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Biomedical subjects

Masaru Miyazaki

Publications and source records attributed to Masaru Miyazaki.

At least 19 recordsLinked to original sources
PubMed2007

Contrast-enhanced three-dimensional fusion sonography of small liver metastases with pathologic correlation.

PURPOSE: To demonstrate that liver metastases with a diameter of < or =40 mm show characteristic features on three-dimensional (3D) fusion sonographic images and that these sonographic findings can be correlated with histopathologic features of surgical specimens. METHODS: Liver metastases measuring < or =40 mm were examined via contrast-enhanced 3D fusion sonography. The characteristic sonographic findings of 17 tumor nodules in 11 patients with a histopathologically confirmed diagnosis of liver metastases were investigated, and their correspondence to the pathologic features were examined in 12 resected nodules. RESULTS: On sonograms, central vessels were visualized in all 17 tumor nodules and peripheral vessels were visualized in 12 nodules. On histopathologic examination, the portal triad vessels corresponded to the central vessels and were located at the center of the tumors. A thin layer of peritumoral hepatocytes showing various changes was also observed, and a group of tiny vessels were seen running along this layer of cells. CONCLUSIONS: Liver metastases measuring 40 mm or less in diameter were characterized by the presence of both central and peripheral vessels on contrast-enhanced 3D fusion sonography. There was good correlation between sonographic and histopathologic findings.

Adult↗
PubMed2006

Chromatin remodeling at the Th2 cytokine gene loci in human type 2 helper T cells.

The differentiation of mouse naïve CD4 T cells into type 2 helper (Th2) cells is accompanied by chromatin remodeling at the nucleosomes associated with the IL-4, IL-13 and IL-5 genes. However, little is known about how chromatin remodeling of these Th2 cytokine gene loci occurs in human Th2 cells. We herein established an in vitro culture system in which both Th1 and Th2 cells are efficiently differentiated from human peripheral blood naïve CD4 T cells. This system allowed us to investigate the chromatin status at the Th2 cytokine gene loci and the IFNgamma locus in human Th2 and Th1 cells, respectively. In typical individuals, the chromatin remodeling indicated by the induction of hyper-acetylation of histone H3 lysine 9 and hyper-methylation of histone H3 lysine 4 was induced at the whole Th2 cytokine gene loci in developing Th2 cells. We more precisely assessed the methylation status of histone H3 lysine 4 at the Th2 cytokine gene loci (IL-5 exon 3, IL-5 promoter, IL-5/RAD50 intergenic region, RAD50 promoter, CGRE, CNS1, IL-13 promoter, IL-4 promoter, and VA enhancer regions) and the IFNgamma locus in developing Th1 and Th2 cells prepared from 20 healthy volunteers. Th2-cell specific chromatin remodeling was induced at most of the Th2 cytokine gene loci. In parallel with the induction of chromatin remodeling, GATA3 mRNA was preferentially expressed in developing Th2 cells, whereas T-bet, HLX and ROG mRNA was selectively expressed in developing Th1 cells.

Acetylation↗
PubMed2006

Sonic Hedgehog-Gli1 signaling pathway might become an effective therapeutic target in gastrointestinal neuroendocrine carcinomas.

Gastrointestinal neuroendocrine carcinomas (NECs) are extremely aggressive and poorly prognostic. We showed previously that human achaete-scute homologue gene 1 (hASH1), a basic helix-loop-helix transcription factor regulated by Notch, was aberrantly expressed in NECs. To date, no effective therapeutic strategies for NECs have been investigated. Notch, Wnt and Hedgehog (Hh) signalings are important for stem cell self-renewal and carcinogenesis in the gastrointestinal epithelium. In this study, we showed that Hh signaling was clearly upregulated in NECs in Gli1-dependent manner. Specific therapeutic effects of cyclopamine on NECs were also demonstrated. RT-PCR showed that among eight frozen samples (three NECs, one carcinoid tumor, three adenocarcinomas and one normal mucosa), the band intensities of Gli1 were the strongest in NECs, moderately strong in a carcinoid tumor, very weak in adenocarcinomas and undetectable in a normal mucosa. In real-time RT-PCR, the expression levels of Gli1 in NECs were 108.4, 28.6 and 16.3 times higher than that in an adenocarcinoma. In immunohistochemistry using 25 paraffin-embedded tissues, all twelve NECs and three of six carcinoid tumors showed positive stainings for Gli1, whereas six of seven adenocarcinomas were negative. In vitro, RT-PCR showed that NEC cell lines expressed Gli1 mRNA significantly. Administration of cyclopamine suppressed cell proliferation and invasion, and induced apoptosis in NECs. In cyclopamine-treated NECs, downregulation of Gli1, Ptch1, Snail and hASH1, and upregulation of E-cadherin were demonstrated at mRNA levels. Such effects were not observed in a Gli1-negative colonic adenocarcinoma cell line or in control alkaloid-treated NECs. Hh signaling may play a crucial role in the pathophysiology of NECs. Blockade of Hh pathway using cyclopamine or its synthetic derivatives might open an effective therapeutic strategy to NECs, not only by suppressing tumor viability but also by altering tumor cell nature.

