Effects of estrogen and tamoxifen on the MAP kinase cascade in experimental rat breast cancer

The mitogen-activated protein kinase (MAPK) cascade, which includes MAPK, MAP kinase kinase (MAPKK) and Raf-l, is involved in the signal transduction of growth factor receptors. We found that the MAPK and Raf-l proteins are increased in human breast cancer. Activated MAPKK was also observed. We then investigated whether the MAPK cascade is activated when 7,12-dimethylbenz(a) anthracene (DMBA)-induced rat mammary cancer is treated with 17 beta-estradiol (E-2). Ovariectomy suppressed MAPK expression in tumors, and E-2 administration induced the activation of MAPK in ovariectomized rats. We also investigated the effects of tamoxifen (TAM) on proliferation and the MAPK cascade in DMBA-induced rat mammary cancers. Although tumor size was reduced significantly by TAM, the expression of the MAPK and Raf-l proteins did not decrease. Additionally, MAPK and Raf-l protein expression increased in tumors of ovariectomized rats given TAM, despite a reduction in the size of the tumors. These results suggest that the activated MAPK cascade is important in human breast cancer, and is an important mechanism in the estrogen-dependent growth of DMBA-induced rat mammary cancer. TAM shows E-2-antagonistic effects on tumor proliferation, and E-2-agonistic effects on the MAPK cascade.

Predicting axillary lymph node involvement in breast cancer patients by ultrasonography

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Background: About 20% of breast cancer patients eligible for sentinel node (SN) biopsy have axillary node metastases. The purpose of this study is to evaluate the sensitivity of preoperative ultrasonography (US) for SN involvement. Methods: Between October 2004 and May 2006, a total of 141 breast cancer patients without clinically node involvement were eligible for SN biopsy. The size (length and height) and cortical thickness of lymph nodes (LN) was measured by US before surgery. Results: Twenty-four (20%) of 141 patients had pathologically involved LN (Positive Group), and 118 (80%) were negative for LN metastases (Negative Group). No LN was detected in 25 patients (21%) of the negative group by US. The number of detected LN was more in the positive group than the negative group (1.59 vs 1.13, p<0.05). There was no significant difference in the size of LN between the two groups. The cortical layer of LN was thicker in the positive group than the negative group (3.11 vs 2.12, p<0.05). Eighteen patients had the LN with more than 4mm of cortical thickness, nine (50%) of which revealed pathologically LN involvement. Conclusions: The measuring of cortical thickness is useful for predicting axillary LN involvement by US. This approach may improve the selection of patients for SN biopsy.

No significant financial relationships to disclose.

Combined neoadjuvant weekly paclitaxel and trastuzumab for HER2-overexpressing breast cancer

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Background: The purpose of this study is to determine the clinical efficacy of neoadjuvant paclitaxel and trastuzumab in women with advanced breast cancer, with or without metastatic disease. Methods: Patients with HER2-positive breast cancer (clinical stage IIB-IV) were included in this study. The patients received trastuzumab 4mg/kg loading dose intravenously then 2mg/kg weekly and concurrently paclitaxel 80mg/m2 (Day 1, 8, 15) weekly for 4 cycles followed by surgery. Results: Preliminary results from 15 patients are reported. Of these, six patients (40%) had a clinical complete response and nine patients (60%) a clinical partial response. Fourteen of 15 patients received surgery; eight breast-conserving surgery and six modified radical mastectomy. Six patients (43%) had pathological complete response. With a median follow-up of 19 months (range, 5–32 months), these 15 patients are alive. Patients with clinical stage IIB-III breast cancer are alive without any distant metastasis. Conclusion: Combined neoadjuvant weekly paclitaxel and trastuzumab had high clinical and pathological response rates for HER2 overexpressing breast cancer.

No significant financial relationships to disclose.

Effects of rainfall on the occurrence of human adenoviruses, total coliforms, and Escherichia coli in seawater

A two-month survey was conducted in order to evaluate the effects of rainfall on the fate of microorganisms in seawater in the Tokyo Bay, Japan. The seawater sample (1,000 mL) was applied to a method to concentrate virus, followed by a quantification of human adenoviruses using the real-time PCR. Total coliforms and E. coli, which were determined by the colony forming method, were detected in all 47 seawater samples, while human adenoviruses were detected in 38 (81%) of the samples. The concentration of tested microorganisms showed 1-2 log units increase after rainfall events, followed by the gradual decrease to the level before the rainfall within a few days.

Dynamic changes in environment condition and microbial community structure in trench and flat seabed sediments of Tokyo Bay, Japan

Dynamic changes in the chemical environment in the bottom of overlying water and microbial community structure in trench and flat seabed sediments were evaluated during summer and autumn in Tokyo Bay, Japan, to elucidate the response of microbial community changes as a consequence of dredging activity. Quinone profile analysis was performed to evaluate the changes in microbial community structure in the sediments. Bottom shape and location of each station affected the chemical environment of the overlying water. The trench bottom shape had longer anoxic conditions than the flat bottom shape. Nitrogen and phosphorus concentrations affected the microbial density in the sediment. During anoxic conditions, the ubiquinone/menaquinone ratio (UQ/MK) was less than unity and increased with rising dissolved oxygen (DO) concentrations. The dominant quinone species in the trench and flat seabed sediments were MK with 6 and 7 isoprene units (MK-6 and MK-7) and UQ with 8 and 9 isoprene units (UQ-8 and UQ-9). MK-6 and UQ-8 containing bacteria might have a great influence on the sulfur cycle of the aquatic ecosystem. While, MK-7 and UQ-9 containing bacteria correlated with the deposition of phototropic bacteria cells onto the seabed sediment. The trench bottom shape contained higher concentrations of MK-6, MK-7, UQ-8 and UQ-9, especially during summer.

