Phase II Study of Preoperative Capecitabine and Oxaliplatin-based Intensified Chemoradiotherapy With or Without Induction Chemotherapy in Patients With Locally Advanced Rectal Cancer and Synchronous Liver-limited Resectable Metastases

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Objectives:

Controversy surrounds the management of patients with locally advanced rectal cancer with synchronous resectable liver metastases (LMs). This study was designed to improve both systemic and local control in these patients.

Methods:

Patients with locally advanced rectal cancer (cT3-4N0 or cTanyN1-2) and synchronous resectable liver-limited metastases (cM1a) were randomly assigned to receive either preoperative treatments of induction CapeOx, followed by chemoradiotherapy with CapeOx (CapeOx-RT) (arm A) or CapeOx-RT alone (arm B). Induction CapeOx consisted of oxaliplatin 130 mg/m² on day 1 and capecitabine 1000 mg/m² twice daily on days 1 to 14, every 3 weeks for 2 cycles; CapeOx-RT consisted of radiotherapy with 45 Gy/25 daily fractions±5.4 Gy/3 fractions, oxaliplatin 50 mg/m² weekly for 5 weeks, and capecitabine 825 mg/m² twice daily on days 1 to 38. Total mesorectal excision and simultaneous liver metastasectomy were planned within 6 weeks after completion of preoperative treatments. The primary endpoint was R0 resection rate of both the primary tumor and LMs.

Results:

Thirty-eight patients were randomly assigned to the present study, 18 to arm A and 20 to arm B. The overall R0 resection rate for both the primary tumor and LMs was 77.8% in arm A and 70.0% in arm B (P=0.72). The median progression-free survival was 14.2 versus 15.1 months (P=0.422) and the 3-year overall survival rate was 75.0% versus 88.8% (P=0.29), respectively.

Conclusions:

Both treatment strategies showed considerable R0 resection rates; however, further study will be warranted to apply these intensified strategies in clinical practice.

Prediction of radio-responsiveness with immune-profiling in patients with rectal cancer

We evaluate whether the tumor immune infiltrate (TIL) could be used for prediction of responsiveness to preoperative chemoradiotherapy (PCRT) in rectal cancers. Using formalin-fixed paraffin-embedded slides of pretreatment biopsies, co-stain for CD4, CD8, CD274 (PD-L1), FOXP3, cytokeratin, and DAPI was performed with Opal multi staining kit (Perkin-Elmer, Waltham, MA). Multispectral imaging and digital analysis to visualize and quantify specific immune infiltrates were performed using the Vectra imaging system (Perkin-Elmer). The density (number of cells per mm²) and proportion of total TILs and specific cell types in the stroma were calculated by inForm™ 2.2.1 software (Perkin-Elmer). The density and proportion of total TILs and specific cell types in the stroma were calculated by inForm™ 2.2.1 software (Perkin-Elmer, Waltham, MA). Patients were classified as group with total regression (TR, n = 25) and group with residual disease (near total, moderate, and minimal regression, RD, n = 50). The mean density of T cell infiltration and CD274 (PD-L1)+ lymphocyte were significantly higher in TR (p = 0.005, p = 0.001). The proportion of CD4+ lymphocyte (p=0.042) and CD274 (PD-L1)+ lymphocyte (p = 0.002) were different between 2 groups. The TR group has lower CD4+ and higher CD274 (PD-L1)+ proportions than RD group. The ratio among CD4+, CD8+, CD274 (PD-L1)+, FOXP3+ T cell was different between groups. TR group showed lower CD4/ CD274 (PD-L1) (p = 0.007), CD8/ CD274 (PD-L1) (p = 0.02), and FOXP3/ CD274 (PD-L1) (p = 0.003) ratio than RD group. The determination of the immune infiltrate in biopsies before treatment could be a valuable information for the prediction of responsiveness to PCRT.

Effect of time interval between capecitabine intake and radiotherapy on local recurrence-free survival in preoperative chemoradiation for locally advanced rectal cancer

Purpose

The concentration of capecitabine peaks at 1–2 hours after administration. We therefore assumed that proper timing of capecitabine administration and radiotherapy would maximize radiosensitization and influence survival among patients with locally advanced rectal cancer.

Materials and Methods

We retrospectively reviewed 223 patients with locally advanced rectal cancer who underwent preoperative chemoradiation, followed by surgery from January 2002 to May 2006. All patients underwent pelvic radiotherapy (50 Gy/25 fractions) and received capecitabine twice daily at 12-hour intervals (1,650 mg/m²/day). Patients were divided into two groups according to the time interval between capecitabine intake and radiotherapy. Patients who took capecitabine 1 hour before radiotherapy were classified as Group A (n = 109); all others were classified as Group B (n = 114).

Results

The median follow-up period was 72 months (range, 7 to 149 months). Although Group A had a significantly higher rate of good responses (44% vs. 25%; p = 0.005), the 5-year local recurrence-free survival rates of 93% in Group A and 97% in Group B did not differ significantly (p = 0.519). The 5-year disease-free survival and overall survival rates were also comparable between the groups.

conclusions

Despite the better pathological response in Group A, the time interval between capecitabine and radiotherapy administration did not have a significant effect on survivals. Further evaluations are needed to clarify the interaction of these treatment modalities.

