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Masatoshi Oya

Publications and source records attributed to Masatoshi Oya.

At least 19 recordsLinked to original sources
PubMed2006

Characteristics of recurrence and surveillance tools after curative resection for colorectal cancer: a multicenter study.

BACKGROUND: The aim of this study was to clarify the characteristics of recurrence and the effectiveness of surveillance tools after curative resection for colorectal cancer. METHODS: We enrolled 5230 consecutive patients (stage I, 1367; stage II, 1912; stage III, 1951) who underwent curative resection at 14 hospitals from 1991 to 1996. All patients were followed up intensively, and their outcomes were investigated retrospectively. RESULTS: Of the 5230 patients, 906 developed recurrence. The recurrence rates of stage I, II, and III cancers were 3.7%, 13.3%, and 30.8%, respectively (P < .0001). The curves of the cumulative appearance rate of recurrence in stage II and III patients showed a rapid increase for the first 3 years. Recurrence after 5 years was less than 1% in each stage. Clinical visits combined with measurements of tumor markers detected the majority of recurrences except in the case of lung metastasis. In contrast, 43.4% of hepatic recurrences were detected by liver imaging, and 48.4% of pulmonary recurrences were noted by chest x-ray. The 5-year survival rates after primary colorectal surgery in patients who underwent resection for recurrence were better than in those without resection: 55% vs 11% in hepatic recurrence, 68% vs 13% in pulmonary recurrence, and 48% vs 22% in local recurrence (all P < .001). CONCLUSION: It is useful to take these characteristics of recurrence into account in the management of patients after curative resection for colorectal cancer and in the setting of clinical trial for follow-up after curative resection for colorectal cancer.

Aged↗
PubMed2006

Anal canal carcinoma with Pagetoid spread: report of a case.

A 70-year-old man with a history of colon polyps was found to have a semipedunculated polyp in the anal canal. The patient was asymptomatic. The lesion was 14 mm in diameter and located 5 mm from the dentate line. Histological examination of biopsy specimens revealed well-differentiated adenocarcinoma of the anal canal. During transanal local excision of the tumor, an abnormality of the perianal skin was recognized. Although intraoperative frozen section of the perianal skin did not show malignancy, permanent sections of the perineal skin revealed Paget's cells in the epidermis. Pathological examination of the anal canal carcinoma revealed submucosally invasive well-differentiated adenocarcinoma with a positive distal surgical margin. Thus, we performed additional wide local excision of the perianal skin including the distal margin of the previous local excision. Pathological examination revealed continuance within the epidermis between the anal canal adenocarcinoma and Paget's cells in the perianal skin lesion. Scattered Paget's cells also formed some glandular structures. Thus, we concluded that the perianal skin lesion was Pagetoid spread of anal canal adenocarcinoma. This report shows that the perianal skin should be examined carefully in patients with anal canal carcinoma.

Adenocarcinoma↗
PubMed2006

[Cancer board--new medical system in cancer clinic].

To proceed with more patient-oriented cancer medicine, the development of a new medical system is necessary in Japan. In Ariake Hospital of the Japanese Foundation for Cancer Research, a new medical system has been developed, which is composed of a common outpatient clinic and a conference system. The core conference system is called "Cancer Board". The practice of patient-oriented medicine in gastroenterological cancer has been introduced as a sample of the Cancer Board system in our hospital.

Ambulatory Care Facilities↗
PubMed2005

Increase in the frequency of K-ras codon 12 point mutation in colorectal carcinoma in elderly males in Japan: the 1990s compared with the 1960s.

The incidence of colorectal carcinomas has been increasing over the last 50 years in Japan. In order to determine whether adenoma-carcinoma sequence (ACS) or de novo cancer development, generally considered to be two separate genetic pathways, might be responsible, K-ras codon 12 mutations, good markers for ACS, were examined in 59 and 84 cases of advanced colorectal cancer surgically resected in Cancer Institute Hospital of the Japanese Foundation for Cancer Research in 1960-1969 and in 1990-1999, respectively. There was no significant difference of K-ras codon 12 mutation between the 25.4% (15/59) in the 1960s and 36.9% (31/84) in the 1990s (P = 0.148), and the reference of distal colon cancer also showed no significant difference between 24.4% (11/45) and 36.4% (20/55). Yet elderly males showed a significant difference: 27.3% (6/22) in the 1960s and 59.3% (16/27) in the 1990s. The references of males, elderly patients (over 75 years old) and distal colon cancer in the 1990s were significantly more likely to demonstrate mutations than their counterparts in the 1960s. There was no variation with the tumor location. The results suggest that the ACS pathway might have primarily contributed to the increased incidence of colorectal cancer in elderly males in Japan.