Predictive value of estrogen receptor status as assessed by ligand-binding assay in patients with early-stage breast cancer treated with breast conserving surgery and radiation therapy

It is important to determine which factors are predictive for the prognosis of patients treated with breast conserving surgery (BCS) and radiation therapy (RT) in order to make a decision as to the adjuvant treatment. Although estrogen receptor (ER) is known to be a predictive marker for antiestrogens in breast cancer, the prognostic effect of hormone receptors has not been fully analyzed in Japanese breast cancer patients treated with BCS and RT. A total of 153 breast cancer patients having up to three positive nodes in the axilla as identified histologically and treated with both BCS and RT with or without systemic therapy were enrolled in this study. All tumors were measured for ER and progesterone receptor (PR) using ligand-binding assay (LBA). ER was inversely related to patients' age, however, PR was not related to any clinical features. When ER was classified into negative, weakly positive and strongly positive categories, with cut-off levels of zero and 50 fmol/mg protein, the relapse-free survival (RFS) was significantly better in patients with tumors having strongly positive ER than in patients with tumors having negative ER. Multivariate analysis revealed that ER as well as nodal status, was an independent predictive factor for RFS, however, PR was not. As a result, we believe that ER measured by LBA is valuable for predicting prognosis of early-stage breast cancer patients treated with BCS and RT.

Prognostic significance of dihydropyrimidine dehydrogenase expression in breast cancer

We have investigated dihydropyrimidine dehydrogenase expression as a prognostic marker in breast cancer. A total of 119 women with breast cancer undergoing surgery between 1985 and 1996 were included in this study. Eighty-seven patients were treated with postoperative chemotherapy including 5-fluorouracil or 5-fluorouracil derivatives. Fifty-nine (50%) of 119 patients were determined to be immunostaining-positive for dihydropyrimidine dehydrogenase. There was no significant difference between dihydropyrimidine dehydrogenase staining and tumour size, lymph node status, clinical stage, oestrogen receptor status, histologic grade, or 5-fluorouracil administration. When evaluated in patients treated with 5-fluorouracil or 5-fluorouracil derivatives, patients with dihydropyrimidine dehydrogenase-positive tumours had a significantly (P<0.05) poorer disease-free survival compared to those with dihydropyrimidine dehydrogenase-negative tumour. No conclusion can be drawn about the prognostic impact of dihydropyrimidine dehydrogenase status in patients who were not treated with 5-fluorouracil regimes due to the small number of such cases in this series. Lymph node and dihydropyrimidine dehydrogenase status were independent prognostic factors for disease-free survival, and lymph node status for overall survival using multivariate analysis. In conclusion, dihydropyrimidine dehydrogenase is a possible prognostic factor in patients with breast cancer treated with 5-fluorouracil or 5-fluorouracil derivatives.

Recurrence of breast cancer following local excision alone for ductal carcinoma in situ

OBJECTIVE

To assess recurrence of breast cancer following local excision alone for ductal carcinoma in situ.

METHODS

Eighteen patients who received complete resection for noninvasive ductal carcinoma between 1982 and 1997 were investigated in this study. The mean age of the patients was 45 (29-78) years old. The initial presentation was a clinically palpable tumor in 4 patients, nipple discharge in 6, and microcalcification on mammograms in 8. Patients with palpable tumor underwent wide excision with at least a 2-cm free margin. Patients whose mammograms showed microcalcification underwent lumpectomy, and those who showed nipple discharge underwent duct-lobular segmentectomy. Five patients who underwent lymph node dissection up to level I or II had no lymph node metastasis. The mean follow-up period was 86 months.

RESULTS

Local recurrence in the conserved breast was seen in five (27.8%) of 18 patients. The actuarial five-year event-free survival was 76.2%. The histological type of the recurrent tumor was ductal carcinoma in situ in three patients and invasive carcinoma in two. There was no difference in age at initial operation or histological subtype between patients with and without recurrent disease, but patients presenting with nipple discharge initially had a significantly shorter ipsilateral disease-free interval than those presenting with tumor or microcalcification on mammograms. All patients with local recurrence in the conserved breast were treated with breast-conserving surgery or subcutaneous mastectomy.

CONCLUSION

Local recurrence frequently occurs in patients presenting with nipple discharge treated by duct-lobular segmentectomy for noninvasive ductal carcinoma. Either wide excision with a larger free margin or adjuvant radiation therapy following duct-lobular segmentectomy should be considered for these patients.

