PIK3CA mutation and methylation influences the outcome of colorectal cancer.

Colorectal cancer (CRC) occurs through the accumulation of genetic and epigenetic alterations. The epigenetic abnormalities, in cooperation with genetic alterations, are capable of causing aberrant gene function that results in cancer. In the present study, we examined mutations and methylation status in 164 CRCs to determine whether the combination of genetic and epigenetic alterations may be used to classify CRC patients in relation to their clinicopathological characteristics and outcomes. Mutation analyses for the KRAS and PIK3CA genes were performed using direct sequencing, and the MethyLight method was used to determine the methylation status of BNIP3, p16 and hMLH1. The combination of the KRAS mutation with methylation status did not have any association with clinicopathological characteristics and outcomes. However, patients with the PIK3CA mutation and/or high methylation (2 or 3 methylated genes) had significantly poorer outcomes in disease-specific survival (DSS) compared with those with wild-type PIK3CA and 0 or 1 methylated genes (P=0.0059). Additionally, multivariate analysis revealed that the PIK3CA mutation and/or a high level of methylation predicts a poor DSS independently of clinicopathological characteristics. Our results suggest that a combination of genetic and epigenetic alterations is a potent biomarker for predicting the prognosis of CRC.

Clinical significance of UNC5B expression in colorectal cancer.

The purpose of this study was to find a methylation-related gene that could become a biomarker or therapeutic target in colorectal carcinoma (CRC). We screened candidate genes suspected to be silenced by DNA methylation using cDNA microarray analysis. To investigate the clinical significance of one candidate gene (UNC5B), we analyzed the correlation between mRNA expression and clinicopathological features using clinical tissue samples. Moreover, methylation specific PCR analysis was performed to reveal whether the promoter region was methylated in CRC cell lines. We found 75 candidate genes that were potentially suppressed by DNA methylation in CRC. We focused on UNC5B, a possible tumor suppressor gene and regulator of apoptosis known to be inactivated in CRC. The mRNA expression analysis using tissue samples revealed that UNC5B mRNA was down-expressed in about 20% of CRC patients, and the patients with low-UNC5B-expression tumors showed a significantly higher recurrence rate after curative surgery. According to the univariate and multivariate analysis, low UNC5B expression was an independent risk factor for postoperative recurrence in stage I, II and III CRC patients. Furthermore, patients with low expression of UNC5B in tumors had significantly poorer prognosis than those with high expression of UNC5B. Although UNC5B mRNA expression was restored by the demethylation treatment in CRC cell lines, the promoter region of UNC5B was not methylated. UNC5B is a potential biomarker for the selection of patients with high risk of postoperative recurrence and worse prognosis in CRC.

[A long-term survival case of neuroendocrine tumor of the sigmoid colon with multiple liver metastases].

It has been reported that neuroendocrine tumor (NET) of the large intestine with distant metastasis is rare and carries poor prognosis. We report a case of colonic NET with hepatic metastases, who was successfully treated by combined therapy. A 71-year-old man with sigmoid colon tumor underwent sigmoidectomy and histopathological examination disclosed the tumor was NET grade 1. Multiple liver metastases and lymph node metastasis on the posterior surface of the pancreatic head were detected at the time of surgery. Trans-catheter arterial chemoembolization (TACE; doxorubicin and ethiodized oil and gelatine sponge particle) was performed. Partial response (PR) was observed after 2 times of administration. Radiation therapy was performed for the lymph node metastasis eight months after surgery and PR was observed. The patient was alive after 48 months and TACE was continued. Combined therapy including surgery, irradiation, and chemotherapy, although not yet standardized, is required against NET with hepatic metastases.

[A case of colonic neuroendocrine carcinoma with severe liver dysfunction by multiple liver metastases successfully treated with hepatic arterial infusion].

A 63-year-old male was diagnosed as ascending colon cancer with severe liver dysfunction caused by multiple liver metastases. Initially, hepatic arterial infusion (HAI) chemotherapy was started to reduce the size of metastatic tumors and to prevent a liver failure. After 7 courses of HAI chemotherapy, he recovered from liver dysfunction, and underwent right hemicolectomy. Pathological examination of the resected specimen revealed the tumor was neuroendocrine carcinoma. After surgery, a systemic infusion of mFOLFOX6/bevacizumab regimen was started. A partial response (PR) of metastatic lesions was observed. Irinotecan/cetuximab was administered as the second-line. He survived for 10 months after HAI. HAI for colonic neuroendocrine carcinoma with severe liver dysfunction by multiple liver metastases might be benefitial to prevent a liver failure.

