN1 vs pN2 when the recommended number of LNs was harvested. The 5-year recurrence-free survival (RFS) rates using the Kaplan-Meier method were compared according to p/yp N stage and the LNR in each group.

RESULTS: Among patients with the same p/ypN stage, the 5-year RFS rate differed according to the LNR. In addition, the 5-year RFS rate was significantly different between pN and LNR groups in patients with No PCRT. In PCRT group, however, only LNR was associated with prognosis. On multivariate analysis, both pN and LNR were significant independent prognostic factors for 5-year RFS in the No PCRT group. In the PCRT group, only LNR category was found to be associated with RFS (HR = 2.36, 95%CI: 1.31-3.84, and P = 0.001).

CONCLUSION: The LNR is an important prognostic predictor of RFS in rectal cancer patients especially treated with PCRT. Current pN categories could not discriminate between prognostic groups of RFS after PCRT.

Preliminary Suggestion about Staging of Anorectal Malignant Melanoma May Be Used to Predict Prognosis

PURPOSE

Anorectal malignant melanomas (AMM) are rare and have poor survival. The study aims to evaluate the clinicopathologic characteristics and outcomes of patients with AMM, and to devise a staging system predictive of survival outcome.

MATERIALS AND METHODS

This was a retrospective study of 28 patients diagnosed with, and treated for AMM. Patients classified by clinical staging of mucosal melanoma (MM) were reclassified via rectal and anal TNM staging. Survival outcomes were compared among patients grouped by the three different staging systems.

RESULTS

The three staging systems were equated with similar figures for 5-year overall survival (OS) and 5-year disease-free survival (DFS) of patients diagnosed with stage I disease. Patients (n=19) diagnosed with MM stage II disease were reclassified by rectal TNM staging into three subgroups: IIIA, IIIB, and IIIC. For these patients, both 5-year OS and 5-year DFS differed significantly between the subgroups IIIA and IIIC (OS: IIIA vs. IIIC, 66.7% vs. 0%, p=0.002; DFS: IIIA vs. IIIC, 51.4% vs. 0%, p < 0.001).

CONCLUSION

The accuracy of prognosis in patients diagnosed with AMM and lymph node metastasis has improved by using rectal TNM staging, which includes information regarding the number of lymph node metastases.

Effectiveness of adjuvant radiotherapy after local excision of rectal cancer with deep submucosal invasion: a single-hospital, case-control analysis

BACKGROUND

The role of postoperative radiation therapy (RT) after local excision (LE) of deep submucosal invasive rectal cancer remains unclear. We evaluated the efficacy of adjuvant RT after LE of early rectal cancer with deep submucosal invasion.

METHODS

We screened 227 patients who underwent transanal excision or endoscopic removal of deep submucosal invasive rectal cancer between 1992 and 2012, of which 66 did not undergo radical surgery owing to the patient's preference or poor medical conditions. Of these, 35 (53 %) underwent LE alone (LE group) and 31 (47 %) received adjuvant RT after LE (LE + RT group). Nine patients in the RT group received concurrent adjuvant chemotherapy with 5-fluorouracil. Two independent pathologists reviewed histological data.

RESULTS

The mean age of patients in the LE + RT and LE groups was 59.5 ± 9.6 and 55.3 ± 11.2 years, respectively. The mean follow-up duration was 78.7 ± 66.7 months in the LE + RT group and 70.5 ± 45.7 months in the LE group. Cancer eventually recurred in six patients (9.1 %; two in the LE + RT group and four in the LE group). In five of these patients, recurrence occurred within 4 years after the initial treatment. The other patient, who was in the LE group, exhibited multiple lymph node metastases at the 116-month follow-up. Kaplan-Meier estimates of recurrence-free survival at 5 years after treatment were 96.8 % in the LE + RT group and 97 % in the LE group (P = 0.657).

CONCLUSION

RT after LE of early rectal cancer with deep submucosal invasion might not improve recurrence-free survival compared with LE alone.

