A rare case of colorectal metastasis found 8 years and 10 months after gastrectomy for advanced gastric cancer: A case report and literature review.

Colorectal metastasis from gastric cancer is rare and may develop several years after gastric cancer surgery. Therefore, colonoscopic findings provide useful diagnostic information. The present report describes a case of gastric cancer colon metastasis diagnosed 8 years and 10 months after gastrectomy for advanced gastric cancer. A 64-year-old male patient underwent gastrectomy in December 2010 and received chemotherapy for 4 years and 10 months after the surgery. Subsequently, the patient was diagnosed as having colorectal cancer by computed tomography in February 2019. Colonoscopy revealed linitis plastica-like colon stenosis; however, biopsy pathology did not reveal any findings indicating malignancy. Right hemicolectomy was performed, and pathological examination revealed colon metastasis from gastric cancer. The patient received chemotherapy but died of peritoneal carcinomatosis 1 year and 8 months after the colectomy. According to literature, colorectal metastasis from gastric cancer is often attributed to hematogenous metastasis and often exhibits characteristic macroscopic features. Treatments, such as chemotherapy for gastric cancer and/or colorectal resection, are considered effective for gastric cancer colorectal metastasis.

Successful resection of port site recurrence of pancreatic ductal adenocarcinoma after laparoscopic distal pancreatectomy.

BACKGROUND: There are many reports of port site recurrence after laparoscopic surgery for various types of cancer. However, only two cases of port site recurrence after laparoscopic pancreatectomy have been reported to date. We herein report a case of port site recurrence after laparoscopic distal pancreatectomy. CASE PRESENTATION: A 73-year-old woman was diagnosed with pancreatic tail cancer and underwent laparoscopic distal pancreatectomy with splenectomy. Histopathological examination revealed pancreatic ductal carcinoma (pT1N0M0 pStage I). The patient was discharged on postoperative day 14 with no complications. However, 5 months after surgery, computed tomography showed a small tumor at the right abdominal wall. No distant metastasis had appeared after 7 months of follow-up. Under the diagnosis of port site recurrence without any other metastases, we resected this abdominal tumor. Histopathological examination showed port site recurrence of pancreatic ductal carcinoma. No recurrence was observed 15 months postoperatively. CONCLUSIONS: This is the report of successful resection of port site recurrence of pancreatic cancer.

Surgical management of primary undifferentiated pleomorphic sarcoma of the rectum: a case report and review of the literature.

BACKGROUND: Undifferentiated pleomorphic sarcoma (UPS) is a malignant soft tissue tumor that has been reclassified from malignant fibrous histiocytoma with the development of the pathological diagnosis. It principally occurs in the extremities but rarely occurs in the rectum. We herein report a rare case of UPS arising in the rectum. CASE PRESENTATION: A 85-year-old woman was referred to our hospital with a complaint of anal pain, which had persisted for several months. Computed tomography (CT) showed a 53 × 58 × 75 mm mass on the left side of the rectum. Colonoscopy revealed a submucosal elevation in the rectum without any exposure of the tumor to the surface. Contrast-enhanced CT and magnetic resonance imaging revealed an 80-mm mass that originated in the rectal muscular propria, and we suspected a gastrointestinal stromal tumor. No lymph node metastasis or distant metastasis was observed. We performed a laparoscopic Hartmann's operation. Intraoperatively, severe adhesion around the tumor caused tumor injury and right ureteral dissection. Thus, laparoscopic right ureteral anastomosis and ureteral stenting were additionally performed. The operation time was 6 h and 3 min, and the estimated blood loss was small. The patient was discharged without complications 25 days after surgery. A pathological examination showed that the tumor was composed of highly heterogeneous cells with no specific differentiation traits, leading to a diagnosis of UPS. Contrast-enhanced CT performed 2 months after surgery showed bilateral pelvic lymph node enlargement, which indicated recurrence. Considering the patient's age, we performed radiotherapy (50 Gy/25 Fr targeting the pelvic region). At present, 16 months have passed since the completion of radiotherapy. Contrast-enhanced CT shows that the recurrent lymph nodes have disappeared, and no new distant metastasis has been observed. CONCLUSIONS: We reported a case of UPS arising in the rectum. The surgical procedure and indication of preoperative therapy should be carefully selected because complete removal of the tumor is desirable in UPS.

