The role of type D prostanoid receptors and PPARγ in gastric cancer progression

Prostaglandin D2 (PGD2) has been demonstrated to have antitumor effects on cancer cells. PGD2 acts through two major receptors of DP1 and DP2, as well as through the peroxisome proliferator-activated receptor γ (PPARγ) via the PGD2 metabolite, 15-deoxy-Δ12-14-PGJ2. The expression levels of DP1, DP2, and PPARγ were analyzed by immunohistochemistry on 277 primary gastric carcinomas. Either DP1- or DP2-positive cases were regarded as DP-positive. DP-Positive tumour was significantly associated with lymph mode metastasis, lymphatic invasion, and venous invasion. PPARγ positivity was not associated with any clinicopathological factors of gastric cancer. DP-Negative and PPARγ-positive cases were significantly associated with T category, lymph metastasis, and lymphatic invasion. The prognosis of DP-negative and PPARγ-positive cases was better than that of the other cases. These findings suggest that DP and PPARγ signaling influence the invasiveness of cancer cells. DP and PPARγ can be used as a potential marker for gastric cancer progression.

[Usefulness of bevacizumab combination chemotherapy for advanced breast cancer]

Bevacizumab combination chemotherapy prolongs progression-free survival but not overall survival in patients with advanced breast cancer. Here, we report our experience with bevacizumab plus paclitaxel treatment in our department. We believe that this regimen confers some benefit to a patient's quality of life. Nineteen patients with inoperable, metastatic, or recurrent breast cancer were treated with bevacizumab plus paclitaxel. The median age was 55 years; all patients were females. Of the 19 patients, 14, 1, and 4 had luminal A, luminal B, and triple-negative type tumors, respectively. The response rate was 63%: partial response (PR) was obtained in 12 patients, stable disease (SD) in 5 patients, and progressive disease( PD) in 2 patients. Adverse events of Grade 3 or more were high blood pressure( 4 patients), peripheral neuropathy (1 patient), and neutropenia (9 patients). All side effects could be tolerated. There was a high rate of response to bevacizumab plus paclitaxel chemotherapy. We believe that this chemotherapy is useful in patients with more advanced breast cancer in whom a high response rate is required.

[Our experience of eribulin treatment in advanced breast cancer]

The clinical outcomes, including adverse events, in 40 advanced breast cancer patients treated with eribulin were analyzed to confirm the effectiveness and safety of this treatment. The objective response rate (ORR) in patients was 35.0%. The median overall survival and time to treatment failure (TTF) in these patients was 479 and 63 days, respectively. Cases wherein eribulin was used as early-line treatment experienced significantly longer TTF compared to the cases wherein eribulin was used as late-line treatment; however, there was no difference in this value according to the breast cancer subtype. Moreover, subtype analysis revealed no significant difference in adverse events. We observed no difference in the benefit or tolerability of eribulin treatment among different breast cancer subtypes. However, our results suggest that a significant therapeutic effect can be expected when using eribulin as early-line treatment.

[Case of a patient with inflammatory breast cancer who responded to preoperative chemotherapy with paclitaxel plus bevacizumab and could subsequently undergo surgery]

A 58-year-old woman observed swelling in her left breast a few weeks prior to presentation. Rigidity in the D area, breast warmth, swelling, and a peau d'orange appearance in the whole left breast was observed. She was diagnosed with inflammatory breast cancer (luminal A type) T4dN2M0, Stage IIIB. The patient underwent primary systemic therapy with 7 courses of FEC. Following FEC treatment, the disease was stable. We subsequently administered 4 courses of bevacizumab plus paclitaxel combination therapy. The patient exhibited a partial response to FEC chemotherapy. Thereafter, a left mastectomy with level II axillary lymph node dissection was performed. At present, 1 year after surgery, the patient is alive with no recurrence. We conclude that the combination therapy of bevacizumab plus paclitaxel is a useful treatment for inflammatory breast cancer.