A comparative study of subcutaneous mastectomy with radical mastectomy

The purpose of this study was to compare the results of 133 cases (131 patients) of subcutaneous mastectomy with axillary dissection between 1983 and 1999 and 910 cases of radical mastectomy during the same period. The median follow-up period of the subcutaneous mastectomy group and the radical mastectomy group were 66 months and 81 months, respectively. The age at operation was significantly (p<0.01) younger in the subcutaneous mastectomy group than in the radical mastectomy group and the clinical stage was significantly (p<0.01) earlier. Lymph node metastasis was significantly (p<0.01) higher in the radical mastectomy than in the subcutaneous mastectomy group. There was no difference in ER status between the two groups. There was local recurrence in 5 (3.8%) members of the subcutaneous mastectomy group and in 12 (1.3%) members of the radical mastectomy group. There was no difference in disease-free survival and overall survival between the two groups. Divided into two subgroups by lymph node status, there was no difference in disease-free survival and overall survival between the two groups. Local recurrence occurred more frequently (p<0.05) in the subcutaneous mastectomy group, however, than in the radical mastectomy group when no lymph node metastasis was found. Multivariate analysis using the Cox hazard model showed that operation method and lymph node status were independent prognostic factors for local recurrence, whereas, lymph node status and ER status were independent prognostic factors of disease-free survival. In conclusion, subcutaneous mastectomy presents a risk factor for local recurrence, but the survival rate of the subcutaneous mastectomy group is as favourable as the radical mastectomy group.

Effects of a dual inhibitor of tumor necrosis factor-alpha and interleukin-1 on lipopolysaccharide-induced lung injury in rats: involvement of the p38 mitogen-activated protein kinase pathway

OBJECTIVE

Sepsis is a major cause of adult respiratory distress syndrome. In this study, we evaluated the effect of FR167653, which is a potent suppressant of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 production, on lipopolysaccharide (LPS)-induced lung injury and lethality in rats, and we examined the involvement of p38 mitogen-activated protein (MAP) kinase in the action of FR167653.

DESIGN

Prospective, randomized study.

SETTING

Animal research facility in a university.

SUBJECTS

Male Sprague-Dawley rats weighing 200-270 g.

INTERVENTIONS

All the animals were assigned to one of the following four groups: control group, FR-only group, LPS-only group, and LPS/FR group. Animals in the LPS-only and LPS/FR groups received 6 mg/kg of LPS intravenously. The animals in the FR-only and LPS/FR groups also received an infusion of FR167653 at 0.2 mg x kg(-1) x hr(-1), commencing 30 mins before the LPS (or vehicle) injection and continuing for 5.5 hrs.

MEASUREMENTS AND MAIN RESULTS

LPS significantly induced the accumulation of pulmonary neutrophils and lung edema, both of which were significantly attenuated by treatment with FR167653. FR167653 also significantly decreased the LPS-induced lethality. Histologically, tissue damage was milder in the LPS/FR group than in the LPS-only group. Serum concentrations of TNF-alpha and IL-1beta and plasma concentrations of thromboxane B2 were all suppressed in the LPS/FR group compared with the LPS-only group. Western blot analysis revealed that FR167653 inhibited the phosphorylation of p38 MAP kinase in lung tissues.

CONCLUSIONS

FR167653 administration decreased serum TNF-alpha and IL-1beta concentrations, which was associated with decreased lung injury and lethality. The mechanism responsible for the decreased TNF-alpha and IL-1 may be related to the inhibitory effect of FR167653 on p38 MAP kinase activation.

Tamoxifen-failed male breast cancer with a high level of circulating estrogen: report of a case

We report herein the case of a 40-year-old man with grade II invasive ductal carcinoma of the breast (pT1, pN0, M0: stage I) in whom a recurrence developed shortly after completion of a 2-year course of tamoxifen and 5-fluorouracil therapy following a mastectomy. Although the metastatic tumor was estrogen receptor-positive, hormone therapy combined with chemotherapy had no significant effect on tumor growth, and the patient died from disseminated tumors 2 years 6 months after completion of the adjuvant therapy. It is noteworthy that the circulating estradiol level increased from 18.0 to 892.3 pg/ml during the period of tumor progression and dissemination. We interpret these findings as an indication of high aromatase activity in the metastatic tumors. We suggest that extending tamoxifen treatment to 5 years or longer be recommended for the standard adjuvant hormone therapy of male breast cancer to prevent the early recurrence of hormone-responsive disease.

Effect of a combined administration of 5-fluorouracil and medroxyprogesterone acetate on pyrimidine nucleoside phosphorylases and thymidylate synthetase in 7,12-dimethylbenz

The effect of a combined therapy of medroxyprogesterone acetate (MPA) and 5-fluorouracil (5-FU) on tumor size, pyrimidine nucleoside phosphorylase (PyNPase) activity, and thymidylate synthetase (TS) activity was examined in Sprague-Dawley (SD) rats with 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumors. MPA augmented the antitumor activity of 5-FU and protected against body weight-loss due to 5-FU administration. PyNPase activity of both the MPA group and the MPA+5-FU group tended to increase compared with that of the 5-FU alone group. TS inhibition levels in the MPA+5-FU group tended to increase compared with those in the 5-FU alone group. These results indicate that MPA tended to augment antitumor activity of 5-FU and to reduce the side effects caused by 5-FU.

FR167653 attenuates ischemia and reperfusion injury of the rat lung with suppressing p38 mitogen-activated protein kinase

BACKGROUND

FR167653 is a potent suppressant of tumor necrosis factor (TNF)-alpha and interleukin-1 (IL-1) production, and was shown to attenuate ischemia and reperfusion (I/R) organ injury in our previous experiment. Because p38 mitogen-activated protein (MAP) kinase has been reported to regulate the production of TNF-alpha and IL-1, we examined the effects of FR167653 in the rat lung I/R model and determined the expression and activation of p38 MAP kinase.