Adenocarcinoma↗
PubMed2003

Scintigraphic comparison of neorectal emptying between colonic J-pouch anastomosis and straight anastomosis after stapled low anterior resection.

BACKGROUND AND AIMS: Colonic J-pouch anastomosis after low anterior resection of the rectum has been reported to be associated with an increased risk of evacuation difficulty. Using scintigraphy we compared neorectal emptying after stapled low anterior resection between colonic J-pouch anastomosis and straight anastomosis. PATIENTS AND METHODS: We studied 19 patients after colonic J-pouch anastomosis and 22 after straight anastomosis. After the introduction of an artificial stool containing (99m)Tc-DTPA into the neorectum sequential lateral gamma images were obtained. From the time activity curve of radioactivity in the whole pelvis the time taken to evacuate one-half of the introduced artificial stool ( t(1/2)) and the percentage of artificial stool evacuated in 1 min (Evac(1)) were calculated. Fourteen volunteers were also studied as the reference group. RESULTS: The t(1/2) was significantly longer and Evac(1) significantly lower in patients after low anterior resection than in the reference group. t(1/2) was significantly longer in the pouch group than in the straight group. Anastomotic height was significantly correlated with both t(1/2) and Evac(1). Neither t(1/2) nor Evac(1) was correlated with the severity of impaired defecatory function. CONCLUSION: Although neither of the two parameters of neorectal emptying was correlated with the severity of impaired defecatory function, less effective neorectal emptying in patients after colonic J-pouch anastomosis than in those after straight anastomosis may be a factor causing evacuation difficulty after colonic J-pouch anastomosis.

Adult↗
PubMed2003

Budding as a useful prognostic marker in pT3 well- or moderately-differentiated rectal adenocarcinoma.

BACKGROUND: Budding along the invasive margin is reported to be associated with greater malignant potential in colorectal adenocarcinoma. We examined the prognostic significance of budding in patients with pT3 rectal carcinoma, particularly in comparison to other routine pathological findings. METHODS: Surgically resected specimens from 83 well- or moderately-differentiated pT3 rectal adenocarcinomas were studied. All resections were curative (R0), and the median postoperative follow-up was 47 months. We examined the presence of budding according to Morodomi's criteria, using hematoxylin-eosin stained sections. RESULTS: Budding was found in 48 patients (57.9%). The incidence of budding was significantly higher in lesions displaying lymphatic invasion and lymph-node metastasis than in those without (P < 0.0001). Both local recurrence and liver metastasis were more frequent in patients with budding-positive lesions (P < 0.002 and 0.02, respectively). Moreover, postoperative survival was significantly decreased in patients with budding-positive lesions than in those with budding-negative lesions (cumulative 5-year survival rate were 51.8 and 85.0%, respectively: P < 0.002). Multivariate proportional hazard model revealed that the presence of budding was the only significant co-factor of postoperative survival. CONCLUSIONS: Budding is a pathological marker suggesting high malignant potential and decreased postoperative survival in patients with well- or moderately-differentiated pT3 rectal adenocarcinoma.

Adenocarcinoma↗
PubMed2003

Multiple primary cancer: an experience at the Cancer Institute Hospital with special reference to colorectal cancer.

BACKGROUND: Cancer patients are at high risk of developing a second cancer after the treatment of initial cancers. Understanding the characteristics of multiple primary cancer is important to establish an effective surveillance program for the early detection of second cancers. METHODS: We analyzed the cancer registry records from 1986 to 1995 at the Cancer Institute Hospital. The combination of the sites of the index and second cancers and the time intervals between the two cancers were examined. For colorectal cancer, another database of patients between 1946 and 1991 was analyzed, with special reference to synchronous and metachronous cancers. RESULTS: Out of 24,498 registered cases, there were 1281 (5.2%) multiple cancers, of which 464 (1.9%) were in the same organs and 817 (3.3%) were in other organs. Gastric or colorectal cancer frequently developed as the second cancer regardless of the site of the index cancer. Although the majority of the second cancers developed within 3 years after the index cancer, some developed 5 years or more after the index cancer. In colorectal cancer, the cases with metachronous cancer were similar to those with hereditary nonpolyposis colon cancer. The frequent combination of an advanced index cancer and an advanced second cancer and relatively poor survival after the second cancers in the metachronous cases may reflect delayed diagnosis of the second colorectal cancer. CONCLUSION: Careful attention should always be paid to the second cancer in treating cancer patients. Further analysis by individual site of the index cancers is needed to construct an effective surveillance for second cancers.

