G-CSF-producing Undifferentiated Pleomorphic Sarcoma Adjacent to the Ascending Colon and in the Right Iliopsoas Muscle: A Case Report and Review of the Literature.

Undifferentiated pleomorphic sarcoma (UPS) is a soft tissue sarcoma, occurring most commonly on the lower extremities. We herein report a rare case of primary UPS adjacent to the ascending colon and in the right iliopsoas muscle. Computed tomography of the abdomen revealed large masses, and the patient experienced a high-grade fever, leukocytosis, elevated serum C-reactive protein level, and hematopoietic activation on 18F-fluorodeoxyglucose-positron emission tomography. This inflammatory reaction was caused by granulocyte colony-stimulating factor secreted by tumor cells. Surgical resection was performed, and the inflammatory reaction disappeared immediately. The patient received adjuvant chemotherapy and survived one year after the operation without evidence of recurrence.

Development of metachronous rectal cancers in a young man with dyskeratosis congenita: a case report.

BACKGROUND: DKC1 (dyskerin pseudouridine synthase 1) is a causative gene for X-linked dyskeratosis congenita. Approximately 8% of patients with dyskeratosis congenita have malignancy, but information about the development of malignancy in patients with dyskeratosis congenita is limited. CASE PRESENTATION: A young Japanese patient with bone marrow failure developed metachronous rectal adenocarcinomas at the ages of 16 and 18 years. He had no family history of cancer. Microsatellite instability testing with rectal tumor tissue demonstrated low-level microsatellite instability. To clarify whether any cancer susceptibility genes were involved in the development of rectal cancer, RNA sequencing was performed. Cancer-related genes were assessed, and a c.361A>G (p.Ser121Gly) germline variant was detected in DKC1. The same missense variant was previously reported in two patients with dyskeratosis congenita as a pathogenic variant, but those patients did not develop malignancies. CONCLUSIONS: Our patient developed rectal cancer at an early age of onset compared with the previously reported typical onset age of patients with dyskeratosis congenita. DKC1 might be involved in predisposition to colorectal cancer in young adulthood; therefore, appropriate surveillance may be considered.

[Three Long-Surviving Cases of Peritoneal Metastasis after Colorectal Cancer Resection].

We experienced 3 impressive colorectal cancer patients who developed peritoneal recurrences and underwent surgery several times and survived for more than 5 years. Case No. 1 was of a 44-year-old woman who underwent right hemicolectomy for her stage II A ascending colon cancer. She developed left ovarian metastasis, which was resected 3 years later. Five years later, she developed a pelvic peritoneal recurrence, which was resected successfully. Thirteen years later, she is doing well. Case No. 2 was of a 61-year-old man who underwent transverse colectomy for his stage II B colon cancer. He developed ileus 2 years 9 months later due to peritoneal recurrence, which was removed successfully. He underwent another resection for peritoneal metastasis 2 years 6 months later. He was administered 15 courses of FOLFOX6. He has remained cancer-free since 2009. Case No. 3 was of a 62-year-old man who underwent sigmoidectomy for his stage II A colon cancer. One year 8 months later, he underwent resection for a painful abdominal wall metastasis. Eight months later, he developed another abdominal wall recurrence, which was resected successfully. He underwent thoracoscopic resection 4 times for lung metastases and was given 16 courses of FOLFOX6. In 2009, he developed pelvic peritoneal nodules, which were resected. He later needed lymphadenectomy twice. He has remained cancer-free for the last 5 years and 6 months. Curative resection must be performed for a patient with peritoneal recurrence of colorectal cancer when surgery is indicated.

Randomized phase III trial comparing surgery alone to UFT + PSK for stage II rectal cancer (JFMC38 trial).

