Seiya Sato

Combination chemotherapy of oxaliplatin and 5-fluorouracil may be an effective regimen for mucinous adenocarcinoma of the ovary: A potential treatment strategy

Resistance of ovarian mucinous adenocarcinoma to standard chemotherapy with paclitaxel and carboplatin is associated with poor prognosis, and an effective treatment is needed. The present study aimed to identify an effective chemotherapy for ovarian mucinous adenocarcinoma. Five human ovarian mucinous adenocarcinoma cell lines (MN‐1, OMC‐1, RMUG‐L, RMUG‐S, TU‐OM‐1) were used in this study. Sensitivity of the cells to the anticancer agents was determined by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay, and we assessed drug sensitivity by calculating the assay area under the curve for each agent. Protein expression was confirmed by Western blot analysis. We also examined the efficacy of combination chemotherapy on survival in a xenograft model of nude mice. The IC50 to anticancer agents ranged widely. The assay area under the curve indicated that two of five cell lines (MN‐1, TU‐OM‐1) were sensitive to oxaliplatin, 5‐fluorouracil and etoposide, and only one (TU‐OM‐1) was sensitive to 7‐ethyl‐10‐hydroxycamptothecin, which is an active metabolite of camptothecin. All cell lines were resistant to cisplatin and paclitaxel. The combination of oxaliplatin and 5‐fluorouracil resulted in additive or synergistic effects on all cell lines. The combination of oxaliplatin and 5‐fluorouracil significantly prolonged survival in a ovarian mucinous adenocarcinoma xenograft model of nude mice. Protein expression levels of the excision repair cross‐complementation group 1 were lower in oxaliplatin sensitive cell lines. Exposure to 5‐fluorouracil down‐regulated cross‐complementation group 1 expression in ovarian mucinous adenocarcinoma cells. We conclude that combination chemotherapy consisting of oxaliplatin and 5‐fluorouracil was an effective treatment for ovarian mucinous adenocarcinoma and may be a pivotal candidate for a novel treatment strategy. (Cancer Sci 2009; 100: 546–551)

The PI3K/mTOR dual inhibitor NVP-BEZ235 reduces the growth of ovarian clear cell carcinoma

Patients with clear cell carcinoma of the ovary (OCCC) have poor survival due to resistance to standard chemotherapy. OCCC has frequent activating mutations of the PIK3CA gene. The present study was conducted to clarify the efficacy of the inhibition of the PI3K-AKT-mTOR pathway in OCCC. We used 8 OCCC cell lines and 5 ovarian serous adenocarcinoma (OSAC) cell lines. The mutation status of the PIK3CA and KRAS genes was examined by direct sequencing. The IC50 values of NVP-BEZ235 (BEZ235) and temsirolimus were determined by WST-8 assay. Protein expression levels of PI3K-AKT-mTOR pathway molecules were examined by western blotting. Cell cycle distribution was analyzed by flow cytometry. Annexin V staining was used for detecting apoptosis. We also investigated the effects of BEZ235 on OCCC tumor growth in a nude mouse xenograft model. Four of the 8 OCCC cell lines showed a PIK3CA mutation while none of the 5 OSAC cell lines showed a mutation. The IC50 values of BEZ235 for the OCCC cell lines were lower than these values for the OSAC cell lines. The IC50 value of temsirolimus was higher than BEZ235 in the OCCC cell lines. The PIK3CA mutation was more frequently noted in OCCC than OSAC cells, but the sensitivity of these cell lines to BEZ235 or temsirolimus was not related to the mutation status. pHER3 and pAkt proteins were expressed more frequently in OCCC compared with OSAC. However, protein expression levels were distributed widely, and were not related to the sensitivity. Treatment with BEZ235 suppressed expression of pAkt, although treatment with temsirolimus did not. OCCC cells exhibited G1 phase arrest after treatment with BEZ235 and apoptosis with a higher concentration of the agent. BEZ235 significantly inhibited tumor growth in mice bearing OVISE and TU-OC-1 cell tumors. The present study indicated that the PI3K-AKT-mTOR pathway is a potential target for OCCC, and that BEZ235 warrants investigation as a therapeutic agent.

