S. Diane Yamada

Adipocytes promote ovarian cancer metastasis and provide energy for rapid tumor growth

Intra-abdominal tumors, such as ovarian cancer, have a clear predilection for metastasis to the omentum, an organ primarily composed of adipocytes. Currently, it is unclear why tumor cells preferentially home to and proliferate in the omentum, yet omental metastases typically represent the largest tumor in the abdominal cavities of women with ovarian cancer. We show here that primary human omental adipocytes promote homing, migration and invasion of ovarian cancer cells, and that adipokines including interleukin-8 (IL-8) mediate these activities. Adipocyte–ovarian cancer cell coculture led to the direct transfer of lipids from adipocytes to ovarian cancer cells and promoted in vitro and in vivo tumor growth. Furthermore, coculture induced lipolysis in adipocytes and β-oxidation in cancer cells, suggesting adipocytes act as an energy source for the cancer cells. A protein array identified upregulation of fatty acid–binding protein 4 (FABP4, also known as aP2) in omental metastases as compared to primary ovarian tumors, and FABP4 expression was detected in ovarian cancer cells at the adipocyte-tumor cell interface. FABP4 deficiency substantially impaired metastatic tumor growth in mice, indicating that FABP4 has a key role in ovarian cancer metastasis. These data indicate adipocytes provide fatty acids for rapid tumor growth, identifying lipid metabolism and transport as new targets for the treatment of cancers where adipocytes are a major component of the microenvironment.

Intensity-modulated whole pelvic radiotherapy in women with gynecologic malignancies.

PURPOSE To describe our initial clinical experience with intensity-modulated whole pelvic radiotherapy (IM-WPRT) in women with gynecologic malignancies. METHODS AND MATERIALS Between February 2000 and August 2001, 40 gynecology patients underwent IM-WPRT. After fabrication of customized immobilization, all patients underwent contrast-enhanced CT, and a clinical target volume was contoured consisting of the upper vagina, parametria, uterus (if present), and presacral and pelvic lymph node regions. The clinical target volume was expanded by 1 cm to create a planning target volume (PTV). Using commercially available software, 7- or 9-field, 6-MV, coplanar IM-WPRT plans were generated for all patients. The worst acute gastrointestinal and genitourinary toxicity during treatment was scored on a 4-point scale: 0, none; 1, mild, no medications required; 2, moderate, medications required; and 3, severe, treatment breaks or cessation, hospitalization. As a comparison, acute toxicities in 35 previously treated conventional WPRT patients were analyzed. No significant differences were noted in the clinicopathologic and treatment factors between the two groups. RESULTS IM-WPRT plans provided excellent PTV coverage, with considerable sparing of the surrounding normal tissues. On average, 98.1% of the PTV received the prescription dose. The average percentage of the PTV receiving 110% and 115% of the prescription dose was 9.8% and 0.2%, respectively. IM-WPRT was well tolerated, with no patient developing Grade 3 toxicity. Grade 2 acute gastrointestinal toxicity was less common in the IM-WPRT group (60 vs. 91%, p = 0.002) than in the conventional WPRT group. Moreover, the percentage of IM-WPRT and WPRT patients requiring no or only infrequent antidiarrheal medications was 75% and 34%, respectively (p = 0.001). Although less Grade 2 genitourinary toxicity was seen in the IM-WPRT group (10% vs. 20%), this difference was not statistically significant (p = 0.22). CONCLUSION IM-WPRT is a promising approach in gynecology patients. IMRT planning resulted in excellent PTV coverage, with considerable sparing of normal tissues. Treatment was well tolerated and associated with less acute gastrointestinal sequelae than conventional WPRT. Longer follow-up and more patients are needed, however, to evaluate the full merits of this novel approach.