BACKGROUND: We conducted a randomized phase III trial comparing tegafur/uracil (UFT) and Polysaccharide-K (PSK) to surgery alone in curatively resected stage II rectal cancer patients. METHODS: Patients were randomly assigned to receive either UFT and PSK or surgery alone in a 1:1 ratio with a minimization method to balance the treatment allocation. The primary end point of this study was the disease-free survival (DFS). The secondary end point was the overall survival (OS). RESULTS: From October 2011 to February 2013, 111 patients were registered from 62 institutions. The study was prematurely closed due to poor accrual after reaching 20% of its goal. The patients' characteristics were similar between the UFT and PSK group and the surgery-alone group. The DFS rate was 76.0% at 3 years and 65.1% at 5 years in the UFT and PSK arm and 84.0% at 3 years and 77.2% at 5 years in the surgery-alone arm. The DFS was slightly worse in the UFT + PSK arm than in the surgery-alone arm, but the difference did not reach statistical significance (log rank p = 0.102). The OS rate was 100% at 3 years and 97.9% at 5 years in the UFT + PSK arm, while that was 100% at 3 years and 93.4% at 5 years in the surgery-alone arm. The OS was similar in the UFT + PSK arm and surgery-alone arm (p = 0.533). CONCLUSION: The present study suggests that UFT and PSK are not attractive candidates to advance to the next phase III study because the DFS was slightly worse in the UFT and PSK arm than in the surgery-alone arm.

[Three Long-Surviving Cases of Recurrent Rectal Carcinomas Treated Non-Surgically and Cured].

Few cases of recurrent colorectal carcinomas were treated non-surgically and cured. Here, we report 3 such cases. Case No. 1 was of a 66-year-old woman, who underwent ISR for very low rectal cancer. Her disease Stage was tub2, T2N0M0. Two years and 6 months later, she developed intrapelvic recurrence involving sacral bones(S1-S3). Radiotherapy of 50 Gy followed by mFOLFOX6 with bevacizumab was administered for a year. She has been cancer-free for 6 years. Case No. 2 was of a 47-year-old man who underwent preoperative CRT of 40 Gy with 5-FU plus Leucovorin, and LAR was performed for very low rectal cancer. The disease Stage was tub2, T3N2M0. One year later, he was diagnosed with recurrent aortic lymph node metastasis. After 7 months of mFOLFOX6 with bevacizumab, he developed an anastomotic fistula. His chemotherapy was discontinued; he was cancer-free for 6 years. Case No. 3 was of a 56-year-old man who underwent TPE for low rectal cancer. The disease Stage was muc, T4b(urinary bladder)N0M1a(perianal skin). One year and 6 months later, he developed ileus and was diagnosed with intrapelvic recurrence. He underwent intestinal bypass operation, and CRT of 46 Gy with capecitabine was administered. He attained CR quickly, and was cancer-free for 5 years. Collecting similar cases to analyze the key to successful treatment is important.

Laparoscopic Versus Open Lateral Lymph Node Dissection for Locally Advanced Low Rectal Cancer: A Subgroup Analysis of a Large Multicenter Cohort Study in Japan.

BACKGROUND: Mesorectal excision with lateral lymph node dissection is the standard treatment for locally advanced low rectal cancer in Japan. However, the safety and feasibility of laparoscopic lateral lymph node dissection remain to be determined. OBJECTIVE: The purpose of this study was to evaluate the safety and feasibility of laparoscopic versus open lateral lymph node dissection for locally advanced low rectal cancer. DESIGN: This was a retrospective cohort study using an exact matching method. SETTING: We conducted a multicenter study of 69 specialized centers in Japan. PATIENTS: Patients with consecutive midrectal or low rectal adenocarcinoma cancer stage II to III who underwent mesorectal excision with curative intent between 2010 and 2011 were recruited. MAIN OUTCOME MEASURES: Short-term and oncological outcomes were compared between the laparoscopic and open-surgery groups. RESULTS: Of the 1500 eligible patients, 676 patients who underwent lateral lymph node dissection were analyzed, including 137 patients who were treated laparoscopically and 539 patients who were treated with open surgery. After matching, the patients were stratified into laparoscopic (n = 118) and open-surgery (n = 118) groups. Operative times in the overall cohort were significantly longer (461 vs 372 min) in the laparoscopic versus the open-surgery group. In the laparoscopic group, the blood loss volume was significantly smaller (193 vs 722 mL), with fewer instances of blood transfusion (7.3% vs 25.5%) compared with the open-surgery group. The postoperative complication rates were 35.8% and 43.6% for the laparoscopic and open-surgery groups (p = 0.10). The 3-year relapse-free survival rates were 80.3% and 72.6% for the laparoscopic and open-surgery groups (p = 0.07). LIMITATIONS: The study was limited by its retrospective design and potential selection bias. CONCLUSIONS: Laparoscopic lateral lymph node dissection is safe and feasible for cancer stage II to III low rectal cancer and is associated with similar oncological outcomes as open lateral lymph node dissection. See Video Abstract at http://links.lww.com/DCR/A334.