[Effectiveness of eribulin chemotherapy for squamous cell carcinoma of the breast]

The patient was a 40-year-old woman who was aware of a tumor in her left breast that was gradually increasing in size. Ultrasonography revealed a hypoechoic mass with a skin cyst, approximately 3 cm in size, in the C area of the left breast. Core needle biopsy indicated estrogen receptor (ER) -negative, progesterone receptor (PR) -negative, and human epidermal growth factor receptor 2 (HER2) -negative squamous cell carcinoma. Overall examination did not indicate distant metastasis. A diagnosis of T4bN2aM0, stage IIIB triple-negative left breast cancer was made. Eribulin was administered at a dose of 1.4 mg/m2. The effect of eribulin was considered to be long-term stable disease( long-term SD). The patient did not experience severe adverse events during treatment. After 24 weeks of eribulin treatment, mastectomy of the left breast with axillary lymph node dissection was performed. At present, 1 year after surgery, the patient is alive with no recurrence. We conclude that eribulin chemotherapy is useful for the treatment of patients with squamous cell carcinoma of the breast.

Abstract 225: A c-Met inhibitor increases the chemosensitivity of cancer stem cells to the irinotecan active metabolite SN38 in gastric carcinoma

Purpose: Gastric cancer remains a major global health threat and most patients with advanced stage disease require chemotherapy. The development of drug resistance is a major obstacle in the treatment of gastric cancer and only few effective therapies for combating chemoresistance are currently available. It has been demonstrated that a small subset of cancer cells with stem cell properties, referred to as “cancer stem cells” (CSCs), survive intensive anticancer therapies better than proliferating progenitor cells or differentiated tumor cells. CSCs have been reported to be postulated mediators of chemoresistance, so it might be important to comprehend the drug resistance mechanisms of CSCs to develop a promising therapy to combat chemoresistance. The stemness signal might be associated with the chemosensitivity of CSCs. In the present study, we analyzed the effect of c-Met inhibitors on the chemosensitivity of stem-like cancer cells in gastric cancer. We demonstrated that a c-Met inhibitor synergistically increased the antitumor activity of SN38 in CSCs. To determine mechanisms underlying this observed synergism, we observed that a c-Met inhibitor combined with SN38 also led to a significant increase in UGT1A1 and its subsequent interaction with apoptosis-related genes, i.e., bcl-2 and caspase-6.

Experimental Design: We used three gastric cancer cell lines and three side population (SP)-enriched cell lines. We used three signal inhibitors, c-Met inhibitor SU11274, GSK3β inhibitor AR-A014418, and mTOR inhibitor rapamycin, and five anticancer drugs. We examined the combined effects of signal inhibitors and anticancer drugs on proliferation, mRNA expression, and cell cycle.

Results: The IC50 of irinotecan, oxaliplatin, taxol, and gemcitabine in SP cells were 10.5, 2.0, 2.8, and 2.0 times higher than their parent cells, respectively. In contrast, the IC50 of 5-fluorouracil did not differ between the two cell lines. There was a synergistic anti-proliferative effect with a combination of c-Met inhibitor and SN38 in SP cells. In contrast, the GSK3β inhibitor and mTOR inhibitor had no synergistic effects in combination with any anticancer drugs. The SP cell lines had higher expression levels of UGT1A1, ABCG2, and ABCB1 than their parent cell lines, while the c-Met inhibitor significantly decreased the expression of UGT1A1, but not ABCG2 and ABCB1. G0-phase of SP cells was higher than their parent cells. c-Met inhibition induced S-phase arrest in SP cells.

Conclusions: CSCs are associated with multiresistance during chemotherapy. c-Met inhibitors could be a novel strategy to overcome chemoresistance. c-Met inhibitor may be a promising target molecule for irinotecan-based chemotherapy of gastric cancer. A UGT1A1 alteration might be involved in the irinotecan refractory process in CSCs.