Identification of Recurrence-Predictive Indicators in Stage I Colorectal Cancer

BACKGROUND

Patients with stage I colorectal cancer (CRC) rarely experience recurrences; therefore, few risk factors for recurrence are known. This study was designed to evaluate oncologic outcomes of patients with stage I CRC and to identify risk factors for recurrence after curative surgery.

METHODS

A retrospective cohort of 860 patients from a single institution who underwent curative surgery for stage I CRC between July 1995 and June 2010 was enrolled. Patients who were diagnosed with hereditary, synchronous, or metachronous cancer and those who received preoperative chemoradiotherapy were excluded. Patients from whom fewer than 12 lymph nodes were retrieved were also excluded.

RESULTS

The 860 patients included 402 (46.7%) with colon tumors and 458 (53.3%) with rectal tumors. Thirty-five patients (4.1%) experienced recurrences; local and systemic recurrence rates were 1.1 and 3.0%, respectively. The 5-year overall survival and recurrence-free survival (RFS) rates were 93.5 ± 0.8% and 95.7 ± 0.8%, respectively. Multivariate analysis showed that preoperative serum carcinoembryonic antigen (CEA) concentration ≥6 ng/mL (hazard ratio [HR] 3.354, 95% confidence interval [CI] 1.373-8.195, p = 0.008) and lymphovascular invasion (LVI) (HR 2.676, 95% CI 1.097-6.531, p = 0.031) were independent risk factors for RFS.

CONCLUSIONS

The overall recurrence rate among patients with stage I CRC after curative surgery was 4.1%. Elevated serum CEA and LVI were significantly associated with recurrence. Large-scale, multicenter studies are needed to confirm the prognostic value of these risk factors.

Total Mesorectal Excision Versus Local Excision After Favorable Response to Preoperative Chemoradiotherapy in "Early" Clinical T3 Rectal Cancer: A Propensity Score Analysis

PURPOSE

To compare oncological outcomes of total mesorectal excision (TME) and local excision (LE) in patients with "early" clinical T3 rectal cancer who received preoperative chemoradiotherapy (PCRT).

METHODS AND MATERIALS

"Early" clinical T3 rectal cancer was radiologically defined as tumors with extramural extension of <5 mm without mesorectal fascia involvement and lateral lymph node metastasis. Patients with "early" clinical T3 rectal cancer who received PCRT followed by TME or LE between January 2007 and December 2013 were retrospectively analyzed. Propensity scores were generated using patient and tumor characteristics, and a one-to-one case-matched analysis was conducted. Local recurrence-free survival (LRFS), disease-free survival (DFS), and overall survival (OS) were compared between the TME and LE groups.

RESULTS

Of the 406 enrolled patients, 351 received TME and 55 received LE. The median follow-up period was 45 months. Following propensity score matching, each group contained 55 patients. Among 103 patients evaluable for pathologic tumor response, 82 patients (79.6%) showed complete response or near-complete response. No significant differences were observed between the TME and LE groups in LRFS (3-year LRFS 98.1% vs 94.4%, P=.312), DFS (3-year DFS 92.1% vs 90.8%, P=.683), and OS (3-year OS 98.2% vs 100.0%, P=.895).

CONCLUSIONS

In "early" clinical T3 rectal cancer, PCRT followed by LE showed comparable oncologic outcomes to TME. Because most of the matched cohort consisted of good responders to PCRT, the present results should be applied to a limited population.

Transanal Minimally-Invasive Surgery for Treating Patients With Regressed Rectal Cancer After Preoperative Chemoradiotherapy

Purpose

Although the standard treatment for patients with locally advanced rectal cancer managed by preoperative chemoradiotherapy (CRT) is a radical resection, local excisions are used in highly-selective cases. Recently, transanal minimally-invasive surgery (TAMIS) has emerged as a feasible technique for local excision of midrectal lesions. We assess the feasibility of using TAMIS to treat patients with locally advanced rectal cancer who showed good response to CRT.

Methods

From October 2010 to June 2013, 35 consecutive patients with rectal cancer managed by using preoperative CRT underwent TAMIS. After a single-incision laparoscopic surgery port had been introduced into the anal canal, a full-thickness local excision with conventional laparoscopic instruments was performed. We retrospectively reviewed a prospectively collected database of these cases.

Results

Of the 35 patients analyzed, 18 showed pathologic complete responses and 17 had residual lesions (2 ypTis, 4 ypT1, 9 ypT2, and 2 ypT3); 34 (97.1%) showed clear deep, lateral margins. The median distance of lesions from the anal verge was 5 cm. All procedures were completed laparoscopically, and the median operating time was 84 minutes. No intraoperative events or morbidities were seen in any of the patients, except one with wound dehiscence, who was treated conservatively. The median postoperative hospital stay and follow-up period were 4 days and 36 months, respectively. During the study period, no patients died, but 5 (14.3%) experienced recurrence, including one recurrence at the TAMIS site.