The risk of colorectal cancer in inflammatory bowel disease: a hospital-based cohort study from Korea

OBJECTIVE

Limited data are available on the incidence and risk factors of colorectal cancer (CRC) in Asian patients with inflammatory bowel disease (IBD).

MATERIAL AND METHODS

Information on 5212 Korean patients with IBD (2414 with Crohn's disease [CD] and 2798 with ulcerative colitis [UC]) was retrieved from the IBD registry of Asan Medical Center. Data on CRC incidence for the entire Korean population were derived from the Korean Statistical Information Service.

RESULTS

During 39,951 person-years of follow-up (17,679 for CD and 22,272 for UC), 30 patients (12 with CD and 18 with UC) developed CRC. The standardized incidence ratio (SIR) of CRC was 6.0 (95% confidence interval [CI], 3.10-10.48) for CD and 1.68 (95% CI, 1.00-2.66) for UC; it was 9.69 (95% CI, 5.01-16.93) for CD with colonic involvement and 4.31 (95% CI, 2.46-7.00) for extensive UC. The SIR was also increased in patients diagnosed with IBD at younger than 30 years old. CRC location was the low rectum in 11 of 12 CD patients (91.7%). The cumulative probability of rectal cancer was higher in CD patients with a perianal fistula than in those without a perianal fistula (p = 0.02).

CONCLUSIONS

A high prevalence of perianal fistulas in Korean CD patients may be the cause of the predominance of low rectal cancer in this population and the higher SIR of CRC in Koreans than in Westerners. In contrast, the SIR of CRC in Korean UC patients may be similar to that in Western UC patients.

Long-term prognosis of ulcerative colitis and its temporal change between 1977 and 2013: a hospital-based cohort study from Korea

BACKGROUND AND AIMS

No previous large-scale studies have evaluated the prognosis of ulcerative colitis (UC) over a period of three decades in a non-Caucasian population. The aims of this study were to update the current information on the natural course of UC in a sizable cohort of Korean patients and to evaluate changes in the treatment paradigms and prognosis of UC over time.

METHODS

We retrospectively analyzed 2802 Korean UC patients who visited Asan Medical Center. We divided the study subjects into three groups based on the year of diagnosis (cohort 1: 1977–1999; cohort 2: 2000–2006; and cohort 3: 2007–2013).

RESULTS

Five-year cumulative probabilities of prescription of thiopurines (azathioprine or 6-mercaptopurine) and anti-tumor necrosis factor (anti-TNF) agents were 4.1% and 0.0%, respectively, in cohort 1 and 27.9% and 12.7%, respectively, in cohort 3 (P < 0.001). A total of 209 patients (7.5%) underwent colectomy, producing cumulative probabilities of colectomy at 10, 20 and 30 years after diagnosis of 7.8%, 14.2% and 21.3%, respectively. The cumulative probability of colectomy was especially low in patients first diagnosed at our center: 3.1% at 10 years and 4.5% at 20 years. Moreover, the cumulative probability of colectomy decreased significantly over the last 30 years (P = 0.039).

CONCLUSION

Thiopurines and anti-TNF agents are used increasingly more frequently and earlier, while the colectomy rate has decreased over the last 30 years in Korean patients with UC. Korean UC patients may have a better clinical course than Western cases, as indicated by a lower colectomy rate.

Impression of prognosis regarding pathologic stage after preoperative chemoradiotherapy in rectal cancer

AIM: To ascertain pathologic stage as a prognostic indicator for rectal cancer patients receiving preoperative chemoradiotherapy (PCRT).

METHODS: Patients with mid- and low rectal carcinoma (magnetic resonance imaging - based clinical stage II or III) between 2000 and 2009 and treated with curative radical resection were identified. Patients were divided into two groups: PCRT and No-PCRT. Recurrence-free survival (RFS) was examined according to pathologic stage and addition of adjuvant treatment.

RESULTS: Overall, 894 patients were identified. Of these, 500 patients received PCRT. Adjuvant chemotherapy was delivered to 81.5% of the No-PCRT and 94.8% of the PCRT patients. Adjuvant radiotherapy was given to 29.4% of the patients in the No PCRT group. The 5-year RFS for the No-PCRT group was 92.6% for Stage I, 83.3% for Stage II, and 72.9% for Stage III. The 5-year RFS for the PCRT group was 95.2% for yp Stage 0, 91.7% for yp Stage I, 73.9% for yp Stage II, and 50.7% for yp Stage III.