Loss of E-Cadherin Promotes Ovarian Cancer Metastasis via α5-Integrin, which Is a Therapeutic Target

E-cadherin loss is frequently associated with ovarian cancer metastasis. Given that adhesion to the abdominal peritoneum is the first step in ovarian cancer dissemination, we reasoned that down-regulation of E-cadherin would affect expression of cell matrix adhesion receptors. We show here that inhibition of E-cadherin in ovarian cancer cells causes up-regulation of alpha(5)-integrin protein expression and transcription. When E-cadherin was blocked, RMUG-S ovarian cancer cells were able to attach and invade more efficiently. This greater efficiency could, in turn, be inhibited both in vitro and in vivo with an alpha(5)beta(1)-integrin-blocking antibody. When E-cadherin is silenced, alpha(5)-integrin is up-regulated through activation of an epidermal growth factor receptor/FAK/Erk1-mitogen-activated protein kinase-dependent signaling pathway and not through the canonical E-cadherin/beta-catenin signaling pathway. In SKOV-3ip1 ovarian cancer xenografts, which express high levels of alpha(5)-integrin, i.p. treatment with an alpha(5)beta(1)-integrin antibody significantly reduced tumor burden, ascites, and number of metastasis and increased survival by an average of 12 days when compared with IgG treatment (P < 0.0005). alpha(5)-Integrin expression was detected by immunohistochemistry in 107 advanced stage ovarian cancers using a tissue microarray annotated with disease-specific patient follow-up. Ten of 107 tissues (9%) had alpha(5)-integrin overexpression, and 39% had some level of alpha(5)-integrin expression. The median survival for patients with high alpha(5)-integrin levels was 26 months versus 35 months for those with low integrin expression (P < 0.05). Taken together, we have identified alpha(5)-integrin up-regulation as a molecular mechanism by which E-cadherin loss promotes tumor progression, providing an explanation for how E-cadherin loss increases metastasis. Targeting this integrin could be a promising therapy for a subset of ovarian cancer patients.

Impact of intensity-modulated radiotherapy on acute hematologic toxicity in women with gynecologic malignancies

PURPOSE To evaluate the impact of intensity-modulated whole pelvic radiotherapy (IM-WPRT) on acute hematologic toxicity (HT) in gynecology patients. METHODS AND MATERIALS Between February 2000 and June 2001, 36 patients (24 cervix, 12 uterus) received IM-WPRT. The target consisted of the upper vagina, parametria, uterus, and presacral and pelvic lymph nodes. Using commercially available software, seven or nine coplanar IM-WPRT plans were generated. The planning goals were to irradiate the target while minimizing the dose to the small bowel, bladder, and rectum. Pelvic bone marrow (BM) was not a constraint in the planning process. The variables analyzed included white blood count (WBC), absolute neutrophil count (ANC), platelets, and hemoglobin (Hgb) obtained before and weekly during RT. As a comparison, the HT in 88 patients (44 cervix, 44 uterus) treated to the same target volume and total dose (45 Gy) with conventional four-field WPRT was analyzed. In addition, the medullary spaces within the pelvic bones in 10 women were contoured and the average dose-volume histograms representing the pelvic BM were compared between the two groups. RESULTS IM-WPRT patients had a lower median age (p = 0.008), higher percentage of squamous histologic features (p = 0.04), and were more likely to receive chemotherapy (CTX) (p = 0.02) than were the WPRT patients. No differences were seen in the baseline WBC, ANC, platelet, or Hgb levels between the two groups. Grade 2 or greater WBC, ANC, and Hgb toxicity was seen in 19.4%, 9.1%, and 8.6% of the IM-WPRT patients, respectively. Comparable rates were seen in the WPRT patients (WBC 21.6%, p = 0.79; ANC 8.3%, p = 0.91; Hgb 9.2%, p = 0.94). No Grade 2 or greater platelet toxicity was seen in either group. Significant HT was infrequent in women treated with RT alone and was comparable in the two groups. In contrast, WPRT + CTX patients experienced more Grade 2 or greater WBC toxicity (60% vs. 31.2%, p = 0.08) and developed lower median WBC (2.8 vs. 3.6 microg/dL, p = 0.05) and ANC (1874 vs. 2669, p = 0.04) nadirs than did IM-WPRT + CTX patients. Moreover, CTX was held more often in the WPRT group secondary to HT (40% vs. 12.5%, p = 0.06). Although Grade 2 or greater ANC (23.5% vs. 15.3%) and Hgb (35.2% vs. 15.2%) toxicity were lower in the IM-WPRT + CTX group, these differences did not reach statistical significance (p = 0.58 and p = 0.22, respectively). The comparison of pelvic BM dose-volume histograms revealed that IM-WPRT planning resulted in significantly less BM volume being irradiated compared with WPRT planning, particularly within the iliac crests. CONCLUSION IM-WPRT has a favorable impact on the risk of acute HT in gynecology patients, particularly in those receiving CTX. Future work is needed to optimize BM sparing in these patients to reduce the risk of significant HT further.