Conclusion

TAMIS seems to be a feasible, safe modality for treating patients with locally advanced rectal cancer who show good response to preoperative CRT.

Matched case-control analysis comparing oncologic outcomes between preoperative and postoperative chemoradiotherapy for rectal cancer

PURPOSE

To investigate patterns of recurrence and oncologic outcomes after recurrence between preoperative and postoperative chemoradiotherapy (CRT).

METHODS

Records of patients with stage II or III locally advanced rectal cancer seen between January 2000 and December 2010 were analyzed. The outcomes for patients undergoing preoperative CRT followed by radical resection (n = 466) were compared with outcomes of patients matched for sex, age, and stage who had surgery and then postoperative CRT (n = 466). Recurrence rates and sites, treatment of recurrence, and oncologic outcomes after recurrence were investigated. The rate of sphincter preservation and permanent stoma formation were also evaluated.

RESULTS

Recurrence occurred in 124 and 140 patients in the pre- and postoperative CRT groups, respectively. The local and systemic recurrence rates were 3.6% and 20.8%, respectively, in the preoperative CRT group and 3.0% and 25.3%, respectively, in the postoperative CRT group (P = 0.245). Time to recurrence was longer in the postoperative CRT group (19 months vs. 24.2 months, P = 0.029). The overall rates of sphincter preservation (sphincter preservation operation and postoperative permanent stoma formation) did not significantly different between the two groups (P = 0.381). The 5-year overall survival rate after recurrence did not differ between the two groups (25.6% vs. 18.6%, P = 0.051).

CONCLUSION

Preoperative and postoperative CRT are both safe and suitable treatment methods for rectal cancer, so the choice can be tailored to the patient's situation.

Overall and cause-specific mortality in Korean patients with inflammatory bowel disease: A hospital-based cohort study

BACKGROUND AND AIM

Limited data are available regarding mortality from inflammatory bowel disease in non-Caucasian populations. Herein, we evaluated overall and cause-specific mortality in a hospital-based cohort of Korean inflammatory bowel disease patients.

METHODS

We determined mortality in 2414 Crohn's disease patients and 2798 ulcerative colitis patients diagnosed between 1977 and 2013. Standardized mortality ratios were calculated in several demographic and phenotypic subgroups.

RESULTS

During the mean 9-year follow up, 114 patients died: 35 with Crohn's disease and 79 with ulcerative colitis. The overall standardized mortality ratios were 1.40 (95% confidence interval: 0.97-1.94) in Crohn's disease and 0.73 (0.58-0.91) in ulcerative colitis. In Crohn's disease, female sex, age < 30 years at diagnosis, disease duration > 10 years, ileocolonic disease at diagnosis, perianal fistula, intestinal resection, and ever-use of corticosteroids were associated with higher mortality. In ulcerative colitis, male sex, age ≥ 30 years at diagnosis, disease duration ≤ 5 years, proctitis at diagnosis, and no history of colectomy were associated with lower mortality, while primary sclerosing cholangitis was associated with higher mortality. In both Crohn's disease and ulcerative colitis, high mortality rates due to nonmalignant gastrointestinal causes (standardized mortality ratios: 4.59 and 2.32, respectively) and gastrointestinal malignancies (standardized mortality ratios: 16.59 and 3.45, respectively) were observed. Cardiovascular mortality was lower in ulcerative colitis (standardized mortality ratio: 0.47).

CONCLUSIONS

The overall mortality tended to be higher in Crohn's disease patients than in the general population; it was slightly lower in ulcerative colitis patients than in the general population.

Clinicopathological features and surgical options for synchronous colorectal cancer

This study was conducted to investigate the clinicopathological features of synchronous cancers and treatment options according to their locations.Records of 8368 patients with colorectal cancer treated at our center between July 2003 and December 2010 were analyzed retrospectively. All synchronous colorectal cancer patients who underwent surgical treatment were included.Synchronous cancers were identified in 217 patients (2.6%). Seventy-nine patients underwent either total colectomy, subtotal colectomy, or total proctocolectomy; 116 underwent 1 regional resection, including local excision; and 22 underwent 2 regional resections. The mean age was 62 years, slightly higher than that for the single-cancer patients. Synchronous cancers were more common in male patients, more frequently located in the left colon, had more microsatellite instability-high status, and showed more advanced stage than single cancer. Extensive resection was mainly performed for synchronous cancers located in both the right and left colon. Two regional resections were performed for cancers in the right colon and rectum. There were no differences in complication rates or the occurrence of metachronous cancer between the 2-region resection and extensive resection groups. Eight years postoperatively, the mean number of daily bowel movements for these 2 groups were 1.9 and 4.3, respectively.We found that synchronous cancer was different from single cancer in terms of age, gender, location, and pathologic features. Synchronous colorectal cancer requires different treatment strategy according to the distribution of lesions. Comparison between the 2 regional resections and extensive resection approaches suggests that 2 regional resections are preferable.