Adenocarcinoma↗
PubMed2006

Laser Doppler assessment of the influence of division at the root of the inferior mesenteric artery on anastomotic blood flow in rectosigmoid cancer surgery.

AIMS: The aim of this study is to evaluate the influence of dividing the inferior mesenteric artery (IMA) and preserving the left colic artery (LCA) on rectosigmoid cancer surgery. PATIENTS AND METHODS: Colonic blood flow at the proximal site of the anastomosis was measured by laser Doppler flowmetry in 96 patients with cancer of the rectum and sigmoid colon while clamping IMA or LCA. Results were analyzed with patient characteristics and postoperative complications. RESULTS: Blood flow was significantly decreased by either IMA or LCA clamping, and its reduction rate was 38.5 +/- 1.8%, ranged from 0 to 82.8%, or 16.4 +/- 1.8%, ranged from 0 to 66.2%, respectively. For multivariate analyses, aging and male gender were predictive factors of high blood flow reduction by IMA clamping. The reduction rate was significantly correlated with aging in male patients, while no such correlation was observed in women. Aging correlation in men was more significant in ultralow anterior resection cases. Three elderly male patients received IMA high ligation among 19 patients who demonstrated more than 50% blood flow reduction by IMA clamping. Among these, two patients, those who underwent ultralow anterior resection, suffered severe anastomotic ischemia. CONCLUSIONS: Colonic blood flow at the proximal site of the anastomosis was significantly decreased by either IMA or LCA clamping. Patients with high reduction by IMA clamping need intraoperative efforts to prevent anastomotic ischemia, particularly in elderly male patients who undergo ultralow anterior resection.

Adult↗
PubMed2006

The post-operative level of serum monocyte chemoattractant protein-1 and its correlation with the severity of surgical stress.

BACKGROUND: Several basic studies have demonstrated that monocyte chemoattractant protein-1 (MCP-1) influences type 2 cytokine production and cell-mediated immunity. However, there have been few reports on the changes in serum MCP-1 levels in patients undergoing major thoracoabdominal surgery. In this study, we examined the kinetics of serum MCP-1 post-operatively and clarified its significance regarding the extent of surgical stress. MATERIALS AND METHODS: Seventeen patients who underwent surgical operations were included in this study. All of them were fed by total parenteral nutrition to deliver the same amount of calories and nitrogen. Of the severely stressed group, nine patients underwent esophagectomy with thoracotomy. Of the group of moderately stressed group, eight patients underwent gastric or colorectal surgery. Serum MCP-1 and interleukin-6 (IL-6) were measured after operation. Cell-mediated immunity was measured by concanavalin A- or phytohemagglutinin-stimulated lymphocyte proliferation on the seventh post-operative day. RESULTS: Serum MCP-1 and IL-6 were increased immediately after surgery in both groups. The level of MCP-1 was significantly higher in the group of severely stressed patients than in the moderately stressed group. Concanavalin A or phytohemagglutinin-stimulated lymphocyte proliferation was significantly lower in the severely stressed group than in the moderately stressed group. CONCLUSIONS: These results indicate that serum MCP-1 levels are directly correlated, and cell-mediated immunity inversely correlated, with the severity of surgical stress.

Aged↗
PubMed2006

Dynamic enhanced MRI predicts chemosensitivity in breast cancer patients.