c-Met Overexpression Is a Prognostic Factor in Ovarian Cancer and an Effective Target for Inhibition of Peritoneal Dissemination and Invasion

The hepatocyte growth factor receptor c-Met is a receptor tyrosine kinase that plays an important role in tumor growth by activating mitogenic signaling pathways. The goal of this study was to evaluate the role of c-Met in the biology of ovarian cancer and to determine its potential as a therapeutic target. c-Met protein expression was detected by immunohistochemistry in 138 advanced-stage ovarian cancers using a tissue microarray annotated with disease-specific patient follow-up. Fifteen of 138 (11%) tissues had c-Met overexpression. Median survival for patients with high c-Met levels was 17 months versus 32 months (P = 0.001) for patients with low c-Met expression. Infection of SKOV-3ip1 cells with an adenovirus expressing a small interfering RNA (siRNA) against c-Met efficiently inhibited c-Met protein and mRNA expression as well as extracellular signal-regulated kinase and phosphatidylinositol 3-kinase signaling. It also inhibited adhesion to different extracellular matrix components, human primary mesothelial cells, and full-thickness human peritoneum and, in vivo, to mouse peritoneum. This was paralleled by a significant reduction in alpha(5) and beta(1) integrin protein and mRNA expression as well as a reduction of urokinase and matrix metalloproteinase (MMP)-2/MMP-9 activity. In SKOV-3ip1 ovarian cancer xenografts, i.p. treatment with the c-Met siRNA significantly reduced tumor burden, ascites formation, protease activity, and the number of peritoneal implants but not tumor size or angiogenesis. These results suggest that c-Met overexpression is a prognostic factor in ovarian cancer and that targeting c-Met in vivo inhibits peritoneal dissemination and invasion through an alpha(5)beta(1) integrin-dependent mechanism. Therefore, c-Met should be explored further as a therapeutic target in ovarian cancer.

Selumetinib in women with recurrent low-grade serous carcinoma of the ovary or peritoneum: an open-label, single-arm, phase 2 study.

BACKGROUND Low-grade serous carcinoma of the ovary is chemoresistant but mutations in the MAPK pathway could be targeted to control tumour growth. We therefore assessed the safety and activity of selumetinib, an inhibitor of MEK1/2, for patients with this cancer. METHODS In this open-label, single-arm phase 2 study, women (aged ≥18 years) with recurrent low-grade serous ovarian or peritoneal carcinoma were given selumetinib (50 mg twice daily, orally) until progression. The primary endpoint was the proportion of patients who had an objective tumour response according to RECIST version 1.1, assessed for all the treated patients. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00551070. FINDINGS 52 patients were enrolled between Dec 17, 2007, and Nov 23, 2009. All were eligible for analyses. Eight (15%) patients had an objective response to treatment-one patient had a complete response and seven had partial responses. 34 (65%) patients had stable disease. There were no treatment-related deaths. Grade 4 toxicities were cardiac (one), pain (one), and pulmonary events (one). Grade 3 toxicities that occurred in more than one patient were gastrointestinal (13), dermatological (nine), metabolic (seven), fatigue (six), anaemia (four), pain (four), constitutional (three), and cardiac events (two). INTERPRETATION Selumetinib is well tolerated, and is active in the treatment of recurrent low-grade serous carcinoma of the ovary or peritoneum. The findings suggest that inhibitors of the MAPK pathway warrant further investigation in these patients. FUNDING National Cancer Institute.

Intensity-modulated radiotherapy as a means of reducing dose to bone marrow in gynecologic patients receiving whole pelvic radiotherapy