METHODS

Experiment 1: After 1 hour of ischemia, p38 MAP kinase, phosphorylated p38 MAP kinase (active form), histologic changes of the lung, and serum levels of TNF-alpha and IL-1beta were examined. Experiment 2: After 2 hours of reperfusion, arterial oxygen content (PaO(2)) and saturation (SaO(2)), serum TNF-alpha and IL-1beta levels, and histologic changes in the lung were examined. Rats were divided into three groups in Experiment 1. In the control group, a saline solution was administered and, in the FR group, 0.1 mg/kg per hour of FR167653 was administered, intravenously throughout the experiment, beginning 30 minutes before ischemia. In the non-ischemic group, samples were taken soon after thoracotomy. The rats were divided into control and FR groups in Experiment 2.

RESULTS

Experiment 1: One hour of ischemia induced almost no changes in the lung or serum cytokine levels. Meanwhile, FR167653 markedly attenuated the expression of phosphorylated p38 MAP kinase. Experiment 2: SaO(2) and PaO(2) were improved, serum cytokines were lower, and lung damage was less extensive in the FR group than in the control group.

CONCLUSION

FR167653 attenuates I/R injury of the lung and this attenuation is associated with suppression of p38 MAP kinase activation.

Serum concentration of pyridinoline cross-linked carboxyterminal telopeptide of type I collagen in patients with metastatic breast cancer

The serum concentration of pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP) was examined in 83 patients with metastatic breast cancer. ICTP levels were significantly higher in patients with bone metastases than in those without bone metastasis. In patients with bone metastasis, significantly higher ICTP levels were observed in those with multiple lesions than in those with a solitary lesion and these levels reflected therapeutic response. Sequential monitoring of ICTP revealed that this elevation was correlated with disease progression. Combined with imaging studies, monitoring of ICTP appears to offer additional information for detection of bone metastasis and evaluation of therapeutic response to bone metastasis.

Highest microvessel count as a long-term prognostic factor in Japanese breast cancer patients

The aim of this study was to determine whether microvessel density (MVD) could add useful information in predicting the prognosis of breast cancer patients. In our study, MVD was calculated by counting microvessels per x200 field in the highest neovascularized area of the tumor (highest microvessel count, HMC). HMC significantly increased according to the increased number of positive nodes. Higher HMC significantly correlated with worse relapse-free survival (RFS) of patients with negative node, one to three positive nodes in the axilla or with stage I and II tumors. HMC, however, was not predictive for RFS of patients with four or more positive nodes or with stage III tumors. Multivariate analysis revealed that HMC was second only to nodal status and tumor size as being predictive for RFS. These results suggest that HMC could be used in selection of patients with early-stage breast cancer who are at high risk for having occult metastasis.

Primary squamous cell carcinoma of the breast during lactation: a case report

A case of primary squamous cell carcinoma of the breast during lactation is reported. The patient was a 32-year-old woman, in post-partum lactating 18 months after delivery, who was referred to our hospital following detection of a lump in her left breast during physical examination in mass screening for breast cancer. The tumor, palpated in the upper outer quadrant of the left breast, was firm, well-defined and 2.8 x 2.6 cm in size. Ultrasonograms identified an irregular-shaped hypoechoic lesion and mammograms revealed a well-defined, circumscribed tumor. Based on these findings, breast cancer was suspected and an excisional biopsy was performed. The resected specimen was a firm, solid and circumscribed tumor with central hemorrhage. Microscopic findings demonstrated that the tumor consisted of an invasive ductal carcinoma with marked squamous metaplasia, such as keratinization and squamo-columnar junction. Breast-conserving surgery was performed and no lymph node involvement was noted. Both estrogen and progesterone receptors of the tumor were negative. Generally, the size of both squamous cell carcinoma and carcinoma during the lactation period tends to be larger than ordinary carcinomas. In this case, the cancerous lesion was detected at a relatively early stage. Although the cancerous lesion was detected at a relatively early stage and no lymph node involvement was noted, lung metastases occurred within 12 months of the surgery. Malignant potential is generally considered to be high in cases of squamous cell carcinoma of the breast with lactation and thus intensive treatment potentially resulting in severe side effects was considered to be necessary for this patient.

The effect of FR167653 on pulmonary ischemia-reperfusion injury in rats

BACKGROUND

A novel synthesized organic compound, FR167653, has been characterized as a potent suppressant of interleukin-1 and tumor necrosis factor-alpha. We designed this experimental study to evaluate the effect of FR167653 on ischemia-reperfusion injury of the rat lung.

METHODS

Following general anesthesia, the left bronchus, pulmonary artery and vein were clamped for 1 hour. FR167653 was administered continuously beginning 30 minutes before the onset of ischemia and extending for 2 hours after reperfusion. Thirty-eight Wistar rats were divided into 4 groups according to the dose of FR167653 at the rate of 0.1, 0.05 and 0.025 mg/kg/hr in each group. After the optimal dose was obtained from the result of 1-week survival rate, the group with the optimal dose was compared with a control group by using such parameters as arterial oxygen saturation (SaO(2)), arterial oxygen tension (PaO(2)), cytokines, the expression of p38 MAP kinase and histologic study.