CONCLUSION: Pathologic stage can predict prognosis in PCRT patients. 5-year RFS is significantly lower among PCRT patients than No-PCRT patients in pathologic stage II and III. These results should be taken into account when considering adjuvant treatment for patients treated with PCRT.

TFAP2E methylation status and prognosis of patients with radically resected colorectal cancer

OBJECTIVES

This study investigates the clinical significance of the gene encoding AP-2ε (TFAP2E) in colorectal cancer (CRC) patients undergoing curative resection.

METHODS

A single-institution cohort of 248 patients who underwent curative resection of stage I/II/III CRCs between March and December 2004 was enrolled, and 193 patients whose tumors were available for the determination of the TFAP2E methylation status were included in the analysis.

RESULTS

TFAP2E hypermethylation was detected in 112 patients (58%) and was significantly associated with distally located CRCs, low pathologic T stage (T1/T2), and stage I tumors. After a median follow-up of 86.3 months, the patients with TFAP2E hypermethylation tended to show better relapse-free survival (RFS) and overall survival (OS) than the patients with TFAP2E hypomethylation (5-year RFS rate: 90 vs. 80%, p = 0.063; 6-year OS rate: 88 vs. 80%, p = 0.083). Multivariate analysis showed that the pathologic nodal stage and TFAP2E methylation status were independent prognostic factors for RFS and OS, and they remained significant factors in the subgroup analysis that included 154 patients with stage II/III CRCs who had received adjuvant chemotherapy.

CONCLUSIONS

TFAP2E hypermethylation is associated with good clinical outcomes and may be considered as an independent prognostic factor in patients with curatively resected CRCs.

Incremental value of liver MR imaging in patients with potentially curable colorectal hepatic metastasis detected at CT: a prospective comparison of diffusion-weighted imaging, gadoxetic acid-enhanced MR imaging, and a combination of both MR techniques

PURPOSE

To prospectively compare diagnostic performance of diffusion-weighted (DW) imaging, gadoxetic acid-enhanced magnetic resonance (MR) imaging, both techniques combined (combined MR imaging), and computed tomography (CT) for detecting colorectal hepatic metastases and evaluate incremental value of MR for patients with potentially curable colorectal hepatic metastases detected with CT.

MATERIALS AND METHODS

In this institutional review board-approved prospective study, with informed consent, 51 patients (39 men, 12 women; mean age, 62 years) with potentially resectable hepatic metastases detected with CT underwent liver MR, including DW imaging and gadoxetic acid-enhanced MR. Two independent readers reviewed DW, gadoxetic acid-enhanced, combined MR, and CT image sets to detect hepatic metastases. The figure-of-merit (FOM) value representing overall diagnostic performance, sensitivity, and positive predictive value (PPV) for each image set were analyzed by using free-response receiver operating characteristic analysis and generalized estimating equations.

RESULTS

There were 104 hepatic metastases in 47 patients. The pooled FOM values, sensitivities, and PPVs of combined MR (FOM value, 0.93; sensitivity, 98%; and PPV, 88%) and gadoxetic acid-enhanced MR (FOM value, 0.92; sensitivity, 95%; and PPV, 90%) were significantly higher than those of CT (FOM value, 0.82; sensitivity, 85%; and PPV, 73%) (P < .006). The pooled FOM value and sensitivity of combined MR (FOM value, 0.92; sensitivity, 95%) was also significantly higher than that of DW imaging (FOM value, 0.82; sensitivity, 79%) for metastases (≤1-cm diameter) (P ≤ .003). DW imaging showed significantly higher pooled sensitivity (79%) and PPV (60%) than CT (sensitivity, 50%; PPV, 33%) for the metastases (≤1-cm diameter) (P ≤ .004). In 47 patients with hepatic metastases, combined MR depicted more metastases than CT in 10 and 14 patients, respectively, according to both readers.