Citation Format: Masakazu Yashiro, Tatsunari Fukuoka, Haruhito Kinoshita, Takafumi Nishii, Tsuyoshi Hasegawa, Taro Matsuzaki, Tamami Morisaki, Kosei Hirakawa. A c-Met inhibitor increases the chemosensitivity of cancer stem cells to the irinotecan active metabolite SN38 in gastric carcinoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 225. doi:10.1158/1538-7445.AM2013-225

Abstract 4054: Significance of CXCR4/SDF-1 axis expression in gastric cancer under hypoxic enviroment

Background: Various types of solid tumors, including gastric cancer, have a heterogeneously hypoxic environment which has been currently considered to be associated with aggressive tumor phenotypes cancer. Stromal cell-derived factor (SDF)-1 and C-X-C chemokine receptor type 4 (CXCR-4) form an important chemokine/receptor pair, and are supposed to be up-regulated by hypoxia inducible factor-1 (HIF-1). Although the chemokine signaling is associated with malignant potential of various carcinomas, few studies have addressed the expression and function of CXCR4 and SDF-1 under hypoxia in gastric cancer. The aim of our study was to clarify the significance of CXCR4 and SDF-1 under hypoxia in gastric carcinoma by evaluating the expression of a hypoxic marker, a carbonic anhydrase 9 (CA-9).

Experimental Design: A total of 297 patients who had undergone a resection of the primary tumor and were confirmed histologically to have sporadic gastric cancer were enrolled in this study. Expressions of CXCR4, SDF-1, and CA-9, were assessed by immunohistochemistry. We examined the association between the expression levels of CXCR4, SDF-1, and CA-9 and clinicopathologic variables of patients with gastric cancers. Furthermore, using three diffuse-type gastric cancer cell lines, OCUM-2M, OCUM-2MD3, and OCUM-12, expression level of CXCR4 and SDF-1 in hypoxia (1% O2) were examined by RT-PCR.

Results: CA-9 expression was found in 48% (143/297) of gastric cancers, CXCR4 was 47% (141/297), and SDF-1 was 41% (122/297). The CA9 expression was significantly correlated with CXCR4 expression and SDF-1. The CA9 expression level was significantly high in cases diffuse-type carcinoma (p=0.028). The prognosis for CA-9-positive patients was significantly poorer than that of CA-9-negative patients (p<0.001,log-rank). The CXCR4 expression level was significantly correlated with lymph node metastasis (p<0.001), and with higher stages (p<0.001). The SDF-1 expression level was significantly higher with lymph node metastasis(p<0.001), and with higher stages (p<0.001). The prognosis for CXCR4-positive patients was significantly poorer than that of CXCR4-negative patients (p<0.001, log-rank). The prognosis for SDF-1-positive patients was significantly poorer than that of SDF-1-negative patients (p=0.008, log-rank). The expression level of CXCR4 mRNA was significantly increased by hypoxia, in comparison with that in normoxia in all of gastric cancer cells.

Conclusion: CXCR4/SDF-1 expression of gastric cancer cells might be regulated with by hypoxic condition. CXCR4/SDF-1 axis might play an important role for the progression of diffuse-type gastric carcinoma with hypoxic environment.

Citation Format: Haruhito Kinoshita, Masakazu Yashiro, Tamami Morisaki, Tatsunari Fukuoka, Tsuyoshi Hasegawa, Toshiki Hirakawa, Naoki Aomatsu, Katsunobu Sakurai, Kenjiro Kimura, Hisashi Nagahara, Takahiro Toyokawa, Ryosuke Amano, Eiji Noda, Naoshi Kubo, Hiroaki Tanaka, Kazuya Muguruma, Hiroshi Otani, Kiyoshi Maeda, Masaichi Ohira, Kosei Hirakawa. Significance of CXCR4/SDF-1 axis expression in gastric cancer under hypoxic enviroment. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4054. doi:10.1158/1538-7445.AM2013-4054

[A successful case of a super-elderly breast cancer patient treated with hormone therapy]

A 104-year-old female patient with a left breast mass was admitted to our hospital. Ultrasonography showed an irregular and low-echoic mass of about 2.4×2.4×1.4 cm size in the left breast EAC area. Core needle biopsy examination indicated invasive ductal carcinoma of the breast: ER (+), PR (+), and HER2 (-). An overall examination did not show a distant metastasis. We diagnosed her with left breast cancer(luminal A type) T2N0M0, stage IIA. We administered anastrozole at a dose of 1 mg/day. After 6 months, the primary tumor diameter was reduced to 2.1 cm, and the effect of anastrozole was considered a clinical partial response. The patient did not experience any adverse events during treatment. The partial response was maintained for about 2 years. We experienced a successful case of a super-elderly breast cancer patient treated with anastrozole. We conclude that hormone therapy is a useful treatment for super-elderly postmenopausal women with estrogen receptor-positive breast cancer.