RESULTS

Survival rate of the group received FR at the rate of 0.1 mg/kg/hr (FR0.1 group) was best among the 4 groups. SaO(2) levels and PaO(2) levels after 2-hour of reperfusion were significantly (p < 0.05, respectively) higher in the FR0.1 group than in the control group. After 2-hour reperfusion, IL-1 beta was lower in the FR0.1 group than in the control group, and the expression of p38 MAP kinase was reduced in the FR0.1 group compared with the control group. In histologic study after 2-hour of reperfusion, alveolar damage with edema and interstitial thickening localized along the alveolar duct were observed in the control group, whereas these findings were remarkably less evident in the FR0.1 group.

CONCLUSIONS

We concluded that FR167653 ameliorates ischemia-reperfusion injury of the lung and may inhibit the production of proinflammatory cytokines by means of the inhibition of p38 MAP kinase.

Immunohistochemical study on primary and recurrent tumors in patients with local recurrence in the conserved breast

One hundred and seventy patients received breast-conserving therapy in the Second Department of Surgery, Gunma University School of Medicine. Six (3.5%) out of the 170 patients showed breast recurrence. We investigated the breast recurrent cases clinicopathologically. The age at the initial operation ranged from 38 to 78 (mean 57) years. One patient was clinical stage I and the others were clinical stage II. Surgical margin at the initial operation was negative in two patients and positive in four. Histological type was invasive ductal cancer in all cases. Three patients had lymph node involvement. The interval from the initial operation to breast recurrence ranged from 19 to 68 months. Five cases were nodular type and one was diffuse type of breast recurrence. Histological type of breast recurrence was the same as the initial one. We performed salvage surgery for all breast recurrent patients, mastectomy for four patients and local resection for two. One patient who showed diffuse type of recurrence could not be controlled with any surgical treatment, and later died of breast cancer. We investigated the expression of estrogen receptor, progesterone receptor, pS2, c-erbB-2 and p53 on both initial and recurrent specimens of the six patients. The expression of each protein on the recurrent specimens was the same as the initial one. We conclude that breast recurrence after breast-conserving therapy has its origin in the residue of cancer cells at the initial operation, even if surgical margins are histopathologically negative.

Regulation of estrogen receptor and epidermal growth factor receptor by tamoxifen under high and low estrogen environments in MCF-7 cells grown in athymic mice

The purpose of this study was to investigate whether tamoxifen (TAM) treatment causes a downregulation of estrogen receptor (ER) and whether TAM induces epidermal growth factor receptor-1 (EGFR). We investigated the expression of ER and EGFR after the treatment of TAM in MCF-7 tumors grown in athymic mice under high and low estrogen environments. MCF-7 tumors were grown in ovariectomized athymic mice by implanting a sustained release 17beta-estradiol (E2) pellet. The E2 pellets were removed after 3 weeks of E2 treatment. Animals were then divided into the following 4 groups: i) an E2 (0. 72 mg/pellet) pellet [E2(+)]; ii) an E2 and a TAM (5 mg/pellet) pellets [E2(+)TAM]; iii) no treatment [E2(-)]; iv) a TAM pellet [E2(-)TAM]. A significant reduction in tumor size was observed in the estrogen-depleted group [E2(-) and E2(-)TAM] compared with the estrogen-completed group [E2(+) and E2(+)TAM]. TAM inhibited estrogen-stimulated growth in the estrogen-completed mice. No additional reduction of the tumor by TAM was observed in the estrogen-depleted mice. Both ER and EGFR protein levels in the tumors of the estrogen-depleted mice were higher than in the estrogen-completed mice. Expression of ER and EGFR protein was increased by TAM in the estrogen-completed mice, however it was decreased by TAM in the estrogen-depleted mice. Changes of ER and EGFR protein levels were similar in all treatments. Transforming growth factor-alpha (TGF-alpha) in tumors, which is known as a ligand of EGFR and as an estrogen-inducible protein in ER positive MCF-7 cells, was decreased by TAM in the estrogen-completed mice, by contrast, it was increased by TAM in the estrogen-depleted mice. Downregulation of ER was observed in TAM-treated mice in an estrogen-depleted environment, this action of TAM was similar to E2. These results suggest that increase of EGFR expression does not lead to a loss of ER after short-term TAM treatment in MCF-7 tumors.

Increased choline kinase activity in 1,2-dimethylhydrazine-induced rat colon cancer

Cancer cells acquire particular characteristics that benefit their proliferation. We previously reported that human colon cancers examined had increased choline kinase activity and phosphocholine levels. The elevated phosphocholine levels were in part due to both activation of choline kinase and increased choline kinase alpha protein levels. In this report, we analyzed choline kinase, which catalyzes the phosphorylation of choline to produce phosphocholine, in rat 1,2-dimethylhydrazine (DMH)-induced colon cancer. This study is the first to demonstrate increased choline kinase alpha enzymatic activity, protein levels, and mRNA levels in DMH-induced colon cancer as well as human colon cancer, although phosphocholine was not increased in DMH-induced rat cancer. The increase in the mRNA level was partly due to an increase in the transcription of the choline kinase alpha gene. The increased choline kinase activity may be a specific characteristic acquired by cancer cells that benefits their proliferation.

