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 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.

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.

Randomized controlled trial comparing oral doxifluridine plus oral cyclophosphamide with doxifluridine alone in women with node-positive breast cancer after primary surgery.

PURPOSE: We compared the therapeutic usefulness of doxifluridine (5'-DFUR) alone and a combination of 5'-DFUR plus cyclophosphamide (CPM), both of which are considered effective against advanced and recurrent breast cancer, to determine which treatment is more beneficial as postoperative adjuvant chemotherapy. PATIENTS AND METHODS: A total of 1,131 women with node-positive primary breast cancer were randomly assigned after primary surgery to receive 5'-DFUR alone or 5'-DFUR plus CPM. All patients initially received 5'-DFUR in an oral dose of 1,200 mg/d for 4 weeks, starting 4 weeks after surgery. Chemotherapy was then not given for 2 weeks. Patients in the 5'-DFUR group subsequently received five 4-week cycles of treatment consisting of oral 5'-DFUR (1,200 mg/d) for the first 2 weeks and no chemotherapy for the next 2 weeks. Those assigned to the 5'-DFUR plus CPM group also received oral CPM 100 mg/d for the first 2 weeks and no chemotherapy for the next 2 weeks. Women 50 years or older concurrently received 20 mg/d of tamoxifen for 2 years in both groups. RESULTS: Of the 1,088 eligible women, 546 were assigned to receive 5'-DFUR alone and 542 were assigned to receive 5'-DFUR plus CPM. Overall disease-free survival was significantly better in women who received 5'-DFUR plus CPM than in those who received 5'-DFUR alone (log-rank test, P =.021). Toxic effects occurred in 20.0% of patients (109 of 546) in the 5'-DFUR group and 32.3% of patients (175 of 542) in the 5'-DFUR plus CPM group (chi(2) test, P <.001). CONCLUSION: Combination therapy with 5'-DFUR plus CPM is more effective in preventing recurrence than 5'-DFUR alone.

[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.

The effect of adjuvant 5'-deoxy-5-fluorouridine in early stage breast cancer patients: results from a multicenter randomized controlled trial.

To assess the efficacy of 5'-DFUR, an intermediate of capecitabine, for adjuvant treatment of early breast cancer, we conducted an open-labeled multi-center randomized controlled trial to compare postoperative 5'-DFUR treatment with surgery alone. We enrolled 1217 primary breast cancer patients and randomly assigned them into two treatment groups; one received six-month postoperative 5'-DFUR treatment by consecutive or intermittent administration, and the other surgery alone. Follow-up surveys were conducted once a year for all subjects simultaneously and examined their outcome/presence or absence of the cancer recurrence. The central study committee reviewed all follow-up data and judged the recurrence data to be used for the analysis. Eight-year follow-up data showed no significant differences in relapse-free and overall survival between the two groups, and 5'-DFUR treatment regimen showed an extremely high tolerance. Possible explanations are discussed for the finding of no significant survival difference between adjuvant 6-month 5'-DFUR monotherapy and surgery alone in early breast cancer.

Impact of established risk factors for breast cancer in nulligravid Japanese women.

BACKGROUND: The mechanism by which pregnancy impacts breast cancer risk remains poorly understood. There is a need for detailed quantification of risk in nulliparous women. We therefore have undertaken a case-referent study of breast cancer employing data from the Hospital-based Epidemiologic Research Program at Aichi Cancer Center (HERPACC), Japan, examining the impact of reproductive and anthropometric factors on breast cancer risk among nulligravid women compared with their parous counterparts. METHODS: In total, 2032 breast cancer cases were included, and 17848 women, confirmed as free of cancer, were recruited as a reference group. Odds ratios (OR) and 95% confidence intervals (95% CI) were determined by multiple logistic regression analysis. RESULTS: A protective effect of later age at menarche was observed among parous women, but it did not alter risk in nulligravid cases. The risk increment with a family history appeared to be most pronounced among premenopausal cases with no history of pregnancy (OR=2.68, 95% CI: 1.41-5.11). Among postmenopausal women, positive associations with height and current body mass index (BMI) in the nulligravid group were similar to those observed in the parous group. The present study indicated that age at menopause, family history in premenopausal women, and height and obesity in postmenopausal women seemed to exert more influence in nulligravid women. Formal tests for interaction between maternity status and these factors, however, did not prove statistically significant. CONCLUSION: Our findings suggest that established risk factors for breast cancer have an additive impact with nulligravid status. Thus, it is implied that obesity control for all women, including nulliparous individuals, is important from a practical viewpoint for primary breast cancer prevention.