PURPOSE To evaluate intensity-modulated whole pelvis radiotherapy (IM-WPRT) (with bone marrow [BM] as a planning constraint) as a means to reduce the volume of pelvic BM irradiated. METHODS AND MATERIALS Ten women with cervical or endometrial cancer previously treated using IM-WPRT were selected for this analysis. Using the treatment planning CT scan, the clinical target volume was defined to encompass the gross tumor, parametrial tissues, uterus (if present), and regional lymph nodes. The clinical target volume was expanded by a 1-cm margin to form the planning target volume (PTV). The bladder, rectum, small bowel, and pelvic BM were delineated in each patient. Three plans were created for each patient: a standard four-field WPRT plan, an IM-WPRT treatment plan designed to conform the dose to the PTV while minimizing dose to the normal tissues (excluding BM), and a BM-sparing (BMS) IM-WPRT plan that included the BM as an additional treatment planning constraint. Dose-volume histograms for the PTV, small bowel, and BM were compared for each patient. RESULTS For each of the 10 patients, BMS IM-WPRT treatment plans demonstrated a significant reduction of the volume of BM receiving >40% (18 Gy) of the prescription dose (45 Gy) compared with both IM-WPRT and four-field treatment. On average, BMS IM-WPRT resulted in only 60% of the BM volume irradiated to >50% of the dose compared with 87.4% (p <0.001) of the BM volume in a four-field plan and 75.7% (p < 0.003) of the volume in an IM-WPRT plan. Furthermore, the BMS IM-WPRT plans resulted in significant sparing of all other normal tissues that was comparable to the original IM-WPRT. In all 10 cases, the BMS IM-WPRT treatment plan did not result in any significant differences in the PTV and small bowel dose-volume histograms compared with the IM-WPRT treatment plans. CONCLUSION BMS IM-WPRT significantly reduces the volume of pelvic BM irradiated compared with conventional WPRT. In addition, BMS IM-WPRT did not compromise the improvements previously seen in IM-WPRT treatment plans that did not consider BM. Clinical studies are necessary to assess the significance of BMS IM-WPRT in reducing hematologic toxicity.

Activity of Sorafenib in Recurrent Ovarian Cancer and Primary Peritoneal Carcinomatosis: A Gynecologic Oncology Group Trial

PURPOSE Sorafenib is a kinase inhibitor targeting Raf and other kinases (ie, vascular endothelial growth factor receptor [VEGFR], platelet-derived growth factor receptor [PDGFR], Flt3, and c-KIT). This study assessed its activity and tolerability in patients with recurrent ovarian cancer (OC) or primary peritoneal carcinomatosis (PPC). METHODS This open-label, multi-institutional, phase II study used a two-stage design. Eligible patients had persistent or recurrent OC/PPC after one to two prior cytotoxic regimens, and they experienced progression within 12 months of platinum-based therapy. Treatment consisted of sorafenib 400 mg orally twice per day. Primary end points were progression-free survival (PFS) at 6 months and toxicity by National Cancer Institute criteria. Secondary end points were tumor response and duration of PFS and overall survival. Biomarker analyses included measurement of ERK and b-Raf expression in tumors and phosphorylation of ERK (pERK) in peripheral-blood lymphocytes (PBLs) before and after 1 month of treatment. Results Seventy-three patients were enrolled, of which 71 were eligible. Fifty-nine eligible patients (83%) had measurable disease, and 12 (17%) had detectable disease. Significant grade 3 or 4 toxicities included the following: rash (n = 7), hand-foot syndrome (n = 9), metabolic (n = 10), GI (n = 3), cardiovascular (n = 2), and pulmonary (n = 2). Only patients with measurable disease were used to assess efficacy. Fourteen survived progression free for at least 6 months (24%; 90% CI, 15% to 35%). Two patients had partial responses (3.4%; 90% CI, 1% to 10%); 20 had stable disease; 30 had progressive disease; and seven could not have their tumor assessed. ERK and b-Raf were expressed in all tumors. Exploratory analyses indicated that pERK in post-treatment PBL specimens was associated with PFS. CONCLUSION Sorafenib has modest antitumor activity in patients with recurrent OC, but the activity was at the expense of substantial toxicity.

Intravenous aflibercept for treatment of recurrent symptomatic malignant ascites in patients with advanced ovarian cancer: a phase 2, randomised, double-blind, placebo-controlled study

