Hepatocyte growth factor-regulated tyrosine kinase substrate (Hgs) is involved in BMP signaling through phosphorylation of SMADS and TAK1 in early mouse embryo.

Hepatocyte growth factor-regulated tyrosine kinase substrate that is encoded by Hgs promotes degradation of ubiquitinated signaling molecule in the early endosome. We previously reported that a targeted mutation in Hgs results in embryonic lethality soon after gastrulation in the mouse. Here, we report that downstream target genes for BMP signaling were highly down-regulated in the Hgs mutant embryos. We also showed that Hgs is required for phosphorylation of SMAD1/5/8 and TAK1/p38 to transduce BMP signaling. Furthermore, we found that HGS functions to localize TAK1 in early endosome for its activation. These results suggest that HGS is critical to localize TAK1 to early endosome for transducing BMP signaling for proper development. Our data revealed a new mechanism to modify BMP signaling by Hgs during early mouse development.

Bmpr1a is required for proper migration of the AVE through regulation of Dkk1 expression in the pre-streak mouse embryo.

Here, we report a novel mechanism regulating migration of the anterior visceral endoderm (AVE) by BMP signaling through BMPRIA. In Bmpr1a-deficient (Bmpr-null) embryos, the AVE does not migrate at all. In embryos with an epiblast-specific deletion of Bmpr1a (Bmpr1a(null/flox); Sox2Cre embryos), the AVE cells migrate randomly from the distal end of embryos, resulting in an expansion of the AVE. Dkk1, which is normally expressed in the anterior proximal visceral endoderm (PxVE), is downregulated in Bmpr-null embryos, whereas it is circumferentially expressed in Bmpr1a(null/flox); Sox2Cre embryos at E5.75-6.5. These results demonstrate an association of the position of Dkk1 expressing cells with direction of the migration of AVE. In Bmpr1a(null/flox); Sox2Cre embryos, a drastic decrease of WNT signaling is observed at E6.0. Addition of WNT3A to the culture of Bmpr1a(null/flox); Sox2Cre embryos at E5.5 restores expression patterns of Dkk1 and Cer1. These data indicate that BMP signaling in the epiblast induces Wnt3 and Wnt3a expression to maintain WNT signaling in the VE, resulting in downregulation of Dkk1 to establish the anterior expression domain. Thus, our results suggest that BMP signaling regulates the expression patterns of Dkk1 for anterior migration of the AVE.

Randomized phase III trial of trastuzumab monotherapy followed by trastuzumab plus docetaxel versus trastuzumab plus docetaxel as first-line therapy in patients with HER2-positive metastatic breast cancer: the JO17360 Trial Group.

We evaluated the efficacy and safety of sequential therapy with trastuzumab monotherapy (H-mono) followed by H plus docetaxel (D) after disease progression (H --> H + D) versus combination therapy with H + D as first-line therapy. Patients with human epidermal growth factor receptor type 2 (HER2)-positive metastatic breast cancer (MBC) and left ventricular ejection fraction >50% were randomly assigned to either (a) H --> H + D [H, once weekly 2 mg/kg (loading dose, 4 mg/kg); D, once every 3 weeks 60 mg/m(2)] or (b) H + D. Primary endpoints were progression-free survival (PFS) for the H-mono stage of the H --> H + D group and H + D group and overall survival (OS) for both groups. Secondary endpoints were overall response rate, time to treatment failure, second PFS and safety. The planned number of patients was 160 patients in total. Of 112 patients enrolled, 107 were eligible. After 112 patients were enrolled, the Independent Data Monitoring Committee recommended stopping enrollment because PFS and OS were greater in the H + D group than the H --> H + D group. Median PFS was 445 days in the H + D group versus 114 days for H-mono in the H --> H + D group [hazard ratio (HR), 4.24; P < 0.01]. OS was significantly longer in the H + D group (HR, 2.72; P = 0.04). H + D therapy is significantly superior to H --> H + D therapy as first-line therapy in patients with HER2-positive MBC, especially in terms of OS.

Phase II study of 4-weekly capecitabine monotherapy in advanced/metastatic breast cancer.