Combination of subareolar blue dye and peritumoral RI for sentinel lymph node biopsy.

BACKGROUND: The identification rate of sentinel lymph nodes (SLNs) is variable because numerous different methods employing different tracers have been used for sentinel lymph node detection. The aim of this study was to determine the optimal technique for sentinel lymph node biopsy (SLNB). METHODS: From May 1999 to December 2001, SLNB was performed for 376 patients with T1-3 and N0-1 primary breast cancer using blue dye alone, radioisotope (RI) alone and combination of RI and blue dye. Two hundred sixty-eight patients underwent SLNB using blue dye alone. They were divided into 4 groups (Group A: n=50; peritumoral injection, Group B: n=83; the first half to receive subareolar injection, Group C: n=83; the second half to receive subareolar injection, and Group D: n=52; small incision according to an axillary skin landmark). One hundred eight patients underwent SLNB using RI. Tin colloid was used in 49 cases (Tin Colloid Group) and phytate in 59 cases (Phytate Group). Among them, 29 patients underwent injection of RI alone and 79 patients received a combination of RI and blue dye. RESULTS: The identification rates of SLN using blue dye alone were 60%, 82%, 92% and 79% in Groups A, B, C and D, respectively. The identification rates of SLN in patients receiving RI alone and in those receiving combination of RI and blue dye were 40% and 89%, respectively, in Tin Colloid Group, and 92% and 94%, respectively, in Phytate Group. CONCLUSION: When using blue dye alone, subareolar injection provided a better identification rate than peritumoral injection. The combination of peritumoral phytate and subareolar blue dye provided the best identification rate (94%) in all the groups. The combination of intraparenchymal phytate and subareolar blue dye was the most efficient technique for sentinel node biopsy in breast cancer patients.

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.

Transforming growth factor B1 T29C polymorphism and breast cancer risk in Japanese women.

BACKGROUND: A cohort study for Caucasians aged 65 years or older demonstrated a marked breast cancer risk reduction for those with the CC genotype of transforming growth factor B1 (TGF B1) T29C polymorphism. This is a prevalent case-control study to examine the reported risk reduction for Japanese women. PATIENTS AND METHODS: A total of 232 histologically diagnosed breast cancer patients who visited Aichi Cancer Center Hospital between June 1999 and March 2000 were enrolled. The controls were 172 female outpatients without cancer at the same hospital. DNA was extracted from peripheral blood, and TGF B1 genotype was determined by PCR-CTPP. RESULTS: The genotype frequency was 23.7% for TT, 49.2% for TC, and 27.1% for CC among controls, and 28.9%, 46.1%, and 25.0%, respectively, among cases. Age-adjusted odds ratio (OR) relative to the TT genotype was 0.81 (95% confidence interval, 0.50-1.31) for the TC genotype and 0.77 (0.45-1.34) for the CC genotype. For premenopausal women, the CC genotype was significantly associated with reduced risk of breast cancer in comparison with the TT genotype (OR=0.45, 0.20-0.98). The association was not observed for postmenopausal women (OR=1.40, 0.64-3.08). CONCLUSION: The present study showed risk reduction for Japanese premenopausal women with the CC genotype, but not for postmenopausal Japanese women.

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.

[Phase I single-dose administration study of exemestane in postmenopausal women].