Association of immunologic markers from complete blood counts with the response to preoperative chemoradiotherapy and prognosis in locally advanced rectal cancer

We investigated retrospectively whether immunologic markers from a complete blood count (CBC) are associated with the responsiveness to preoperative chemoradiotherapy (PCRT) and oncologic outcomes in 984 patients with locally advanced rectal cancer (LARC) who also underwent radical surgery from 2005 to 2013. CBC parameters including the neutrophil to lymphocyte ratio (NLR), lymphocyte to monocyte ratio (LMR), and platelet to lymphocyte ratio (PLR) were recorded. Pathologic responses to PCRT were evaluated in the resected specimens using the tumor regression grade system. The cut-off values of the immunologic markers were calculated to analyze their association with recurrence-free survival (RFS). One hundred ninety-five patients achieved total regression of their primary tumor. By receiver operating characteristic analysis, NLR, PLR, and LMR could not distinguish total regression from residual disease after PCRT. The NLR, LMR and PLR cut-off values were 1.7, 6.8 and 92.88, respectively. By univariate analysis, low NLR (≤1.7), high LMR (>6.8) and high PLR (>92.88) were indicators of a favorable RFS outcome. By multivariate analysis, high PLR was associated with an improved RFS (HR, 0.649; 95% CI, 0.473-0.89; P=0.007). High NLR (>1.7) was an independent negative prognostic factor for RFS in stage II (HR, 1.868; 95% CI, 1.08-3.109; P=0.025) and high PLR was a positive prognostic factor in stage III (HR, 0.675; 95% CI, 0.421-0.957; P=0.03). Immunologic markers derived from CBCs are independently associated with the RFS outcome in LARC patients treated with PCRT followed by radical resection. However, these markers are not predictive of total primary tumor regression after PCRT.

Prognostic and Oncologic Significance of Perineural Invasion in Sporadic Colorectal Cancer

BACKGROUND

The presence of perineural invasion (PNI) in colorectal cancer (CRC) indicates a more aggressive phenotype, resulting in a poor prognosis. The aims of this study were to evaluate the oncologic outcome of PNI+ tumors and to investigate whether PNI status affects patient survival.

METHODS

The study retrospectively enrolled 3807 patients from a single institution who underwent surgery for colorectal adenocarcinoma between January 2006 and December 2010. The patients were classified into two groups based on PNI status: PNI+ and PNI-.

RESULTS

The PNI+ group included 565 patients (14.8 %) and had significantly more involved circumferential resection margins (p = 0.001) and a more advanced TNM stage (p = 0.001) than the PNI- group. Compared with the PNI- group, the PNI+ group had worse 5-year overall survival (65 vs. 88 %; p = 0.001) and 5-year disease-free survival (63 vs. 85 %; p = 0.001). Among PNI+ patients with stage IIA disease, those who received adjuvant therapy had significantly greater 5-year overall survival than those who did not (89.3 vs. 50.8 %; p = 0.001). In multivariate analyses, PNI+ was an independent negative prognostic factor for 5-year overall survival (hazard ratio [HR] 1.518, 95 % confidence interval [CI] 1.175-1.961; p = 0.001) and 5-year disease-free survival (HR 1.495, 95 % CI 1.237-1.806; p = 0.001).

CONCLUSIONS

PNI positivity is an independent predictor of aggressive behavior and unfavorable prognosis in CRC. Further evaluation is needed to confirm the impact of PNI status on survival in stage IIA CRC.

Microsatellite Instability was not Associated with Survival in Stage III Colon Cancer Treated with Adjuvant Chemotherapy of Oxaliplatin and Infusional 5-Fluorouracil and Leucovorin (FOLFOX)

BACKGROUND

The impact of microsatellite instability (MSI) on survival in stage III colon cancer treated with adjuvant 5-fluorouracil-oxaliplatin combination (FOLFOX) chemotherapy is not clear. We evaluated the association between MSI and survival in this population.

METHODS

We analyzed 598 patients with curatively resected stage III colon cancer treated with adjuvant FOLFOX chemotherapy. We determined MSI status using polymerase chain reaction amplification; tumors were classified as high MSI (MSI-H, ≥2 unstable markers), low MSI (MSI-L, 1 unstable marker), or microsatellite stable (MSS, no unstable marker).

RESULTS

Of 598 patients, 8.4% showed MSI-H. Tumors classified as MSI-H were more commonly located in the ascending colon (54.0 vs. 27.7%, p < 0.0001) and had poorly differentiated features (32.0 vs. 8.0%, p < 0.0001). After the median follow-up of 52.8 months, 5-year disease-free (DFS) and overall survival (OS) rates were 77.0 and 85.9%, respectively. In univariate analysis, pathologic T4 (pT4) and pathologic N2 (pN2) was associated with reduced DFS (p < 0.0001 and p < 0.0001, respectively) and OS (p = 0.002 and p = 0.001, respectively), whereas MSI status did not affect either DFS (p = 0.114) or OS (p = 0.525). In patients with pN2 tumors; however, MSI-H was associated with better survival compared with MSS/MSI-L; DFS and OS in patients with MSI-H/pN2 were comparable to those in patients with pN1 tumors.