[Tamoxifen maintained long-term complete response in an elderly patient with breast cancer]

The patient was an 82-year-old woman. Three years ago, she was aware of a tumor in her left breast that was gradually increasing in size and bleeding, prompting her to visit our hospital. Ultrasonography showed an irregular and low- echoic mass with a skin ulcer of about 2×2 cm in size in the left breast A area. Skin biopsy examination indicated adenocarcinoma, estrogen receptor-positive, progesterone receptor-positive, and human epidermal growth factor receptor type 2-negative. An overall examination did not show a distant metastasis. We diagnosed left breast cancer (luminal A type) with T4bN0M0, stage IIIB. We administered tamoxifen at a dose of 20 mg/day. After 8 months of tamoxifen treatment, no signs of an apparent mass were observed by palpation and ultrasonography. The effect of tamoxifen was considered a clinical complete response (CR). The patient did not experience any adverse events during treatment. Although CR was maintained for nearly 6 years by continuation of hormone therapy, tumor growth was observed after 6 years and 9 months. We performed partial resection of the left breast under local anesthesia. At present, 3 months after the operation, our patient is alive with no recurrence. We conclude that hormone (tamoxifen) therapy is a useful treatment for elderly postmenopausal woman with estrogen receptor-positive advanced breast cancer.

[Needle biopsy using a Monopty Biopsy Instrument for the accurate diagnosis of thyroid cancer]

Aspiration biopsy cytology (ABC) is commonly performed for the diagnosis of thyroid tumor. Because ABC may not provide sufficient tissue for pathological diagnosis, we performed needle biopsy using a Monopty Biopsy Instrument for the accurate diagnosis of thyroid cancer. Furthermore, it is difficult to safely perform a core needle biopsy (CNB) for the diagnosis of breast cancer in the thyroid gland region. In this study, we evaluated the feasibility of using a Monopty Biopsy Instrument as an alternative to conventional ABC or CNB for the biopsy-based diagnosis of thyroid cancer. Twenty patients with clinically suspected thyroid cancer were enrolled, and all patients were thoroughly examined. Seven cases of thyroid cancer were diagnosed, of which 5 cases were papillary carcinoma and 2 were undifferentiated carcinoma.

[Day surgery of early breast cancer treated with breast-conserving operation following sentinel lymph node navigation biopsy under local anesthesia]

In the early stages of breast cancer when axillary lymph node dissection is avoidable, we performed same day surgery with a breast-conserving operation following sentinel lymph node navigation biopsy under local anesthesia. Initial sentinel lymph node biopsy under local anesthesia is performed to avoid false-negative sentinel lymph node metastasis. Resected sentinel lymph nodes were examined in fixed sections by hematoxylin-eosin staining and immunohistochemistry. The enrolled subjects were 20 patients with breast cancer whose diagnoses were confirmed before treatment. Two (10.0%) patients had metastasis.

[Four cases of meningeal metastasis originating from breast cancer]

Carcinomatous meningitis due to breast cancer is comparatively rare in Japan. Here, we report 4 cases of carcinomatous meningitis due to breast cancer. Meningeal metastasis was present in only 1 of the 4 cases, and the other 3 cases were associated with brain metastasis. Meningeal metastasis frequently causes symptoms associated with intracranial hypertension. Gadolinium-enhanced magnetic resonance imaging and cerebrospinal fluid cytology were useful for the diagnosis of meningeal metastasis. Multidisciplinary therapy, such as radiation and chemotherapy, was performed. Two of the 4 patients were treated with combined intrathecal administration of methotrexate and whole brain radiation. The quality of life was improved by multidisciplinary therapy.