BACKGROUND: A multicenter, phase II study was conducted to evaluate the efficacy and safety of the Japanese intermittent 4-week regimen of capecitabine in patients with advanced/metastatic breast cancer. METHODS: Fifty patients who had received no more than one prior chemotherapy regimen for advanced/metastatic disease were enrolled from 23 centers and received at least two 4-weekly cycles of capecitabine (828 mg/m² orally twice daily for 3 weeks followed by a 1-week rest period). RESULTS: The overall response rate assessed by the Independent Review Committee (standard population, n = 46) was 28.3% (95% confidence interval 16.0-43.5%), including complete responses in 6.5%. Stable disease was observed in 20 patients and maintained for more than 6 months in 10 patients. The median duration of response in 13 evaluable responders was 5.3 months. Among evaluable patients (n = 47), median time to disease progression was 5.1 months. Median overall survival was 20.2 months. The most common treatment-related adverse events (all grades) were hand-foot syndrome (66%), nausea (26%), stomatitis (22%) and diarrhea (20%). Grade 3/4 treatment-related adverse events were seen in 23 patients (46%). The most common grade 3/4 adverse events were lymphocytopenia (22%), hand-foot syndrome (18%) and hyperbilirubinemia (10%). CONCLUSIONS: Although the target overall response rate was not reached, the Japanese intermittent 4-week regimen of capecitabine was shown to be an effective and well-tolerated first- or second-line therapy for advanced/metastatic breast cancer.

Randomized trial of cyclophosphamide, epirubicin, and fluorouracil chemotherapy compared with cyclophosphamide, methotrexate, and fluorouracil with node-positive breast cancer in Japan.

BACKGROUND: To compare the cyclophosphamide, methotrexate, and fluorouracil (CMF) chemotherapy and the anthracycline-containing regimen cyclophosphamide, epirubicin, and fluorouracil (CEF) to evaluate the efficacy and safety of the latter. METHODS: A total of 294 patients with axillary node-positive primary breast cancer of STAGE I-IIIa were randomly assigned to either CEF [cyclophosphamide (CPA) 500 mg/m(2) i.v. days 1 and 8; epirubicin (EPI) 60 mg/m(2) i.v. day 1; and 5-fluorouracil (5-FU) 500 mg/m(2) i.v. days 1 and 8] or CMF [CPA 500 mg/m(2) i.v. days 1 and 8; methotrexate (MTX) 40 mg/m(2) i.v. days 1 and 8; and 5-FU 500 mg/m(2) i.v. days 1 and 8]. Both treatment regimens were comprised of six cycles at 4-week intervals. Tamoxifen (TAM) 20 mg/day was concomitantly given to estrogen receptor (ER)-positive patients and those with undetermined ER status for 2 years. RESULTS: The overall 5-year survival was 77.1% for CEF and 71.4% for CMF [p = 0.24; hazard ratio 0.79 (95% CI 0.50-1.24)], and the 5-year disease-free survival was 55.7% for CEF and 48.9% for CMF [p = 0.15; hazard ratio 0.80 (95% CI 0.57-1.12)]. Although the log-rank test did not show a significant difference, both overall and disease-free survivals were higher for CEF according to the point estimates. Adverse drug reactions (ADRs) occurred more frequently in CEF. CONCLUSION: Whereas CEF had a good trend compare with CMF, it could not be proven statistically significant. The principal cause of the failure seems to be insufficient power, that is, the dose intensity (EPI: 60 mg/m(2)) set 10 years ago, when the trial began, was low, and the number of trial subjects was small because of the background of the times, which made the accumulation of cases extremely difficult. However, the trial should be considered to be meaningful, as it was the first, formally conducted controlled trial on chemotherapy in Japan.

Mannose-binding lectin (MBL)-associated serine protease (MASP)-1 contributes to activation of the lectin complement pathway.

The complement system plays an important role in innate immunity. In the lectin complement pathway, mannose-binding lectin (MBL) and ficolins act as recognition molecules, and MBL-associated serine protease (MASP) is a key enzyme. It has been suggested that MASP-2 is responsible for the activation of C4. Other serine proteases (MASP-1 and MASP-3) are also associated with MBL or ficolins; however, their functions are still controversial. In this study, a MASP-1- and MASP-3-deficient mouse model (MASP1/3(-/-)) was generated by a gene targeting strategy to investigate the roles of MASP-1 and MASP-3 in the lectin pathway. Serum derived from MASP1/3(-/-) mice showed significantly lower activity of both C4 and C3 deposition on mannan-agarose, and this low activity was restored by the addition of recombinant MASP-1. MASP-1/3-deficient serum showed a significant delay for activation of MASP-2 compared with normal serum. Reconstitution of recombinant MASP-1 in MASP-1/3-deficient serum was able to promote the activation of MASP-2. From these results, we propose that MASP-1 contributes to the activation of the lectin pathway, probably through the activation of MASP-2.