CONCLUSIONS

In patients with stage III colon cancer treated with adjuvant FOLFOX, pT4 and pN2 was associated with reduced survival, but MSI status alone did not affect survival.

Preoperative chemoradiotherapy followed by local excision in clinical T2N0 rectal cancer

Purpose

To investigate whether preoperative chemoradiotherapy (PCRT) followed by local excision (LE) is feasible approach in clinical T2N0 rectal cancer patients.

Materials and Methods

Patients who received PCRT and LE because of clinical T2 rectal cancer within 7 cm from anal verge between January 2006 and June 2014 were retrospectively analyzed. LE was performed in case of a good clinical response after PCRT. Patients’ characteristics, treatment record, tumor recurrence, and treatment-related complications were reviewed at a median follow-up of 49 months.

Results

All patients received transanal excision or transanal minimally invasive surgery. Of 34 patients, 19 patients (55.9%) presented pathologic complete response (pCR). The 3-year local recurrence-free survival and disease free-survival were 100.0% and 97.1%, respectively. There was no recurrence among the patients with pCR. Except for 1 case of grade 4 enterovesical fistula, all other late complications were mild and self-limiting.

Conclusion

PCRT followed by an LE might be feasible as an alternative to total mesorectal excision in good responders with clinical T2N0 distal rectal cancer.

The role of radiofrequency ablation for treatment of metachronous isolated hepatic metastasis from colorectal cancer

We investigated recurrence pattern and oncologic outcomes after treatment of metachronous isolated liver metastases from colorectal cancer according to treatment modality.We retrospectively analyzed 123 patients treated with hepatic resection and 82 patients treated with radiofrequency ablation (RFA) for metachronous isolated hepatic metastasis from colorectal cancer (HMCRC). We compared clinicopathological data, recurrence pattern, and recurrence-free survival (RFS) rates after the treatment of hepatic metastasis between patients treated with RFA and resection.The patients in the 2 groups were similar in gender, location of primary tumor, disease-free interval to hepatic metastasis, pathologic stage of primary tumor, and number of hepatic metastasis. The age was older in RFA group but it was not statistically different. The mean diameter of the largest hepatic mass was greater in the resection group than in the RFA group (3.1 vs 1.9 cm, P < 0.001). Chemotherapy after the treatment of hepatic metastasis was more commonly given in hepatic resection group (76.4% vs 62.2%, P = 0.04). Recurrence after the treatment of hepatic metastasis was not significantly different between the 2 groups (54.5% vs 65.9% in the resection and RFA groups). However, intrahepatic recurrence without extra-hepatic metastases was more common in the RFA group than in the resection group (47.5% vs 12.1%, P < 0.001). The RFS rate after the treatment of hepatic metastasis was significantly higher in resection group (48.6% vs 33.7%, P = 0.015). The size and number of hepatic metastasis, primary tumor stage, disease-free interval to hepatic metastasis, and the modality of treatment (RFA vs resection) for hepatic metastasis were confirmed as associated factors with re-recurrence after the treatment of hepatic metastasis. Among patients with solitary hepatic metastases of ≤3 cm, marginal recurrence was higher in the RFA group (3% vs 17.2%) and re-RFA was performed to achieve comparable recurrence rate (3% vs 5.2%, P = 0.662), the RFS rate was not different between the resection and RFA group (52.4% vs 53.4%, P = 0.491).Surgical resection for HMCRC showed higher RFS. However, the RFS rate in patients with a solitary hepatic metastasis of ≤3 cm was similar between the resection and RFA groups.

Influence of a Positive Family History on the Clinical Course of Inflammatory Bowel Disease

BACKGROUND AND AIMS

Previous studies on the difference in phenotypes and disease course between familial and sporadic inflammatory bowel disease (IBD) have been controversial, although family history is considered to increase the risk of developing IBD.

METHODS

The influence of family history on phenotype and disease course of IBD was analysed in 2805 Korean patients with Crohn's disease (CD) and 3266 with ulcerative colitis (UC). Familial IBD was defined as the existence of one or more first-, second- and/or third-degree relatives affected with CD or UC.

RESULTS

A positive family history of IBD was noted in 191 patients with CD (6.8%) and 212 patients with UC (6.5%). In the patients with CD, the probability of anti-TNF use was higher in the familial cases than in the sporadic cases (56.3 vs 43.4%, respectively, at 10 years, p = 0.019). When analysed after excluding patients who had undergone intestinal resection within 1 year of diagnosis, the cumulative probability of intestinal resection was higher in the familial cases than in the sporadic cases (55.0 vs 32.2%, respectively, at 10 years; p = 0.007). In multivariate analysis, family history was an independent risk factor for the time to first intestinal resection in patients with CD (hazard ratio: 1.61, 95% confidence interval: 1.13-2.29; p = 0.009). In patients with UC, younger age at diagnosis and more females were observed in the familial cases (p < 0.001).

CONCLUSIONS

The present study suggests the possibility of a more aggressive clinical course of CD in familial compared with sporadic cases.