A single-dose administration study of a new type of aromatase inactivator, exemestane, was performed in normal healthy postmenopausal Japanese women. The study was conducted to investigate the safety, effect on serum and urinary estrogen concentrations, and pharmacokinetics of exemestane at 25 or 50 mg. A crossover study using a single dose (25 mg) was also conducted in order to study the effect of meals on these parameters. Adverse events, in which a causal relationship with the study drug could not be excluded, were as follows: hot flushes (2/4), sleepiness (1/4), and glycogeusia (1/4), all of which were mild and transient. There were no clinically significant laboratory test or physical finding abnormalities with either dose, except for one patient in the 50 mg group who had an increase in levels of GPT, ALP and gamma-GTP. Maximal suppression of serum estrogen concentration (22-37% suppression) was achieved 3-4 days after single-dose administration of exemestane (25 mg or 50 mg), and almost no suppression was observed 2 weeks later. A significant decrease in the amount of urinary estrogen excretion occurred on day 4 and day 8 after exemestane administration. The level of urinary estrogen excretion almost returned to baseline levels in the 25 mg group and returned to 65% of baseline levels in the 50 mg group 2 weeks after drug administration. Both serum estrogen concentration and the amount of urinary estrogen excreted decreased in a similar fashion under both fasting and fed conditions, suggesting no effect of meals on the suppression of estrogen concentrations. Exemestane was adsorbed immediately after single-dose administration, and this was followed by a gradual decrease in serum concentrations in a multiphase pattern. An increase in Cmax and AUC0-tz values was observed after meals compared with those values obtained under fasting conditions, yet the increase was not statistically significant, suggesting that the increase was not clinically relevant. The results of this study verified the safety and the estrogen suppressive effects on serum and urinary concentrations of estrogen of a single dose of exemestane up to 50 mg. Furthermore, results suggest that the suppression of serum and urinary estrogen concentrations and pharmacokinetics of exemestane were not affected by food.

[Phase I multiple-dose administration study of exemestane in postmenopausal women].

A multiple-dose administration study of exemestane (0.5-50 mg/day after breakfast for 7 days) was conducted in 32 normal healthy postmenopausal Japanese women using a single-blind, 3-step dose-titration method in order to investigate the safety, effect on serum concentration, amount of urinary estrogen excretion, and pharmacokinetics of the drug. Subjective/objective symptoms, in which a causal relationship with exemestane administration could not be excluded, were as follows: headache (8 cases: 1 each in the 0.5 and 25 mg groups, 2 in the 10 mg group and 4 in the 50 mg group), dizziness (2 cases: 1 each in the 0.5 and 25 mg groups), and fever (1 in the 25 mg group), all of which were mild and disappeared without treatment. The only abnormal laboratory findings were a mild increase in levels of GOT and GPT in 1 case and in the number of basophils in another case. There were no notable abnormal findings in vital signs, body weight or EKG. A dose-dependent decrease in serum estrogen level was observed between doses of 0.5 mg and 25 mg. The decrease was maximal at 25 mg, at which serum estrogen concentrations decreased to 14-27% of those observed at day 0. This decrease was maintained for one week, returning to baseline levels 2 weeks after the completion of drug administration. A similar result was also observed in the suppression of 24-hour urinary estrogen excretion. Exemestane was absorbed immediately after initial administration, reaching Cmax 0.9-2.6 hours post-administration. This was followed by a rapid decrease over the next 4-8 hours followed by a gradual decrease Cmax reached normal steady state values on day 5. Cmax and AUC0-24 values taken between administration of the first and final doses increased proportionally in a dose-dependent manner, suggesting that exemestane has a linear pharmacokinetic profile. Furthermore, results of the comparison of the trough concentrations of the initial dose with those of the final dose suggested no accumulative effects of the study drug.

[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.

[Late phase II study of exemestane in postmenopausal patients with breast cancer resistant to anti-estrogenic agents].