Mitogen-activated protein kinase cascade in breast cancer

The mitogen-activated protein (MAP) kinase is considered to play a central role in diverse cellular events including carcinogenesis and tumor progression. Indeed, expression of MAP kinase, tyrosine-phosphorylated MAP kinase, and Raf-1 protein was greater in cancerous human tissues than in the surrounding noncancerous glands. In a 7,12-dimethylbenz[a]anthracene-induced rat mammary carcinoma model, estrogen promoted and ovariectomy and antiestrogen, tamoxifen (TAM) inhibited the tumor growth. Ovariectomy suppressed expression of MAP kinase, tyrosine-phosphorylated MAP kinase and Raf-1, whereas estrogen as well as TAM induced expression of MAP kinase and Raf-1 under castrated conditions. Since it was reported that MAP kinase was activated during the progression of breast carcinoma cells, such estrogenic actions of TAM toward the MAP kinase cascade might be responsible for malignant progression.

The mechanisms of antitumor effects of luteinizing hormone-releasing hormone agonist (buserelin) in 7, 12-dimethylbenz(a)anthracene-induced rat mammary cancer

We evaluated the mechanism of antitumor effects of buserelin, which is one of LH-RH agonists, on a hormone dependent breast cancer model, using 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary cancer. Rats developing solid mammary tumors within 5-7 weeks following the DMBA administration were divided into groups weekly, and treated without delay. The tumor bearing rats were randomized into five groups with regard to tumor size or average weight (15 rats per group). Each group received one of the following treatments during 4 weeks: a) no treatment (NT); b) ovariectomy (Ovx); c) buserelin; d) Ovx and 17beta-estradiol (E2) (Ovx+E2); e) Ovx+E2+buserelin. Tumor regression immediately began at one week after both buserelin treatment and ovariectomy. A significant reduction of tumor size was observed in both buserelin-treated rats and Ovx rats compared with NT rats (p<0.01). No significant difference of tumor size was observed between buserelin-treated rats and ovariectomized rats. No reduction of tumor size was observed in Ovx+E2 rats and Ovx+E2+buserelin rats. Although the mean uterine wet weight of the buserelin group was significantly higher than that of the Ovx group, it was significantly lower than that of the NT group. The mean uterine wet weight of the NT group, the Ovx+E2 group and the Ovx+E2+buserelin group was similar and was significantly higher than that of the Ovx group. Buserelin did not inhibit exogenous estrogen-dependent tumor growth in DMBA-induced rat mammary cancers. These results suggest that buserelin has no direct effects on DMBA-induced rat mammary cancers, and the main mechanism of action of buserelin for tumor-reduction is due to ovarian estrogen deficiency.

A case control study on the effectiveness of breast cancer screening by clinical breast examination in Japan

A case-control study was conducted in Miyagi and Gunma prefectures, Japan, to evaluate the effectiveness of breast cancer screening by clinical breast examination (CBE) alone in reducing breast cancer mortality. Case subjects, who were female and had died of breast cancer, were collected from residential registry files and medical records. Control subjects matched in sex, age and residence were randomly selected from residential registry files. The screening histories during 5 years prior to the cases having been diagnosed as breast cancer were surveyed using the examinee files of the screening facilities. Finally, the data of 93 cases and 375 controls were analyzed. The odds ratio (OR) of breast cancer death for participating in screening at least once during 5 years was 0.93 (95% confidence interval (95% CI) 0.48-1.79). The cases were more symptomatic than the controls when screened. If the participants who had had symptoms in their breasts were classified as not screened, the OR decreased to 0.56 (95% CI 0.27-1.18). The case control study suggests that the current screening modality (CBE) lacks effectiveness (OR = 0.93), although it might be effective for an asymptomatic population (OR = 0.56). The number of cases was small, and a larger case-control study is desirable to define whether CBE is effective or not. However, it is necessary to consider the introduction of mammographic screening to reduce breast cancer mortality in Japan.

Effects of interferon-alpha on cellular proliferation and adhesion of breast carcinoma cells

We examined the potent inhibitory effects of interferon-alpha (IFN-alpha) on both cellular adhesion and cell proliferation of MCF-7 breast carcinoma cells. When MCF-7 cells were exposed to IFN-alpha at a concentration of 5x10(3) IU/ml for 5 days, cell proliferation was markedly inhibited. Cell attachment assay demonstrated that incubation with IFN-alpha for up to 48 h reduced alpha2beta1 integrin-mediated cellular adhesion. However, fluorescence activated cell sorter (FACS) analysis revealed that incubation with IFN-alpha for 24 h had no effect upon the cell surface expressions of either alpha2 and beta1 integrin on MCF-7 cells. These antiproliferative and antiadhesive actions of IFN-alpha may be applied to treatment for patients with metastatic breast carcinoma.

The efficacy of technetium-99m-MIBI scan and intraoperative methylene blue staining for the localization of abnormal parathyroid glands

The efficacy of the technetium-99m-2-methoxyisobutylisonitrile (Tc-MIBI) scan and intraoperative methylene blue staining was analyzed in a consecutive series of 15 patients with primary hyperparathyroidism who underwent neck surgical exploration. A total of 17 abnormal parathyroid glands were removed, 7 of which were confirmed histologically as adenomas and 10 as hyperplasias. The Tc-MIBI scan and the thallium-201-technetium-99m subtraction (Tl/Tc) scan preoperatively localized 11 (69%) of 16, and 6 (40%) of 15 abnormal parathyroid glands, respectively. The Tc-MIBI scan correctly localized two ectopic abnormal parathyroid glands which were not localized by the Tl/Tc scan or ultrasonography (US). However, it also demonstrated false-positive accumulations caused by thyroid diseases in two patients. There were 4 abnormal parathyroid glands not detected by the preoperative imaging techniques, whereas all 17 abnormal parathyroid glands were stained with methylene blue, the infusion of which caused no adverse effects or toxicity. In conclusion, Tc-MIBI scanning and intraoperative methylene blue staining are effective techniques for the localization of abnormal parathyroid glands in patients with primary hyperparathyroidism.