Variability in the lymph node retrieval after resection of colon cancer: Influence of operative period and process

The purpose of this study was to evaluate variations in the number of retrieved lymph nodes (LNs) over time and to determine the factors that influence the retrieval of <12 LNs during colon cancer resection.Patients with colon cancer who were surgically treated between 1997 and 2013 were identified from our institutional tumor registry. Patient, tumor, and pathologic variables were evaluated. Factors that influenced the retrieval of <12 LNs were evaluated using multivariate logistic regression modeling, including time effects.In total, 6967 patients were identified. The median patient age was 61 years (interquartile range [IQR] = 45-79 years) and 58.4% of these patients were male. The median number of LNs retrieved was 21 (IQR = 14-29), which increased from 14 (IQR = 11-27) in 1997 to 26 (IQR = 19-34) in 2013. The proportion of patients with ≥12 retrieved LNs increased from 72% in 1997 to 98.8% in 2013 (P < 0.00001). This corresponded to the more recent emphasis on a multidisciplinary approach to adequate LN evaluation. The number of retrieved LNs was also found to be associated with age, sex, tumor location, T stage, and operative year. Tumor location and T stage influenced the number of retrieved LNs, irrespective of the operative year (P < 0.05). Factors including a tumor location in the sigmoid/left colon, old age, open resection, earlier operative year, and early T stage were more likely to be associated with <12 recovered LNs (P < 0.5; chi-squared test) (P < 0.001).The total number of retrieved LNs may be influenced by tumor location and T stage of a colon cancer, irrespective of the year of surgery. LN retrieval after colon cancer resection has increased in recent years due to a better awareness of its importance and the use of multidisciplinary approaches.

Paired Primary and Metastatic Tumor Analysis of Somatic Mutations in Synchronous and Metachronous Colorectal Cancer

Purpose

Although the mutation status of KRAS is highly concordant in primary and metastatic lesions, it has not been generalized to other major pathway genes.

Materials and Methods

In this study, 41 genes were evaluated and the mutational profiles were compared in 46 colorectal cancer patients with paired surgical specimens of primary and metastatic lesions: synchronous (n=27) and metachronous (n=19) lesions. A high-throughput mass spectrometry-based genotyping platform validated by orthogonal chemistry, OncoMap v.4.4, was used to evaluate the formalin-fixed, paraffin-embedded surgical specimens. The patients’ demographics, tumor characteristics, and microsatellite instability status were analyzed by a retrospective chart review.

Results

In this study,with OncoMap, mutationswere identified in 80.4% of patientswith the following frequency: KRAS (39.1%), TP53 (28.3%), APC (28.3%), PIK3CA (6.5%), BRAF (6.5%), and NRAS (4.3%). Although 19.6% (9/46) of the patients showed no gene mutations, 43.5% (20/46) and 37.0% (17/46) had mutations in one and two or more genes, respectively. The synchronous and metachronous lesions showed similar mutational profiles. Paired samples between primary and metastatic tumors differed in 7.4% (2/27) and 10.5% (2/19) for synchronous and metachronous according to OncoMap.

Conclusion

These findings indicate the major pathway genes, including KRAS, TP53, APC, PIK3CA, BRAF, and NRAS, are often concordant between the primary and metastatic lesions regardless of the temporal relationship of metastasis.

Long-Term Outcomes of Infliximab Treatment in 582 Korean Patients with Crohn's Disease: A Hospital-Based Cohort Study

BACKGROUND AND AIMS

To date, no large-scale studies have evaluated long-term outcomes of infliximab (IFX) treatment in Korean patients with Crohn's disease (CD).

METHODS

We analyzed long-term clinical responses to IFX in 582 Korean CD patients who received scheduled IFX treatments at Asan Medical Center. Clinical responses were defined as maintaining IFX without major abdominal surgery (MAS) or dose intensification.

RESULTS

Between February 2002 and July 2015, a total of 11,990 IFX infusions were administered to 582 Korean patients with CD over a median period of 36 months. At the end of follow-up, 316 (54.3 %) were still receiving IFX without MAS (71 patients, 12.2 %) or dose intensification (86 patients, 14.8 %). IFX was stopped in 109 (18.7 %) patients because of a loss of response (48 patients, 8.2 %), adverse events (30 patients, 5.2 %), or patient preferences or problems with reimbursement (31 patients, 5.3 %). The cumulative survival for maintenance of IFX without MAS or dose intensification was 89.0, 75.9, 68.3, and 50.8 % at 1, 2, 3, and 5 years, respectively. Multivariate regression analysis identified older age at the initiation of IFX (≥40 years, P = 0.006) and a longer disease duration (≥3 years, P = 0.020) as independent positive predictors of a poorer response to IFX.

CONCLUSIONS

The long-term efficacy of IFX in a large, real-life cohort of Korean patients with CD appears to be similar to that in previously published Western studies. Our findings support the early use of IFX to obtain better clinical outcomes.