CONCLUSION

Gadoxetic acid-enhanced MR and combined MR are more accurate than CT in detecting colorectal hepatic metastases, have an incremental value when added to CT alone for detecting additional metastases, and can be routinely performed in patients with potentially curable hepatic metastases detected with CT.

TNFSF15 is an independent predictor for the development of Crohn's disease-related complications in Koreans

BACKGROUND

Crohn's disease (CD) is a chronic idiopathic inflammatory bowel disease involving the whole gastrointestinal tract. TNFSF15 has been proved as a susceptibility gene for CD, but there are few reports about the association between TNFSF15 single nucleotide polymorphisms (SNPs) and the clinical course of CD.

AIM

To investigate the association between TNFSF15 genotypes and the clinical course of CD in Koreans.

METHODS

A total of 906 CD patients having TNFSF15 genotype data and clinical information were recruited from CD registry database of a tertiary referral center. The association between five TNFSF15 SNPs (rs4574921, rs3810936, rs6478108, rs6478109, and rs7848647) and various clinical parameters including stricture, non-perianal penetrating complications, bowel resection, and reoperation was investigated.

RESULTS

Among the five SNPs, rs6478108 CC genotype was associated with the development of stricture and non-perianal penetrating complications during follow-up (HR for stricture=1.706, 95% confidence interval 1.178-2.471, P=0.005; HR for non-perianal penetrating complications=1.667, 95% confidence interval 1.127-2.466, P=0.010), and rs4574921 CC genotype was associated with the development of perianal fistula (HR=2.386, 95% confidence interval 1.204-4.727, P=0.013) by multivariate analysis. However, there was no significant association of cumulative operation and reoperation rate with 5 SNPs of TNFSF15.

CONCLUSION

In Korean patients with CD, non-risk allele homozygotes of TNFSF15 SNPs rs6478108 and rs4574921 are independent genetic predictive factors for the development of strictures/non-perianal penetrating complications and perianal fistula, respectively.

The role of surgical resection following imatinib treatment in patients with recurrent or metastatic gastrointestinal stromal tumors: results of propensity score analyses

BACKGROUND

Although benefits of surgical resection of residual gastrointestinal stromal tumors (GISTs) after imatinib therapy have been suggested, those benefits over imatinib alone have not been proven. We compared the clinical outcomes of surgical resection of residual lesions after imatinib treatment (S group) with imatinib treatment alone (NS group) in patients with recurrent or metastatic GISTs.

METHODS

A total of 134 patients (42 in the S group, 92 in the NS group) with recurrent or metastatic GIST who had stable disease for more than 6 months after responding to imatinib were included.

RESULTS

There were no statistically significant differences in the baseline characteristics of the S and NS groups except for age and number of peritoneal metastases. The median follow-up period was 58.9 months. Progression-free survival (PFS) and overall survival (OS) were significantly longer in the S group compared with the NS group (median PFS: 87.7 vs. 42.8 months, p = 0.001; median OS: not reached vs. 88.8 months, p = 0.001). Multivariate analysis revealed that S group, female sex, KIT exon 11 mutations, and low initial tumor burden were associated with longer PFS, and S group and low initial tumor burden were associated with a longer OS. Even after applying inverse probability of treatment weighting adjustment, the S group demonstrated significantly better outcomes in terms of PFS (HR 2.326; 95 % confidence interval [CI] 1.034-5.236; p = 0.0412) and OS (HR 5.464; 95 % CI 1.460-20.408; p = 0.0117).

CONCLUSION

Surgical resection of residual lesions after disease control with imatinib is likely to be beneficial to patients with recurrent or metastatic GISTs.

Adenomatous neoplasia: postsurgical incidence after normal preoperative CT colonography findings in the colon proximal to an occlusive cancer

PURPOSE

To determine the postoperative incidence of adenomatous neoplasia in the colon proximal to an occlusive colorectal cancer where preoperative computed tomographic (CT) colonography findings were normal.