BACKGROUND: Primary chemotherapy for breast cancer is effective as postoperative adjuvant therapy. However, one of the critical disadvantages was a treatment delay for patients with progressive disease. The present study attempts to clarify quantitative parameters on MRI which can be used to predict the sensitivity to treatment in breast cancer patients. METHODS: The subjects consisted of 26 patients with invasive ductal breast cancer who received primary chemotherapy before surgery. The mean maximum tumor dimension was 3.3cm, and 21 cases had nodal involvements. Three cases demonstrated histological grade 3. Dynamic enhanced MRI was evaluated at three different time periods; prior to, in the midst of preoperative chemotherapy, and just before the initial operation. The signal intensity ratio (SIR) and early contrast uptake (ECU) were calculated, as well as the correlation between these dynamic data and the tumor reduction rates were analyzed retrospectively. P-values of less than 0.05 were considered to indicate statistically significant. RESULTS: Responders to chemotherapy had the significantly higher SIR and ECU values than non-responders (p=0.0454 and 0.0334, respectively). ECU value significantly decreased as tumor reduction by chemotherapy (p=0.0028). Pathological tumor dimension was significantly correlated with the tumor size estimated on presurgical MRI (p<0.0001). CONCLUSIONS: Our current series demonstrated the significant correlation between pretreatment MRI data and tumor reduction by chemotherapy in breast cancer patients. With these results, it seems possible to define good and non-responders prior to treatment.

Adult↗
PubMed2006

Hormonal stimulation increases the recruitment of bone marrow-derived myoepithelial cells and periductal fibroblasts into the mammary gland.

Recent reports have revealed that bone marrow (BM)-derived cells can be constituents in a number of organs, especially in remodeling tissue. Using bone marrow transplantation (BMT) technique, we found that BM can serve as a source of both myoepithelial cells and periductal fibroblasts in the mammary gland. The numbers of BM-derived myoepithelial cell were 4.8-fold, and those of periductal fibroblast were 2.4-fold higher in the mice when BMT which was performed at the pubertal stage, as compared with BMT was performed at the postpubertal stage. Treatment with estrogen+progesterone pellet increased numbers of BM-derived myoepithelial cells and periductal fibroblasts, to levels 4.5- and 2.6-fold higher than in placebo mice, respectively. In situ hybridization revealed BM-derived periductal fibroblasts expressed insulin-like growth factor I mRNAs that are known to regulate mammary gland. These results suggest that drastic structural change that is induced by hormonal stimulation increased the recruitment of BM-derived myoepithelial cells and periductal fibroblasts to the mammary gland context.

Animals↗
PubMed2006

Changes in growth factor and cytokine expression in biliary obstructed rat liver and their relationship with delayed liver regeneration after partial hepatectomy.

AIM: To study the effects of obstructive jaundice on liver regeneration after partial hepatectomy. METHODS: Hepatocyte growth factor (HGF), its receptor, c-Met, vascular endothelial growth factor (VEGF) and transforming growth factor-beta1 (TGF-beta1) mRNA expression in both liver tissue and isolated liver cells were investigated after biliary obstruction (BO) by quantitative reverse-transcription polymerase chain reaction (RT-PCR) using a LightCycler. Immunohistochemical staining for desmin and alpha-smooth muscle actin (alpha-SMA) was also studied. Regenerating liver weight and proliferating cell nuclear antigen (PCNA) labeling index, and growth factor expression were then evaluated after 70% hepatectomy with concomitant internal biliary drainage in BO rats or sham-operated rats. RESULTS: Hepatic TGF-beta1 mRNA levels increased significantly 14 days after BO, and further increased with duration of cholestasis. Meanwhile, HGF and VEGF tended to increase, but was not significant. In cell isolates, TGF-beta1 mRNA was found mainly in the hepatic stellate cell (HSC) fraction. Immunohistochemical studies revealed an increased number of HSCs (desmin-positive cells) and activated HSCs (alpha-SMA-positive cells) in portal areas after BO. In a hepatectomy model, liver regeneration was delayed in BO rats, as compared to sham-operated rats. TGF-beta1 mRNA was significantly up-regulated up to 48 h after hepatectomy, and the earlier HGF mRNA peak was lost in BO rats. CONCLUSION: BO induces HSCs proliferation and activation, leading to up-regulation of TGF-beta1 mRNA and suppression of HGF mRNA in livers. These altered expression patterns may be strongly involved in delayed liver regeneration after hepatectomy with obstructive jaundice.

Actins↗
PubMed2006

Relation of inflammatory cytokines to atrial fibrillation after off-pump coronary artery bypass grafting.