Increased choline kinase activity and elevated phosphocholine levels in human colon cancer

Nuclear magnetic resonance spectroscopy has detected elevated phosphocholine levels in human tumor tissues and cells, and in cells that were transformed with the activated Ha-ras gene and stimulated in vitro with growth-promoting factors such as platelet-derived growth factor, epidermal growth factor, and phorbol ester. However, the mechanism of the elevation and the function of the increased phosphocholine levels have not been clearly demonstrated. We studied phosphocholine levels enzymatically and analyzed the activity of choline kinase, which catalyzes the phosphorylation of choline to produce phosphocholine, in human colon cancer and adenoma. Both choline kinase activity and phosphocholine levels were increased in colon cancer and adenoma tissue. The activation of choline kinase and the increased levels of choline kinase alpha were partly responsible for the elevated phosphocholine levels. This study suggests that choline kinase might play a role in growth promotion or signal transduction in carcinogenesis.

Antitumor effect of 22-oxacalcitriol on estrogen receptor-negative MDA-MB-231 tumors in athymic mice

The purpose of this study was to evaluate the usefulness of 22-oxacalcitriol (OCT) in the treatment of estrogen receptor (ER)-negative breast cancer. The antitumor effect of this agent and its effect combined with doxifluridine (5'-DFUR) on MDA-MB-231 tumors in female athymic mice were investigated. We also examined the effect of OCT on the expression of vascular endothelial growth factor (VEGF) which had been reported to generate angiogenesis in tumors. OCT significantly suppressed the growth of tumors without inducing hypercalcemia in a dose dependent manner. The effect of OCT combined with 5'-DFUR did not exceed the effect of a single agent therapy. The expressions of VEGF analyzed by enzyme-linked immunosorbent assay were significantly decreased in the OCT-treated group. These results suggest that OCT may partially suppress tumor growth by inhibiting neovascularization and it would likely have positive application as a treatment of ER-negative breast cancer.

A novel aromatase inhibitor, vorozole, shows antitumor activity and a decrease of tissue insulin-like growth factor-I level in 7, 12-dimethylbenz[a]anthracene-induced rat mammary tumors

Effects of vorozole, a potent and specific non-steroidal aromatase inhibitor, were evaluated on female Sprague-Dawley (SD) rats with 7, 12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumors. Vorozole at a dose of 0.25, 1.0 and 4.0 mg/kg was orally administered once a day for 28 consecutive days. A significant regression in tumor size was observed in each treated group at 1, 2, 3 and 4 weeks after the start of treatment compared with control group. Tissue insulin-like growth factor I (IGF-I) in the DMBA-induced tumors in each treated group significantly decreased in a dose-dependent fashion compared with control group. These results show the mechanism of vorozole in DMBA-induced rat mammary tumors.

Expression and possible functional role of the beta3-adrenoceptor in human and rat detrusor muscle

PURPOSE

To investigate the presence of the beta3-adrenoceptor (beta3-AR) in human and rat detrusor muscle and the usefulness of beta3-AR agonists as drugs for the treatment of urinary frequency.

MATERIALS AND METHODS

FK175, ethyl [(S)-8-[(R)-2-(3-chlorophenyl)-2-hydroxyethylamino]-6,7,8,9-tetrah ydro-5H-benzocyclohepton-2-yloxy]acetate monohydrochloride monohydrate, was used as a beta3-AR selective agonist. The expression of beta-AR subtypes (beta1-, beta2-, beta3-AR) mRNA was investigated in rat and human detrusor muscle by RT-PCR. Beta3-AR agonist induced cyclic AMP (cAMP) levels were measured in rat detrusor muscle strips. The relaxation response produced by a beta3-AR agonist was measured in a KCl induced tonic contraction model in rat detrusor muscle strips. The effect of a beta3-AR agonist on urinary bladder function was investigated by cystometry using a conscious rat model of urinary frequency.

RESULTS

beta3-AR mRNA was substantially expressed in both rat and human detrusor muscles. The beta3-AR agonist, FK175 (10(-7) M), increased the cAMP level by 30% in rat detrusor muscle. In isolated rat detrusor muscle strips contracted with KCl, the beta3-AR agonist, FK175 (10(-8) to 10(-4) M), produced a concentration-dependent relaxation. Moreover, although the relaxation induced with FK175 was blocked by the non-selective beta-AR antagonist, bupranolol, it was unaffected by ether the beta1-AR selective antagonist, CGP 20712A, or the beta2-AR selective antagonist, ICI 118551, suggesting that FK175 induced the relaxation via the beta3-AR. Furthermore, in the rat model, the orally administered beta3-AR agonist, FK175 (10 mg./kg.) significantly increased bladder capacity with no change of micturition pressure or threshold pressure.

CONCLUSIONS

These results suggest that beta3-AR agonists may be effective in the treatment of urinary frequency.

Natural history of fibroadenomas based on the correlation between size and patient age

BACKGROUND

Several recent studies have reported that most fibroadenomas remain static or regress when they are managed conservatively; however, no such studies have evaluated the breast disorder in Japanese women. To understand the natural history of fibroadenomas in Japanese women, we examined the correlation between the sizes of the fibroadenomas and the women's age.