Phase III study to evaluate the use of high-dose chemotherapy as consolidation of treatment for high-risk postoperative breast cancer: Japan Clinical Oncology Group study, JCOG 9208.

A randomized controlled trial was conducted to evaluate the efficacy of high-dose chemotherapy (HDC) as consolidation of the treatment of high-risk postoperative breast cancer. Patients under 56 years of age with stage I to IIIB breast cancer involving 10 or more axillary lymph nodes were eligible. The primary endpoint was relapse-free survival (RFS). Between May 1993 and March 1999, 97 patients were enrolled, and two patients became ineligible. The median age of the 97 patients was 46 years (range 27-55 years), and 72 (74%) were premenopausal. The median number of involved axillary nodes was 16 (range 10-49). All patients had undergone a radical mastectomy. Major characteristics were well balanced between the treatment arms. Forty-eight patients in the standard-dose (STD) arm received six courses of cyclophosphamide, doxorubicin, and 5-fluorouracil followed by tamoxifen. Forty-nine patients were assigned to undergo HDC with cyclophosphamide and thiotepa after six courses of cyclophosphamide, doxorubicin, and 5-fluorouracil followed by tamoxifen; however, 15 of these patients (31%) did not undergo HDC. HDC was well tolerated without any treatment-related mortality. At a median follow-up of 63 months, the 5-year RFS of 47 eligible patients in the STD arm and 48 eligible patients in the HDC arm was 37% and 52% on an intent-to-treat basis, respectively (P = 0.17). Five-year overall survival of all randomized patients was 62% for the STD arm and 63% for the HDC arm (P = 0.78). Although the prespecified values of the two arms were not so accurate as to allow detection of the observed difference, no advantage of HDC was observed in terms of RFS or overall survival.

The DVE changes distal epiblast fate from definitive endoderm to neurectoderm by antagonizing nodal signaling.

To assess the function of the distal visceral endoderm (DVE) of embryonic day 5.5 (E5.5) embryos, we established a system to directly ablate the DVE and observe the consequences after culture. When the DVE was successfully ablated, such embryos (DVE-ablated embryos) showed deregulated expression of Nodal and Wnt3 and ectopically formed the primitive streak at the proximal portion of the embryo. The DVE and anterior visceral endoderm (AVE) are implicated in the development of neurectoderm. We found that the distal epiblast of E5.5 embryo rotates anteriorly by the beginning of gastrulation. These cells remained to be anteriorly located during gastrulation and contributed to the ectoderm in the anterior side of the embryo. This indicates that the distal epiblast of E5.5 embryo becomes neurectoderm in normal development. In DVE-ablated embryos, the distal epiblast did not show any movement during culture and was abnormally fated to early definitive endoderm lineage. The data suggest that down-regulation of Nodal signaling in the distal epiblast of E5.5 embryo may be an initial step of neural development.

BMP signaling in the epiblast is required for proper recruitment of the prospective paraxial mesoderm and development of the somites.

Bmpr1a encodes the BMP type IA receptor for bone morphogenetic proteins (BMPs), including 2 and 4. Here, we use mosaic inactivation of Bmpr1a in the epiblast of the mouse embryo (Bmpr-MORE embryos) to assess functions of this gene in mesoderm development. Unlike Bmpr1a-null embryos, which fail to gastrulate, Bmpr-MORE embryos initiate gastrulation, but the recruitment of prospective paraxial mesoderm cells to the primitive streak is delayed. This delay causes a more proximal distribution of cells with paraxial mesoderm character within the primitive streak, resulting in a lateral expansion of somitic mesoderm to form multiple columns. Inhibition of FGF signaling restores the normal timing of recruitment of prospective paraxial mesoderm and partially rescues the development of somites. This suggests that BMP and FGF signaling function antagonistically during paraxial mesoderm development.

[Assessment of goserelin treatment in adjuvant therapy for premenopausal patients with breast cancer in Japan-zoladex breast cancer study group trial-B].