OBJECTIVE: It has been observed that a systemic inflammatory response after on-pump coronary artery bypass grafting (CABG) participates in the pathogenesis of postoperative atrial fibrillation (AF). In patients undergoing off-pump CABG, it is plausible that inflammation is associated with the development of postoperative AF. The present study examined relation of proinflammatory cytokines, which play an important role in the upstream of inflammatory cascade, to the development of AF after off-pump CABG. METHODS: The present study included 39 patients undergoing off-pump CABG. Tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, and IL-8, were measured by enzyme-linked immunosorbent assay, on anesthetic induction, after sternotomy before anastomoses, at the completion of anastomoses, 3 and 6h thereafter, and on postoperative days (POD) 1-4. C-reactive protein (CRP) was also measured by turbidimetric immunoassay, preoperatively, and on POD 1, 2, 3, 6, 9, and 13. RESULTS: Eleven patients (28%) developed postoperative AF. Patients with postoperative AF were older (70+/-6.4 years vs 60+/-8.8 years, P=0.001); however, there was no difference in other pre- and perioperative variables. TNF-alpha level did not change during the study period. However, IL-8 and CRP levels significantly increased after the surgery, although there was no significant difference between the two groups. IL-6 level also increased after the surgery with its peak at 6h after the completion of anastomoses. IL-6 levels of 3 and 6h after anastomoses were significantly higher in patients with postoperative AF (360+/-143 pg/ml vs 230+/-94 pg/ml, P=0.0047, 435+/-175 pg/ml vs 247+/-102 pg/ml, P=0.0005, respectively). Logistic regression analysis indicated that the highest quartile of IL-6 level immediately after the surgery (odds ratio 7.63; 95% CI, 1.06-54.9; P=0.04) and age (odds ratio 1.18; 95% CI, 1.01-1.39; P=0.04) independently predict postoperative AF. Furthermore, the maximum level of IL-6 immediately after the surgery significantly correlated to age and intraoperative blood loss (r=0.04, P=0.01, and r=0.47, P=0.04, respectively). CONCLUSIONS: Advanced age was a major risk factor for postoperative AF. Furthermore, inflammatory response induced by surgical trauma was also associated with the development of AF after off-pump CABG.

Age Factors↗
PubMed2006

Circulating cytokines, chemokines, and stress hormones are increased in patients with organ dysfunction following liver resection.

BACKGROUND: Humoral mediators are potentially involved in the pathogenesis of postoperative complications following surgery. The aim of the present study is to evaluate the postoperative responses of circulating cytokines, chemokines, and stress hormones following liver resection, and their effects on postoperative infectious complications and organ dysfunction. PATIENTS AND METHODS: Perioperative plasma concentrations of interleukin (IL)-6, IL-10, IL-4, IL-8, macrophage chemoattractant protein (MCP)-1, cortisol, macrophage migration inhibitory factor (MIF), and leptin were measured by immunoassays in 128 consecutive patients undergoing liver resection. RESULTS: Forty-three patients had postoperative infection and 11 had infection-related organ dysfunction. Plasma levels of all mediators except for IL-4 increased postoperatively. Postoperative levels of IL-6, IL-10, IL-8, MCP-1, cortisol, and leptin were significantly higher in patients with organ dysfunction than in those without organ dysfunction (P < 0.05). However, postoperative MIF levels were not affected by postoperative infection or organ dysfunction. Plasma levels of IL-6, IL-10, IL-8, and MCP-1 were positively correlated with operation time (P < 0.0001) or blood loss (P < 0.0001), and higher in patients with jaundiced liver (P < 0.05). In univariate logistic regression analyses, elevated IL-6, IL-10, IL-8, and MCP-1, advanced age, large volume of blood loss, long operation time, long hepatic ischemia time, and major liver resection were significantly correlated with postoperative infection (P < 0.05). In multivariate analyses, IL-6 and IL-10 were significant predisposing factors for postoperative infection (P < 0.05), and blood loss and IL-6 for organ dysfunction (P < 0.01). CONCLUSIONS: These results suggest that IL-6, IL-10, IL-8, MCP-1, cortisol, and leptin are released after liver resection in response to surgical stress and correlated with postoperative infection and organ dysfunction, and that of these circulating mediators, IL-6 and IL-10, have a close relationship to the complications.

Adult↗
PubMed2006

Induction and recovery of colonic motility/defecatory disorders after extrinsic denervation of the colon and rectum in rats.

