The diagnostic management of acute venous thromboembolism during pregnancy: recent advancements and unresolved issues

Adequate diagnostic management of suspected venous thromboembolism (VTE) in pregnant women is of great importance. The diagnostic performance of clinical decision rules and D-dimer testing is influenced by physiological changes during pregnancy and is understudied. Recent studies have addressed these issues by developing a new clinical decision rule and raising the D-dimer level cut-off points. With imaging of suspected pulmonary embolism (PE) the radiation exposure remains a concern. Recent studies have adjusted CT settings and scan length to minimize this exposure without loss of image quality. Furthermore the first choice imaging modality of suspected PE in pregnant women remains a matter of debate in view of studies showing high inadequacy rates for both CT scanning and VQ scanning. Issues concerning the diagnostic management of VTE in pregnant women and advancements made in recent years will be discussed.

Primary anti-VEGF-refractory metastatic renal cell carcinoma (mRCC): Clinical characteristics, risk factors, and subsequent therapy

305

Background: A proportion of patients treated with anti-VEGF therapy first line exhibit progressive disease (PD) as best response (per RECIST). The characteristics and outcome of this population are poorly understood.

Methods: Data from patients with mRCC treated with anti-VEGF therapy were collected through the International mRCC Database Consortium from 12 centers.

Results: One thousand fifty-six evaluable patients were treated with VEGF-inhibitors as their first-line antiangiogenic therapy. Of those, 272 (26%) patients had PD as best response. Their initial treatment was sunitinib (n=203), sorafenib (n=51), or bevacizumab (n=18). Six percent of patients were favorable risk, 55% intermediate risk, and 39% poor risk as per Heng et al JCO 2009 prognostic factors. On multivariable analysis, predictors of PD at first restaging were KPS < 80% (OR 2.3, p < 0.0001), diagnosis to treatment < 1 year (OR 2.1, p < 0.0001), neutrophilia (OR 1.9, p = 0.0021), thrombocytosis (OR 1.7, p = 0.0068), and anemia (OR 1.6, p = 0.0058). The median progression-free survival (PFS) and overall survival (OS) in patients with primary refractory disease vs. patients without (i.e., partial response or stable disease) was 2.4 vs. 11 months (p<0.0001) and 6.8 vs. 29 months (p<0.0001), respectively. Only 108 (40%) VEGF-refractory patients proceeded to receive 2nd line VEGF inhibitors (sunitinib (n=32), sorafenib (n=44), axitinib (n=2), bevacizumab (n=4)), mTOR inhibitors (temsirolimus (n=14), everolimus (n=11)), or interferon (n=1). The response rate, PFS and OS of this second-line therapy was 9%, 2.5 months and 7.4 months, respectively. The response rate, PFS and OS of those receiving second-line VEGF vs. mTOR inhibitors was 10% vs. 6% (p=NS), 2.8 vs. 2.0 months (p=0.069) and 7.9 vs. 4.7 months (p=0.40), respectively.

Conclusions: Primary anti-VEGF-refractory mRCC patients have a dismal prognosis. Second-line anti-mTOR agents may not be better than alternate anti-VEGF agents after primary anti-VEGF failure. Investigation into the mechanism of primary resistance and alternative therapeutic strategies are needed.

[Table: see text]

Validation of the AJCC staging system (7th edition) in Asian patients with localized prostate cancer undergoing radical radiotherapy

112

Background: The epidemiology of prostate cancer (PCa) varies widely internationally. Although prostate cancer is usually regarded as uncommon in Asia, dramatic rises in recent years have resulted in it being ranking third by incidence in Singapore. Conventional prognostic parameters derived from Western populations have been integrated into systems such as the new AJCC seventh edition staging system, the validity of which is unclear in Asia. We thus sought to validate its performance, alongside other prognostic factors in a large Asian series of radiotherapy patients.

Methods: A retrospective review of 404 consecutive Singaporean patients receiving radical radiotherapy between 1997 and 2005 at the National Cancer Centre was performed. The primary outcome was biochemical relapse free survival (BRFS), defined by the Phoenix criteria. Prognostic risk groups were defined using AJCC seventh edition. Univariate analysis (UVA) and multivariate analysis (MVA) was performed for other putative risk factors: age, race, Gleason score, prognostic risk grouping, tumour classification, radiation delivery technique, radiotherapy dose, hormonal therapy (HT) and initial PSA.

Results: Median age was 69; median BRFS was 55 months with 71 biochemical relapses. 4 risk factors showed univariate association with BRFS: AJCC risk groups (p=0.038), T-stage (p=0.018), RT dose (p=0.025) and initial PSA value (p=0.013) with AJCC risk groups and initial PSA value remaining significant after MVA ( Table ). Harrell's c-index for AJCC risk grouping was 0.56, with no significant difference seen in outcomes between AJCC risk group II and III.

Conclusions: Our results validate the new AJCC seventh edition prostate cancer prognostic risk grouping in an Asian radiotherapy population for the first time; the actual association however is relatively weak possibly due to differences in biology, screening or epidemiology.