Adult↗
PubMed2003

Synchronous colorectal carcinoma: clinico-pathological features and prognosis.

OBJECTIVE: The present study was undertaken to clarify the clinical and pathological features of synchronous colorectal carcinomas, to compare prognosis between cases with synchronous carcinomas and those with single carcinomas and to explore prognostic factors of synchronous carcinomas. PATIENTS AND METHODS: Among 876 surgically resected primary colorectal carcinomas, 42 cases (4.8%) with synchronous carcinomas were identified. Clinical characteristics, routine pathological findings according to the TNM classification and postoperative survival were compared between synchronous cases and single cases. Prognostic factors of synchronous cases were explored using the proportional hazard model. RESULTS: The index lesions of synchronous cases did not differ from single lesions in age, size, differentiation, location, pT value, pN value, pathological stage, morphology or lymphatic invasion. However, the male:female ratio was higher and distant metastasis was more frequent in synchronous cases than in single cases. Although postoperative survival of synchronous cases was shorter than that of single cases, they were similar in the multivariate proportional hazard model including pathological stage and curability as co-factors. Only pathological stage and curability of the index lesion were significant co-factors of postoperative survival of synchronous cases. CONCLUSION: Synchronous carcinomas and single carcinomas were similar in clinical characteristics and routine pathological findings. The prognosis of synchronous cases and that of single cases did not differ if the pathological stages were identical and the resections were curative.

Adult↗
PubMed2003

Recent advances in diagnosis and treatment of colorectal T1 carcinoma.

PURPOSE: Colorectal T1 tumors (submucosally invasive carcinoma) have special characteristics in terms of pathology, diagnosis, and treatment. The clinicopathologic features of T1 tumors are reviewed. RESULTS: Incidence of T1 tumors was approximately 10 percent, and the percentage of node metastasis was 10 to 11 percent, whereas hepatic metastasis was <1 percent. Macroscopically they were divided into three types: polypoid, ulcerating, and flat. The ulcerating type was divided into two subgroups: polypoid growth and nonpolypoid growth based on the histologic appearance of resected specimens. The tools for detecting T1 tumors were fecal occult blood test and colonoscopy, and magnifying colonoscopy and chromography facilitate more precise diagnosis. Ultrasonography also was useful for the correct diagnosis of the depth of cancer invasion. Most polypoid and some flat T1 tumors were safely treated by polypectomy or endoscopic mucosal resection alone; however, when resected specimens contained risk factors for metastasis, such as deep invasion (sm2, sm3) and vessel invasion, additional surgery was necessary for cure. For rectal T1 tumors, the most appropriate procedure should be carefully selected from several therapeutic options to preserve anal function. CONCLUSION: The management of colorectal T1 tumors should be determined according to the types of macroscopic appearances. The risk of node metastasis could be predicted based on risk factors that were characterized by the level of cancer invasion and the presence or absence of vessel invasion. Minimally invasive treatment should be chosen for colorectal T1 tumors.

Clinical Trials as Topic↗
PubMed2002

Vasoactive intestinal peptide and its relationship to tumor stage in colorectal carcinoma: an immunohistochemical study.

BACKGROUND: Vasoactive intestinal peptide (VIP) is considered to influence cellular proliferation through its action on adenylate cyclase. This study examined VIP in the tumor-neighboring mucosa (TM) and remote normal mucosa (RM) in patients with colorectal carcinoma, and explored its relationship to tumor stage. METHODS: Immunohistochemical staining of VIP, using the avidinbiotin peroxidase complex technique, was performed on TM and RM from 55 patients, surgically resected colorectal carcinomas. The VIP immunoreactivity in the lamina propria (LP) of TM and RM was semiquantitatively graded, according to the density of VIP immunoreactive fibrous strands, and correlated with clinical characteristics, pathological findings, and tumor stage. RESULTS: VIP immunoreactivity in the LP of TM and RM was found mainly as fibrous strands, some of which were nerve fibers. A few pericryptal myofibroblasts also showed VIP immunoreactivity. The VIP immunoreactivity in the LP was significantly greater in TM than in RM. The VIP immunoreactivity in the LP of TM was marginally greater in lesions with distant metastasis. The VIP immunoreactivity in the LP of RM was significantly greater in lesions with deeper wall penetration, in those with lymph node metastasis, and in those at more advanced stages. CONCLUSIONS: These results suggest a possible trophic role of VIP in the progression of colorectal carcinoma, or enhanced VIP secretion secondary to or in parallel with the progression of carcinoma.

