Clinical correlations and prognostic relevance of tissue angiogenic factors in patients with gastric cancer.

AIMS: To evaluate the relationship between vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) levels in gastric cancer tissue and clinicopathological features and to determine whether these factors were correlated with survival. MATERIALS AND METHODS: We analysed tissue samples from 58 patients with gastric cancer and used 24 normal gastric mucosae as controls. Tissue levels of VEGF and HGF were measured in tissue extracts by enzyme-linked immunosorbent assay. RESULTS: HGF and VEGF levels were significantly higher in gastric cancer tissue than in matched normal gastric mucosa. VEGF levels were significantly increased in cancer tissue from cases involving lymphatic invasion. HGF levels were significantly increased according to the disease stage. Patients with high levels of VEGF or HGF showed significantly worse survival rates than patients with low levels. Using multivariate analysis, a high level of VEGF or HGF was an independent factor predicting poor survival. CONCLUSIONS: Intratumoral levels of HGF and VEGF are an important prognostic determinant in gastric cancer. The current findings suggest that high concentrations of HGF and VEGF may induce aggressive tumour growth and metastasis.

Clinical significance of CD133 and hypoxia inducible factor-1α gene expression in rectal cancer after preoperative chemoradiotherapy.

AIMS: The mechanism of distant recurrence in rectal cancer after preoperative chemoradiotherapy (CRT) has yet to be fully elucidated. Further improvements in survival rates cannot be achieved without decreasing distant recurrence after preoperative CRT. Recently, it was reported that hypoxic conditions were correlated with cancer stem cell generation. Therefore, we investigated the correlation between the expression of CD133 and hypoxia inducible factor-1α (HIF-1α), and their association with clinical outcome. MATERIALS AND METHODS: Fifty-two patients with rectal cancer underwent preoperative CRT. Residual cancer cells after CRT were obtained from formalin-fixed paraffin-embedded specimens using micro-dissection. The expression levels of CD133 (PROM1) and HIF-1α genes were measured using real-time reverse transcription polymerase chain reaction. The correlation between expression and irradiation was evaluated using colon cancer cell lines. Immunohistochemical staining of these proteins after CRT was also investigated. RESULTS: We observed a significant inverse correlation between the gene expression of CD133 (PROM1) and HIF-1α genes in residual cancer cells after CRT. Elevated CD133 gene expression was associated with distant recurrence and poor recurrence-free survival. Elevated HIF-1α gene expression was associated with poor overall survival. In vitro, the change in gene expression levels after irradiation showed inverse patterns. Immunohistochemical analyses showed that residual cancer cells strongly expressed CD133 and lacked HIF-1α expression. CONCLUSION: Our results suggest that CD133 and HIF-1α expression is associated with tumour re-growth and distant recurrence after CRT. These results may assist in clarifying the development of future cancer therapeutics in rectal cancer patients undergoing preoperative CRT.

Loss of tumoral expression of soluble IL-6 receptor is associated with disease progression in colorectal cancer.

BACKGROUND: Interleukin-6 (IL-6) binds both the membrane and soluble forms of the IL-6 receptor (sIL-6R), which induces a complex with gp130, and proliferation of tumour cells. The aim of this study is to clarify the relationship between tumoral sIL-6R expression and disease progression in colorectal cancer patients. METHODS: We measured tissue concentrations of sIL-6R in tumour and normal mucosa from 161 colorectal cancer patients undergoing surgery, and in supernatants from colon cancer cell lines. The expression of IL-6, IL-6R and gp130 was evaluated by immunohistochemical analysis. RESULTS: Loss of tumour expression of sIL-6R as defined by sIL-6R Ca/N ratio <1.0 was significantly associated with factors reflecting disease progression, and was an independent prognostic factor not only in all the patients in this study, but also in the patients with curative intent. Colon cancer cell lines produced sIL-6R in vitro, and the production of sIL-6R in cancer cell lines was stimulated by cytokine stimulation. Immunohistochemistry revealed that loss of tumour expression of sIL-6R was significantly inversely correlated with intense IL-6 expression in the cytoplasm of cancer cells. In addition, tumoral IL-1beta expression was significantly correlated with sIL-6R expression. CONCLUSION: Loss of tumour expression of sIL-6R is associated with colorectal cancer disease progression.

Effect of tiotropium bromide on airway inflammation and remodelling in a mouse model of asthma.