[Table: see text]

No significant financial relationships to disclose.

The effect of low serum sodium on treatment outcome to vascular endothelial growth factor (VEGF)-targeted therapy in metastatic renal cell carcinoma: Results from a large international collaboration

322

Background: Hyponatremia has been associated with poor survival in many solid tumors and more recently found to be of prognostic and predictive value in metastatic renal cell cancer (mRCC) patients (pts) treated with immunotherapy (Jeppesen et al, Br J Cancer. 2010). We sought to investigate the influence of baseline hyponatremia in mRCC pts treated with contemporary vascular endothelial growth factor (VEGF)- targeted therapy in a larger international and multi-institutional database.

Methods: Baseline characteristics and outcomes on 855 pts treated with first-line anti-VEGF therapy for mRCC were available from 8 Cancer Centers to study the impact of hyponatremia (defined as serum Na<135 mmol/L) on clinical outcome as measured by overall survival (OS), time to treatment failure (TTF), best response (CR, PR, SD and PD).

Results: Median OS after treatment initiation was 16.8 months (mos) (95% CI: 14.9, 18.5 mos), with 334 (39%) of patients remaining alive. Median follow-up in pts alive was 18.8 mos. Median baseline serum sodium was 138 mmol/L (range: 122–159), and hyponatremia was found in 16.7% of pts. On univariate analysis, hyponatremia was associated with shorter OS (6.5 vs. 18.8 mos; HR 2.32 [95% CI: 1.86–2.89], p<0.0001), shorter TTF (2.8 vs. 6.9 mos.; HR 2.20 [95% CI: 1.81–2.68], p<0.0001), and lower disease control rate (DCR) as defined by CR+PR+SD (51.2% vs. 74.6%, OR 0.36 [95% CI: 0.2–0.57], p<0.0001). In multivariate analysis adjusted for MSKCC or Heng's risk criteria (JCO 2009), these effects remain significant with p<0.001 for OS and TTF and p=0.01 for DCR. The results were similar (p<0.001) if sodium was analyzed as a continuous variable.

Conclusions: This is the first large multi-institutional report to show that low serum sodium is independently associated with a worse outcome in mRCC pts treated with VEGF-targeted agents.

No significant financial relationships to disclose.

Survival and human papillomavirus in oropharynx cancer in TAX 324: a subset analysis from an international phase III trial

BACKGROUND

The association between human papillomavirus (HPV) and overall survival (OS) in oropharynx cancer (OPC) was retrospectively examined in TAX 324, a phase III trial of sequential therapy for locally advanced head and neck cancer.

METHODS

Accrual for TAX 324 was completed in 2003 and data updated through 2008. Pretherapy tumor biopsies were studied by PCR for human papillomavirus type 16 and linked to OS, progression-free survival (PFS) and demographics.

RESULTS

Of 264 patients with OPC, 111 (42%) had evaluable biopsies; 56 (50%) were HPV+ and 55 (50%) were HPV-. HPV+ patients were significantly younger (54 versus 58 years, P = 0.02), had T1/T2 primary cancers (49% versus 20%, P = 0.001), and had a performance status of zero (77% versus 49%, P = 0.003). OS and PFS were better for HPV+ patients (OS, hazard ratio = 0.20, P < 0.0001). Local-regional failure was less in HPV+ patients (13% versus 42%, P = 0.0006); at 5 years, 82% of HPV+ patients were alive compared with 35% of HPV- patients (P < 0.0001).

CONCLUSIONS

HPV+ OPC has a different biology compared with HPV- OPC; 5-year OS, PFS, and local-regional control are unprecedented. These results support the possibility of selectively reducing therapy and long-term morbidity in HPV+ OPC while preserving survival and approaching HPV- disease with more aggressive treatment.

The Singapore liver cancer recurrence (SLICER) score for relapse prediction in patients with resected hepatocellular carcinoma

169

Background: Hepatocellular carcinoma (HCC) is a common worldwide cancer associated with extremely poor survival, with surgery the only option for cure in patients with localized disease. Current prognostic models for HCC are algorithms developed on datasets of mainly patients with metastatic or unresectable cancer, and may be less relevant to resectable HCC. Nomograms provide individualized outcome estimates. We constructed a postoperative nomogram, the Singapore liver cancer recurrence (SLICER) score, to predict outcomes of HCC patients who have undergone surgical resection.

Methods: Records for Singaporean patients undergoing first-line curative surgery for localized HCC in one institution between 1992 and 2007 were retrospectively reviewed (n=405). Freedom from relapse (FFR) was the primary outcome measure. An outcome-blinded modeling strategy including clustering, data reduction and transformation, was used. Calibration was tested with bootstrapping (n=200). We compared the performance of this model with other alternative models including CLIP, CUPI, BCLC, and Okuda scores using c-indices and likelihood analysis.

Results: A nomogram (SLICER score) predicting FFR was designed, incorporating vascular invasion, tumor size, multifocality, ECOG status, pre-operative AFP, Childs-Pugh score and cirrhosis. Bootstrap estimates show good calibration at 1, 2, 3, and 5 years postsurgery Comparison of the SLICER score with alternative prognostic models shows superior performance (Table).