BACKGROUND: Anterior resection for rectal disease is associated with extrinsic autonomic denervation of the neorectum, which may influence the myenteric plexus, and subsequently the motility/defecatory status after operation. METHODS: A rat model with denervated neorectum was constructed. Colonic contractile activity in vivo, the amount of generic neuron marker (PGP 9.5) and nitric oxide synthase (NOS) were measured periodically. The responses of the muscle strip in each period to electrical field stimulation were evaluated using various neurotransmitters. RESULTS: In rats with denervated neorectum, giant migrating contractions (GMCs) of the distal colon, the number of fecal lumps per day and their small size, significantly increased in the early phase postoperatively, although both recovered in the late-phase period. The contractile response of the muscle strip of the denervated colon to acetylcholine was reduced throughout the period; however, contraction of the denervated colon under the addition of NO inhibitor (l-NAME) was enhanced significantly in the late-phase period, and recovered to the control level by atropine. Neuronal NOS, but not PGP 9.5 concentration, in the myenteric plexus at the distal denervated colon, significantly increased in the late-phase period. None of the above items differed from the control at other colonic portions throughout the period. CONCLUSIONS: Extrinsic autonomic denervation causes abnormal hyper-motility in the neorectum, which may be associated with multiple evacuations in the early phase postoperatively. Increased acetylcholine and the subsequent increase of neuronal NOS in the myenteric plexus may be an adaptive mechanism to compensate for such abnormal colonic motility after extrinsic denervation.

Animals↗
PubMed2006

Serum osteopontin levels in patients with acute liver dysfunction.

OBJECTIVE: Fulminant hepatic failure (FHF) is a clinical syndrome of sudden and severe liver dysfunction accompanied by encephalopathy in a previously healthy person. In FHF, hepatocytes are severely damaged and ordinary liver regeneration is impaired. We demonstrated that the expression of osteopontin (OPN), a multifunctional cytokine, was up-regulated in mouse oval cell (a stem-cell progenitor) induction models. MATERIAL AND METHODS: Based on this finding, serum OPN levels were examined in 43 patients with FHF and in 45 patients with acute self-limited hepatitis (AH). To determine the cellular source of OPN, the expression of OPN was studied in a liver specimen derived from an FHF patient. RESULTS: The mean OPN level of patients with FHF was 2.80+/-0.48 ng/ml (log(10), +/-SD), which was significantly higher than that of the patients with AH (2.42+/-0.39 ng/ml) (p=0.003, unpaired t-test). Patients with elevated serum OPN levels had a significantly poorer prognosis than patients whose serum OPN levels were not elevated. In the FHF patient's liver, OPN protein was expressed not only in inflammatory cells but also in regenerating hepatocytes and bile ductular structures. CONCLUSIONS: Our current study indicates that serum OPN levels increased in patients with FHF and that OPN might play an important role in liver regeneration due to activation of hepatic stem cells.

Acute Disease↗
PubMed2006

Increased plasma levels of IL-6 and IL-8 are associated with surgical site infection after pancreaticoduodenectomy.

OBJECTIVES: Cytokines and chemokines potentially modulate postoperative immune response. Association of circulating cytokines and chemokines with postoperative infectious complications after pancreaticoduodenectomy was evaluated. METHODS: Plasma concentrations of interleukin (IL) 6, IL-10, IL-8, macrophage chemoattractant protein 1, heat shock protein 70, and amylase, as well as amylase levels in peritoneal exudative fluid, were measured perioperatively in 60 consecutive patients who underwent pancreaticoduodenectomy. RESULTS: Of the 60 patients, 27 patients had surgical site infection (SSI), including peritoneal infection in all, intra-abdominal abscess in 14, and radiologically visualized pancreatic leakage in 6. Postoperative plasma levels of IL-6, IL-8, and macrophage chemoattractant protein 1, as well as peritoneal amylase levels, were significantly higher in patients with SSI than in those without SSI (P < 0.05). Nonpancreatic cancer as a histopathologic diagnosis, high pancreatic juice flow, and increased levels of IL-6 and IL-8 were independently associated with SSI (P < 0.05) in multiple logistic regression analysis. Plasma levels of IL-6 and IL-10 among patients with SSI were significantly higher in those with pancreatic leakage than in those without leakage. CONCLUSIONS: These results suggest that, in addition to pancreatic exocrine function, IL-6 and IL-8 are associated with postoperative SSI, including pancreatic leakage after pancreaticoduodenectomy.

Adult↗
PubMed2006

Assessment of rectal aberrant crypt foci by standard chromoscopy and its predictive value for colonic advanced neoplasms.