[Repeated resections for originally unresectable liver metastasis from colorectal cancer after multiagent chemotherapy].

We describe the case of a 74-year-old man with liver resection for originally unresectable liver metastasis from colorectal cancer after multiagent chemotherapy. Eleven bilobar liver metastases appeared four months after curative resection for double cancer of sigmoid colon and upper rectum. After 6 courses of multiagent chemotherapy (mFOLFOX 6 with bevacizumab), the number of liver metastasis decreased from 11 to 5. The patient underwent curative resection for liver metastasis. A new lesion of 7 mm in the segment 6 appeared 8 months after an initial liver resection. After 3 months' observation, two more liver metastases appeared. All liver metastases were resected. Solitary lung metastasis appeared 10 months after the second liver resection. The lung metastasis was also resected. The patient was alive with no evidence of disease in 33 months after the initial liver resection. We experienced the case with repeated liver resections after multiagent chemotherapy for originally unresectable bilobar liver metastasis. The therapeutic strategy which combines surgical resection with cytotoxic chemotherapy will be important more than ever.

[A surgical case of descending colon cancer with abdominal wall abscess after drainage of abscess].

We report a surgical case of descending colon cancer with abdominal wall abscess. A 72-year-old man was admitted to a hospital because of left lower abdominal mass with slight pain. An abdominal CT showed a left lower abdominal wall abscess adjacent to the descending colonic wall thickening. We diagnosed an abdominal wall abscess due to descending colon cancer or colon diverticulitis. The abscess was drained under local anesthesia releasing foul-smelling pus and air. After abscess drainage and general improvement in his condition, we conducted subtotal colectomy with lymph node dissection and excision of abdominal wall abscess cavity. Pathological findings indicated moderately differentiated adenocarcinoma of the descending colon (pT4, pN0, sH0, sP0, sM0, fStage II). The carcinoma had invaded the abdominal wall and transverse colon, but the cancer cells were not shown in the abdominal wall abscess cavity. In abdominal wall abscess treatment, colon cancer should be considered as a potential underlying cause. CT proved useful for assessing the status of the tumor and the abscess. We conducted a radical operation for descending colon cancer after the drainage for abdominal wall abscess.

Clinical significance of lymph node ratio and location of nodal involvement in patients with right colon cancer.

BACKGROUND/AIMS: Increasing negative lymph node count has been reported to be associated with better outcomes in patients with colon cancer. The present study aimed to clarify the clinical significance of the lymph node ratio (LNR) and location of lymph node metastasis (LNM) in patients with stage III right colon cancer. METHODS: We enrolled 820 patients who had undergone curative resection due to colon cancer at a single institution between 1991 and 2005. Among them, 197 underwent curative resection for T2-T4 right colon cancer. We evaluated the oncological outcomes according to LNR (quartiles) and distribution of LNM (n1 = LNM adjacent to the colon or along the vascular arcades of the marginal arteries; n2 = LNM along the major vessels; n3 = LNM near the roots of the major vessels). RESULTS: The rates of LNM in T2, T3 and T4 right colon cancer were 11.1, 38.6 and 58.0%, respectively (p < 0.0001). Recurrence rates were 27.3, 37.5 and 57.1% in patients with n1, n2 and n3 LNM, respectively (p < 0.0001). LNR (p < 0.0001) and distribution of LNM (p = 0.046) were independent risk factors for recurrence in patients with stage III right colon cancer. CONCLUSIONS: Some patients with extensive LNM benefited from lymph node dissection with high ligation. Those with T3-T4 right colon cancer are suitable candidates for lymph node dissection with high ligation. Adding the concept of LNR and location of LNM to conventional TNM staging could improve the accuracy of evaluating nodal status.

Effect of classification based on combination of mutation and methylation in colorectal cancer prognosis.