Predictive model for high-frequency microsatellite instability in colorectal cancer patients over 50 years of age.

Microsatellite instability (MSI) is an important biomarker for screening for Lynch syndrome, and also of response to immune checkpoint inhibitors. The aim of this study is to create a predictive model to determine which elderly patients with colorectal cancer (CRC) should undergo MSI and/or immunohistochemistry testing on the basis of clinicopathological data. We analyzed a test cohort of CRC patients aged ≥50 years (n = 2219) by multivariate logistic regression analyses to identify predictors of high-frequency MSI (MSI-H). The created prediction model was validated in an external cohort (n = 992). The frequency of MSI-H was 5.5% among CRC patients aged ≥ 50 years. The following five predictors of MSI-H were identified in the test cohort: female (1 point), mucinous component (2 points), tumor size ≥ 60 mm (2 points), location in proximal colon (3 points), and BRAF mutation (6 points). The area under curve (AUC) in the receiver-operating characteristic (ROC) analysis of this prediction model was 0.832 (95% confidence interval: 0.790-0.874). The sensitivity and specificity were 74.4% and 77.7%, respectively, for a cut-off score of 4 points. The receiver-operating characteristic curve of the validation cohort also showed an AUC of 0.856 (95% CI: 0.806-0.905). This prediction model is useful to select elderly CRC patients who should undergo MSI testing, and who may benefit from treatment with 5-FU-based adjuvant chemotherapy and cancer immunotherapy.

Lymph Node Ratio as a Risk Factor for Recurrence After Adjuvant Chemotherapy in Stage III Colorectal Cancer.

BACKGROUND: Although several markers, including the lymph node ratio (LNR), have been proposed as a clinically prognostic tool for colorectal cancer (CRC), it remains unclear which markers have the most relevance in determining recurrence following adjuvant chemotherapy for stage III CRC. METHODS: Independent risk factors for recurrence-free survival (RFS) were retrospectively determined using the Cox proportional hazard model in 360 stage III CRC patients and validated using an independent cohort comprising 172 stage III CRC patients. RESULTS: The LNR was independently associated with RFS (HR, 1.96; 95% CI, 1.11 to 3.28; P = 0.020). A higher LNR value was significantly associated with recurrence, microsatellite stable, and shorter time to recurrence. A combination of the LNR with pre-chemotherapy CEA and CA19-9, other independent risk factors, provided accurate risk stratification of RFS and conferred additional information on recurrence within each stage III CRC subgroup, which was then validated in an independent cohort. A beneficial effect in patients at risk of recurrence, and a reduced effect in patients at low risk, was exhibited by the addition of oxaliplatin to 5-fluorouracil-based adjuvant chemotherapy. CONCLUSION: A higher LNR is one of the most aggressive phenotypes with recurrence risk following adjuvant chemotherapy for stage III CRC.

Local control of sphincter-preserving procedures and abdominoperineal resection for locally advanced low rectal cancer: Propensity score matched analysis.