Adenocarcinoma↗
PubMed2002

Comparison of defecatory function after colonic J-pouch anastomosis and straight anastomosis for stapled low anterior resection: results of a prospective randomized trial.

PURPOSE: Although defecatory function after low anterior resection for rectal cancer is reported to be better following colonic J-pouch than straight anastomosis, few prospective randomized trials comparing the two forms of anastomosis have been reported. We performed a prospective randomized trial comparing straight anastomosis with colonic J-pouch anastomosis both clinically and physiologically in patients undergoing stapled low colorectal anastomosis. METHODS: A total of 42 consecutive patients were intraoperatively randomized to undergo either straight anastomosis or colonic J-pouch anastomosis. Clinical defecatory function was evaluated by a questionnaire answered preoperatively, then 6 and 12 months postoperatively. Anorectal physiological assessment was also carried out before surgery, then 12 months postoperatively. RESULTS: The clinical defecatory function assessed 6 months and 12 months after surgery did not differ between the two groups. However, while the length of high-pressure zone was significantly shortened, and (neo)rectal capacity was significantly reduced postoperatively in the straight group, none of these physiological parameters were significantly altered in the pouch group. CONCLUSION: Although the aim of colonic J-pouch to preserve reservoir function was physiologically achieved, the improvement in clinical defecatory function was not significant. Thus, further prospective studies are needed to confirm the functional superiority of colonic J-pouch anastomosis for stapled low colorectal anastomosis after low anterior resection.

Adult↗
PubMed2002

Poor neorectal evacuation as a cause of impaired defecatory function after low anterior resection: a study using scintigraphic assessment.

PURPOSE: Patients who have undergone low anterior resection (LAR) of the rectum occasionally complain of symptoms related to impaired neorectal evacuation. Using scintigraphy, we assessed neorectal evacuation in 22 patients who underwent LAR and straight anastomosis, and correlated the results with clinical defecatory function, clinical factors, and anorectal manovolumetric parameters. METHODS: After the introduction of an artificial stool containing 99mTc-DTPA into the neorectum, sequential lateral gamma images were obtained. From the time-activity curve of radioactivity in the whole pelvis, the time taken to evacuate half of the introduced artificial stool (T(1/2)) and the percentage of artificial stool evacuated in 1 min (Evac1) were calculated. RESULTS: The Evac1 was significantly lower in the patients who had undergone LAR than in reference normal volunteers. A long T(1/2) was significantly associated with worse defecatory function. The Evac1 was also significantly lower in patients with a low anastomosis. The rectal sensory threshold was significantly greater in patients with a shorter T(1/2). The maximum tolerable volume of the neorectum was significantly greater in patients with a shorter T(1/2) and a higher Evac1. CONCLUSION: Poor neorectal evacuation is associated with impaired defecatory function after LAR. Therefore, it is suggested that optimizing both reservoir function and evacuation of the neorectum would improve defecatory function after LAR.

Adult↗
PubMed2002

Clinical and functional comparison between stapled colonic J-pouch low rectal anastomosis and hand-sewn colonic J-pouch anal anastomosis for very low rectal cancer.

PURPOSE: We investigated intersphincteric resection with hand-sewn coloanal anastomosis, which may be an alternative to standard low anterior resection for very low rectal cancer when stapled anastomosis is technically impossible. METHODS: The present study compared the clinical and functional results of 16 patients who underwent stapled colonic J-pouch low rectal anastomosis (CJLRA) with those of 15 patients who underwent intersphincteric excision and hand-sewn colonic J-pouch anal anastomosis (CJAA). RESULTS: After a median follow-up period of 59 months, local recurrence was found in four patients from the CJAA group, three of whom subsequently underwent curative abdominoperineal resection. Defecatory function 6 and 12 months after surgery did not differ between the groups, although pads were used significantly more frequently in the CJAA group. Anorectal physiologic study before and 12 months after surgery revealed that the internal anal sphincter function was impaired to a larger extent after CJAA than after CJLRA, probably due to the partial or subtotal resection of the internal sphincter, and the anal dilatation during resection and anastomosis. CONCLUSION: Although the prevention of intraoperative tumor implantation and the early detection of local recurrence is of utmost importance, CJAA may be an acceptable sphincter-preserving procedure for selected patients in whom stapled anastomosis is impossible.

Anal Canal↗
PubMed2002

Budding as a risk factor for lymph node metastasis in pT1 or pT2 well-differentiated colorectal adenocarcinoma.