[A case of primary mesenteric schwannoma with secondary ossification].

Schwannoma is a tumor that usually originates soft tissue peripheral nerves. Primary mesenteric schwannomas are rare, and furthermore, there are few reports of this with secondary ossification, which is extremely rare. Herein we report a case of primary mesenteric schwannoma with secondary ossification in a 46-year-old Japanese woman with recurrent postprandial abdominal pain and weight loss. Her vital signs were stable, and her blood test was almost normal except for a slight elevation of CA125. Computed tomography revealed a whirl sign indicative of superior mesenteric torsion. In contiguity with a constricted portion of the intestine, an approximately 70-mm, well-circumscribed tumor with calcifications, which was fed by the superior mesenteric artery was visible. On magnetic resonance imaging, the tumor appeared hypointense on T1-weighted images and inhomogeneous hyperintense on T2-weighted images. As a gastrointestinal mesenchymal tumor was suspected, we performed partial small intestinal resection including the tumor. Intraoperatively, the tumor was found to be incarcerated into a hernial orifice created by the adhesion of the sigmoid colon with the abdominal wall and uterus. Pathologically, the tumor had no continuity with the intestinal wall. It mainly consisted of hypocellular mucous, and spindle-shaped cells were sparsely distributed. Some areas were hypercellular with palisading arrangement cells. This was suggestive of an Antoni B>Antoni A type schwannoma. It also included secondary ossification and blood vessel assembly. The patient has had an uneventful postoperative course without recurrence for about 17 months. Primary mesenteric schwannoma is rare, and to our knowledge, only 20 cases including this case have been reported. Moreover, there has only been one report of primary mesenteric ossified schwannoma in 2018, and there has been no report in Japan so far. We report our experience with the successful treatment of primary mesenteric ossified schwannoma and review the literature.

Analysis of risk factors for surgical site infection and postoperative recurrence following inguinal and femoral hernia surgery in adults.

OBJECTIVE: We aimed to evaluate the causes of complications following surgery for inguinal and femoral hernia, using surgical site infection (SSI) and recurrence rate as indicators of outcomes to consider appropriate treatments. METHODS: We retrospectively assessed the medical histories of 1,098 patients with adult inguinal and femoral hernias who underwent herniorrhaphy between July 2010 and March 2019. Using SSI and recurrence rate as indicators of outcomes, we statistically assessed the influence of preoperative and operative conditions on surgical outcomes. RESULTS: The occurrence of postoperative SSI was significantly more frequent in patients who experienced a long surgical duration, excessive blood loss, and incarceration; underwent emergency surgery and bowel resection; and in whom no mesh sheet insertion was performed. There was no correlation between mesh use and SSI in cases that did not require emergency incarceration repair. For cases involving hernia incarceration, the use of a mesh sheet was avoided to prevent potential infection, which could explain the high incidence of SSI in cases where mesh was not used. The hernia may have recurred due to technical issues during the procedure, as well as failure to ligate the hernia sac. CONCLUSIONS: Selecting the appropriate surgical method for hernia repair may reduce the incidence of SSI. If manual reduction of inguinal hernias is not possible, an appropriate surgical procedure should be determined based on laparoscopic findings in facilities where laparoscopic hernia surgeries are frequently performed. Moreover, in cases without infection and bowel resection, mesh use may be beneficial. Recurrence can be prevented by ligating the hernia sac during surgery and solving relevant technical problems.

Catamenial pneumothorax with partial liver herniation due to diaphragmatic laceration: a case report and literature review.