Sphincter-preserving procedures (SPPs) for surgical treatment of low-lying rectal tumors have advanced considerably. However, their oncological safety for locally advanced low rectal cancer compared with abdominoperineal resection (APR) is contentious. We retrospectively analyzed cohort data of 1500 consecutive patients who underwent elective resection for stage II-III rectal cancer between 2010 and 2011. Patients with tumors 2-5 cm from the anal verge and clinical stage T3-4 were eligible. Primary outcome was 3-year local recurrence rate, and confounding effects were minimized by propensity score matching. The study involved 794 patients (456 SPPs and 338 APR). Before matching, candidates for APR were more likely to have lower and advanced lesions, whereas SPPs were carried out more often following preoperative treatment, by laparoscopic approach, and at institutions with higher case volume. After matching, 398 patients (199 each for SPPs and APR) were included in the analysis sample. Postoperative morbidity was similar between the SPPs and APR groups (38% vs 39%; RR 0.98, 95% CI 0.77-1.27). Margin involvement was present in eight patients in the SPPs group (one and seven at the distal and radial margins, respectively) and in 12 patients in the APR group. No difference in 3-year local recurrence rate was noted between the two groups (11% vs 14%; HR 0.77, 95% CI 0.42-1.41). In this observational study, comparability was ensured by adjusting for possible confounding factors. Our results suggest that SPPs and APR for locally advanced low rectal cancer have demonstrably equivalent oncological local control.

High concordance rate of KRAS/BRAF mutations and MSI-H between primary colorectal cancer and corresponding metastases.

Genetic testing is needed for the treatment of colorectal cancer (CRC), especially molecular-targeted therapy. The effects of anti-EGFR therapy and prognosis are affected by the presence of KRAS mutations. However, whether primary CRC or metastatic tissues are appropriate in the analysis is still unclear. In the present study, we assessed the concordance of KRAS/BRAF mutation status and microsatellite instability (MSI) in primary CRC and corresponding metastases. This study enrolled 457 patients with surgically resected primary and corresponding metastatic CRC (499 synchronous metastases and 57 metachronous metastases) and seven local recurrences, and KRAS/BRAF mutation and MSI status were analysed for these tumours. The concordance rates of KRAS mutation, BRAF mutation, wild-type, MSI-H and MSS between primary CRC and corresponding metastases were 93.9% (214/228), 100% (30/30), 99.3% (304/306), 87.5% (21/24) and 100% (137/137), respectively. These high concordance rates were not different between synchronous and metachronous metastases. In conclusion, a high concordance of KRAS/BRAF mutation status and MSI status was observed between primary CRC and corresponding metastases in this study. Either primary CRC or metastatic tissues can be used for testing KRAS/BRAF mutation status and MSI status.

Metastatic Pattern of Stage IV Colorectal Cancer with High-Frequency Microsatellite Instability as a Prognostic Factor.

BACKGROUND: A recent clinical trial on the immune check-point inhibitor pembrolizumab demonstrated that microsatellite instability (MSI) is a good biomarker for response to this inhibitor. However, clinicopathological features of advanced colorectal cancer (CRC) with high-frequency MSI (MSI-H) are unclear. PATIENTS AND METHODS: A total of 2,439 surgically resected CRC tissues were analyzed for MSI status, and mutational status of V-Ki-Ras2 Kirsten rat sarcoma 2 viral oncogene homolog (KRAS), neuroblastoma RAS viral oncogene homolog (NRAS) and v-Raf murine sarcoma viral oncogene homolog B (BRAF). Stage IV cases were selected, and clinical and molecular features were evaluated. RESULTS: There was no significant survival difference observed between MSI-H CRC and microsatellite-stable (MSS) CRC in patients with stage IV disease (3.92 vs. 2.50 years; p=0.766). However, hematogenous and lymphogenous metastasis-dominant CRC with MSI-H demonstrated poor prognosis, whereas peritoneal metastasis-dominant CRC with MSI-H demonstrated good prognosis, (1.33 vs. 5.2 years; p=0.006). CONCLUSION: Prognosis of stage IV CRC with MSI-H depended on the metastatic pattern. These findings provide useful information for the adaptation of CRC immunotherapy.