A multi-center trial of exemestane 25 mg, an oral aromatase irreversible inactivator, was conducted to evaluate its efficacy and safety in 33 postmenopausal patients, and to investigate the pharmacokinetics/serum hormone levels in 16 postmenopausal patients, respectively, with breast cancer and anti-estrogen resistance. Exemestane 25 mg was given once daily for up to 48 weeks (maximum). The objective of this study was to confirm the reproducibility of the results shown in two studies in other countries with similar patients, to investigate the possibility of extrapolating the overseas data to Japanese. The response rate (CR + PR) was 24.2% (8.33%), which exceeded the minimum number (6 cases) required to evaluate efficacy. The response rate in this study was very similar to that observed in the two international open studies. Adverse events (subjective/objective symptoms), in which a causal relationship with exemestane administration could not be excluded, were observed in 26 cases (78.8%). Of these, hot flushes, increased sweating, fatigue, and insomnia occurred in more than 10% of patients, which was similar to that observed in the two international open studies. Abnormal laboratory results occurring in more than 10% of patients, in which a causal relationship with exemestane administration could not be excluded, were as follows: lymphocyte count decrease, alkaline phosphate increase, GOT increase, GPT increase, gamma-GTP increase, triglyceride increase, and inorganic phosphate increase, most of which were either grade 1 or 2. A remarkable decrease in serum hormone concentration was observed only for estrogen. The values of AUC0-infinity at day 1 and AUC0-24 h at day 29 (steady state) were similar, suggesting no accumulative effect of exemestane. These results demonstrate the anti-tumor effect and safety of exemestane in postmenopausal anti-estrogen resistant breast cancer patients. The reproducibility of the results of the two foreign studies was verified in Japanese patients, and it is concluded that the foreign trial data on exemestane can be extrapolated to Japanese.

[Early phase II dose-finding study of exemestane in postmenopausal patients with advanced/recurrent breast cancer].

Exemestane was administered orally to postmenopausal women with advanced/recurrent breast cancer at a dose of 10 mg/day or 25 mg/day once daily for more than 8 weeks in order to evaluate the drug's anti-tumor effects and safety in a dose-finding study. The response rate (CR + PR) in the 10 mg and 25 mg group was 25.0% (8/32) and 31.4% (11/35), respectively, demonstrating no significant differences between the two groups, yet a higher efficacy rate was observed in 25 mg group. The efficacy rate in hormone-treatment-resistant patients within the 10 mg and 25 mg groups was 14.3% (3/21) and 26.1% (6/23), respectively, demonstrating more than a 20% response rate in 25 mg group. Incidences of the adverse events of which relevance to the drug could not be excluded were 30.6% (11/36) in the 10 mg group. 13.9% (5/36) in the 25 mg group and 22.2% (16/72) in the total group. The major adverse events were, hot flashes, numbness of the limbs, nausea, headache etc. Abnormal findings in clinical laboratory tests were as follows: ALP increase; GOT increase; GPT increase; gamma-GTP increase; total cholesterol increase; urinary sediment present. Abnormal findings in endocrine function were as follows: aldosterone decrease; testosterone.cortisol.DHEA-S decrease. But discontinuation due to abnormal laboratory findings was not found. No abnormal findings in physical tests were observed. A significant decrease in plasma estrogen concentration at week 4 was observed in both the 10 mg and 25 mg groups compared with baseline. These low levels were maintained throughout the study period. On the basis of these results, the efficacy of exemestane 25 mg/day was verified to be slightly higher than 10 mg/day. In addition the safety profile had no major adverse events to notice. In these patients with advanced/recurrent breast cancer, 25 mg/day was recommended as the most appropriate dose to be used clinically.

[Axillary lymph node dissection in clinically node-positive breast cancer].

Many Japanese surgeons think that clinically node-positive breast cancer is already a systemic disease. However, about 60% of surgeons believe that the survival rate increases with axillary lymph node dissection. Furthermore, 64% of surgeons change the area of axillary lymph node dissection based on the intraoperative diagnosis of lymph node metastases. We analyzed axillary lymph node dissection in clinically node-positive breast cancer using evidence-based medicine. We recommend that the level I and II axillary dissection be the preferred procedure and that the removal of level III axillary nodes is not necessary for staging. However, if grossly positive nodes are identified intraoperatively, a level III dissection should be carried out to maximize local control.