Abstract 3380: Comparison proteome analysis of scirrhous gastric carcinoma stem cell-like SP and hypoxia-resistant cell lines

Intro Cancer stem cells (CSCs) are considered to be responsible for cancer metastasis, and hypoxia is supposed to be an important regulator of CSCs differentiation. Furthermore, tumor hypoxia was reported to be associated with more aggressive tumor phenotypes such as high metastatic ability and resistance to various anti-cancer therapies which may lead to a poorer prognosis. This raises the question of whether there might be proteins representing similar alterations which are responsible for the correlation between hypoxic and CSCs phenotypes. We have established a diffuse-type of gastric carcinoma cell line (OCUM-12), and a hypoxia-resistant cancer cell line (OCUM-12/Hypo) cloned from parent OCUM-12 cells by continuous exposure to 1% oxygen. The side population (SP), as evaluated by a flow cytometric analysis using Hoechst 33342, has been known as CSC-rich population. To investigate and compare the proteomes of the hypoxic (OCUM-12/Hypo), stem cell (OCUM-12SP) and parent OCUM-12 diffuse-type gastric carcinoma cell lines, protein lysates from those cell lines were analyzed using QSTAR Elite LC MS/MS. Method Triplicate pooled samples (10 ug protein each) from stomach cancer cell lines were prepared and labeled with iTRAQ reagents. MS/MS data were searched against the Swiss Protein database (HUMAN) using ProteinPilot™ 2.0 software (AB Sciex). The Ingenuity Pathway analysis program was utilized, to assign biological significance, and to identify networks of interacting differentially expressed proteins, functional groups and pathways. Result In both OCUM-12SP and OCUM-12/Hypo cells, significant overexpression of Wnt signaling pathway was obvious. Furthermore, elevation of MTHFD1, a protein controlling histidine and purine nucleotide metabolism, cytokeratins 18 (CK18), and 19 (CK19) regulating cell cycle, apoptosis and angiogenesis, transcriptional regulator ANP32A, and cellular chaperones heat shock proteins A9 and STIP was observed as compared to the parent OCUM-12 cell line. Furthermore, anterior gradient homolog 2 (AGR2)was down-regulated in both cell lines. Conclusion Wnt signal, MTHFD1, CK18, CK19, ANP32A, HSPA9 and STIP, AGR2 might be responsible for the stem-like phenotype, hypoxia resistance and higher invasiveness of gastric cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3380. doi:1538-7445.AM2012-3380

Abstract 708: Clinical significance of insulin-like growth factor 1 receptor (IGF1R) expression in pancreatic cancer

Introduction: Insulin like growth factor 1 receptor (IGF1R) reported to be overexpressed in some types of human carcinomas, including lung cancer, and breast cancer. However no report of the significance of IGF1R expression was available in pancreatic cancer. Most patients with pancreatic cancer die within 2 years at diagnosis even after curative resection. The objective of this study was to evaluate the significance of IGF1R expression in human pancreatic cancer. Material and Methods: A total 122 patients with pancreatic cancer was studied. Paraffin embedded species of pancreatic cancers were stained with antibodies against IGF1R. IGF1R expression was evaluated by intensity of staining. Semi-quantitative scores of zero (no staining), 1+ (weak staining), 2+ (moderate staining), or 3+ (strong staining) were assigned to each sample based on the intensity of staining. Scores of 2+ or 3+ were defined as IGF1R-positive staining. The association between IGF1R expression and clinicopathologic variables was examined. Results: IGF1R expression was positive in 50 (40.1%) of 122 cases. Kaplan-Meier analysis demonstrated the prognosis of IGF1R-positive patients was significantly (p=0.0076) poorer than that of IGF1R-negative, and median survival time of patients with IGF1R-positive was 37.3 months, while that of patients with IGF1R-negative samples was 60.8 months. There were no associations between IGF1R overexpression and clinicopathological factors, including tumor location, tumor size, tumor differentiation, and T/N categories according to the International Union against Cancer. Multivariate analysis showed IGF1R expression and lymph node metastasis were independent predictors of worse prognosis in pancreatic cancer. Conclusion: The expression of IGF1R might be a novel predictive prognostic marker for patients with pancreatic cancers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 708. doi:1538-7445.AM2012-708

Abstract 707: CD133 is a useful surrogate marker to predict chemosensitivity of neoadjuvant chemotherapy for breast cancer