BACKGROUND: Catamenial pneumothorax is generally uncommon, with an incidence of less than 3-6% in women with spontaneous pneumothorax. As few cases of catamenial pneumothorax with diaphragmatic defect and liver herniation have been reported, this case report may be useful for understanding the cause and treatment. This case highlights the importance of the approach for liver hernia in patients with catamenial pneumothorax and endometriosis. CASE PRESENTATION: We report a case of catamenial pneumothorax in a 43-year-old woman with diaphragmatic partial liver hernia who was treated with thoracoscopic surgery. She was diagnosed with a right pneumothorax at menstruation onset. Chest computed tomography showed a nodule protruding above the right diaphragm. We performed thoracoscopic surgery to treat the persistent air leak and biopsied the nodule on the right diaphragm. There were blueberry spots on the diaphragm; the nodule was found to be the herniated liver. The diaphragmatic defect was sutured. Histological examination of the tissue near the partial prolapsed liver revealed endometrial tissue. CONCLUSIONS: It is speculated that ectopic endometrial tissue in the diaphragm will periodically necrose to become a diaphragmatic tear, which is a pathway for air to enter the thoracic cavity and eventually a herniated liver. Thoracoscopic surgery should be considered in patients with catamenial pneumothorax when a diaphragmatic lesion is suspected.

Risk Factors Associated with the Development of Metastases in Patients with Gastroenteropancreatic Neuroendocrine Tumors: A Retrospective Analysis.

Neuroendocrine tumors develop from systemic endocrine and nerve cells, and their occurrence has increased recently. Since these tumors are heterogeneous, pathological classification has been based on the affected organ. In 2019, the World Health Organization introduced a change expected to influence neuroendocrine tumor research, as gastroenteropancreatic neuroendocrine tumors are now included within a unified classification. This retrospective study aimed to investigate the characteristics (e.g., lymph node metastases and all other metastases) of gastroenteropancreatic neuroendocrine tumors using this new classification in 50 cases. Tumor size, depth, MIB-1 index, lymphatic invasion, venous invasion, and neuroendocrine tumor grade were significantly correlated with lymph node metastasis and other metastases. The venous invasion was more strongly correlated with lymph node metastasis and all other types of metastases than with lymphatic invasion. Identification rates for lymphatic invasion were considered lower because of structural problems such as lymphatic vessels being much thinner than veins. However, venous invasion was considered effective in compensating for the low identification rate in cases of lymphatic invasion. In future research, a unified classification and standardized framework for assessment will be important when analyzing the characteristics of neuroendocrine tumors, and large-scale studies are required.

Significance of Primary Malignant Tumors on the Outcome of Patients With Resected Gastrointestinal Stromal Tumors.

AIM: This study aimed to clarify the significance of primary malignant tumors for the outcome of resected gastrointestinal stromal tumors (GISTs). PATIENTS AND METHODS: The medical history, pathological findings and prognosis of 66 patients with GISTs resected at our institute between January 2003 and December 2018 were investigated retrospectively and compared statistically. RESULTS: Among 66 patients with GISTs, 24 (36%) had concomitant malignant tumors. In an average study period of 57 months, one patient died from GIST, seven from other malignant tumors, and one from another disease. Only coexistence of GIST and other malignant tumors was recognized as a prognostic factor. Increasing age was significantly correlated with other malignant tumor in combination with GIST. When comparing patients with GIST alone and GIST with other malignant tumors, the latter showed significantly poorer prognosis. CONCLUSION: Coexistence of other malignant tumors was commonly observed in patients with GIST, and was associated with poorer prognosis. This association should be carefully considered and monitored in patients with GISTs.

Ruptured visceral artery aneurysms in a patient of neurofibromatosis type 1 (NF-1) successfully treated by endovascular treatment.

BACKGROUND: Neurofibromatosis type 1 (NF-1) is an autosomal dominant disease and arteriovenous abnormalities are a well-recognized complication. There are several case reports of ruptured aneurysms; however, among them, reports of superior pancreaticoduodenal artery (PDA) and superior mesenteric artery (SMA) aneurysms are rare. We experienced the case of ruptured PDA and SMA aneurysms in a patient of neurofibromatosis type I successfully treated by endovascular treatment. CASE PRESENTATION: A 55-year-old woman with NF-1 came to our hospital with abdominal pain and vomiting. Enhanced abdominal computed tomography revealed a hematoma in the retroperitoneum and an aneurysm in the head of the pancreas. Angiography was performed, and a ruptured aneurysm was suspected the periphery of the PDA, and we embolized it using coils. However, on postoperative day 2, the hemoglobin level decreased, and a branch of the SMA was ruptured. She underwent embolization using coils again and discharged on postoperative day 27 without any further hemorrhage. CONCLUSIONS: To our knowledge, this is the first successfully treated case of ruptured SMA and PDA aneurysms in a patient with NF-1.

