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Biomedical subjects

Tadashi Ikeda

Publications and source records attributed to Tadashi Ikeda.

17 recordsLinked to original sources

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.

Administration, Oral↗

Phase I study of docetaxel and cyclophosphamide in patients with advanced or recurrent breast cancer.

BACKGROUND: A phase I clinical study of combination chemotherapy with docetaxel and cyclophosphamide (CPA) was performed to determine the maximum tolerated dose (MTD), the incidence and severity of toxicities and the pharmacokinetics in patients with advanced or recurrent breast cancer. METHODS: Docetaxel was administered by intravenous drip infusion over 60 minutes, followed by intravenous bolus injection of CPA every 3-4 weeks. The dosage of docetaxel/CPA was 40/200, 40/400, 50/400, or 60/400 mg/m(2)/day. RESULTS: Fifteen patients were enrolled and received a total of 33 cycles of the combined therapy. The dose limiting toxicities (DLTs) were leukopenia, neutropenia and thrombocytopenia. The MTD was estimated to be docetaxel 60 mg/m(2) in combination with CPA 400 mg/m(2) per day. Plasma clearance of both drugs was similar regardless of dose. The recommended doses of docetaxel/CPA for a phase Utrial are 50/400 mg/m(2)/day every 3-4 weeks. CONCLUSION: The MTD of this combined therapy was docetaxel 60 mg/m(2) and CPA 400 mg/m(2). Neutropenia and leukopeina were common and severe. It is important to stress the need for modification of the dosing scheme.

Adult↗

Long-term results of breast-conserving treatment for early-stage breast cancer in Japanese women from multicenter investigation.

BACKGROUND: Although many clinical data regarding breast-conserving treatment have already been reported from European and North American countries, few clinical data with long-term follow-up have been reported from Japan. METHOD: We collected information on therapeutic and possible or developed prognostic factors and follow-up data for Japanese women who had received breast-conserving treatment consisting of wide excision of the primary tumor, axillary dissection and radiotherapy for unilateral breast cancer considered suitable for breast-conserving treatment from 18 Japanese major breast cancer treating hospitals; 1561 patients were registered. RESULTS: The median follow-up period was 77 months. Five-year disease-free and overall survival rates were 89.4 and 95.9%, respectively. The 5-year local recurrence-free rate was 96.3%. The patients with histologically positive margins (P < 0.0001) or estrogen receptor negative tumor (P = 0.0340) or younger than 40 years old (P < 0.0001) developed statistically significantly more local recurrences. Adjuvant endocrine therapy was essential for the estrogen receptor positive patients to have a lower local recurrence rate. Endocrine therapy did not change the local recurrence rate among estrogen receptor negative patients at all. Multivariate analysis showed histological margin status and the combination of estrogen receptor status and endocrine therapy were independent prognostic factors for local recurrence. CONCLUSION: The 5-year local recurrence rate of Japanese breast cancer patients who were treated with breast-conserving treatment using radiotherapy was 3.7%. Independent prognostic factors for local recurrence were histological margin status and the combination of estrogen receptor status and adjuvant endocrine therapy.

Adult↗

[Globalization of clinical trials].

Based on reviews of the Japanese clinical trial situation in lung cancer, gastric cancer, prostate cancer and breast cancer, it was clear that much progress has been made in short time. There are considerable differences between Japan and the West and also differences between clinical areas in Japan. For regulatory purposes bridging studies have become increasingly important. Use of identical protocols are required for effective bridging. Participations in global phase III trials is the best way of achieving registration in Japan. For successful global trials in Japan it is important to include Japanese investigators in the preparation of the protocol and to recognise the challenges facing such a project. Clinical practice in diagnosis and treatment have many differences, thus it is recommended to have clear and detailed information in the protocol. Hard end points like survival are important since they are not biased by cultural differences. There are clear difficulties with HE or QOL outcomes. The emergence of focus on evidence based medicine is also happening in Japan and will help to harmonize documentation across the world. For large adjuvant or prevention cancer global trials are essential. To facilitate global studies further development of infrastructure is necessary in Japan. Use of electronic data capture web based communication etc. will help overcome communication difficulties. Other improvements that will make Japanese participation in global trials easier and better include establishment of clinical trial centre at each hospital, introduction of trial coordinators or study nurses and an improved collaboration with company staff. A critical issue that also need addressing is agreement of centre target recruitment. We need to introduce a new flexible system in Japan if participation in global trial is to be optimised. If we can address these issues Japanese investigators and collaborative groups should be able to initiate and lead global trials in the future.

