Tadahiko Shien

The estrogen receptor influences microtubule-associated protein tau (MAPT) expression and the selective estrogen receptor inhibitor fulvestrant downregulates MAPT and increases the sensitivity to taxane in breast cancer cells

IntroductionMicrotubule-associated protein tau (MAPT) inhibits the function of taxanes and high expression of MAPT decreases the sensitivity to taxanes. The relationship between estrogen receptor (ER) and MAPT in breast cancer is unclear. In this study, we examined the correlation of MAPT expression with the sensitivity of human breast cancer cells to taxanes, and the relationship between ER and MAPT.MethodsThe correlation between MAPT expression and sensitivity to taxanes was investigated in 12 human breast cancer cell lines. Alterations in cellular sensitivity to taxanes were evaluated after knockdown of MAPT expression. ER expression was knocked down or stimulated in MAPT- and ER-positive cell lines to examine the relationship between ER and MAPT. The cells were also treated with hormone drugs (tamoxifen and fulvestrant) and taxanes.ResultsmRNA expression of MAPT did not correlate with sensitivity to taxanes. However, expression of MAPT protein isoforms of less than 70 kDa was correlated with a low sensitivity to taxanes. Downregulation of MAPT increased cellular sensitivity to taxanes. MAPT protein expression was increased by stimulation with 17-β-estradiol or tamoxifen, but decreased by ER downregulation and by fulvestrant, an ER inhibitor. The combination of fulvestrant with taxanes had a synergistic effect, whereas tamoxifen and taxanes had an antagonistic effect.ConclusionsExpression of MAPT protein isoforms of less than 70 kDa is correlated with a low sensitivity to taxanes in breast cancer cells. ER influences MAPT expression and fulvestrant increases the sensitivity to taxanes in MAPT- and ER-positive breast cancer cells.

Tumor inhibitory effect of gefitinib (ZD1839, Iressa) and taxane combination therapy in EGFR-overexpressing breast cancer cell lines (MCF7/ADR, MDA-MB-231)

Some kinds of breast cancer cell lines, similar to several types of solid tumors, express epidermal growth factor receptor (EGFR). However, gefitinib, an EGFR tyrosine kinase inhibitor, is not effective for all these cell lines. Similarly, taxane is effective for many of the cell lines, although some, such as the multidrug‐resistant MCF7/ADR cell line, show taxane‐resistance. Here, we examined the growth inhibitory effect of combination treatment with gefitinib and taxane on the breast cancer cell lines MDA‐MB‐231 (EGFR‐positive) and MCF7/ADR (EGFR‐ and HER2‐positive). To estimate the combined effect, a Combination Index was calculated for each cell line. The combination of gefitinib and taxane showed a strong synergistic effect on MCF7/ADR cells, but an invitro additive‐antagonistic effect on MDA‐MB‐231 cells. Similarly, the combination treatment showed a significantly increased tumor inhibitory effect on MCF7/ADR xenografts, but not on MDA‐MB‐231 xenografts. Regarding the mechanism of the synergistic effect, Western blotting analysis revealed that taxane activated the EGFR‐Akt pathway in MCF7/ADR cells but not in MDA‐MB‐231. To determine the optimal sequential administration of gefitinib and taxane for MCF7/ADR cells, we used flow cytometry to analyze the cell cycle and apoptosis; finding that taxane treatment followed by gefitinib produced a higher rate of G2 arrest and apoptosis than gefitinib treatment followed by taxane. These results suggest gefitinib overcomes the drug‐resistance of these cells, thereby increasing the effects of taxane on MCF7/ADR cells. Further, activation of the EGFR‐Akt pathway by taxane is related to this synergistic effect.

Combination treatment with fulvestrant and various cytotoxic agents (doxorubicin, paclitaxel, docetaxel, vinorelbine, and 5-fluorouracil) has a synergistic effect in estrogen receptor-positive breast cancer

Patients with estrogen receptor (ER)‐positive breast cancers have a better prognosis than those with ER‐negative breast cancers, but often have low sensitivity to chemotherapy and a limited survival benefit. We have previously shown a combination effect of taxanes and fulvestrant and suggested that this treatment may be useful for ER‐positive breast cancer. In this study, we evaluated the effects of combinations of hormone drugs and chemotherapeutic agents. In vitro, the effects of combinations of five chemotherapeutic agents (doxorubicin, paclitaxel, docetaxel, vinorelbine, and 5‐fluorouracil) and three hormone drugs (fulvestrant, tamoxifen, and 4‐hydroxytamoxifen) were examined in ER‐positive breast cancer cell lines using CalcuSyn software. Changes in chemoresistant factors such as Bcl2, multidrug resistance‐associated protein 1, and microtubule‐associated protein tau were also examined after exposure of the cells to hormone drugs. In vivo, tumor sizes in mice were evaluated after treatment with docetaxel or doxorubicin alone, fulvestrant alone, and combinations of these agents. Combination treatment with fulvestrant and all five chemotherapeutic agents in vitro showed synergistic effects. In contrast, tamoxifen showed an antagonistic effect with all the chemotherapeutic agents. 4‐Hydroxytamoxifen showed an antagonistic effect with doxorubicin and 5‐fluorouracil, but a synergistic effect with taxanes and vinorelbine. Regarding chemoresistant factors, Bcl2 and microtubule‐associated protein tau were downregulated by fulvestrant. In vivo, a combination of fulvestrant and docetaxel had a synergistic effect on tumor growth, but fulvestrant and doxorubicin did not show this effect. In conclusion, fulvestrant showed good compatibility with all the evaluated chemotherapeutic agents, and especially with docetaxel, in vitro and in vivo. (Cancer Sci 2011; 102: 2038–2042)