Background:Current studies have demonstrated that neoadjuvant chemotherapy (NAC) improves survival outcomes and increases the chance for breast conservation when applied preoperatively. However, no reliable maker to predict chemosensitivity of NAC is not available. CD133 has been considered as a cancer stem cells (CSCs) marker in many kinds of tumors such as breast cancer, colorectal cancer and brain cancer. The aim of this study was to evaluate the value of CD133 as a surrogate maker to predict chemosensitivity of NAC for breast cancer. Experimental Design: A total of 102 patients with breast cancer of stage II and III, as evaluated by core needle biopsy and ultrasonography, was treated with NAC. Expressions of CD133, estrogen receptor, progesterone receptor, and HER2 were assessed by immunohistochemistry. Results: The clinical complete response (CR) rate of all patients was 18% (18/102), partial response (PR) was 61% (62/102), no change (NC) was 20% (20/102), and progressive disease (PD) was 2% (2 /102). The response rate (RR) was 78% (80/102). The pathological complete response rate (pCR) was 29%. The pCR rate and pathological response of CD133-positive cases was significantly lower than that of CD133-negative cases. The recurrence rate of CD133-positive cases was significantly higher than that of CD133-negative cases. CD133 expression showed a poor disease free survival and overall survival time. A multivariate logistic regression analysis showed that CD133 expression was an independent prognostic factor in breast cancers treated with NAC. Conclusion: CD133 is a useful surrogate maker to predict chemosensitivity of NAC chemotherapy for breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 707. doi:1538-7445.AM2012-707

Abstract 780: An EGFR inhibitor enhances the efficacy of SN38, an active metabolite of irinotecan, in SN38-refractory gastric carcinoma cells

Background: Acquired drug resistance to irinotecan is one of the significant obstacles in the treatment of advanced gastric cancer. This study was performed to clarify the effect of epidermal growth factor receptor (EGFR) inhibitors in combination with SN38, an active metabolite of irinotecan, on the proliferation of irinotecan-refractory gastric cancer. Methods: Two irinotecan-resistant gastric cancer cell lines, OCUM-2M/SN38 and OCUM-8/SN38, were respectively established by stepwise exposure to SN38 from the parent gastric cancer cell lines OCUM-2M and OCUM-8. The combination effects of two EGFR inhibitors, gefitinib and lapatinib, with SN38 on proliferation, apoptosis, and cell-cycle on gastric cancer cells were examined. Results: Gefitinib or lapatinib showed synergistic anti-tumor effects against OCUM-2M/SN38 and OCUM-8/SN38 cells when used in combination with SN38, but not against OCUM-2M or OCUM-8 cells. SN38 increased the expression of EGFR and HER2 in OCUM-2M/SN38 and OCUM-8/SN38 cells. The combination of an EGFR inhibitor and SN38 significantly increased the levels of apoptosis-related molecules, caspase-6, p53, and DAPK-2, and resulted in the induction of apoptosis of irinotecan-resistant cells. The EGFR inhibitors increased the S-phase and decreased the UGT1A1 and ABCG expression in irinotecan-resistant cells. The SN38 plus Lapatinib group more effectively suppressed in vivo tumor growth by OCUM-2M/SN38 cells than either alone group.Conclusion: The combination treatment with an EGFR inhibitor and irinotecan might produce synergistic anti-tumor effects for irinotecan-refractory gastric cancer cells. The regulation of SN38 metabolism-related genes and cell cycle by EGFR inhibitors might be responsible for the synergism.

Abstract 2411: The epithelial-mesenchymal transition of gastric cancer cells was stimulated by TGFβR signaling in hypoxia