Factors affecting poor nutritional status after small bowel resection in patients with Crohn disease

In Crohn disease, bowel-preserving surgery is necessary to prevent short bowel syndrome due to repeated operations. This study aimed to determine the remnant small bowel length cut-off and to evaluate the clinical factors related to nutritional status after small bowel resection in Crohn disease.We included 394 patients (69.3% male) who underwent small bowel resection for Crohn disease between 1991 and 2012. Patients who were classified as underweight (body mass index < 17.5) or at high risk of nutrition-related problems (modified nutritional risk index < 83.5) were regarded as having a poor nutritional status. Preliminary remnant small bowel length cut-offs were determined using receiver operating characteristic curves. Variables associated with poor nutritional status were assessed retrospectively using Student t tests, chi-squared tests, Fisher exact tests, and logistic regression analyses.The mean follow-up period was 52.9 months and the mean patient ages at the time of the last bowel surgery and last follow-up were 31.2 and 35.7 years, respectively. The mean remnant small bowel length was 331.8 cm. Forty-three patients (10.9%) underwent ileostomy, 309 (78.4%) underwent combined small bowel and colon resection, 111 (28.2%) had currently active disease, and 105 (26.6%) underwent at least 2 operations for recurrent disease. The mean body mass index and modified nutritional risk index were 20.6 and 100.8, respectively. The independent factors affecting underweight status were remnant small bowel length ≤240 cm (odds ratio: 4.84, P < 0.001), ileostomy (odds ratio: 4.70, P < 0.001), and currently active disease (odds ratio: 4.16, P < 0.001). The independent factors affecting high nutritional risk were remnant small bowel length ≤230 cm (odds ratio: 2.84, P = 0.012), presence of ileostomy (odds ratio: 3.36, P = 0.025), and currently active disease (odds ratio: 4.90, P < 0.001).Currently active disease, ileostomy, and remnant small bowel length ≤230 cm are risk factors affecting the poor nutritional status of patients with Crohn disease after small bowel resection.

Change in the diagnosis of inflammatory bowel disease: a hospital-based cohort study from Korea

BACKGROUND/AIMS

Accurately diagnosing inflammatory bowel disease (IBD) remains a challenge, but is crucial for providing proper management for affected patients. The aim of the present study was to evaluate the frequency of change in diagnosis in Korean patients who were referred to our institution with a diagnosis of IBD.

METHODS

We enrolled 1,444 patients diagnosed with ulcerative colitis (UC) and 1,452 diagnosed with Crohn's disease (CD), who had been referred to the Asan Medical Center between January 2010 and December 2014. These patients were assessed and subsequently classified as having UC, CD, indeterminate colitis, possible IBD, or non-IBD.

RESULTS

During a median follow-up of 15.9 months, 400 of the 2,896 patients (13.8%) analyzed in this study experienced a change in diagnosis. A change in diagnosis from UC to CD, or vice-versa, was made in 24 of 1,444 patients (1.7%) and 23 of 1,452 patients (1.6%), respectively. A change to a non-IBD diagnosis was the most common modification; 7.5% (108 of 1444) and 12.7% (184 of 1452) of the patients with a referral diagnosis of UC and CD, respectively, were reclassified as having non-IBD. Among the 292 patients who were ultimately determined not to have IBD, 135 (55 UC and 80 CD cases) had received IBD-related medication.

CONCLUSIONS

There are diagnostic uncertainties and difficulties in relation to IBD. Therefore, precise assessment and systematic follow-up are essential in the management of this condition.

Prognostic Factors in Terms of the Number of Metastatic Nodules in Patients With Colorectal Cancer Liver Metastases

Purpose

The hepatic resection is the gold-standard treatment for patients with colorectal-cancer liver metastases (CLM). This study aimed to identify prognostic factors in patients with synchronous CLM who underwent a surgical curative (R0) resection with respect to the number of metastatic nodules.

Methods

Of 1,261 CLM patients treated between January 1991 and December 2010, 339 who underwent a R0 resection for synchronous CLM were included in this retrospective analysis. Patients were grouped according to the number of CLM nodules: 1–2 CLM nodules, n = 272 (group 1) and 3–8 CLM nodules, n = 67 (group 2).

Results

The 5-year progression-free survival (PFS) rate in group 1was better than that in group 2 (P = 0.020). The multivariate analysis identified lymph-node metastasis (N2), lymphovascular invasion (LVI), and three or more CLM nodules as independent poor prognostic factors for PFS in all patients and lymph-node metastasis (N2) and LVI as independent poor prognostic factors for patients in group 1. No independent prognostic factors were identified for patients in group 2. CLM treatment method and neoadjuvant chemotherapy were not associated with survival.

Conclusion

Three or more metastatic nodules, lymph-node metastasis (N2), and LVI were independent poor prognostic factors for PFS in patients with synchronous CLM who underwent a R0 resection. The latter 2 factors were also independent prognostic factors for PFS in patients with less than 3 CLM nodules; however, in patients with three or more CLM nodules, the prognosis for PFS may be related only to liver metastasis.