MATERIALS AND METHODS

Institutional review board approval, with a waiver of informed consent, was obtained. This observational study included patients with occlusive colorectal cancer who underwent preoperative CT colonography between April 2007 and March 2010 that revealed normal findings (ie, no lesions ≥ 6 mm) in the proximal colon and who underwent postoperative colonoscopy. The primary outcome was postoperative colonoscopic discovery of clinically relevant lesions (ie, nondiminutive [≥ 6 mm] adenomas, advanced adenomas, or cancers) in the proximal colon. The cumulative incidence of clinically relevant lesions in preoperatively normal proximal colon over the postsurgical follow-up time was analyzed by using the Kaplan-Meier method.

RESULTS

The final cohort included 204 patients (102 men and 102 women; mean age, 57.3 years ± 11.3 [standard deviation]). At a total of 435 postoperative colonoscopies performed over a median follow-up of 29 months (range, 1-74 months), clinically relevant lesions were detected in the proximal colon in 30 patients: Nonadvanced adenomas were detected in 23 patients, and advanced adenomas were detected in seven patients. The cumulative incidence of clinically relevant adenomatous lesions in the preoperatively normal proximal colon 12 and 18 months after preoperative CT colonography was 8.1% (95% confidence interval [CI]: 3.9%, 12.2%) and 9.6% (95% CI: 5%, 14%), respectively. Clinically relevant adenomatous lesions found in the proximal colon within 18 months of preoperative CT colonography were nonadvanced adenomas in 10 of 15 patients.

CONCLUSION

When the portion of the colon proximal to an occlusive cancer is devoid of nondiminutive lesions at preoperative CT colonography, colonoscopy of the proximal colon following cancer resection rarely finds clinically relevant lesions and is unlikely to reveal any lesions requiring immediate removal until routine 1-year postsurgical follow-up. Online supplemental material is available for this article .

Comparison of abdominal and perineal procedures for complete rectal prolapse: an analysis of 104 patients

Purpose

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.

Methods

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.

Results

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.

Conclusion

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.

Current issues in locally advanced colorectal cancer treated by preoperative chemoradiotherapy

In patients with locally advanced rectal cancer, preoperative chemoradiotherapy has proven to significantly improve local control and cause lower treatment-related toxicity compared with postoperative adjuvant treatment. Preoperative chemoradiotherapy followed by total mesorectal excision or tumor specific mesorectal excision has evolved as the standard treatment for locally advanced rectal cancer. The paradigm shift from postoperative to preoperative therapy has raised a series of concerns however that have practical clinical implications. These include the method used to predict patients who will show good response, sphincter preservation, the application of conservative management such as local excision or “wait-and-watch” in patients obtaining a good response following preoperative chemoradiotherapy, and the role of adjuvant chemotherapy. This review addresses these current issues in patients with locally advanced rectal cancer treated by preoperative chemoradiotherapy.

Rectal gastrointestinal stromal tumor: clinical features, endoscopic findings and prognosis

BACKGROUND/AIMS

Rectal gastrointestinal stromal tumor (GIST) accounts for only a small portion of all GISTs, and reports regarding its clinical features and endoscopic findings are still lacking.

METHODOLOGY

Thirty-two patients diagnosed as rectal GIST at Asan Medical Center, a tertiary university hospital in Korea between May 2003 and January 2011 were enrolled.

RESULTS

The median age was 54 years (range, 31-79) with 18 males (56.2%). Common symptoms were hematochezia, anal pain, and defecation difficulty, although 11 patients were asymptomatic. The median size of tumor was 6.1 cm (range, 0.4-12.0 cm), and the median distance from the anal verge was 4 cm (range, 3 cm). The most common endoscopic finding was subepithelial tumor with normal overlying mucosa (63.1%), followed by subepithelial tumor with erosion, ulceration, or bleeding (31.6%). Preoperative imatinib was administered in eight patients (25.0%) that helped the downsizing the tumor and anal sphincter preserved. High-risk group by NIH risk classification and tumor size were associated with tumor recurrence, with the overall five-year recurrence-free survival of 67.2%.

CONCLUSIONS

Common endoscopic feature of rectal GIST was subepithelial tumor with normal mucosa. Patients treated by definite resection with or without imatinib for rectal GIST seem to show a favorable clinical course.