METHODS

Fifty-eight consecutive patients (age range, 17-51 years; mean, 33.9 years) with histologically confirmed fibroadenoma were enrolled in this study. The sizes of the excised fibroadenomas were analyzed in relation to the women's ages.

RESULTS

The fibroadenomas decreased significantly in size (Y, mm) with patient age (X, years) (P = 0.0012) according the equation Y = -0.340X + 27.0 (95% confidence limits for the slope, -0.139 to -0.540). From this equation, the mean sizes of the fibroadenoma in women aged 20, 30 and 40 years were expected to be 20.2 mm (95% confidence interval, 16.2-24.2 mm), 16.8 mm (95% confidence interval, 10.8-22.8 mm) and 13.4 mm (95% confidence interval, 5.4-21.4 mm), respectively. The mean annual decrease in the size of the fibroadenomas was 0.340 mm.

CONCLUSIONS

Our results indicate that in Japanese women fibroadenomas increase in size more frequently in younger than in older women. Moreover, it is speculated that most fibroadenomas might stop growing when they reach an approximate maximum diameter of 20 mm, after which time they might remain static or regress.

Efficacy of mammography for detecting early breast cancer in women under 50

Screening mammography (MMG) for women aged 50 years and older has been widely accepted all over the world. However, the efficacy of screening mammography for women aged under 50 years has not been established. We compared mammographic findings of the patients under age 50 (the younger group) and those of patients 50 and older (the older group). From 1992 to 1997, 107 patients with early breast cancer (non-invasive and Stage I) were treated in our hospital. There was no difference between the groups in background. Of 53 patients in the younger group, 40 (75.5%) were diagnosed as having cancer using mammography, while 44 of 54 (81.5%) of the older group were diagnosed as having cancer. A total of 46 (86.8%) patients in the younger group were diagnosed using MMG and physical examination (PE), and 50 (92.6%) in the older group were diagnosed as cancer using MMG and PE. There was no difference in the successful diagnosis rate using mammography in the two groups. Breast cancer screening using MMG may also be useful for women aged under 50.

Local resection after breast-conserving therapy

We analyzed the results of local re-excision after radiation therapy on seven patients with positive surgical margins at the initial breast-conserving surgery. The age of the patients ranged from 30 to 55 years, and the tumor sizes from 1.1 to 4.7 cm. Both estrogen receptor and progesterone receptor status were positive in two patients, negative in four, and unknown in one. Pathological examination revealed residual carcinoma in one (14.3%) of seven patients. The immunohistochemical results of the initial specimen were estrogen receptor-positive, c-erbB-2-positive, and Bax-negative. We performed local re-excision after radiation therapy and found only one incidence of residual carcinoma in the conserved breast.

Inhibitory effects of an antiestrogen, toremifene, on the phorbol ester-induced adhesive capacity of breast carcinoma cells

Previous studies have revealed that protein kinase C (PKC) is responsible for malignant progression. In the present study, we investigated the potent inhibitory effects of an antiestrogen, toremifene, on PKC-mediated cellular adhesion. A phorbol ester, phorbol 12-myristate 13-acetate (PMA), significantly enhanced alpha2beta1 integrin-dependent adhesion of MCF-7 breast carcinoma cells. This PMA-induced adhesion was partially inhibited by incubating cells with toremifene prior to PMA exposure in a time- and dose-dependent manner. FACS analysis demonstrated that the PMA-induced alpha2beta1-dependent cellular adhesion was accompanied with elevated expression of alpha2beta1+integrin subunit on the cell surface. However, toremifene did not affect the elevated expression levels of these integrins but rather the avidity of alpha2beta1 integrin. We concluded that toremifene inhibited cellular adhesion activated by PMA, probably through mechanism which inhibits PKC.

Age-dependent characteristics of screen-detected patients with breast cancer

A consecutive series of 128 breast cancer patients detected by breast screening were enrolled in this study to analyze their age-dependent characteristics. They were classified into three groups; 40 years or less (young): 26 patients, 41-55 years (middle-aged): 67 patients and 56 years or over (old): 35 patients. The percentage of patients who had noticed breast abnormality by self-examination at the time of the breast screening increased from the young patients to the old without statistical significance. Nonpalpable breast cancer was more frequently (p < 0.05) observed in the young patients or the middle-aged rather than the old patients. The incidence of noninvasive carcinoma decreased from the young patients to the old without statistical significance. Decreased survival was seen in older patients rather than younger patients, without statistical significance. As a result, prognostic features were more favorable in patients aged 40 years or less than the other. Women aged 35-40 years should be recommended to attend breast screening.

Serum concentration of hepatocyte growth factor in patients with metastatic breast cancer

The serum concentration of hepatocyte growth factor (HGF) was examined in 34 patients with metastatic breast cancer. Although no significant difference was observed between HGF concentration and the site of metastasis, serum HGF levels were slightly higher in patients with liver metastasis and in patients with multiple metastatic sites than in patients with other lesions. Significantly higher levels of serum HGF were observed in patients with progressive metastasis of breast cancer compared with those with stable metastasis. The patients with high HGF levels exhibited a significantly shorter survival rate than those with low HGF levels. Circulating HGF levels may be a useful indicator for the progression of metastatic lesions and the prognosis of patients with metastatic breast cancer.