OBJECTIVE: Goserelin (GOS) therapy in an adjuvant setting for estrogen receptor(ER)-positive premenopausal patients with breast cancer was assessed in a randomised comparative study. METHODS: ER positive premenopausal patients with n + or n 0 and T > or = 3 cm received tamoxifen (TAM) 20 mg/day, GOS 3.6 mg/4 weeks or GOS + TAM for 2 years, and the clinical efficacy and safety of these regimens were assessed. RESULTS: In the data analysis of total 207 patients, hazard ratios of disease free survival (DFS) and overall survival (OS) in the GOS group compared to the TAM group were 0.87 and 2.10,respectively. The incidence of adverse drug reactions was similar (42-55%) in all three groups. Since the number of patients in this study did not reach the target number, the efficacy could not be assessed from a statistical aspect. Therefore,meta-analysis with similar foreign studies(ZIPP) was implemented. The results of meta-analysis showed that the hazard ratios of DFS and OS in the GOS group compared to the non-GOS group were 0.83 and 0.85, respectively. CONCLUSION: Although the analysis of 207 patients did not show any statistically significant difference between each of the treatment groups, the results of meta-analysis showed a significant prolongation of DFS in the GOS group. Also high tolerability of GOS was suggested. From these results, GOS was considered highly useful in adjuvant therapy for ER-positive premenopausal patients with breast cancer.

Postoperative adjuvant therapy with tamoxifen, tegafur plus uracil, or both in women with node-negative breast cancer: a pooled analysis of six randomized controlled trials.

PURPOSE: This article reports the results of a pooled analysis of six randomized trials conducted to study the efficacy of uracil and tegafur (UFT) in the adjuvant treatment of node-negative breast cancer patients. PATIENTS AND METHODS: Six randomized controlled trials on node-negative breast cancer patients were conducted from 1992 through 1995 in Japan that included the three, three-arm trials (control [no adjuvant], UFT, and tamoxifen [TAM] groups) and the three, four-arm trials (control, UFT, TAM, and UFT plus TAM groups). Pooled analysis was performed on the data obtained from these six trials (involving 2,934 patients). RESULTS: Overall survival was compared between the UFT group (including both the UFT group and the TAM plus UFT group) and the non-UFT group (control group and TAM group). A significant difference (P = .04) was observed in 5-year survival rates between the UFT (95.9%) and the non-UFT (94.0%) groups. Overall survival was also compared between the TAM group (TAM group and TAM plus UFT group) and the non-TAM group (control group plus UFT group). The 5-year survival rate (95.2%) in the TAM group was not significantly different from that (93.9%) in the non-TAM group, but the subset analysis showed a significant (P = .01) improvement in the estrogen receptor-positive subset. CONCLUSION: Adjuvant UFT improves the overall survival of node-negative breast cancer patients. Given that UFT has milder adverse effects, it is suggested that UFT can be a useful alternative to doxorubicin and cyclophosphamide, or cyclophosphamide, methotrexate, and fluorouracil in the adjuvant treatment for node-negative breast cancer.

Hrs, a mammalian master molecule in vesicular transport and protein sorting, suppresses the degradation of ESCRT proteins signal transducing adaptor molecule 1 and 2.

The degradation and sorting of cytoplasmic and cell-surface proteins are crucial steps in the control of cellular functions. We previously identified three mammalian Vps (vacuolar protein sorting) proteins, Hrs (hepatocyte growth factor-regulated tyrosine kinase substrate) and signal transducing adaptor molecule (STAM) 1 and -2, which are tyrosine-phosphorylated upon cytokine/growth factor stimulation. Hrs and the STAMs each contain a ubiquitin-interacting motif and through formation of a complex are involved in the vesicle transport of early endosomes. To explore the mechanism and cellular function of this complex in mammalian cells, we established an Hrs-defective fibroblastoid cell line (hrs(-/-)); embryos with this genotype died in utero. In the hrs(-/-) cells only trace amounts of STAM1 and STAM2 were detected. Introduction of wild-type Hrs or an Hrs mutant with an intact STAM binding domain (Hrs-dFYVE) fully restored STAM1 and STAM2 expression, whereas mutants with no STAM binding ability (Hrs-dC2, Hrs-dM) failed to express the STAMs. This regulated control of STAM expression by Hrs was independent of transcription. Interestingly, STAM1 degradation was mediated by proteasomes and was partially dependent on the ubiquitin-interacting motif of STAM1. Revertant Hrs expression in hrs(-/-) cells not only led to the accumulation of ubiquitinated proteins, including intracytoplasmic vesicles, but also restored STAM1 levels in early endosomes and eliminated the enlarged endosome phenotype caused by the absence of Hrs. These results suggest that Hrs is a master molecule that controls in part the degradation of STAM1 and the accumulation of ubiquitinated proteins.

A phase II study of S-1 in patients with metastatic breast cancer--a Japanese trial by the S-1 Cooperative Study Group, Breast Cancer Working Group.