CA19-9 Concentration After First-line Chemotherapy Is Prognostic Predictor of Metastatic Colon Cancer.

BACKGROUND/AIM: To evaluate whether the serum levels of CEA or CA19-9 concentration is a useful predictor of survival in patients with metastatic colon cancer (mCC). PATIENTS AND METHODS: Between 2012 and 2015, 113 patients with mCC who underwent chemotherapy according to the Japanese Colorectal Cancer Treatment Guidelines at four Jikei University Hospitals were enrolled in this study. The two serum tumor makers, CEA and CA19-9 were measured before first-line chemotherapy and at four months thereafter. RESULTS: Serum CA19-9 concentration at four months after first-line chemotherapy (p=0.003, HR=3.761) and first-line chemotherapy including oxaliplatin (p=0.038, HR=0.312) were independent predictors of survival in patients with mCC. By excluding the transverse colon, only serum CA19-9 concentration at four months after first-line chemotherapy (p=0.005, HR=3.660) was identified as the predictor of survival. CONCLUSION: Serum CA19-9 concentration after first-line chemotherapy seems to be a useful predictor of survival in patients with mCC.

Schwannoma of the Small Intestine.

Schwannomas of the gastrointestinal tract are rare. Herein, we report a case of schwannoma originating from the small intestine. A 78-year-old woman underwent medical follow-up after surgery for bladder cancer, and a mass in the upper part of the pelvis was revealed by abdominal CT. With the diagnosis of a submucosal tumor of the small intestine, she underwent partial intestinal resection. The submucosal tumor was pathologically composed of S100-positive spindle cells and diagnosed as schwannoma. We report this case of rare schwannoma of the small intestine and review the literature.

Reevaluation of Preoperative Chemoradiotherapy for Clinical T3 Lower Rectal Cancer: A Multicenter Collaborative Retrospective Clinical Study.

AIM: This study aimed to re-evaluate the usefulness of preoperative chemoradiotherapy for clinical T3 lower rectal cancers without lateral lymph node metastasis. PATIENTS AND METHODS: Between 2010 and 2014, 132 patients with clinical T3 lower rectal cancer without lateral lymph node metastasis, 80 years of age or younger, who underwent curative resection at four Jikei University Hospitals were enrolled into this retrospective study. Of these, 22 patients received chemoradiotherapy (CRT) before surgery, 16 patients received intensive chemotherapy after surgery without preoperative CRT, and 94 patients underwent neither preoperative CRT nor intensive chemotherapy after surgery including 47 patients with postoperative oral chemotherapy for pathological diagnosis of stage III. RESULTS: The 3-year disease-free survival (DFS) of the 22 patients who received preoperative CRT was 95.5%, whereas that of the 94 patients who received neither preoperative CRT nor intensive chemotherapy was 72.0% (p=0.024). However, there was no significant difference in 5-year DFS between the two groups. No significant difference was identified in DFS between the 22 patients who received preoperative CRT and the 16 patients who received intensive chemotherapy after surgery without preoperative CRT. CONCLUSION: Intensive chemotherapy after surgery seems to yield a similar prognosis to preoperative CRT in patients with clinical T3 lower rectal cancer without lateral lymph node metastasis.

[Elastofibroma Dorci;Report of a Case].

Elastofibroma is a relatively rare tumor that occurs commonly at the apex of scapula in elderly people. We report a case of elastofibroma of a female in her seventies. She visited our hospital with complaints of painful mass in her back, which was increasing in size. On the magnetic resonance imaging (MRI),the T1 and the T2-weighted images showed the same signal intensity as the muscle between the right scapula and the intercostal muscles. The internal fat component was cord-like, with high signal intensity. Based on the site of the tumor and characteristic findings on imaging, it was diagnosed as elastofibroma and resection was performed. Pathological findings revealed bundle-like proliferation of fibrous and spherical hyaline substances, together with collagen fibers. The hyaline substance stained in black on Elastica van Gieson staining and was confirmed to be elastic fiber. Thus, it was diagnosed as elastofibroma. The patient is on regular follow-up, with no recurrence after surgery.