Neoadjuvant chemotherapy in advanced ovarian cancer: latest results and place in therapy

Approximately 70% of women with epithelial ovarian cancer (EOC) are diagnosed with advanced stage disease, which is associated with high morbidity and mortality. The standard approach to treating patients with advanced EOC remains primary debulking surgery (PDS) followed by chemotherapy. EOC is one of the most sensitive of all solid tumors to cytotoxic drugs, with over 80% of women showing a response to standard chemotherapy combined with taxane and platinum. Furthermore, residual disease is a major prognostic factor for survival. On the basis of the clinical features, neoadjuvant chemotherapy (NACT) followed by interval debulking surgery (IDS) is considered to be an alternative treatment option to standard treatment in patients unable to undergo complete resection during PDS. Noninferiority of NACT-IDS to PDS has been demonstrated in some randomized controlled trials and meta-analyses. NACT would also lead to improved quality of life (QOL) of patients, however there are still problems to be solved in the treatment strategy. The uncertainty of perioperative visual assessment of tumor dissemination after NACT has been reported. In addition, several papers have shown the possibility that NACT induces platinum resistance. Furthermore, a notable risk associated with NACT is that patients with significant side effects and refractory disease will lose the opportunity for debulking surgery. Appropriate selection of the patient cohort for NACT is an important issue. Bevacizumab (Bev) is active in patients with advanced EOC. However, the use of Bev is not recommended in the neoadjuvant setting. Bev has a specific adverse event profile that needs to be considered, especially for surgical management, such as gastrointestinal perforation, hemorrhage, and thromboembolic events. NACT could be an alternative treatment option in patients with stage III or IV EOC. However, further studies are needed to clarify the precise role of NACT in the management of advanced EOC.

Simultaneous inhibition of the mitogen‐activated protein kinase kinase and phosphatidylinositol 3′‐kinase pathways enhances sensitivity to paclitaxel in ovarian carcinoma

Paclitaxel (PTX), one of the key drugs used to treat ovarian cancer, activates the Raf–mitogen‐activated protein kinase kinase (MEK) and phosphatidylinositol 3′‐kinase (PI3K) pathways, both considered to be proliferation and cell‐survival pathways. The present study aimed to clarify whether and how MEK and PI3K inhibitors affect sensitivity to PTX in ovarian cancer cells. We treated five ovarian cancer cell lines using PTX combined with MEK inhibitor (PD98059 [PD]) and PI3K inhibitor (LY294002 [LY]), then assessed cell viability, apoptosis, and expression of phosphorylated (p) MEK and pAkt. We also investigated the effect of combined treatment on survival in a xenograft model. The protein expression levels of MEK, pMEK, Akt, and pAkt were confirmed in all cell lines. pMEK levels increased after PTX treatment in all five ovarian cancer cell lines. Combining PTX with either PD or LY had an additive effect on cell‐growth inhibition. In contrast, we observed a synergistic effect when PTX was combined with both PD and LY. The number of apoptotic cells was significantly higher after treatment with PTX combined with PD and LY, compared with PTX alone or PTX with either PD or LY (P < 0.05). PD with PTX downregulated the protein expression level of pMEK and upregulated pAkt in all five cell lines. Treating nude mice with PTX and PD and LY prolonged survival in an ovarian cancer xenograft model (P < 0.005). These results indicate that further study is warranted for PTX combined with MEK inhibitor and PI3K inhibitor to treat ovarian carcinoma. (Cancer Sci 2007; 98: 2002–2008)

Chemotherapy consisting of paclitaxel and carboplatin benefits a patient with malignant mixed müllerian tumor of the fallopian tube

Malignant mixed müllerian tumors (MMMT) of the fallopian tube are extremely rare, and optimal therapy for them is unknown. A 71-year-old woman presented to us with symptoms of abdominal distension and nausea. A right salpingo-oophorectomy was performed. Pathological examination determined International Federation of Gynecology and Obstetrics (FIGO) stage IIIc MMMT of the right fallopian tube. Of note, multiple tumoral nodules were attached to the sigmoid colon. The patient received three courses of chemotherapy, consisting of 175 mg/m2 paclitaxel and AUC = 5 carboplatin (TC therapy), administered at 3-week intervals. A second, debulking, surgery was then performed, consisting of total abdominal hysterectomy, left salpingo-oophorectomy, and pelvic and paraaortic lymphadenectomy. The tumor attached to the sigmoid colon had shrunk by 60% after chemotherapy. The patient received an additional five courses of adjuvant TC therapy. The patient is alive and free of disease 28 months after the debulking surgery. TC therapy may be effective for MMMT of the fallopian tube.