BACKGROUND: S-1 is a newly developed novel oral dihydrouracil dehydrogenase inhibiting fluoropyrimidine drug consisting of 1 M tegafur (FT), 0.4 M 5-chloro-2, 4-dihydroxypyrimidine (gimeracil), and 1 M potassium oxonate (oteracil), with efficient antitumor activity and low gastrointestinal toxicity which is widely used in Japan against advanced gastric, head and neck cancers. We investigated its clinical efficacy against metastatic breast cancer. METHODS: A non-blind phase II study was carried out to evaluate the efficacy and toxicity in metastatic breast cancer patients. Patients with measurable metastasis foci (n=111) were enrolled, and 108 patients were regarded as eligible. S-1 was administered orally at a standard dose of 80 mg/m2/day b.i.d. One course consisted of 28 consecutive days of administration followed by a 14-day rest, and courses were repeated up to six times. RESULTS: Among the eligible patients, 10 had a complete response and 35 had a partial response, with an overall response rate (CR+PR) of 41.7% (95% confidence interval: CI, 32.3-51.5%). The incidences of toxicity (> or =grade 3) were neutropenia 9.1%, anemia 0.9%, anorexia 3.6%, stomatitis 1.8%, nausea/vomiting 1.8%, diarrhea 0.9%, and fatigue 2.7%, however no treatment-related deaths were observed. The median survival time was 872 days (95% CI, 572-1,110 days). There was no difference in response rate or toxicity between the under 65-year-old group and the older group. CONCLUSION: S-1 was demonstrated to have high efficacy with low gastrointestinal toxicity even in older patients and will be a promising new chemotherapy drug for metastatic breast cancer.

BMP receptor IA is required in the mammalian embryo for endodermal morphogenesis and ectodermal patterning.

BMPRIA is a receptor for bone morphogenetic proteins with high affinity for BMP2 and BMP4. Mouse embryos lacking Bmpr1a fail to gastrulate, complicating studies on the requirements for BMP signaling in germ layer development. Recent work shows that BMP4 produced in extraembryonic tissues initiates gastrulation. Here we use a conditional allele of Bmpr1a to remove BMPRIA only in the epiblast, which gives rise to all embryonic tissues. Resulting embryos are mosaics composed primarily of cells homozygous null for Bmpr1a, interspersed with heterozygous cells. Although mesoderm and endoderm do not form in Bmpr1a null embryos, these tissues are present in the mosaics and are populated with mutant cells. Thus, BMPRIA signaling in the epiblast does not restrict cells to or from any of the germ layers. Cells lacking Bmpr1a also contribute to surface ectoderm; however, from the hindbrain forward, little surface ectoderm forms and the forebrain is enlarged and convoluted. Prechordal plate, early definitive endoderm, and anterior visceral endoderm appear to be expanded, likely due to defective morphogenesis. These data suggest that the enlarged forebrain is caused in part by increased exposure of the ectoderm to signaling sources that promote anterior neural fate. Our results reveal critical roles for BMP signaling in endodermal morphogenesis and ectodermal patterning.

BMP4 supports self-renewal of embryonic stem cells by inhibiting mitogen-activated protein kinase pathways.

The fate of pluripotent stem cells is tightly controlled during early embryonic development. Both the derivation and the maintenance of embryonic stem cells (ES cells) in vitro depend on feeder cell-derived growth factors that are largely unidentified. To dissect the mechanisms governing pluripotency, we conducted a screen to identify factors that are produced by mouse embryonic fibroblast STO cells and are required to maintain the pluripotency of ES cells. One of the factors is bone morphogenetic protein 4 (BMP4). Unexpectedly, the major effect of BMP4 on the self-renewal of ES cells is accomplished by means of the inhibition of both extracellular receptor kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) pathways, and inhibitors of ERK and p38 MAPKs mimic the effect of BMP4 on ES cells. Importantly, inhibition of the p38 MAPK pathway by SB203580 overcomes the block in deriving ES cells from blastocysts lacking a functional Alk3, the BMP type IA receptor. These results uncover a paradigm for BMP signaling in the biology of pluripotent stem cells.

[A late phase II clinical study of S-1 in patients with progressed, refractory breast cancer].