BACKGROUND AND AIMS: Aberrant crypt foci (ACF) are thought to be preneoplastic lesions and are assessed by magnifying chromoscopy with methylene blue staining. The aim of this study was to evaluate the predictive value of rectal ACF recognized by conventional chromoscopy for colonic advanced neoplasms. METHODS: Total colonoscopy, involving rectal chromoscopy using indigo carmine with standard colonoscopies, was performed on 386 patients. Patients who showed no ACF were classified as Grade 0, and those who had 1-4, 5-9, and 10+ ACF were classified as Grades 1, 2, or 3, respectively. The correlation between ACF grading and the prevalence of colonic advanced neoplasm, any adenoma>or=1 cm in size and/or with villous or tubulovillous morphology, and/or with high-grade dysplasia or invasive cancer, was assessed. RESULTS: Sixty-three patients were classified as ACF Grade 0, 119 as Grade 1, 116 as Grade 2, and 88 as Grade 3. Colonic advanced neoplasm was observed in 4 patients (6.3%) for Grade 0, 43 (36.1%) for Grade 1, 61 (52.6%) for Grade 2, and 57 (64.8%) for Grade 3. As the ACF grade increased, the chance of a patient having a colonic advanced neoplasm increased. For multivariate analyses, compared with patients with Grade 0, those with Grades 1, 2, or 3 had a greater risk of colonic advanced neoplasm (odds ratio [OR] 9.18, 95% CI 3.08-27.33, OR 20.44, 95% CI 6.81-61.42, and OR 32.94, 95% CI 10.49-103.41, respectively). CONCLUSIONS: Chromoscopic assessment of rectal ACF by conventional techniques is useful for predicting colonic advanced neoplasms.

Adult↗
PubMed2006

Relationship between pancreatic secretory trypsin inhibitor and early recurrence of intrahepatic cholangiocarcinoma following surgical resection.

OBJECTIVES: The extremely unfavorable prognosis of intrahepatic cholangiocarcinoma (ICC), even after surgical resection, is mainly attributed to a high rate of recurrence. The aim of this study was to identify the molecules associated with early recurrence of ICC following resection. METHODS: Between December 1984 and July 2003, 46 patients with ICC underwent surgical resection. The clinical outcome of these patients was evaluated in view of the time of recurrence. Consequently, we categorized ICC patients into subgroups, based on the clinical results, and screened differentially expressed genes by DNA microarray analysis. Furthermore, the obtained results were validated in an independent sample set by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR). Immunohistochemistry was performed to assess the expressed genes at the protein level. RESULTS: The survival of patients with early recurrence, occurring within a year after surgical resection, was significantly poor after surgery and even after recurrence, as compared to that of patients whose recurrence occurred beyond a year after surgery. By the DNA microarray analysis, 13 differentially expressed genes were picked up, and quantitative RT-PCR reaction identified the pancreatic secretory trypsin inhibitor (PSTI) as a candidate gene associated with early recurrence of ICC after resection. This observation was confirmed through examination of an independent set of samples, in which the patients with higher levels of PSTI mRNA expression had significantly shorter recurrence-free survival. Immunohistochemically, PSTI was expressed in the cytoplasm of cancer cells. CONCLUSIONS: PSTI might be a potential marker for identifying ICC patients with an increased risk of early recurrence after surgical resection.

Aged↗
PubMed2006

Sentinel node micrometastasis and distant failure in breast cancer patients.

BACKGROUND: Lymphatic mapping and sentinel lymph node (SN) biopsy has rapidly replaced axillary lymph node dissection for clinically node-negative breast cancers. Because of a short follow-up period when the procedure was new, there were few reports of the clinical recurrence rate in breast cancer patients treated with SN biopsy. The present study attempts to clarify the occurrence of distant failure after SN biopsy, especially in breast cancer patients with SN micrometastasis. METHODS: The subjects consisted of 375 cases with clinically node-negative breast cancer, who had undergone SN biopsies. Chemotherapy and/or hormonal therapy was recommended based on the pathological primary tumor characteristics. The patients with SN micrometastasis also received adjuvant therapy equal to node-positive patients. RESULTS: Examinations of lymph nodes indicated metastases in 73 cases. Among the invasive cancers, 54 cases had macrometastasis, 19 cases had micrometastasis and 241 cases had a tumor free SN. The median follow-up period ws 30 months (range 6 to 66 months). Distant relapse rates per person-years were 0.3% in the cases with tumor free SN and 3.3% among the macrometastatic cases. However, systemic disease was not observed in the cases with SN micrometastasis. CONCLUSIONS: These results may show that upstaging due to SN investigation increases the number of cases who should receive anti-cancer drugs, and consequently reduces the distant relapse rate. Further studies in a large number of cases as well as longer follow-up are needed to determine the prognostic significance of SN micrometastasis.

Adult↗