21-Gene expression profile assay on core needle biopsies predicts responses to neoadjuvant endocrine therapy in breast cancer patients.

This study examined postmenopausal estrogen receptor-positive breast cancer patients who received prospective neoadjuvant endocrine therapy (NAET) with tamoxifen or anastrozole to determine if the 21-gene recurrence score (RS) predicts NAET responses. RS scores were determined from pretreatment core biopsy specimens. Although half of the specimens yielded insufficient RNA, the remaining samples were highly representative. Patients with a low RS tended to respond better than those with an intermediate or high RS (n=43). Response rates by RS were similar between the tamoxifen and anastrozole groups. Patients with a low RS tended to have better relapse-free survival (RFS) than those with an intermediate or high RS (5y-RFS; 100% vs. 84% and 73%, respectively). These results suggest that RS predicts responses to NAET with tamoxifen or anastrozole. Because this pilot study examined a small sample size, these results should be validated in larger studies.

Clinical and pathological features of intracystic papillary carcinoma of the breast.

PurposeTo evaluate the clinicopathological features of intracystic papillary carcinoma (ICPC), which have not been established given its rarity and lack of standard diagnostic criteria.MethodsWe reviewed the clinicopathological findings and treatment outcomes of 14 patients with ICPC diagnosed between 2002 and 2006.ResultsIntracystic papillary carcinoma was diagnosed by fine-needle aspiration biopsy in three patients and by core-needle biopsy in six patients. A preoperative diagnosis was not made in five patients. Three patients underwent magnetic resonance imaging preoperatively, which helped to differentiate benign tumors and maintain free surgical margins. The final pathological diagnosis was invasive carcinoma in 2 (14.2%) of the 14 patients. The patients were followed up for 1–72 months, during which time only one died, of a cancer-unrelated cause.ConclusionOur results show that ICPC is more difficult to diagnose than common breast cancer preoperatively. Excisional biopsy was necessary when fine-needle aspiration and core-needle biopsy could not provide a diagnosis. Magnetic resonance imaging is helpful to differentiate a benign tumor from invasive disease.

Functional interaction of fibroblast growth factor-8, bone morphogenetic protein and estrogen receptor in breast cancer cell proliferation.

Estrogen is involved in the development and progression of breast cancer. Here we investigated the effect of fibroblast growth factor (FGF)-8 on breast cancer cell proliferation caused by estrogen using human breast cancer MCF-7 cells. MCF-7 cells express estrogen receptor (ER)α, ERβ, FGF receptors, and Smad signaling molecules. Estradiol stimulated MCF-7 cell proliferation in a concentration-responsive manner, whereas BSA-bound estradiol had a weak effect on MCF-7 cell mitosis compared with the effect of free estradiol. It is notable that estrogen-induced cell proliferation was enhanced in the presence of FGF-8 and that the combined effects were reversed in the presence of an FGF-receptor kinase inhibitor or an ER antagonist. It was also revealed that FGF-8 increased the expression levels of ERα, ERβ and aromatase mRNAs, while estradiol reduced the expression levels of ERs, aromatase and steroid sulfatase in MCF-7 cells. FGF-8-induced phosphorylation of FGF receptors was augmented by estradiol, which was reversed by an ER antagonist. FGF-8-induced activation of MAPKs and AKT signaling was also upregulated in the presence of estrogen. On the other hand, FGF-8 suppressed BMP-7 actions that are linked to mitotic inhibition by activating the cell cycle regulator cdc2. FGF-8 was revealed to inhibit BMP receptor actions including Id-1 promoter activity and Smad1/5/8 phosphorylation by suppressing expression of BMP type-II receptors and by increasing expression of inhibitory Smads. Collectively, the results indicate that FGF-8 acts to facilitate cell proliferation by upregulating endogenous estrogenic actions as well as by suppressing BMP receptor signaling in ER-expressing breast cancer cells.