A late phase II clinical study of S-1 against advanced or refractory breast cancer was done by 37 institutes in Japan. S-1 was administered twice daily at 80, 100 or 120 mg/body/day consecutively for 28 days followed by 14 days of rest (1 course). Eighty-three patients were enrolled and 81 were eligible for the study. The response ratio was 42.0% with 6 CR and 28 PR and its 95% confidence interval for the response was 31.1 to 53.5%. The median survival period was 910 days (95% confidence interval was 493-1, 083 days). The observed major adverse reactions (> or = grade 2) were as follows: hematological toxicities: leukopenia 21.0% (17/81), neutropenia 28.4% (23/81), erythropenia 4.9% (4/81); gastrointestinal toxicities: anorexia 9.9% (8/81), nausea and vomiting 12.3% (10/81), diarrhea 8.6% (7/81), stomatitis 1.2% (1/81), and fatigue 8.6% (7/81). The severe adverse reactions (> or = grade 3) were as follows; hematological toxicities: neutropenia 8.6% (7/81), anorexia 4.9% (4/81), fatigue 3.7% (3/81), nausea and vomiting 1.2% (1/81), diarrhea 1.2% (1/81), stomatitis 1.2% (1/81). Grade 4 adverse reactions (neutropenia and fatigue) were observed only in 1 patient. The ratio without hospitalization was 87.7%. These results strongly suggest the superior efficacy and safety of S-1 against patients suffering from advanced, refractory breast cancer. Therefore, S-1 may be a new therapeutic agent to prolong the survival period of breast cancer patients due to its high antitumor activity and low toxicity.

Four cases of chylous fistula after breast cancer resection.

Chylous fistulas in cases treated surgically for breast cancer only, are rare. We encountered four chylous fistula cases after breast cancer operations out of a total of 851 cases, all of which involved the left breast. Chylous fistulas were confirmed by axillary white fluid and were unrelated to obesity, surgical method or the area of axillary lymph node dissection. All four cases of chylous fistulas were successfully treated conservatively, with no special dietary control and no surgical treatment.

Association of p53 codon Arg72Pro and p73 G4C14-to-A4T14 at exon 2 genetic polymorphisms with the risk of Japanese breast cancer.

BACKGROUND: The association between breast cancer risk and genetic polymorphisms of p53 at codon 72 (Arg72Pro) has been investigated by several studies, but the results are not consistent. The aim of this case-control study conducted in Nagoya, Japan, was to reconfirm the results of prior studies of polymorphisms of p53 Arg72Pro, and to test if polymorphisms of p73 G4C14-to-A4T14 at exon 2 (G4A) were also associated with breast cancer risk. METHODS: The cases were 200 breast cancer patients who visited Aichi Cancer Center Hospital. The controls were 282 local citizens who underwent a health check-up. All cases and controls were recruited from Chubu Japan. Genotyping was carried out by polymerase chain reaction with confronting two-pair primers. RESULTS: The p53 genotype distribution was 40.4% for Arg72 homozygous, 48.9% for heterozygous, and 10.7% for Pro72 homozygous in controls, and 32.0%, 50.0%, and 18.0% in cases, respectively. A comparison between cases and controls indicated a significantly increased risk for Pro72 homozygosity in cases (odds ratio=2.14; 95% confidence interval=1.21-3.79). The genotypic frequencies for p73 G4A were 54.3% for G/G, 39.7% for G/A, and 6.0% for A/A in controls; and 59.0%, 32.0%, and 9.0% in cases, respectively. There were no significant differences in p73 G4A frequency between cases and controls. CONCLUSIONS: This study implies an association of breast cancer risk with the p53 polymorphism Arg72Pro, but not with p73 G4A.

Dietary factors protective against breast cancer in Japanese premenopausal and postmenopausal women.

Since components of the Japanese diet that might be responsible for the relatively low breast cancer incidence rates observed in Japan have not been clarified in detail, a case-referent study with reference to menopausal status was conducted using data from the hospital-based epidemiologic research program at Aichi Cancer Center (HERPACC). In total, 2,385 breast cancer cases were included, and 19,013 women, confirmed as free of cancer, were recruited as the reference group. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were determined by multiple logistic regression analysis. There were reductions in risk associated with high intake of milk and green-yellow vegetables (green leafy vegetables, carrots and pumpkins) among both pre- and postmenopausal women. The protective effects of the Japanese diet were more prominent among postmenopausal than premenopausal women. The adjusted OR of fish consumption (5 or more times per week vs. fewer than 3 times per month) was 0.75 (95% CI 0.57-0.98, p(trend) = 0.01) for postmenopausal breast cancer. A significant decrease in postmenopausal breast cancer risk was also observed for increasing intake of fruit (OR = 0.61, 95% CI 0.41-0.91). Thus, traditional Japanese dietary factors may protect against breast cancer development, especially among postmenopausal women.