Expression of CXCR-4 and IDO in human colorectal cancer: An immunohistochemical approach.

C-X-C chemokine receptor type 4 (CXCR4), the receptor for the chemokine stromal cell-derived factor (SDF)-1 [also known as C-X-C motif chemokine 12 (CXCL12)], is involved in lymphocyte trafficking. Recent studies have demonstrated that, during pregnancy, a placental enzyme called indoleamine 2, 3-dioxygenase (IDO) exerts a key role in suppressing the maternal T-cell response against the fetus. In the present study, the significance of CXCR4 and IDO expression in human colorectal cancer (CRC) has been investigated by immunohistochemical assay, and their association with survival was analyzed. Tumor specimens (n=60) from patients with different American Joint Committee on Cancer (AJCC) stages of CRC (I or IV) were assessed. In the stage IV group, 23 of 30 cases (77%) stained positive for CXCR4, and 9 of 30 (30%) were positive for IDO. By contrast, in the stage I group, 7 of 30 cases (23%) stained positive for CXCR4, and 15 of 30 cases (50%) were positive for IDO. The 5-year survival rate of those with high CXCR4 expression in tumor specimens (n=30) was significantly worse compared with those with negative CXCR4 expression (16.3 vs. 60.7%, P=0.02). By contrast, the 5-year survival rate of those with high IDO expression in tumor specimens (n=24) was not significantly different compared with those with negative IDO expression (36.4 vs. 56.8%). In the stage I group, 4 patients in the high IDO expression group (n=15) had distant metastases (2 in the liver 1 in the brain, and 1 in the lung). Taken together, CXCR4 appears to be a novel predictive indicator of survival, and IDO expression in the early stage may be a predictor of distant metastasis.

Preoperative peripheral blood neutrophil count predicts long-term outcomes following hepatic resection for colorectal liver metastases.

Preoperative systemic inflammatory response is associated with a poor long-term prognosis following resection surgery for malignant tumors. Several markers of systemic inflammation have been reported to be associated with the outcome; however, they have not currently been fully investigated. Therefore, the association between preoperative peripheral blood neutrophil count and oncological outcome following hepatic resection for colorectal liver metastasis (CRLM) was retrospectively investigated. The present study comprised 89 patients who had undergone hepatic resection for CRLM between January 2000 and March 2010. The association between preoperative peripheral blood neutrophil count and disease-free survival, in addition to overall survival, was investigated. In multivariate analysis, the presence of neoadjuvant chemotherapy (P=0.015), bilobar distribution (P=0.015) and neutrophil count ≥3,500/µl (P=0.025) were independent and significant predictors of poor disease-free survival, while significant predictors of poor overall survival consisted of >4 lymph node metastases (P=0.001), neo-adjuvant chemotherapy (P=0.003), bilobar distribution (P=0.039) and neutrophil count ≥3,500/µl (P=0.040). Additionally, tumor diameter (P=0.021) and monocyte count (P<0.0001) were observed to be significantly greater in the elevated neutrophil count group. In conclusion, preoperative peripheral blood neutrophil count may be an independent and significant indicator of poor long-term outcomes in patients with CRLM following hepatic resection.

Laparoscopic surgical challenge for T4a colon cancer.

For patients with T4a colon cancer, the risk of peritoneal dissemination after surgery remains unclear. Seven hundred and eleven patients with T3 or T4a colon cancer, 80 years of age or younger, underwent curative resection (open surgery in 512 and laparoscopic surgery in 199) at the four Jikei University hospitals between 2006 and 2012. Their risk factors for peritoneal dissemination after surgery were evaluated retrospectively. Number of lymph node metastases, postoperative liver metastases and postoperative peritoneal dissemination events in the T4a group were significantly greater than the number in the T3 group. Peritoneal dissemination after surgery developed in four patients (0.7%) in the T3 group and in six patients (5%) in the T4a group. Risk factors for peritoneal dissemination consisted of macroscopic type (P = 0.016), serosal invasion (P = 0.017) and number of lymph node metastases (P = 0.009) according to the Cox proportional hazards regression model. However, tumor diameter and surgical approach (laparoscopic vs open) were not significant factors for peritoneal dissemination. There were no significant differences between the postoperative relapse-free survival rates for each surgical approach within the T3 or T4a group. Because of comparable postoperative peritoneal dissemination in T3 and T4a colon cancer by the surgical approach (laparoscopic or open), laparoscopic surgery for patients with T4a colon cancer seems justified.