Antineoplastic Agents↗

The role of neoadjuvant chemotherapy for breast cancer treatment.

Neoadjuvant chemotherapy has become popular, especially for patients with advanced breast cancer. The pros and cons of neoadjuvant chemotherapy for treating breast cancer patients are reviewed. The advantages of neoadjuvant chemotherapy are 1) overall survival and recurrence-free survival rate are the same as post-operative chemotherapy, 2) serves as an in vivo sensitivity test, 3) increases the rate of breast conserving therapy, 4) facilitates the study of cancer biology. On the other hand, the disadvantages of neoadjuvant chemotherapy are 1) it modifies the stage, 2) treatment delay of PD cases, 3) residual intraductal component may be left behind after breast conserving surgery, 4) there are some cases of over-treatment. Combination chemotherapy is one possible way to increase the pathological CR rate, although the optimal order and cycles have not been determined. To avoid residual cancer cells after breast conserving surgery, the shrinkage pattern should be evaluated by MRI. Core needle biopsy should be performed before neoadjuvant chemotherapy to avoid over-treatment. It is essential to develop more effective regimens and stratify patients based on predictive factors.

Antineoplastic Agents↗

Sentinel lymph node biopsy in breast cancer using technetium-99m tin colloids of different sizes.

Axillary lymph node dissection (ALND) in the treatment of breast cancer is essential for predicting the prognosis and regional control of the tumor. At the same time ALND is associated with pain, numbness and sometimes lymphedema. Sentinel lymph node biopsy (SLNB) is a potential alternative procedure to conventional ALND in clinically node-negative breast cancer. In this study, we prepared the technetium-99m-labeled tin colloids with different sizes and compared their efficacy in SLNB. From September 1998 to February 2002, 184 clinically node-negative breast cancer patients were enrolled in the study at Keio University Hospital. Sentinel lymph nodes (SLNs) were identified by both blue dye and radioisotope. We prepared small-sized technetium-99m-labeled tin colloid (particle size: 200-400 nm in diameter). Regular-sized technetium-99m-labeled tin colloid is 400-1000 nm in diameter. In 74 patients, a SLNB was performed using regular-sized tin colloid; small-sized tin colloid was used in 110 patients. Subsequently, all of the patients were immediately followed by ALND. All dissected lymph nodes were evaluated by routine histopathological examination. The clinicopathological characteristics of the two groups were comparable. The lymphoscintigram detected SLN more frequently in the small-sized colloid group than in the regular-sized colloid group (P < 0.01). Small-sized tin colloid was also superior to regular-sized tin colloid in the SLN identification rate (97.3% versus 86.5%; P = 0.01). The mean value for ex vivo counts of the hottest sentinel lymph nodes of the small-sized colloid group was significantly higher than the counts of the regular-sized colloid group (P < 0.01). There was no significant difference in the accuracy between the two groups. It was concluded that SLNB using the small-sized tin colloid was technically feasible and provided higher detection and identification rates than the regular-sized tin colloid.

Adult↗

Overview: current status of breast conserving therapy in Japan.