Colorectal cancer (CRC) is caused by an accumulation of genetic alterations and epigenetic alterations. The molecular classification of CRCs based on genetic alterations and epigenetic alterations is evolving. Here, we examined mutations and methylation status in CRCs to determine if the combination of genetic and epigenetic alterations predicts prognosis. We examined 134 sporadic CRCs. We used the direct sequencing method to identify mutations in BRAF and AKT1, which are downstream of KRAS and PIK3CA, respectively, in the EGFR pathway. We used the Methylight method to determine the methylation status of hMLH1, p16, MINT1, MINT2 and MINT31. Both BRAF and AKT1 mutations were found in only one case (0.75%). Aberrant methylation of hMLH1, p16, MINT1, MINT2 and MINT31 was detected in 22.4, 35.1, 32.8, 59.7 and 41.0% of cases, respectively. The clinicopathological factors were not significantly correlated to mutation or methylation. Among the patients who had no mutation in the EGFR pathway, the overall survival was significantly shorter in the patients with methylation compared to the patients with no methylation in hMLH1 and p16 (p=0.0318). Methylation could play a key role in the prognosis of patients without mutations in the EGFR pathway. The combination of genetic and epigenetic alterations may be a good marker for the prognosis of CRC patients.

Validation and clinical use of the Japanese classification of colorectal carcinomatosis: benefit of surgical cytoreduction even without hyperthermic intraperitoneal chemotherapy.

BACKGROUND: This study aimed to validate an easy to use practical classification of peritoneal metastasis arising from colorectal cancer. PATIENTS AND METHODS: Data from 2,134 consecutive patients who underwent resection for colorectal cancer at a single institution were reviewed. Peritoneal metastasis was classified depending on extent into three groups (P1-P3). The macroscopic radical resection rates and survival of patients with colorectal cancer complicated with peritoneal metastasis were analyzed. RESULTS: Of the 2,134 patients, 116 (5.4%) had peritoneal metastasis. Among them, 20 (17.2%) underwent macroscopic radical resection. Tumor location on the right side was associated with more extensive peritoneal metastasis (p = 0.010). Male gender (p = 0.0027), liver metastasis (p = 0.0021), and P3 peritoneal metastasis were independent risk factors for noncurative resection. The Cox proportional hazards model showed that gender (p = 0.031), operation period (p = 0.031), and macroscopic radical resection for colorectal cancer and peritoneal metastasis (p = 0.031) were independent prognostic factors. CONCLUSIONS: Being female with left colon cancer complicated with P1 or P2 peritoneal metastasis is a good indicator for macroscopic radical resection if liver metastasis is absent. The present classification helped to determine surgical indication for patients with colorectal cancer complicated with synchronous peritoneal metastasis in routine clinical practice.

[A case of colon cancer with multiple liver metastases effectively treated with hepatic arterial infusion followed by systemic chemotherapy].

A 63-year-old female was diagnosed as descending colon cancer with severe liver dysfunction caused by multiple liver metastases. Her performance status (PS) was 3 because of liver dysfunction and high fever. Initially, hepatic arterial infusion (HAI) chemotherapy was started to reduce the size of metastatic tumors and to prevent a liver failure. After 10 courses of HAI chemotherapy, she recovered from liver dysfunction, and CapeOX plus bevacizumab regimen was started. A partial response of metastatic liver tumors was observed after 8 cycles of this regimen and metastatic lung tumors were disappeared. The patient was alive after 12 months with PS 0 and CapeOX was continued.

[Clinicopathological studies and patterns of recurrence of mucinous colorectal carcinoma with curative resection].

In 771 cases of Stage II and III colorectal carcinoma with curative resection, clinicopathological characteristics, recurrent rate, patterns of recurrence, and prognosis of 24 cases (3%) of mucinous carcinoma were compared with those of 725 cases (94%) of well-moderately differentiated adenocarcinoma. Compared with well-moderately differentiated adenocarcinoma, mucinous carcinoma was found to be larger in tumor size, more severe lymphatic invasion, and a greater likelihood of Stage IIIb. Mucinous carcinoma had a highly recurrent rate and poorer prognosis than well-moderately differentiated adenocarcinoma. About the patterns of recurrence, mucinous carcinoma was found to be more significantly often as lymph node recurrences, but there was no liver metastasis in mucinous carcinoma. As for mucinous colorectal carcinoma, we should consider other different therapeutic strategies and surveillance.