Initial Report of Phase II Study on Bi-weekly SOX plus Cetuximab Treatment for Wild-type K-RAS Advanced and Recurrent Colorectal Cancer.

AIM: This prospective study was designed to evaluate the tolerability and the efficacy of bi-weekly SOX (S-1 and oxaliplatin)+cetuximab as first-line chemotherapy for wild-type K-RAS metastatic colorectal cancer. PATIENTS AND METHODS: We studied patients with previously untreated, unresectable, advanced or recurrent colorectal cancer who were treated in our hospital between October 2010 and March 2013. Their performance status (PS) was 0 to 1. Cetuximab was combined with S-1 and oxaliplatin (SOX+cetuximab). S-1 was given orally at a dose of 40 mg/m(2) (40-60 mg, calculated according to body surface area) twice daily after meals for 2 weeks, followed by a 2-week rest (course 1). Oxaliplatin (85 mg/m(2)) was given on days 1 and 15 of each course. Cetuximab was administered on days 1 (400 mg/m(2)), 8 (250 mg/m(2)) and 15 (500 mg/m(2)) of course 1, followed by every 2 weeks (500 mg/m(2)) thereafter. RESULTS: The study group comprised of 18 patients. The mean age was 61 (range=32-72) years, the male:female ratio was 10:8 and the PS was 0 in 12 patients and 1 in 6 patients. The median number of administered courses was 6 (range=2-12). The treatment response was complete response (CR) in 2 and partial response (PR) in 10 (response rate=67% (12/18 patients)). The minimum number of treatment courses until a PR was 2, indicating an early response. Liver resection was performed in 4 patients (22.2%). The incidence of any adverse events (Grade 3/4) was 28% (5/18), including skin disorder (16.7%) as dry skin, cutaneous pruritus, contusion and paronychia, as well as peripheral sensory neuropathy (11.1%). The any-grade events of skin disorders and peripheral sensory neuropathy were mostly observed in all patients. These events were controllable by preventive skin care and by withdrawal and dose reduction, respectively. Death due to adverse events was not observed. Adverse events did not require the withdrawal of this regimen. CONCLUSION: Based on the 18 patients studied, combined therapy with SOX+cetuximab was free of serious adverse events and could be safely administered by reducing the dose or temporarily suspending treatment, as required. These regimens seem to be promising for conversion therapy (4 out of 18 patients) because of good outcomes and an early response.

The Usefulness of Diffusion MRI in Detection of Lymph Node Metastases of Colorectal Cancer.

The aim of this study was to assess the sensitivity and specificity of preoperative diagnosis by diffusion magnetic resonance imaging (D-MRI) for lymph node metastasis of colorectal cancer. The b-value represents the diffusion factor (measured in s/mm(2)) and the strength of the diffusion gradients. The b-value used in this study was 1,000 s/mm(2). A total of 119 patients underwent D-MRI before resection of primary colorectal cancer (52 of the rectum, 67 of the colon) at our hospital between February 2005 and April 2006. Lymph node metastases judged by D-MRI were compared with postoperative pathological results. The form of lymph node metastasis was classified either as abundant or scarce type. The predictive values for lymph-node metastasis (sensitivity and specificity) by D-MRI were calculated from the result of this classification and lymph-node size. The study was divided into two periods: before the consensus meeting in January 2006, (n=79) (P-I), and after the adjustment of the criteria to improve the sensitivity and specificity based on the results of P-I (n=40) (P-II). Detection of lymph node metastasis using D-MRI in P-I had sensitivity of 61%, specificity of 73%, positive predictive value (PPV) of 55%, and negative predictive value (NPV) of 77%, while in P-II, these values improved to 79%, 95%, 94%, and 83%, respectively. Specificity and PPV for P-II were significantly higher than those for P-I (p<0.05). The diameter of lymph nodes judged to be metastatic on D-MRI (P-I vs. P-II: n=32 vs. 16) was 10.3±5.4 (3-28) vs. 9.1±3.0 (4-14) mm; 11.5±6.2 (4-28) vs. 9.2±3.1 (4-14) mm for truly positive nodes (n=18 vs. 15), and 6±3.8 (3-14) vs. 8 mm for false-positive nodes (n=14 vs. 1). On the other hand, lymph nodes judged negative by D-MRI (n=47 vs. 24) was 5.9±2.4 (3-16) vs. 5.7±2.8 (2-15) mm; 5.9±2.1 (3-16) vs. 5.3±2.1 (2-8) mm for truly negative (n=36 vs. 20), and 5.7±2.7 (3-12) vs. 7.8±4.9 (4-15) mm for false negative (n=11 vs. 4). As to the form of metastasis, all truly positive nodes were of the abundant type, and 6/11 (55%) in P-I and 1/4 (25%) in P-II false-negatives were of the scarce type. In conclusion, D-MRI seems useful for preoperative detection of metastatic lymph nodes in colorectal cancer, especially if the node is hyperintense and more than 9 mm in diameter.