Evaluation of axillary status in patients with breast cancer using thin-section CT

BackgroundIn recent years, the surgical management of patients with breast cancer has shifted to a locoregional approach, and evaluating the patient’s axillary lymph node status is of the greatest importance in determining the appropriate treatment strategy. We evaluated on the efficacy of preoperative axillary staging using contrast-enhanced computed tomography (CE-CT).MethodsBetween 2000 and 2003, 235 patients with operable breast cancer who underwent CE-CT before surgery and 137 patients who received neoadjuvant chemotherapy (NAC) and underwent CE-CT before NAC and surgery were enrolled in this study. The axillary status was evaluated based on three criteria (short-axis diameter, shape, and enhancement type), and the diagnosis was correlated with the histopathological results.ResultsIn patients who did not receive NAC, the size criterion of a short-axis diameter of more than 5 mm provided a sensitivity of 78%, a specificity of 75%, and an accuracy of 76% in predicting node-positive status. According to the size criterion of a short-axis diameter of more than 5 mm and the shape criterion of the absence of intranodal fat density, the specificity and accuracy were 90% and 81%, respectively, and according to the enhancement type criterion of early enhancement, the corresponding values were 89% and 78%. Evaluation was more difficult in patients who received NAC and the sensitivity of the size-based criterion in the patients who received NAC was lower than in those who did not.ConclusionThese findings suggest that CE-CT based on size criteria is useful for evaluating the preoperative axillary status of breast cancer patients, but that evaluation is more difficult and the sensitivity is reduced in patients who have received NAC.

Diagnosis of Complete Response to Neoadjuvant Chemotherapy Using Diagnostic Imaging in Primary Breast Cancer Patients

Abstract:   Advances in the therapeutic agents used for neoadjuvant chemotherapy (NAC) have recently achieved higher response rates and induced a greater number of pathologic complete responses (pCR) than ever before. The aim of this study is the diagnosis of pCR after NAC by diagnostic imaging of clinical complete response (cCR) patients. This study included 35 breast cancer patients who demonstrated cCR after receiving NAC with a combination of anthracycline and taxane from May 1998 to August 2003. Surgical treatment included breast‐conserving therapy followed by radiotherapy or mastectomy. The identity of post‐NAC lesions as either a complete response (CR) or partial response (PR) were made by mammography, ultrasonography, and contrast‐enhanced computed tomography (CT). Among the 35 patients, 11 achieved pCR, including the disappearance of both invasive and intraductal components. Of the patients achieving pCR, eight were defined as CR and three were determined to be PR by CT. There was a significant relationship between the pCR and the determination of CR by CT. The determination of CR by ultrasonography was indicative of the disappearance of pathologic invasive components. While mammography appeared to reflect the observed histologic results, we did not observe any statistical differences. A subset of cases exhibited discrepancies between the imaging and pathologic results, likely due to the replacement of destroyed tumor cells by fibrosis and granulomatous tissue. The evaluation of CR by CT was significantly indicative of pCR. The positive predictive value, however, was not large enough to avoid surgical treatment. Further studies will be needed to establish a diagnosis of pCR. 

Primary small cell carcinoma of the breast

Primary small cell carcinoma of the breast is a very rare disease, and only a few case reports have described small cell carcinoma of the breast that responds to chemotherapy. Here, we report a case of primary small cell carcinoma of the breast that was treated with surgery and chemotherapy for postoperative local recurrence in the chest wall and metastasis to the liver. The metastatic lesions showed a partial response (PR) to carboplatin and irinotecan, but did not respond to subsequent Taxotere and doxifluridine (5′-DFUR) treatment. We then treated the metastatic lesions with CBDCA and etoposide (VP-16), and were able to stop disease progression. Small cell carcinoma of the breast is as aggressive as its pulmonary counterpart. Therefore, the best therapy for primary small cell carcinoma of the breast may be surgery followed by adjuvant therapy similar to that recommended for small cell lung carcinoma.

Unmet Information Needs and Quality of Life in Young Breast Cancer Survivors in Japan.

Background: Young breast cancer survivors have specific needs related to age. Clarifying the relationships between unmet information needs and quality of life (QOL) in young breast cancer survivors can contribute to constructing a support system to enhance QOL in patients. Objective: This study aimed to identify the unmet information needs and examine the relationships between unmet information needs and QOL in young breast cancer survivors in Japan. Methods: Participants completed an information needs questionnaire containing 26 items, the World Health Organization Quality of Life Instrument–Short Form (WHOQOL-BREF), and a demographic and medical information questionnaire. Results: Fifty participants (30.7%) were unsatisfied with “overall communication with medical professionals.” The mean scores on all subscales of the WHOQOL-BREF of the participants who were satisfied with “overall communication with medical professionals” were significantly higher than those of the unsatisfied group. “follow-up tests,” “treatment for recurrence of breast cancer,” “strategies about communication with medical staff,” and “nutrition” were significantly related with all subscales in the WHOQOL-BREF. “Secondary menopause caused by hormonal therapy” was significantly related with physical and psychological health. Conclusions: Japanese young breast cancer survivors have unmet information needs, including age-specific issues. These unmet information needs are related to QOL. In particular, “overall communication with medical professionals,” which is the most unmet information need, is related to QOL. Implications for Practice: Oncology nurses should teach patients communication skills, provide adequate information, and provide education and emotional support to medical professionals to improve QOL in young breast cancer survivors.