[Curative resection for bulky rectal gastrointestinal stromal tumor after neoadjuvant imatinib mesylate].

Gastrointestinal stromal tumor is the most common mesenchymal tumor of the gastrointestinal tract. However, the frequency of rectal gastrointestinal stromal tumor is relatively low. We described the case of a 54-year-old man with bulky rectal gastrointestinal stromal tumor of which a diameter was 10 cm. After eight-week neoadjuvant imatinib mesylate, the diameter of tumor was reduced to 6 cm. The patient did not have any distant metastases on preoperative computed tomography and magnetic resonance imaging. He underwent abdominoperineal resection. The radial margin was negative. Immunohistochemical staining showed that KIT and CD34 were positive. The number of mitosis was 13 per 50 high-power fields. Adjuvant imatinib mesylate was administered for one year. No recurrence was found for 43 months after a curative resection. Curative resection is the most promising treatment for gastrointestinal stromal tumor. However, neoadjuvant imatinib mesylate followed by surgical procedure seems to be one of the treatment options for locally advanced gastrointestinal stromal tumor.

Methylated BNIP3 gene in colorectal cancer prognosis.

The DNA methylation of apoptosis-related genes in various cancers contributes to the disruption of the apoptotic pathway and results in resistance to chemotherapeutic agents. Irinotecan (CPT-11) is one of the key chemotherapy drugs used to treat metastatic colorectal cancer (CRC). However, a number of metastatic CRC patients do not benefit from this drug. Thus, the identification of molecular genetic parameters associated with the response to CPT-11 is of interest. To identify apoptosis-related genes that may contribute to CPT-11 resistance, microarray analysis was conducted using colon cancer cells in which 5-aza-2'deoxycytidine (DAC) enhanced sensitivity to CPT-11. Microarray analysis identified 10 apoptosis-related genes that were up-regulated following treatment with DAC. Among the genes, Bcl-2/adenovirus E1B 19 kDa protein interacting protein 3 (BNIP3), a Bcl-2 family pro-apoptotic protein, was identified as being involved in CPT-11 resistance following methylation of its promoter. An analysis of 112 primary CRC cases revealed that approximately 58% of cases showed BNIP3 methylation, and that patients with methylation exhibited a poorer outcome compared to those without methylation. In addition, in 30 patients who received first-line CPT-11 chemotherapy, patients with methylation exhibited resistance to chemotherapy compared to patients with no methylation. The results suggest that methylation of BNIP3 is a predictive factor in the prognosis and response to CPT-11 treatment in CRC patients.

[A case of rectal cancer with lung metastases responding to cetuximab].

We report a 73-year-old male patient who underwent low anterior resection for rectal cancer (Stage IIIb). Nine months after the surgery, multiple metastases of liver, lung, brain and lymph node were detected. He was treated with FOLFOX4 and FOLFIRI though lung metastases progressed and caused dyspnea. Cetuximab plus irinotecan therapy was dramatically effective, which improved his quality of life for over 10 months.

[A case of rectal cancer successfully treated by multidisciplinary strategy for liver and pulmonary metastases].

We report a case of rectal cancer with distant metastases, which was successfully treated with multidisciplinary treatments. The 60s female underwent an abdomino-perineal resection (APR) for low rectal cancer. One year after the APR, two hepatic metastases were found and initially treated by radiofrequency ablation and later by hepatectomy. One month after the hepatectomy, three pulmonary metastases of 10 mm in diameter were found in the right lung. Several regimens of chemotherapy (S-1, CPT-11 and FOLFOX6) were performed. After 3 years of chemotherapy, pulmonary metastases re- grew in size but no new lesion developed. Pneumonectomy was performed to remove all metastatic tumors. A half year after the initial pneumonectomy, a new metastasis was found in the left lung, which was again removed by surgery after 6 months of observation. Postoperative course was uneventful, and she is alive without recurrence for 7 years since the initial rectal surgery.

[A case of advanced rectal cancer with severe liver dysfunction due to multiple liver metastases].