PURPOSE: Lymph node metastasis is an important indicator of tumor stage and prognosis in pT1 and pT2 colorectal adenocarcinomas. Lymphovascular invasion is an established risk factor of lymph node metastasis, whereas budding at the invasive front of tumors is also reported to correlate with lymph node metastasis. We examined whether the coexistence of lymphovascular invasion and budding provides any better information than lymphovascular invasion alone in the prediction of lymph node metastasis of pT1 or pT2 well-differentiated colorectal adenocarcinomas. METHODS: Surgically resected specimens of 101 pT1 or pT2 well-differentiated colorectal adenocarcinomas were studied. Using sections stained with hematoxylin-eosin, we examined lymphovascular invasion and budding according to Morodomi's definition. RESULTS: Lymphovascular invasion was present in 39 lesions (38 percent), whereas budding was found in 42 lesions (41 percent). Budding was more frequently detected in pT2 tumors than in pT1 tumors. The presence of budding significantly correlated with lymphovascular invasion. Sensitivity, specificity, positive predictive value, and negative predictive value of lymphovascular invasion alone for lymph node metastasis were 79, 76, 34, and 96 percent, respectively, whereas those of the combination of lymphovascular invasion and budding (either lymphovascular invasion or budding) were 93, 52, 24, and 98 percent, respectively. CONCLUSION: Because the risk of lymph node metastasis in pT1 or pT2 well-differentiated colorectal adenocarcinomas having neither lymph node metastasis nor budding is very low, budding in combination with lymphovascular invasion seems to be a simple and inexpensive pathologic marker in predicting lymph node metastasis. Therefore, the presence or absence of budding should be examined in the routine pathologic diagnosis of pT1 or pT2 well-differentiated colorectal adenocarcinomas.

Adenocarcinoma↗
PubMed2002

A prospective randomized comparison between an open hemorrhoidectomy and a semi-closed (semi-open) hemorrhoidectomy.

A semi-closed hemorrhoidectomy is a popular surgical procedure among Japanese coloproctologists because it is thought that the risk of postoperative bleeding is reduced, and postoperative pain is milder after a semi-closed hemorrhoidectomy than after an open hemorrhoidectomy. However, no prospective randomized trial comparing an open and semi-closed hemorrhoidectomy has yet been published. We conducted a prospective randomized trial comparing both clinically and physiologically an open and semi-closed hemorrhoidectomy. Thirty-four consecutive patients undergoing a hemorrhoidectomy for third-degree hemorrhoids were randomized to receive either an open hemorrhoidectomy (n = 17) or a semi-closed hemorrhoidectomy (n = 17). Postoperative pain was evaluated using an analog scale by the patients themselves. An anorectal physiological study was performed before the operation and 2 months after the operation. Pain at 1 week after operation was significantly more severe after a semi-closed hemorrhoidectomy than after an open hemorrhoidectomy. The postoperative physiological parameters including sphincter pressures did not differ between the two forms of hemorrhoidectomy. However, younger patients and patients having higher sphincter pressures preoperatively had more severe pain at 2 weeks after a semi-closed hemorrhoidectomy. Although both forms of hemorrhoidectomy appear to be almost equivalent, the degree of early postoperative pain may be less after an open hemorrhoidectomy in both young patients and in those patients having high preoperative anal sphincter pressures.

Anal Canal↗
PubMed2002

Budding (sprouting) as a useful prognostic marker in colorectal mucinous carcinoma.

PURPOSE: Budding (sprouting) along the invasive margin is reported to be associated with high malignant potential of colorectal carcinoma. We examined the prognostic significance of budding in colorectal mucinous carcinoma. PATIENTS AND METHODS: Surgically resected specimens from 31 patients with colorectal mucinous carcinoma were studied. The median postoperative follow-up was 27 months. The presence of budding was examined according to Morodomi's criteria using hematoxylin-eosin-stained sections. RESULTS: Budding was found in 18 lesions (58%). Budding was more frequently observed in lesions with venous invasion and lymph node metastasis than in those without (P = 0.04, P = 0.03, respectively). The incidence of budding was higher in lesions with distant metastasis than in those without (P < 0.03). Overall recurrence and peritoneal disseminated recurrence were significantly more frequent in patients with budding-positive lesions than in those with budding-negative lesions (P = 0.05, P = 0.04, respectively). The cumulative 5-year survival rate of curative resected cases was lower in patients with budding-positive lesions than in those with budding-negative lesions (25.0% versus 90.9%, P = 0.01, log-rank test). Moreover, both the univariate and multivariate proportional hazard models revealed that the presence of budding was the only significant co-factor of postoperative survival. CONCLUSION: Budding is a pathological marker suggesting high malignant potential and decreased postoperative survival in patients with colorectal mucinous carcinoma.

Adenocarcinoma, Mucinous↗