BACKGROUND: Tiotropium bromide, a long acting muscarinic receptor inhibitor, is a potent agent for patients with bronchial asthma as well as chronic obstructive pulmonary disease. OBJECTIVE: The aim of this study was to evaluate whether tiotropium bromide can inhibit allergen-induced acute and chronic airway inflammation, T helper (Th)2 cytokine production, and airway remodelling in a murine model of asthma. METHODS: Balb/c mice were sensitized and challenged acutely or chronically to ovalbumin (OVA). The impact of tiotropium bromide was assessed using these mice models by histologic, morphometric, and molecular techniques. Moreover, the effect of tiotropium bromide on Th2 cytokine production from purified human peripheral blood mononuclear cells (PBMCs) was assessed. RESULTS: Treatment with tiotropium bromide significantly reduced airway inflammation and the Th2 cytokine production in bronchoalveolar lavage fluid (BALF) in both acute and chronic models of asthma. The levels of TGF-beta1 were also reduced by tiotropium bromide in BALF in a chronic model. The goblet cell metaplasia, thickness of airway smooth muscle, and airway fibrosis were all significantly decreased in tiotropium bromide-treated mice. Moreover, airway hyperresponsiveness (AHR) to serotonin was significantly abrogated by tiotropium bromide in a chronic model. Th2 cytokine production from spleen cells isolated from OVA-sensitized mice was also significantly inhibited by tiotropium bromide and 4-diphenylacetoxy-N-methylpiperidine methiodide, which is a selective antagonist to the M3 receptor. Finally, treatment with tiotropium bromide inhibited the Th2 cytokine production from PBMCs. CONCLUSION: These results indicate that tiotropium bromide can inhibit Th2 cytokine production and airway inflammation, and thus may reduce airway remodelling and AHR in a murine model of asthma.

Gene expression profiles of epidermal growth factor receptor, vascular endothelial growth factor and hypoxia-inducible factor-1 with special reference to local responsiveness to neoadjuvant chemoradiotherapy and disease recurrence after rectal cancer surgery.

AIMS: To establish a causal relationship between the gene expression profiles of angiogenetic molecular markers, including epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1 (HIF-1), in rectal cancer and the local responsiveness to neoadjuvant chemoradiotherapy and subsequent disease recurrence. MATERIALS AND METHODS: We examined the pre-treatment tumour biopsies (n=40) obtained from patients with rectal adenocarcinoma (clinical International Union Against Cancer stage ll/III) who were scheduled to receive neoadjuvant 5-fluorouracil-based chemoradiotherapy for EGFR, VEGF and HIF-1 expression by quantitative real-time polymerase chain reaction. RESULTS: Responders (patients with significant tumour regression, i.e. pathological grades 2/3) showed significantly lower VEGF, HIF-1 and EGFR gene expression levels than the non-responders (patients with insignificant tumour regression, i.e. pathological grades 0/1) in the pre-treatment tumour biopsies. The elevated expression level of each gene could predict patients with a low response to chemoradiation. During the median follow-up of all patients (41 months; 95% confidence interval 28-60 months), 6/40 (15%) developed disease recurrence. Although local responsiveness to neoadjuvant chemoradiotherapy was associated with neither local nor systemic disease recurrence, lymph node metastasis and an elevated VEGF gene expression level were independent predictors of systemic disease recurrence. The 3-year disease-free survival rates of the patients with lower VEGF or EGFR expression levels were significantly lower than those of patients with higher VEGF or EGFR expression levels. CONCLUSIONS: Analysing VEGF expression levels in rectal cancer may be of benefit in estimating the effects of neoadjuvant chemoradiotherapy and in predicting systemic recurrence after rectal cancer surgery.

Mitotic checkpoint genes, hsMAD2 and BubR1, in oesophageal squamous cancer cells and their association with 5-fluorouracil and cisplatin-based radiochemotherapy.

AIMS: HsMAD2 and BubR1 are crucial components of a functional mitotic checkpoint. Recently, impaired mitotic checkpoints or decreased expression of mitotic checkpoint genes have been associated with sensitivity to certain anticancer drugs. The current study aimed to evaluate the association of hsMAD2 and BubR1 with sensitivity to various anticancer drugs in oesophageal squamous cell carcinoma (ESCC) cell lines. We also investigated responses to 5-fluorouracil and cisplatin-based radiochemotherapy in ESCC patients. MATERIALS AND METHODS: HsMAD2 and BubR1 mRNA levels in six ESCC cell lines and 21 ESCC patients were determined by real-time reverse transcription polymerase chain reaction. Responses to 5-fluorouracil, cisplatin, paclitaxel and docetaxel in human oesophageal cancer cell lines, TE1 and TE2, were evaluated by WST-8 colorimetric assay. HsMAD2 and BubR1 levels were compared with clinicopathological characteristics and responses to radiochemotherapy. RESULTS: TE1, with lower hsMAD2 and BubR1, showed greater sensitivity to paclitaxel and docetaxel compared with TE2, with higher hsMAD2 and BubR1. HsMAD2 and BubR1 were significantly higher in cancer tissue than in adjacent normal tissue (P < 0.01). Tumoral hsMAD2 and BubR1 were significantly decreased after radiochemotherapy (P < 0.01). There was a significantly strong positive association between hsMAD2 and BubR1 in cancer tissue (P < 0.01). Neither clinicopathological characteristics nor the response to radiochemotherapy was associated with hsMAD2 or BubR1. CONCLUSION: The mitotic checkpoint genes, hsMAD2 and BubR1, were co-ordinately overexpressed in ESCC. Low hsMAD2 and BubR1 was associated with sensitivity to paclitaxel and docetaxel. Decreased hsMAD2 and BubR1 after radiochemotherapy may indicate the potential efficacy of taxanes as second-line chemotherapy for recurrent and metastatic oesophageal cancer.