We report a case of rectal cancer with unresectable multiple liver metastases, which was worried about the transition from liver dysfunction to liver failure. The male patient in his 70s was diagnosed as advanced rectal cancer with severe liver dysfunction because of multiple liver metastases. Hepatic arterial infusion (HAI) chemotherapy, which was effective to reduce the size of metastatic liver tumors, was initially started. During HAI chemotherapy, sigmoid colostomy was performed. He recovered from liver dysfunction after he had been treated with 13th cycle HAI chemotherapy. He was treated with the modified FOLFOX6 regimen following a resection of rectal cancer. Although the standard therapy for colorectal cancer with unresectable liver metastases is firstly systemic chemotherapy such as FOLFOX or FOLFIRI, it might be better to control the liver metastases by HAI chemotherapy when a liver function is severely damaged by extensive liver tumors.

Messenger RNA expression of COX-2 and angiogenic factors in primary colorectal cancer and corresponding liver metastasis.

Several new drugs that are targeted towards various angiogenic factors have shown considerable potential for controlling tumor proliferation and metastases. Expression levels of the targeted genes in primary tumors and metastases should be understood to maximize the use of such drugs. The present study aimed to clarify associations between mRNA levels of cyclooxygenase 2 (COX-2) and angiogenic factors [vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8)] in primary colorectal cancer and in corresponding liver metastasis. We also compared these gene expressions of primary colorectal cancer between patients with and without liver metastasis. In 31 pairs of formalin-fixed and paraffin-embedded primary and metastatic liver tumors as well as 27 specimens of consecutive stage II patients without recurrence, mRNA was quantified by real-time reverse transcription-polymerase chain reaction following the laser capture microdissection. We found a significantly positive correlation in IL-8 between primary tumors and matched liver metastases (p=0.034, rs=0.39) and in VEGF (p=0.0083, rs=0.48), but not in COX-2, which was associated with both VEGF (p=0.044, rs=0.37) and IL-8 (p=0.0004, rs=0.64) in primary colorectal cancers. Multiple regression analysis revealed that COX-2 was independently associated with IL-8 (p<0.0001). There were no differences in mRNA levels between patients with and without liver metastasis. The mRNA levels of VEGF and IL-8 in liver metastasis can be predicted from those in primary colorectal cancer. COX-2 might exert angiogenic activity more through the IL-8, than the VEGF pathway. These angiogenic factors were sufficiently up-regulated before hematogenous metastasis. These preliminary data merit further validation studies.

Colorectal Carcinoma: Local Tumor Staging and Assessment of Lymph Node Metastasis by High-Resolution MR Imaging in Surgical Specimens.

Purpose. To assess the accuracy of high-resolution MR imaging as a means of evaluating mural invasion and lymph node metastasis by colorectal carcinoma in surgical specimens. Materials and Methods. High-resolution T1-weighted and T2-weighted MR images were obtained in 92 surgical specimens containing 96 colorectal carcinomas. Results. T2-weighted MR images clearly depicted the normal colorectal wall as consisting of seven layers. In 90 (94%) of the 96 carcinomas the depth of mural invasion depicted by MR imaging correlated well with the histopathologic stage. Nodal signal intensity on T2-weighted images (93%) and nodal border contour (93%) were more accurate than nodal size (89%) as indicators of lymph node metastasis, and MR imaging provided the highest accuracy (94%-96%) when they were combined. Conclusion. High-resolution MR imaging is a very accurate method for evaluating both mural invasion and lymph node metastasis by colorectal carcinoma in surgical specimens.

[A case report of a patient with hand-foot syndrome induced by bolus 5-fluorouracil therapy].

We present a case of hand-foot syndrome (HFS) induced by bolus 5-fluorouracil (5-FU) therapy. A 54-year-old man received bolus 5-FU for adjuvant treatment of rectal cancer. After second cycle, he presented to the clinic with a rash on the both palms accompanied by symptoms of pain, erythema, swelling, and desquamation consistent with grade 2 HFS. HFS appears more frequently with 5-FU delivered by continuous infusion or with the 5-FU oral derivative capecitabine than with bolus 5-FU therapy. HFS is a leading cause of treatment interruption which may impact on the efficacy of the treatment regimen. This possibility must be considered when patient is receiving a bolus 5-FU treatment, and effective and appropriate patient education is an essential part of management to prevent progression to a more severe grade of toxicity by early detection of HFS.