Novel therapeutic strategy for cervical cancer harboring FGFR3-TACC3 fusions

We previously found that therapeutic targetable fusions are detected across various cancers. To identify therapeutic targetable fusion in uterine cervical cancer, for which no effective gene targeted therapy has yet been clinically applied, we analyzed RNA sequencing data from 306 cervical cancer samples. We detected 445 high confidence fusion transcripts and identified four samples that harbored FGFR3-TACC3 fusion as an attractive therapeutic target. The frequency of FGFR3-TACC3-fusion-positive cervical cancer is also 1.9% (2/103) in an independent cohort. Continuous expression of the FGFR3-TACC3 fusion transcript and protein induced anchorage-independent growth in the cervical epithelial cell line established from the ectocervix (Ect1/E6E7) but not in that from endocervix (End1/E6E7). Injection of FGFR3-TACC3 fusion-transfected-Ect1/E6E7 cells subcutaneously into NOG mice generated squamous cell carcinoma xenograft tumors, suggesting the association between FGFR3-TACC3 fusion and squamous cell carcinogenesis. Transfection of a FGFR3-TACC3 fusion transcript into four cervical cancer cell lines (SiHa, ME180, HeLa, and Ca Ski) induced activation of the MAPK pathway and enhancement of cell proliferation. Transcriptome analysis of the FGFR3-TACC3 fusion-transfected cell lines revealed that an IL8-triggered inflammatory response was increased, via activation of FGFR3–MAPK signaling. Continuous expression of FGFR3-TACC3 fusion led to activation of the PI3K–AKT pathway only in the two cell lines that harbored PIK3CA mutations. Sensitivity to the FGFR inhibitor, BGJ398, was found to depend on PIK3CA mutation status. Dual inhibition of both FGFR and AKT showed an obvious synergistic effect in cell lines that harbor mutant PIK3CA. Additionally, TACC3 inhibitor, KHS101, suppressed FGFR3-TACC3 fusion protein expression and showed antitumor effect against FGFR3-TACC3 fusion-transfected cell lines. FGFR3-TACC3 fusion-positive cancer has frequent genetic alterations of the PI3K/AKT pathway and selection of appropriate treatment based on PI3K/AKT pathway status should be required.

Profile of farletuzumab and its potential in the treatment of solid tumors

Folate receptor (FR) α expression in normal tissues is restricted to a subpopulation of epithelial cells. In contrast, FRα is overexpressed in epithelial ovarian cancer (EOC) and non-small-cell lung carcinoma. Therefore, FRα is considered a promising therapeutic target for EOC and non-small-cell lung carcinoma. Farletuzumab (MORAb-003) is a humanized monoclonal antibody of immunoglobulin G subtype 1 kappa, targeting human FRα. To date, Phase I/II clinical trials have clearly demonstrated the feasibility and safety of farletuzumab as a treatment option against solid tumors. However, in Phase III clinical trial that was conducted to verify the combined effect of paclitaxel–carboplatin combination therapy and farletuzumab for patients with recurrent EOC, improvement in progression-free survival was not statistically significant. This result might be owing to the fact that the eligibility criteria for these studies did not include FRα expression. The significance of FRα as a predictive/prognostic biomarker remains unclear. In addition, there is currently no established biomarker to predict the response and toxicities among patients receiving farletuzumab therapy. Furthermore, the primary mechanism of action of farletuzumab has not yet been identified. Therefore, further research to identify the mechanism of farletuzumab in tumor suppression is necessary to clarify the full potential of this chemotherapeutic agent.

Feasibility Study of Adjuvant Chemotherapy Using Taxane Plus Carboplatin for High-Risk Patients With Uterine Cervical Non-Squamous Cell Carcinoma After Radical Hysterectomy.