BACKGROUND Targeting of VEGF is a potential therapeutic option in patients with malignant ovarian ascites. We present the final results of a multicentre study of the efficacy and safety of aflibercept, a potent inhibitor of both VEGF and placental growth factor, in the treatment of malignant ascites. METHODS In this double-blind, placebo-controlled, parallel-group, phase 2 study, patients with advanced chemoresistant ovarian cancer and recurrent symptomatic malignant ascites were randomly assigned (1:1) via an interactive voice response system to either intravenous aflibercept (4 mg/kg every 2 weeks) or placebo, stratified by interval of time (≤ 2 weeks vs > 2 weeks) between the two most recent paracenteses before randomisation. Patients participated in the double-blind period (during which patients, investigators, and sponsor personnel were masked to treatment assignment) until they had a repeat paracentesis and for at least 60 days, and could also participate in an optional open-label period during which all patients received aflibercept. The primary efficacy endpoint was time to repeat paracentesis based on response during the double-blind period alone, and was analysed in the intention-to-treat population with censoring of patients who did not have a repeat paracentesis as of the last day of the double-blind period. Safety analyses included both double-blind and open-label periods. This study is registered at ClinicalTrials.gov, number NCT00327444. FINDINGS 55 patients with a median of four (range two to 11) previous lines of chemotherapy were randomly assigned to receive placebo (n=26) or aflibercept (n=29). Mean time to repeat paracentesis was significantly longer with aflibercept than with placebo (55·1 [SE 7·3] vs 23·3 [7·7] days; difference 31·8 days, 95% CI 10·6-53·1; p=0·0019). In the aflibercept group, two patients did not need a repeat paracentesis during 6 months of double-blind treatment. The most common grade 3 or 4 treatment-emergent adverse events were dyspnoea (six [20%] aflibercept vs two [8%] placebo), fatigue or asthenia (four [13%] vs 11 [44%]), and dehydration (three [10%] vs three [12%]). The frequency of fatal gastrointestinal events was higher with aflibercept (three intestinal perforations) than with placebo (one intestinal fistula leading to sepsis). INTERPRETATION This study shows the effectiveness of VEGF blockade in the reduction of malignant ascites, but confirms the significant clinical risk of fatal bowel perforation in this population of patients with very advanced cancer. VEGF blockade should be used with caution in advanced ovarian cancer with abdominal carcinomatosis, and the benefit-risk balance should be thoroughly discussed for each patient. FUNDING Sanofi Oncology.

Significant pelvic recurrence in high-risk pathologic stage I--IV endometrial carcinoma patients after adjuvant chemotherapy alone: implications for adjuvant radiation therapy.

OBJECTIVE To evaluate the risk of pelvic recurrence (PVR) in high-risk pathologic Stage I--IV endometrial carcinoma patients after adjuvant chemotherapy alone. METHODS Between 1992 and 1998, 43 high-risk endometrial cancer patients received adjuvant chemotherapy. All patients underwent primary surgery consisting of total abdominal hysterectomy and bilateral salpingo-oophorectomy. No patients received preoperative radiation therapy (RT). Regional lymph nodes and peritoneal cytology were sampled in 62.8% and 83.7% of cases, respectively. Most patients had Stage III--IV disease (83.7%) or unfavorable histology tumors (74.4%). None had evidence of extra-abdominal disease. All patients received 4-6 cycles of chemotherapy as the sole adjuvant therapy, consisting primarily of cisplatin and doxorubicin. Recurrent disease sites were divided into pelvic (vaginal, nonvaginal) and extrapelvic (para-aortic, upper abdomen, liver, and extra-abdominal). Median follow-up was 27 months (range, 2--96 months). RESULTS Twenty-nine women (67.4%) relapsed. Seventeen (39.5%) recurred in the pelvis and 23 (55.5%) in extrapelvic sites. The 3-year actuarial PVR rate was 46.5%. The most significant factors correlated with PVR were cervical involvement (CI) (p = 0.01) and adnexal (p = 0.05) involvement. Of the 17 women who developed a PVR, 8 relapsed in the vagina, 3 in the nonvaginal pelvis, and 6 in both. The 3-year vaginal and nonvaginal PVR rates were 37.8% and 26%, respectively. The most significant factor correlated with vaginal PVR was CI (p = 0.0007). Deep myometrial invasion (p = 0.02) and lymph nodal involvement (p = 0.03) were both correlated with nonvaginal PVR. Nine of the 29 relapsed patients (31%) developed PVR as their only (6) or first site (3) of recurrence. Factors associated with a higher rate of PVR (as the first or only site) were CI and Stage I--II disease. CONCLUSIONS PVR is common in high-risk pathologic Stage I-IV endometrial cancer patients after adjuvant chemotherapy alone. These results support the continued use of locoregional RT in patients undergoing adjuvant chemotherapy. Further studies are needed to test the addition of chemotherapy to locoregional RT.