Phase 1 Study of Preoperative Chemoradiation Therapy With Temozolomide and Capecitabine in Patients With Locally Advanced Rectal Cancer

PURPOSE

Preoperative chemoradiation therapy (CRT) with capecitabine is a standard treatment strategy in patients with locally advanced rectal cancer (LARC). Temozolomide improves the survival of patients with glioblastoma with hypermethylated O(6)-methylguanine DNA methyltransferase (MGMT); MGMT hypermethylation is one of the colorectal carcinogenesis pathways. We aimed to determine the dose-limiting toxicity (DLT) and recommended dose (RD) of temolozomide in combination with capecitabine-based preoperative CRT for LARC.

METHODS AND MATERIALS

Radiation therapy was delivered with 45 Gy/25 daily fractions with coned-down boost of 5.4 Gy/3 fractions. Concurrent chemotherapy comprised fixed and escalated doses of capecitabine and temozolomide, respectively. The MGMT hypermethylation was evaluated in pretreatment tumor samples. This trial is registered with ClinicalTrials.gov with the number NCT01781403.

RESULTS

Twenty-two patients with LARC of cT3-4N0 or cTanyN1-2 were accrued. Dose level 3 was chosen as the RD because DLT was noticeably absent in 10 patients treated up to dose level 3. An additional 12 patients were recruited in this group. Grade III adverse events were noted, and pathologic complete response (pCR) was observed in 7 patients (31.8%); MGMT hypermethylation was detected in 16. The pCR rate was 37.5% and 16.7% in the hypermethylated and unmethylated MGMT groups, respectively (P=.616).

CONCLUSIONS

There was a tendency toward higher pCR rates in patients with hypermethylated MGMT. Future randomized studies are therefore warranted.

Clinicopathological features of familial adenomatous polyposis in Korean patients

AIM: To identify prognostic factors and to correlate APC mutations with clinical features, including extracolic manifestations.

METHODS: One hundred thirty-five patients who underwent surgical procedures for familial adenomatous polyposis (FAP) were included. FAP was diagnosed when the number of adenomatous polyps was > 100. Data related to patient, extracoloic manifestations, cancer characteristics, operative procedure, follow up and surveillance were collected. APC mutation testing was performed in the 30 most recent patients. DNA was extracted from peripheral blood and polymerase chain reaction products using 31 primer pairs on APC gene were sequenced. A retrospective study was performed to investigate a causal relationship between prognosis and feature of patient.

RESULTS: The mean age of the 51 patients with colorectal cancer (CRC) was older than that of those without CRC (30.5 vs 36.9, P = 0.002). Older individuals were more likely to have colon cancer at the time of FAP diagnosis [odds ratio, 4.75 (95%CI: 1.71-13.89) and 5.91(1.76-22.12) for 40-49 years and age > 50 vs age < 30). The number of confirmed deaths was 13 and the median age at death was 40 years (range, 27 to 85 years). Ten of the deaths (76.9%) were from CRC. Another cause of two cases of death were desmoid tumors (15.4%). Development of cancer on remnant rectal or ileal mucosa after surgery was not observed. The APC mutation testing revealed 23 pathogenic mutations and one likely pathogenic mutation, among which were four novel mutations. The correlation between mutational status and clinical manifestations was investigated. Mutations that could prodict poor prognosis were at codon 1309 which located on mutation cluster region, codon 1465 and codon 1507.

CONCLUSION: Identification of APC mutations should aid in the diagnosis and counseling of family members in terms of early diagnosis and management of FAP.

Oncologic Safety of Local Excision Compared With Total Mesorectal Excision for ypT0-T1 Rectal Cancer: A Propensity Score Analysis

Good oncologic outcomes, demonstrated by a complete pathologic response after preoperative chemoradiotherapy (PCRT), have led to local excision (LE) in selected patients with rectal cancer. We evaluated the oncologic safety of LE compared with total mesorectal excision (TME) in patients with ypT0-T1 rectal cancer.A retrospective review of 304 patients who underwent PCRT, followed by LE or TME, for ypT0-T1 rectal cancer was performed. Propensity scores were computed and used to match groups (LE:TME = 1:1), and analysis of disease-free survival (DFS) and overall survival (OS) was made by comparing patients who underwent LE or TME. Prognostic factors of relapse were analyzed for all patients.Tumor categories were ypT0 in 25 (61.9%) cases, ypTis in 6 (14.3%) cases, and ypT1 in 11 (26.2%) cases for the LE group, and ypT0 in 28 (66.7%) cases, ypTis in 4 (9.5%) cases, and ypT1 in 10 (23.8%) cases for the matched TME patients. There was no significant difference between the matched LE and TME groups in relapse (4.8% and 7.14%, respectively; P = 0.646), 5-year DFS (95.2% vs 91.6%; P = 0.33) and 5-year OS (96.6% vs 88.0%; P = 0.238). In the multivariate Cox regression analysis, tumor distance from the anal verge (hazard ratio [HR] = 0.78; 95% confidence interval (CI) = 0.616-0.992) and the tumor grade (HR = 4.29; 95% CI = 1.430-12.886) were significantly associated with the recurrence risk.LE results in oncologic outcomes that are comparable to those achieved by TME in selected patients with ypT0-T1 rectal cancer after PCRT.