Tissue distribution of aryl hydrocarbon receptor in the intestine: Implication of putative roles in tumor suppression.

Intestinal homeostasis is maintained by complex interactions between intestinal microorganisms and the gut immune system. Dysregulation of gut immunity may lead to inflammatory disorders and tumorigenesis. We previously have shown the tumor suppressive effects of aryl hydrocarbon receptor (AhR) in intestinal carcinogenesis. In the present study, we investigated AhR distribution in the mouse and human intestine by histochemical analysis. In the normal intestine, AhR was mainly localized in the stroma containing immune cells in the lamina propria and lymphoid follicles. On the other hand, in the tumor tissue from human colon cancer and that developed in Apc(Min/+)mice, AhR expression was elevated. AhR immunostaining was found in both stromal and tumor cells. Although AhR was localized in the cytoplasm of tumor cells in most cases, nuclear AhR was also observed in some. AhR knockdown using siRNA resulted in significant promotion of cell growth in colon cancer cell lines. Furthermore, AhR activation by AhR ligands supplemented in culture medium suppressed cell growth. Our study results suggest that tumor suppressive roles of AhR are estimated in two distinct ways: in normal tissue, AhR is associated with tumor prevention by regulating gut immunity, whereas in tumor cells, it is involved in growth suppression.

[Three Successful TUR Treatments of Urinary Bladder Recurrence of Colorectal Carcinoma].

We analyzed whether TUR was feasible in 4 cases of urinary bladder recurrence of sigmoid colon cancer that invaded into the bladder. Case No. 1 involved a 66-year-old male who presented with sigmoid colon cancer that had invaded the urinary bladder; he underwent sigmoidectomy with partial bladder resection. Six months after the operation, a small, protruded lesion in his urinary bladder was detected and TUR was performed. He has been cancer free for 10 years. Case No. 2 involved a 53- year-old female who underwent sigmoidectomy and hepatectomy for her sigmoid colon cancer and liver metastasis. She developed bladder and liver metastases, which were resected. Four months later, she underwent TUR because she developed a small recurrent tumor in the bladder. Since then, she has had no intrapelvic recurrence for 6 years. Case No. 3 was a 44- year-old male who underwent bladder-preserving resection for a sigmoid colon cancer that had invaded his bladder. He developed a relatively large bladder tumor 1 year 6 months later. TUR was performed and he was administered CRT. He has had no recurrences for 2 years 5 months. Case No. 4 was a 68-year-old male who underwent bladder-preserving surgery for a sigmoid colon cancer that had invaded his bladder. Because he developed a recurrence in the bladder, he underwent TUR 3 months later. He developed a recurrence in the bladder again 1 year 7 months later, and he underwent TUR again. Multiple organ metastases became evident and was prescribed chemotherapy for 2 years. From these cases, we conclude that TUR may be a feasible option for small, protruded recurrences in the bladder, but we should not hesitate to perform total cystectomy if the first TUR is unsuccessful.

[Case of Laparoscopic Sigmoidectomy for a Patient with Persistent Descending Mesocolon].

A 65-year-old man with bloody stools was diagnosed with sigmoid colon cancer on colonoscopy. A preoperative barium enema and a computed tomography colonography scan showed a medial displacement of his descending colon. The preoperative clinical diagnosis was stage cT1 colon cancer, N0, M0, cStage I . Laparoscopic sigmoidectomy was performed. We found adhesions between the descending colon mesentery and the pelvic wall, and noted that the descending colon was not fused with the retroperitoneum and was shifted to the midline. The patient was diagnosed with persistent descending mesocolon (PDM). PDM is a congenital anomaly of fixation resulting from the failure of the descending colon mesentery to fuse with the parietal peritoneum. Anatomical findings should have been noted during the operation, including the fact that the descending colon artery, sigmoid colon artery, and superior rectal artery often branch radially from the inferior mesenteric artery. It is important to understand the anatomical characteristics of PDM and to improve on existing surgical procedures to ensure safe laparoscopic surgery for these patients.