Adjuvant chemotherapy for the perineural invasion of colorectal cancer.

BACKGROUND: To evaluate the association of perineural invasion (PNI) with outcomes in patients after colorectal resection of colorectal cancer (CRC) and to assess the effect of PNI on the response to adjuvant chemotherapy. PATIENTS AND METHODS: Data were retrospectively reviewed for 178 patients with consecutive stages I-III CRC who underwent curative surgery between January 1999 and December 2004. PNI data were examined, and the overall survival (OS) and disease-free survival rates were analyzed. RESULTS: PNI was detected in 36 of 178 patients (20%) and positively correlated with lymphatic invasion (P = 0.020), venous invasion (P = 0.037), and the incidence of metastasis or recurrence (P = 0.029). Five-year disease-free survival was 46% and 68% (P < 0.001) and the 5-y OS was 64% and 80% (P < 0.001) for patients with and without PNI, respectively. In stage III CRC, multiple regression analysis identified PNI as a strong negative prognostic factor of OS; among PNI-positive patients, median OS with adjuvant chemotherapy was almost twofold higher than that without adjuvant chemotherapy (6 versus 2.8 y; P = 0.017). CONCLUSIONS: PNI was a poor predictor of survival among patients with stage III CRC, and adjuvant chemotherapy may attenuate the adverse effects of PNI on survival.

Thymidine phosphorylase mRNA expression may be a predictor of response to post-operative adjuvant chemotherapy with S-1 in patients with stage III colorectal cancer.

The aim of the present study was to investigate markers in surgically resected specimens of colorectal cancer that can be used to predict the response to chemotherapy. The mRNA expression levels of enzymes involved in 5-fluorouracil (5-FU) metabolism and folate metabolism were measured in formalin-fixed, paraffin-embedded tumor sections obtained from the primary tumors of 54 patients with resected stage II or III colorectal cancer who received S-1 for one year. The 5-FU metabolizing enzymes studied were thymidylate synthase, dihydropyrimidine dehydrogenase and thymidine phosphorylase (TP). The folate metabolizing enzymes studied were folypolyglutamate synthetase, γ-glutamyl hydrolase and dihydrofolate reductase. The associations between the mRNA expression levels of these enzymes and clinical variables were investigated. Tumors were classified as exhibiting high or low expression as compared with the median mRNA expression level of each metabolizing enzyme defined as the cutoff value. The associations between the high and low expression levels of each enzyme and disease-free survival (DFS) were analyzed with the use of Kaplan-Meier curves and the log-rank test. DFS was not significantly associated with the relative mRNA expression level of any metabolizing enzyme in the study group as a whole, but there was a trend toward longer DFS in patients with high TP expression (P=0.066). In patients with stage III colorectal cancer, high TP expression was associated with significantly improved outcomes compared with low TP expression (P=0.039). These results indicate that the mRNA expression of TP, a metabolizing enzyme of 5-FU, is a significant predictor of response to post-operative chemotherapy with S-1 in patients with stage III colorectal cancer.