Development and characterization of a colon PDX model that reproduces drug responsiveness and the mutation profiles of its original tumor

Cultures of primary tumors are very useful as a personalized screening system for effective therapeutic options. We here describe an effective method of reproducing human primary colon tumors through primary culture and a mouse xenograft model. A total of 199 primary colon tumor cultures were successfully established under optimized conditions to enrich for tumor cells and to expand it for long-term storage in liquid nitrogen. To examine whether these stored cultures retained original tumor properties, fifty primary cultures were xenografted into NOD-SCID mouse. Histological and tumor marker analysis of four representative tumor xenografts revealed that all of the xenograft retained its primary tumor characteristics. Oncomap analysis further showed no change in the major mutations in the xenografts, confirming that our method faithfully reproduced human colon tumors. A drug sensitivity assay revealed that two of the primary cultures were hypersensitive to oxaliplatin rather than 5-FU, which was used in the patients, suggesting it as an effective therapeutic option. We thus present an effective, reproducible preclinical model for testing various personalized therapeutic options in colon cancer patients.

Clinical implication of additional selective lateral lymph node excision in patients with locally advanced rectal cancer who underwent preoperative chemoradiotherapy

PURPOSE

To identify the indication and prognostic significance of lateral lymph node (LLN) excision in locally advanced rectal cancer patients underwent preoperative chemoradiotherapy.

METHODS

Included were 67 consecutive patients with suspicious LLN metastasis who underwent chemoradiotherapy and surgery including selective LLN excision (82 excisions). The excisions were grouped according to the presence of LLN metastasis and compared in terms of the clinicopathological findings and oncological results. The correlation between the largest short-axis diameter of LLN measured by imaging and metastasis rates was explored.

RESULTS

LLN metastases were identified in 32 excisions (40.0 %). The calculated short-axis LLN diameter predicting metastasis was 11.7 mm (before chemoradiotherapy) and 11.4 mm (before surgery). LLN metastasis was observed more frequently in the low rectum (p = 0.031) and associated with higher CEA levels (p = 0.048). The 3-year overall survival rates for patients with and without LLN metastasis were 60.3 % and 90.3 % (p = 0.048), while the 3-year disease-free survival rates were 31.4 % and 70.5 % (p = 0.009). The hazard ratio of LLN metastasis for recurrence was 2.938 (95 % CI = 1.258-6.863).

CONCLUSIONS

LLN metastasis in rectal cancer patients underwent chemoradiotherapy was a distinct poor prognostic factor. Selective LLN excision based on imaging studies may have a role for such patients.

Characteristics and survival of korean anal cancer from the Korea central cancer registry data

Purpose

In Korea, anal cancer is rare disease entity with specific clinical characteristics. Therefore, no survival analysis with a sufficient patient population has been performed. The aim of this study was to evaluate the characteristics of Korean anal cancer, focusing on the survival according to tumor histologies, sex, and a specific age group, using the nationwide cancer registry.

Methods

Using the Korea Central Cancer Registry, we analyzed a total of 2,552 cases from 1993 to 2010. We assessed the 5-year relative survival by using tumor histology. In addition, survival differences of Surveillance Epidemiology and End Results (SEER) stage were analyzed for both sexes and for young-age cancer (younger than 40 years) and advanced-age cancer (older than 70 years).

Results

The 5-year relative survival among anal cancer patients increased from 38.9% for the period 1993-1995 to 65.6% for the period 2006-2010. The anal squamous cell carcinoma was the most common histology and showed better survival than other types of cancer. Females demonstrated better survival than males in all SEER stages. The 5-year survivals for patients in whom anal cancer developed before the age of 40 and at or after the age of 40 were 62.4% and 51.6%, respectively. The 5-year survival for patients in whom cancer developed at or after the age of 70 was much worse than that for patients in whom the cancer had developed prior to that age.

Conclusion

Korean anal cancer has certain distinctive characteristics of survival according to tumor histology, sex, and age. Despite limitations on available data, this study used the nationwide database to provide important information on the survival of Korean patients with anal cancer.