Introduction: Epithelial mesenchymal transition (EMT) is a cellular process during which epithelial cells acquire mesenchymal properties while losing cell-cell interactions and apicobasal polarity. EMT is considered to be correlated with malignancy of cancer cells and responsible for cancer invasion and metastasis. Patients with gastric cancer show a poor prognosis because of frequent metastasis. We previously reported that distant metastasis was associated with hypoxia in gastric cancer. Therefore, we investigated the effect of hypoxic condition on EMT of gastric cancer cells. Materials and Methods:Seven gastric cancer cell lines derived from gastric cancer were used. Cells were cultured in normoxia (21% O2) or hypoxia (1% O2) for 24h. EMT rate was evaluated as the percentage of spindle-shaped cells of total cells. The expression level of TGFβ and TGFβ receptor was evaluated by real time RT-PCR. Effect of several inhibitors on the EMT was evaluated by cell morphology. The TGFβ1 level of the cell culture supernate was measured by a quantitative sandwich enzyme immunoassay technique. Results: Hypoxia stimulated EMT of OCUM-2MD3 and OCUM-12 cells, but not that of other cell lines. The level of TGFβ expression was increased significantly (p<0.01) under hypoxia in comparison with normoxia. The level of TGFβ receptor expression was increased in OCUM-2MD3 cells, but not OCUM-2M cells. TGFβR inhibitor, SB431542, significantly suppressed EMT of OCUM-2MD3 (p=0.03) and OCUM-12 (p<0.01). In OCUM-2MD3 and OCUM-12, the quantity of TGFβ1 in cell culture supernatant significantly increased under hypoxia compared to normoxia, but not OCUM-2Mcells. Conclusion: Hypoxia stimulates the EMT of gastric cancer cells via TGFβ/ TGFβ receptor signaling. TGFβ receptor inhibitor might be promising for the treatment of metastasis of gastric cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2411. doi:1538-7445.AM2012-2411

[Lumpectomy and sentinel lymph node navigation surgery for breast cancer under local anesthesia]

We studied and analyzed therapeutic outcomes of a radical surgery under local anesthesia for breast cancer in our department. Subjects were 42 patients with breast cancer whose diagnoses were definitely made before surgery. Indications were: localized DCIS diagnosed preoperatively; invasive carcinoma less than 3 cm in tumor diameter on ultrasound; and clinically tumors with negative axillary lymph nodes. Operative procedures included lumpectomy associated with sentinel lymph node navigation biopsy. We could perform the operation under local anesthesia in all of the 42 patients, and were not demanded to shift from local to general anesthesia. Two patients had sentinel lymph nodes metastasis. Surgical stumps were positive in 14 patients( 33.3%). None of serious complications were encountered. Today's radical operation under local anesthesia for breast cancer is a useful procedure as minimally invasive surgery as for the indications employed in this study.

[Usefulness of immediate reconstruction after mastectomy for inflammatory breast cancer with muscle cutaneous flap]

CASE 1: A 59-year-old female patient with left inflammatory breast cancer (HER2 type) T4N1M0, stage III B. Although a partial response (PR) was observed after chemotherapy, an increase of the tumor was confirmed, and thus she underwent pectoralis-conserving mastectomy and immediate reconstruction with a rectus abdominis flap. After the surgery, the patient continued to undergo radiotherapy and administration of trastuzumab. At present, after 1 year and 3 months, she is alive with no recurrence. CASE 2: A 67-year-old female patient with left inflammatory breast cancer (triple negative) T4N2M0, stage III B. Since a variety of chemotherapeutics were ineffective, she underwent mastectomy with pectoralis resection and immediate reconstruction with a rectus abdominis flap to control pain/bleeding caused by the increased tumor. Although radiotherapy and chemotherapy were performed after the surgery, lung and hepatic metastases were developed 6 months after the surgery, and she died in the 10th month after the surgery.

CONCLUSION

In mastectomy for inflammatory breast cancer, an immediate reconstruction with a muscle cutaneous flap enabled unhesitating mastectomy in a wide area, and thus we consider this will be a useful technique.

[Ultrasound guided vacuum-assisted biopsy for diagnosis of malignant lymphoma]

Tailor-made treatment for lymphoma has been proposed, based on the information on prognostic on predictors or on molecular targets. This recent evolutions necessitated the collection of sufficient tissue samples for their preoperative evaluation. Since needle biopsy or needle aspiration cytology may not provide enough tissue for histo-pathologic diagnosis, incisional and excisional biopsies are commonly performed. In this study, we applied a handheld vacuum-assisted biopsy (VAB) system, as an alternative to the conventional incisional and excisional biopsies, to evaluate its feasibility in the biopsy -based diagnosis of malignant lymphoma. The subjects were nine patients with clinically suspected malignant lymphoma. All of them were correctly diagnosed with a diagnostic accuracy of 100%, and lymphoma sub-types could be defined according to the New WHO classification. There was no complication associated with the procedure. Lymph node biopsy for diagnosis of malignant lymphoma using this minimally invasive VAB technique allows a simple and safe collection of sufficient samples with good-quality, and promises to contribute to a precise molecular-based diagnosis.