Prognostic value of KRAS and BRAF mutations in curatively resected colorectal cancer.

AIM: To investigate the prognostic role of KRAS and BRAF mutations after adjustment for microsatellite instability (MSI) status in Japanese colorectal cancer (CRC) population. METHODS: We assessed KRAS and BRAF mutations and MSI status in 813 Japanese patients with curatively resected, stage I-III CRC and examined associations of these mutations with disease-free survival (DFS) and overall survival (OS) using uni- and multivariate Cox proportional hazards models. RESULTS: KRAS and BRAF mutations were detected in 312 (38%) of 812 and 40 (5%) of 811 tumors, respectively. KRAS mutations occurred more frequently in females than in males (P=0.02), while the presence of BRAF mutations was significantly associated with the female gender (P=0.006), proximal tumor location (P<0.001), mucinous or poorly differentiated histology (P<0.001), and MSI-high tumors (P<0.001). After adjusting for relevant variables, including MSI status, KRAS mutations were associated with poorer DFS (HR=1.35; 95%CI: 1.03-1.75) and OS (HR=1.46; 95%CI: 1.09-1.97). BRAF mutations were poor prognostic factors for DFS (HR=2.20; 95%CI: 1.19-4.06) and OS (HR=2.30; 95%CI: 1.15-4.71). Neither the BRAF by MSI interaction test nor the KRAS by MSI interaction test yielded statistically significant results for DFS and OS. CONCLUSION: KRAS and BRAF mutations are associated with inferior survival, independent of MSI status, in Japanese patients with curatively resected CRC.

[Five-Year Recurrence-Free Survival after mFOLFOX6 Administration, Right Hemicolectomy, and Lymphadenectomy for Portal Venous Tumor Thromboembolism].

A 71-year-old woman was admitted for fever and appetite loss. She was diagnosed with ascending colon cancer, with portal vein tumor thromboembolism extending to the portosplenic junction. This was deemed unresectable despite the absence of distant metastasis. She underwent 16 courses of mFOLFOX6 therapy, and because the effect of chemotherapy was PR, right hemicolectomy with high ligation of the ileocolic vessels and the right branch of the middle colic vessels was performed. The tumor stage was yp-T3N1bM0, StageⅢB with a few remaining cancer cells in the portal venous system. Staging after chemotherapy effect was Grade 1a. Postoperatively, 13 courses of mFOLFOX6 were administered. A repeat CT scan showed lymph node recurrence along the SMV, which was subsequently resected again. After the second operation, 9 courses of the DeGramont regimen was administered and discontinued. Five years after the last operation, the patient remains well and without any recurrences. Colonic carcinoma with portal venous tumor thromboembolism has been reported in 9 cases, including ours. Among these, 8 cases involved the ascending colon. Seven of the affected patients were female while 3 were poorly differentiated adenocarcinoma. None of the other patients, except for our case, reported a 5 year patient survival rate without recurrence.

[A Case of Long-Term Survival after Nine Surgeries for Recurrent Sigmoid Colon Cancer].

A 67-year-old man was operated for sigmoid colon cancer. Histopathological examination revealed pT3 (SS), N0, M0, Stage Ⅱ cancer. In March 2005, abdominal computed tomography (CT) showed recurrences in the abdominal wall and associated localized dissemination. The patient underwent chemotherapy using TS-1 and CPT-11; however, the disease progressed. Therefore, surgery was performed to resect the recurrences. A re-recurrence developed during the adjuvant chemotherapy. The patient was operated 9 times for recurrences, which were macroscopically resectable, in addition to chemotherapy and radiation. It has been 3 years and 7 months since the last operation, and he is alive with no recurrence. Metachronous peritoneal seeding and distant metastasis developed, but we have observed that surgical resection of each recurrence can prolong patient survival. We conclude that surgical resection can become a treatment of choice for resectable metachronous peritoneal seeding from colon cancer.