Objective We conducted this study to evaluate the efficacy and safety of adjuvant chemotherapy using taxane plus carboplatin (CBDCA) for high-risk stage IB–IIB patients with uterine cervical non-squamous cell carcinoma after radical hysterectomy. Methods Thirty-seven patients were eligible. Pelvic lymph node involvement and/or parametrial invasion were defined as high-risk factors. The patients were treated with 6 cycles of paclitaxel (PTX, 175 mg/m2) or docetaxel (DTX, 60 mg/m2) followed by CBDCA (area under the curve, 6) every 3 weeks. The primary end point was 2-year progression-free survival (PFS) rate, and the secondary end point was the assessment of adverse events. Results Twenty-two patients received PTX/CBDCA (TC) chemotherapy, and the remaining 15 patients underwent DTX/CBDCA (DC) chemotherapy. The 2-year PFS rate was 62.1% (95% confidence interval, 44.6%–75.5%). Patients receiving DC chemotherapy showed a better 2-year PFS rate compared to those with TC chemotherapy, but the difference was not statistically significant (80.0% vs 50.0%, P = 0.1400). The most common grade 3/4 adverse events were hematologic toxicities, which were generally well tolerable. Nonhematologic toxicity was generally mild. Conclusions Taxane and CBDCA combination chemotherapy, especially DC chemotherapy, may be one of the useful adjuvant treatments for high-risk stage IB–IIB patients with uterine cervical non-squamous cell carcinoma after radical hysterectomy.

Fertility-sparing surgery for uterine cervical cancer

The standard treatment for early cervical cancer of the uterus (CC) is radical hysterectomy with resection of the parametrium and pelvic lymphadenectomy. At least 40% of patients develop early-stage CC during child-bearing age, therefore preserving the uterus to maintain fertility has been an important consideration. Several surgical procedures including conization and vaginal or abdominal radical trachelectomy have been reported. These procedures are safe for removing lymph node negative CC tumors with <2 cm diameter. Recently, less radical surgical procedures that maintain fertility, such as conization, simple trachelectomy, minimally invasive surgery and neoadjuvant chemotherapy, have been indicated for tumors greater than 2 cm in diameter. In this review, we discuss the currently accepted surgical approaches for treating CC while maintaining fertility.

Serum Vascular Endothelial Growth Factor-a as a Prognostic Biomarker for Epithelial Ovarian Cancer

Background Bevacizumab, which targets vascular endothelial growth factor (VEGF)-A, has recently been proven to be effective for the treatment of epithelial ovarian cancer (EOC). Thus, interest in VEGF-A has increased. There are few reports on concomitant detection of both ligands and its soluble receptors in serum samples, and the significance of serum VEGF-A in EOC is unclear, unlike the situation with tissue samples. We conducted the present study to explore the levels of serum VEGF family and its receptors and to evaluate their utility as prognostic biomarkers. Methods A total of 128 patients with EOC, who were consecutively treated at Tottori University Hospital between 2006 and 2012, were included. Blood samples were collected before initial surgery. Serum concentrations of VEGF-A, VEGF-C, VEGFR-1, and VEGFR-2 were analyzed by enzyme-linked immunosorbent assay. We also examined the mRNA and protein expression of VEGF-A in tumor tissue from 30 cases by real-time reverse transcription polymerase chain reaction and immunohistochemistry. Results The levels of VEGF-A in patients with stage III/IV disease were significantly higher than those with stage I/II disease (P = 0.0036). On the other hand, the level of VEGFR-2 in stage III/IV was significantly lower than that in stage I/II (P = 0.0026). With the cutoff value of VEGF/VEGFRs at the median level, the overall survival (OS) for patients with high VEGF-A levels was significantly lower than those with low levels (P = 0.015). Patients with high VEGFR-2 levels showed better prognosis than those with low VEGFR-2 levels (P = 0.023). Multivariate analysis revealed that International Federation of Gynecology and Obstetrics stage and serum VEGF-A were independent prognostic factors for OS [hazard ratio 2.01, 95% confidence interval (1.13–3.63), P = 0.017]. There was no significant correlation between mRNA or protein expression and serum levels of VEGF-A. Conclusions Serum VEGF-A is an independent prognostic factor for OS in patients with EOC, implying that serum VEGF-A is a prognostic biomarker for EOC. Further study to validate the data is needed.