Breast conserving operations have become the standard operation for early breast cancer. They were performed in about 40% of all breast cancer patients in Japan in 2000, and the percentage is still increasing. Ductal carcinoma in situ (DCIS) accounts for about 7% of all breast cancers and breast conserving operations for DCIS have been followed by a low in-breast recurrence rate, leading to wider indications for breast conserving operations as screening mammography has come to be used in Japan. In-breast recurrence is correlated to surgical margin status. It is important to evaluate the surgical margin for volume of cancer cell nests as well as for positivity. Neoadjuvant chemotherapy has become popular as an in vivo sensitivity test and as a means of down-staging to increase the possibility of performing a breast conserving operation. There are two patterns of shrinkage when neoadjuvant chemotherapy is effective: cocentric and honeycomb, and the pattern of residual cancer cell nests must be determined before surgery. MRI is an effective method of evaluating residual cancer cell nests. The in-breast recurrence rate after down-staging to perform breast conserving operations is reported to be higher than among candidates for breast conserving operation at the start. Sentinel node biopsy techniques and endoscopic operations are now being assessed in conjunction with breast conserving operations. The current status of breast conserving operations in Japan is reviewed in comparison with their status in Western countries.

Breast Neoplasms↗

Chordal-sparing mitral valve replacement using artificial chordae tendineae for rheumatic mitral stenosis: experience of the "oblique" method.

Chordal-sparing mitral valve replacement (CSMVR) has been proven to be beneficial for postoperative left ventricular (LV) function. In patients with mitral stenosis, however, diseased chordae tendineae (CT) often have to be replaced using artificial CT to achieve CSMVR. Previously, we reported that resusupension of artificial CT in an oblique direction enhances systolic LV function. Among 40 consecutive patients with mitral valve replacement (MVR), 17 (4 men and 13 women; mean age 66.5 years) with rheumatic mitral stenosis underwent CSMVR with oblique resuspension. Echocardiography was done before the operation, early (mean 25 days) after the operation, and at a late stage (mean 14 months). There was no mortality or major morbidity. LV ejection fraction late after the operation (68 +/- 8%) was better than that in the early period (61 +/- 8%, p < 0.01), and comparable to the preoperative level (65 +/- 9%). The oblique method may help to improve the results of MVR.

Aged↗

[Intra-arterial infusion chemotherapy for breast cancer].

Intra-arterial infusion chemotherapy has a significant effect in down-staging locally advanced breast cancer by providing a high dose intensity. It is also used for the treatment of liver metastasis. A better response rate and lower incidence of adverse effects are reported when patients are treated with intra-arterial infusion chemotherapy than with systemic chemotherapy using the same dose of the same drugs. Recent advances in devices such as access ports and portable infusion pumps make it possible to perform intra-arterial infusion chemotherapy repeatedly and safely. However, it remains uncertain whether or not intra-arterial infusion chemotherapy can improve the prognosis of cancer patients because of the lack of data from phase III trials. Accordingly, further studies including combined use of systemic chemotherapy are mandatory to the control of micrometastases outside the target organ.

Antineoplastic Combined Chemotherapy Protocols↗

[Globalization of anti-cancer therapies].

Based on short reviews of lung, gastric, colorectal, prostate, breast and ovarian cancer, there remain significant differences between Japan and the West in the therapeutic regimen for most cancers. Some of the differences are due to differences in stage of disease at diagnosis or historical factors affecting availability of products. In both Japan and the West, there are initiatives to prepare treatment guidelines based on published data. For Japan this initiative is limited by the lack of Japanese clinical trial data or even safety data. When guidelines are prepared from international data, many of the products have limited indications in Japan and therefore not reimbursed. Availability of the most appropriate therapies to Japanese patients will depend on a facilitation of clinical trials in both primary and additional indications. However, the experience in other countries is that, even where data and registration approval are available, guidelines are hard to agree and are not uniformly accepted by prescribers. The ICH E5 guideline on the use of bridging studies to interpolate Western data to Japanese regulatory dossiers provides an opportunity to accelerate availability of new medicines to Japanese prescribers and patients. The use of bridging studies has so far been limited for anti-cancer therapies. Where relevant pharmacodynamic endpoints can be measured, (e.g. aromatase inhibition) there can increase confidence in bridging. The newer types of agent which act to stabilise disease rather than tumour shrinkage present a special problem. In some cases surrogate markers can be valuable but in each case they need to be validated. As globalization continues, an alternative approach is to include a significant cohort of Japanese patients in Japanese patients but this depends on sufficient similarity in the patient population and background therapy. The most significant limitation to either large outcome studies in Japan or for Japanese centers to join international trials has been the environment for conduct of clinical trials. There have been some recent improvements and further progress is expected so that Japanese doctors can play a full role in the evaluation of new therapies.