[Recurrence of Rectal Cancer with Submucosal Invasion in the Bone and Lymph Nodes 89 Months after Surgery--A Case Report].

A woman in her 60s showed positive results on a fecal occult blood test and consulted her doctor. Early-stage cancer of the lower rectum was diagnosed, and a transanal local excision was performed. Histopathological examination revealed that the depth of submucosal invasion was ≧1,000 mm, and the submucosal invasive part of the tumor was a poorly differentiated adenocarcinoma. Therefore, she was referred to our hospital for additional resection. Intersphincteric resection was performed 11 months after the initial operation. The cancer stage was T1N0M0, Stage Ⅰ(UICC 7th edition), and the cancer did not recur. The patient visited our hospital again, 78 months after the additional resection, because of left hip-joint pain. Positron-emission tomography revealed fluorodeoxyglucose uptake in the left acetabulum, para-aortic lymph nodes, and left external iliac lymph nodes; these findings indicated recurrence of the rectal cancer. The patient received radiation therapy (57 Gy) and FOLFIRI; bevacizumab was added from the third course onward. The therapy reduced the size of the tumor recurrence in the bone. This was a rare case of rectal cancer with submucosal invasion that showed recurrence in the bone and lymph nodes 78 months after the additional resection.

Combined microsatellite instability and BRAF gene status as biomarkers for adjuvant chemotherapy in stage III colorectal cancer.

BACKGROUND: The clinical relevance of combined microsatellite instability (MSI) and BRAF status for adjuvant treatment in stage III colorectal cancer (CRC) remains elusive. METHODS: In 405 patients with curatively resected stage III CRC, the prognostic value of combined MSI and BRAF status was assessed in four groups, as follows: high-levels of microsatellite instability (MSI-H) and BRAF-wild type, MSI-H and BRAF-mutation, microsatellite stable (MSS) and BRAF-wild type, and MSS and BRAF-mutation. RESULTS: Combined MSI and BRAF status provided significant prognostic stratification of disease-free survival (DFS), and was independently associated with worse DFS. The MSI-H and BRAF-wild type group had similar outcomes to stage II CRC patients, despite no benefit from 5-FU monotherapy. Further, patients in the MSS and BRAF-wild type group with stage IIIA CRC had favorable outcomes to 5-FU monotherapy, similar to those with stage II CRC. In contrast, 5-FU monotherapy was insufficient among patients in the MSS and BRAF-wild type group with stage IIIB or IIIC CRC or patients in the MSS and BRAF-mutation group with stage III CRC. CONCLUSIONS: The combination of MSI and BRAF status serves as both a prognostic and predictive marker and may provide much-needed guidance during the planning of therapeutic strategies.

Inverse effect of mucinous component on survival in stage III colorectal cancer.

BACKGROUND: Although mucinous adenocarcinoma (MAC) is has been recognized as a separate entity in colorectal cancer (CRC), adenocarcinoma with a mucinous component (ACM) remains poorly understood. METHODS: The association of MAC and ACM with disease-free survival (DFS) and overall survival (OS) was examined using the Cox proportional hazard model in 425 consecutive stage III CRCs. RESULTS: Compared with conventional adenocarcinoma (CAC), patients with MAC exhibited independently worse DFS (hazard ratio [HR], 2.64; 95% CI, 1.21-5.80; P = 0.014) and OS (HR, 3.56; 95% CI, 1.53-8.30; P = 0.003). Unexpectedly, ACM was significantly associated with worse OS than CAC (P = 0.002), despite having a similar DFS to CAC. Further, ACM patients after recurrence exhibited significantly worse OS than CAC patients (P < 0.001), similar to MAC. CONCLUSIONS: Although ACM is similar to CAC with regard to estimated risk of recurrence, the outcome is extremely poor once recurrence occurs and is identical to MAC; one of the most aggressive phenotypes of stage III CRC. Thus, both MAC and ACM are adverse prognostic factors for OS.