Inhibitory effects of suplatast tosilate on the differentiation and function of monocyte-derived dendritic cells from patients with asthma.

BACKGROUND: Dendritic cells (DCs) are antigen-presenting cells that efficiently activate T cells. OBJECTIVE: We examined the effects of suplatast tosilate, which prevents T-helper type 2 responses, on the differentiation and function of monocyte-derived DCs (moDCs). METHODS: DCs were differentiated in vitro from peripheral monocytes from patients with asthma by the addition of granulocyte macrophage colony-stimulating factor and IL-4 in the presence or absence of suplatast tosilate. Cell surface molecules (CD1a, CD14, CD80, CD83, CD86, HLA-DR) on immature and mature DCs were analysed with flow cytometry, and the secretion of CC chemokine ligand (CCL)17 (thymus and activation-regulated chemokine), IL-12p70, IL-12p40, and IL-10 was measured with an ELISA. We also studied the proliferative responses of allogeneic CD4(+) T cells from healthy subjects to DCs differentiated in the presence of suplatast tosilate. In addition, the production of IFN-gamma and IL-5 by CD4(+) T cells after coculture with untreated DCs or suplatast tosilate-treated DCs was measured with ELISA. RESULTS: Suplatast tosilate significantly inhibited the expression of CD1a, CD80, and CD86 on immature DCs and of CD1a, CD80, CD83, and CD86 on mature DCs. Suplatast tosilate also significantly inhibited the secretion of CCL17, IL-12p70, and IL-12p40; however, the secretion of IL-10 was not affected. The proliferative responses of allogeneic CD4(+) T cells to suplatast tosilate-treated DCs were suppressed. Moreover, suplatast tosilate-treated DCs had an impaired capacity to stimulate CD4(+) T cells to produce IFN-gamma and IL-5. CONCLUSION: Suplatast tosilate inhibits the differentiation, maturation, and function of moDCs.

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.

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.

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.

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.

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.

Trends of IL-6 and IL-8 levels in patients with recurrent breast cancer: preliminary report.

BACKGROUND: We reported that IL-6 and IL-8 levels at the beginning of treatment are predictive indicators of response to therapy and prognosis of patients with recurrent breast cancer. The aim of this study was to investigate the trend of IL-6 and IL-8 levels in heavily pretreated patients with recurrent breast cancer. METHODS: Cytokine level trends in 12 patients heavily pretreated with anthracyclines were studied. Patients were divided into two groups according to the objective response. There were 5 partial response (PR)/no change (NC), and 7 progressive disease (PD) patients. Blood was taken every four weeks. IL-6 was measured by chemiluminescent enzyme immunoassay. IL-8 was measured by ELISA. RESULTS: The pretreatment level of IL-6 in the PR/NC group (11.0+/-2.1 pg/ml) was significantly lower than that (15.3+/-2.7 pg/ml) in the PD group. However, there was no difference in IL-8 level between the PR/NC group (12.5+/-5.5 pg/ml) and the PD group (11.5+/-1.1 pg/ml). IL-6 levels in the PR/NC group were maintained within normal levels or decreased to within normal levels after treatment, while levels of IL-6 in the PD group gradually increased until the time of patient death. A decrease in IL-8 level after treatment was observed in only one patient in the PR/NC group. Mild increase of IL-8 levels was observed in the PD group. CONCLUSION: Continuous elevation of IL-6 levels indicates poor prognosis in heavily pretreated patients with recurrent breast cancer. Combination therapy including agents that reduce IL-6 levels will be a new strategy for aggressively treating recurrent breast cancer.

A case report of advanced male breast cancer with an objective response to tamoxifen treatment.

A 70-year-old man presented with a firm tumor in his right breast first noticed eight years ago. The tumor had enlarged gradually and had produced an ulcer with bleeding. On physical examination, a huge tumor entirely occupied the right breast and extensively had infiltrated the chest wall. Chest X-ray and CT showed massive pleural effusion and multiple small nodular lesions in the lung. Invasive ductal carcinoma of the breast was diagnosed by incisional biopsy,confirming advanced breast cancer with lung metastases and bilateral pleural effusion(T4cN2M1, Stage IV). Because ER and PgR levels were 110 fmol/mg and 190 fmol/mg, respectively, and because his general condition was poor, we selected medical treatment with tamoxifen(TAM). Thirty-two weeks later, the tumor had showed pronounced reduction with scarring. The patient underwent local excision of the scar tissue. The quality of life of the patient was favorably improved and no severe adverse events were observed. The tumor in the chest wall recurred two months after the end of TAM treatment, possibly because the patient did not accept continuous TAM therapy. The patient died from complications of brain metastasis 32 months after the start of TAM treatment. We report a rare case of advanced male breast cancer and on the effectiveness of continuous TAM treatment.

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.

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.

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.

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.