Antineoplastic Combined Chemotherapy Protocols↗

[Developments in endocrine therapy for breast cancer].

After the usefulness of ovariectomy in breast cancer patients was demonstrated, endocrine therapy has been one of the most effective treatments of breast cancer. Thereafter, it became clear that estrogen receptors (ERs) existed in the cells of breast cancer. After it was found that ERs could be used as a predictive factor of endocrine therapy for breast cancer, the validity of endocrine therapy has became more certain. Tamoxifen, a major selective estrogen receptor modulator, is the first agent which has shown evidence of improving survival time and disease-free survival time in the treatment of breast cancer, and is the standard treatment, widely used in the treatment of breast cancer all over the world. LH-RH analogue, commonly used in ablation treatment among premenopausal women, produces the same effect as ovariectomy, and recently has shown good results equivalent to chemotherapy in premenopausal breast cancer treatment. Furthermore, aromatase inhibitors as a form of ablation treatment of postmenopausal women have been used recently. In comparison with tamoxifen, aromatase inhibitors have revealed the same or more effective result in postmenopausal breast cancer treatment. In the near future, endocrine mechanisms in the body and the molecular mechanisms of transcription by ER will be more clearly elucidated, and then new kinds of agent and combined therapies for the endocrine treatment of breast cancer will be developed. Currently, many clinical randomized trials are being conducted to examine the effectiveness of new endocrine treatment. Significant changes are occurring in the endocrine treatment of breast cancer.

Antineoplastic Agents, Hormonal↗

[Breast cancer].

Adjuvant chemo-endocrine therapy for breast cancer (ACETBC) trial has been the first large scaled clinical trial performed in Japan. Several prospective randomized trials have been performed in Japan since ACETBC-1 trial started in 1985. The effect of oral 5-FU agents had been tested in prospective randomized trials and the statistically marginal effect of oral 5-FU agents in adjuvant settings has been reported. Several trials having CMF as a control arm started in 1996 when CMF combination chemotherapy was approved by the government. The results of these trials have not been published. To perform good clinical trials, it is imperative to construct infrastructures including clinical research coordinator, and abolish governmental regulation of the dose of anticancer agents.

Antineoplastic Combined Chemotherapy Protocols↗

[Post launch studies].

Evidence Based Medicine (EBM) is a growing concept in Japan as it is elsewhere. Central to improving the use of EBM is generation of data through well conducted controlled clinical studies. There are many problems associated with conduct of clinical studies after launch in Japan, and many initiatives are ongoing to improve the situation. Development of Clinical Research Coordinators (CRO) and central Data Management centers are key to improving the quality of clinical research in Japan. Currently Japan has an undeveloped legal system with regard to post-launch trials and off-label use of registered drugs. There is no reimbursement for off-label and various restrictions imposed on the recipients of the Ministry of Health, Labour and Welfare's (MHLW) funds. Maybe the biggest problem is the high cost of post-marketing studies sponsored by pharmaceutical manufacturers. A high quality system to support post launch clinical studies need a solid financial base. There is a need for a suitable review system for investigator initiated multi-centre studies, as the current IRB system is not sufficient. There are also challenges regarding the differences, perceived or real, in treatment practice and available registrations in Japan and in the West, causing problems in choosing suitable comparators and study designs. At the present time it is not clear whether investigator initiated trials will be acceptable for registration purposes in Japan. The agreed first priority is to build a suitable and strong infrastructure within the academic community to support researchers to investigate important questions with or without pharmaceutical company support. Despite all these issues, several groundbreaking projects are under way throughout Japan, in many different areas and by different collaborative groups, some with government support. In fact, researcher-initiated clinical trials achieved a rapid growth in Japan in the past year.