Conclusions: The SLICER score enables individualized relapse predictions for patients following curative resection of localized HCC. It permits optimal patient selection for adjuvant therapy trials, biomarker development, and individual counseling.

[Table: see text]

No significant financial relationships to disclose.

Metastatic breast tumors express increased tau, which promotes microtentacle formation and the reattachment of detached breast tumor cells

The cytoskeletal organization of detached and circulating tumor cells (CTCs) is currently not well defined and may provide potential targets for new therapies to limit metastatic tumor spread. In vivo, CTCs reattach in distant tissues by a mechanism that is tubulin-dependent and suppressed by polymerized actin. The cytoskeletal mechanisms that promote reattachment of CTCs match exactly with the mechanisms supporting tubulin microtentacles (McTN), which we have recently identified in detached breast tumor cells. In this study, we aimed to investigate how McTN formation is affected by the microtubule-associated protein, tau, which is expressed in a subset of chemotherapy-resistant breast cancers. We demonstrate that endogenous tau protein localizes to McTNs and is both necessary and sufficient to promote McTN extension in detached breast tumor cells. Tau-induced McTNs increase reattachment of suspended cells and retention of CTCs in lung capillaries. Analysis of patient-matched primary and metastatic tumors reveals that 52% possess tau expression in metastases and 26% display significantly increased tau expression over disease progression. Tau enrichment in metastatic tumors and the ability of tau to promote tumor cell reattachment through McTN formation support a model in which tau-induced microtubule stabilization provides a selective advantage during tumor metastasis.

Osteopontin induces angiogenesis through activation of PI3K/AKT and ERK1/2 in endothelial cells

Angiogenesis is a key step in tumor growth and metastasis. The mechanism by which osteopontin (OPN) induces the angiogenesis of endothelial cells remains unclear. Here, we show that OPN confers cytoprotection through the activation of the PI3K/Akt pathway with subsequent upregulation of Bcl-xL and activation of nuclear factor-kappaB. OPN enhances the expression of vascular endothelial growth factor (VEGF) through the phosphorylation of AKT and extracellular signal-regulated kinase (ERK). In turn, OPN-induced VEGF activates PI3K/AKT and the ERK1/2 pathway as a positive feedback signal. Blocking the feedback signal by anti-VEGF antibody, PI3-kinase inhibitor or ERK inhibitor can partially inhibit the OPN-induced human umbilical vein endothelial cell (HUVEC) motility, proliferation and tube formation, while blocking the signal by anti-OPN or anti-alphavbeta3 antibody completely abrogates the biological effects of OPN on HUVECs. In addition, blood vessel formation is also investigated in vivo. The antiangiogenesis efficacy of anti-OPN antibody in vivo is more effective than that of anti-VEGF antibody, which only blocks the feedback signals. These data show that OPN enhances angiogenesis directly through PI3K/AKT- and ERK-mediated pathways with VEGF acting as a positive feedback signal. The results suggest that OPN might be a valuable target for developing novel antiangiogenesis therapy for treatment of cancer.

Drug Response Indicator Test (DRIT) as a predictive test for treatment outcomes in advanced breast cancer patients (ABC)

1119

Background: There are limited options for selecting an optimal treatment regimen for ABC patients (pts). DRIT is a platform technology that provides a profile of a patient's tumor's sensitivity or resistance to commonly used chemotherapeutic, hormonal, or biological agents as a basis for individualized anticancer treatment approach. DRIT may allow physicians to choose more effective drug treatments before initiation of therapy and improve the efficacy and toxicity profile of cancer therapies. Methods: DRIT analysis is based on fluorescent dye-labeled monoclonal antibody staining followed by computer-assisted microscopy to quantitatively measure expression levels in tumor sections. The interpretation of DRI expression levels results in classification of tumors as sensitive or resistant to treatment with a mechanistically related drug. This study utilized the following drug/DRI combinations: hormonal therapy/estrogen receptor; capecitabine/thymidylate synthase; docetaxel, paclitaxel, abraxane/β-tubulin isoform III; trastuzumab/HER-2; gemcitabine/ribonucleotide reductase. DRIT was performed on the tumor tissue of consented study participants with ABC who were then deemed to be sensitive or resistant to a given agent/agents. We then analyzed retrospectively clinical treatment outcomes (clinically sensitive to therapy defined as-stable disease+partial response+complete response or resistant to therapy-no response to therapy) for 91 treatment interventions in 71 pts with the DRIT tissue data. Results: We found that the DRIT sensitivity was 0.99, with specificity of 0.59, positive predictive value of 0.88, negative predictive value of 0.93 and overall predictive value of 88% for treatment outcomes for this cohort of ABC pts. Conclusions: This study suggests that DRIT can provide more accurate prediction of treatment outcomes for ABC pts than the standard of care approach and therefore has a potential to avoid unnecessary ineffective drug treatment exposure. Prospective study in ABC pts is currently conducted at the UMGCC.

[Table: see text]