Prognostic impact of diagnosing colorectal neuroendocrine carcinoma using the World Health Organization 2010 classification

BACKGROUND

Neuroendocrine carcinomas (NECs) arising in the large intestine are rare neoplasms with highly aggressive behavior. The aim of the study was to compare the 2000 and 2010 World Health Organization (WHO) classification of these colorectal NECs.

METHODS

We conducted a retrospective study of patients diagnosed with colorectal NECs according to the WHO 2000 classification who underwent surgery at the Asan Medical Center between May 2000 and December 2010. The data were reevaluated to assess their consistency with the WHO 2010 classification.

RESULTS

For 20 of the 34 patients (59%), the 2000 and 2010 WHO classifications yielded the same NEC diagnosis (NEC group), whereas for 14 of the 34 patients (41%), the WHO 2010 classification mandated a diagnosis of G1 or G2 neuroendocrine tumors (NETs) rather than NECs (G1/G2 NET group). The NEC group was older than the G1/G2 NET group (64 vs 55 years; P = .05). Tumor differentiation in the NEC group was poorer than in the G1/G2 NET group (percentage of poorly differentiated tumor, 70% vs 7%; P < .001). In both groups based on the 7th American Joint Committee on Cancer staging, most of the tumors were advanced at the time of diagnosis, reaching stage IIIB (6 NEC vs 10 NET) and stage IV (10 NEC vs 3 NET). The 5-year overall survival in the 2 groups was different (P = .02), but not the 5-year disease-free survival (P = .24).

CONCLUSION

These results indicate that the WHO 2010 classification of colorectal NEC is more accurate and has better prognostic value than the WHO 2000 classification.

The effects of surgical cytoreduction prior to imatinib therapy on the prognosis of patients with advanced GIST

BACKGROUND

Baseline tumor size is one of important prognostic factors for imatinib therapy in patients with advanced gastrointestinal stromal tumor (GIST). The purpose of this study was to determine whether surgical cytoreduction before imatinib therapy can improve the prognosis.

METHODS

A total of 249 patients with advanced GIST were reviewed retrospectively. Patients were categorized into two groups according to the degree of initial cytoreduction: 35 patients with ≥75 % of initial tumor bulk removed (cytoreduction group) and the other 214 patients (no cytoreduction group). The median follow-up was 44.0 months.

RESULTS

Patients in the cytoreduction group were younger, in better performance, showed more initially metastatic disease, peritoneal metastases, but fewer liver metastases. The baseline tumor size when starting imatinib became significantly reduced in the cytoreduction group, which made significant difference between the two groups. By multivariate analyses, mutational status, tumor size, and granulocyte count at presentation were associated with progression-free survival. Age and tumor size were associated with overall survival. However, initial cytoreduction was not significantly related to the prognosis.

CONCLUSIONS

Cytoreduction before imatinib therapy appears not to improve the prognosis. Imatinib therapy should still represent the initial treatment for advanced GIST.

Poorly differentiated colorectal cancers: correlation of microsatellite instability with clinicopathologic features and survival

OBJECTIVES

To evaluate the association of microsatellite instability (MSI) with clinicopathologic features and oncologic outcomes in patients with poorly differentiated colorectal cancer (PD).

METHODS

Study patients were divided into well-differentiated colorectal cancer (WD) and PD, which were compared according to histologic differentiation and MSI status.

RESULTS

Among 1,941 patients, PD was more frequent among microsatellite-unstable tumors (23.6%) than among microsatellite-stable (MSS) tumors (4.2%, P < .001). Patients with PD had worse 4-year overall survival rates than patients with WD (78.6% vs 88.2%, P = 0.010). Compared with MSS-PD tumors, MSI-PD tumors were characterized by right-colon predilection, larger size, and infrequent lymph node metastasis (P < .001 to P = .007).

CONCLUSIONS

The clinicopathologic characteristics of PD were closely associated with those of MSI. The outcomes of MSI-PD tumors were better than those of MSS-PD tumors, but this finding did not reach statistical significance.