Clinical Trials as Topic↗

[Predictive factors affect the choice of strategy for breast cancer surgery].

Predictive factors are those factors that predict the effects of chemotherapeutic or other agents on the tumor or the host. Many factors have been investigated for their predictive value of the effect of chemotherapeutic or hormonal agents. Estrogen or progesterone receptors are the most established predictive factors for hormonal therapy. Her-2/neu is a predictive of the effect of the monoclonal antibody trastuzumab and of certain chemotherapeutic agents. Other predictive factors remain under clinical investigation. Most cases of breast cancer are initially considered to be systemic disease. Cure can only achieved with surgery that leaves no residual cancer cells, followed by an appropriate form of systemic therapy. In the clinical situation, local therapy and systemic therapy for breast cancer have been considered independently. However, preoperative chemotherapy has become common recently. The interaction between chemotherapy and surgery should be considered because the results of preoperative chemotherapy affect the choice of operative technique. Predictive factors for the effect of radiation therapy should also be taken into account after breast-conserving surgery. It remains to be determined which predictive factors should be considered at which time.

Antineoplastic Agents, Hormonal↗

A rat model of ischemic cardiomyopathy for investigating left ventricular volume reduction surgery.

OBJECTIVE: The effects of volume reduction surgery (VRS) for ischemic cardiomyopathy are not fully understood. The development of a proper animal model will help to resolve this issue. METHODS: Study 1 (Noninvasive study): Twenty-six rats developed large akinetic left ventricular (LV) aneurysms or ischemic cardiomyopathy after anterior descending artery ligation (first surgery). Four weeks after the surgery, 13 rats underwent volume reduction surgery (second surgery) (VRS group), while 13 underwent rethoracotomy alone (sham group). Before the first surgery, and before and after the second surgery, the LV dimensions were measured by echocardiography, and the heart rate and systolic blood pressure were recorded by the tail cuff method. Study 2 (Invasive study): In 7 rats undergoing the VRS and 9 undergoing the sham operation, LV pressure was measured with a manometer-tipped catheter, immediately before and after the second surgery. RESULTS: Study 1: All rats survived the second surgery, after which LV end-diastolic diameter decreased and LV fractional shortening increased (both p < 0.001) in the VRS group. This group also increased heart rate after the second surgery (p < 0.05). Study 2: There were no differences in LV end-systolic or end-diastolic pressure between the two groups before and after the second surgery. CONCLUSIONS: This model enables reproducible physiological evaluation of the LV after VRS, and since the rats show postoperative survival, it provides a useful tool for various investigations.

Animals↗

The cytotoxicity of a conjugate composed of human epidermal growth factor and eosinophil cationic protein.

BACKGROUND: Conventional targeted therapy with foreign proteins is highly immunogenic. In this study, we developed targeted therapy composed of human endogenous proteins and evaluated its efficacy in vitro. MATERIALS AND METHODS: Human epidermal growth factor (EGF) was chemically linked to human eosinophil cationic protein (ECP). The cytotoxicity of the EGF-ECP conjugate was evaluated by MTT assay. RESULTS: The conjugate showed dose-dependent cytotoxicity on EGF receptor (EGFR)-overexpressing BT-20 cells with an IC50 of 1.5 x 10(-7) M, whereas the IC50 of ECP alone was almost 10(-4) M. The conjugate had no detectable cytotoxicity against EGF receptor-deficient H69 cells. Excess EGF protected BT-20 cells from the cytotoxicity of the conjugate. Comparing the cytotoxicity and the level of EGFR expression, the cytotoxicity of the conjugate was positively correlated with the level of EGFR expression of each cell line. CONCLUSION: Conjugates composed solely of human proteins might be useful with less immunogenicity and less toxicity than the conventional immunotoxins for targeted therapy.

Blood Proteins↗