Large retroperitoneal lymphadenopathy as a predictor of venous thromboembolism in patients with disseminated germ cell tumors treated with chemotherapy.

PURPOSE: Cisplatin-based chemotherapy, a mainstay of treatment for disseminated germ cell tumors (GCTs), is associated with venous thromboembolism (VTE). Many patients with disseminated GCTs have large retroperitoneal lymph node (RPLN) metastases that may cause venous stasis and increase the risk of VTE development. We hypothesized that there was an association between large RPLN and chemotherapy-associated VTE risk. PATIENTS AND METHODS: The training cohort was composed of patients with disseminated GCT receiving first-line chemotherapy at Princess Margaret Cancer Centre between January 2000 and December 2010. Large RPLN was defined as more than 5 cm in maximal axial diameter. The predictive and discriminatory accuracies of a model using large RPLN in predicting VTE were compared with high-risk Khorana score (≥ 3) using logistic regression and area under receiver operator characteristic curves (AUROCs). The model was externally validated in a cohort of patients treated at the London Health Sciences Centre. RESULTS: The training cohort comprised 216 patients, 21 (10%) of whom developed VTE during chemotherapy. VTE was associated with large RPLN (odds ratio [OR], 5.26; P = .001), high-risk Khorana score (OR, 11.8; P < .001), intermediate-/poor-risk disease (OR, 3.76; P = .005), and hospitalization during chemotherapy (OR, 4.24; P = .002). Large RPLN showed higher discriminatory accuracy than high-risk Khorana score (AUROC, 0.71 v 0.67, respectively). Superior discriminatory accuracy of large RPLN over high-risk Khorana score was validated in the London cohort (AUROC, 0.61 v 0.57, respectively). CONCLUSION: Large RPLN is associated with VTE in patients with disseminated GCT and provides higher discriminatory accuracy than high-risk Khorana score. Results should be validated in larger, prospective studies. Prophylactic anticoagulation may be considered in high-risk patients.

Consolidative high-dose chemotherapy after conventional-dose chemotherapy as first salvage treatment for male patients with metastatic germ cell tumours.

INTRODUCTION: Some men with metastatic germ cell tumours that have progressed after response to initial cisplatin-based combination chemotherapy are cured with conventional dose first salvage chemotherapy (CDCT)--however, many are not. High-dose chemotherapy with autologous stem cell rescue (HDCT) may be of value in these patients. Prognosis has recently been better defined by International Prognostic Factor Study Group (IPFSG) prognostic factors. HDCT after response to CDCT has been offered at our institution over the past two decades. We retrospectively assessed the validity of the IPFSG prognostic factors in our patients and evaluated the value of HDCT. METHODS: We identified eligible men with metastatic germ cell tumour progressed after at least 3 cycles of cisplatin-based chemotherapy and treated with cisplatin-based CDCT alone or with carboplatin-based HDCT. We also collected their clinical data. Patients were classified into risk groups using IPFSG factors, and progression-free and overall survival factors were analyzed and compared in patients treated with CDCT alone and with HDCT. RESULTS: We identified 38 eligible first salvage patients who had received a median of 4 cycles (range, 1 to 7 cycles) of CDCT. Twenty patients received CDCT alone and 18 patients received CDCT plus HDCT. The overall median progression- free survival was 24.6 months (95%CI, 7.3 to 28.7 months) and overall median overall survival was 34.6 months (95%CI, 17.2 to 51.3 months). Distribution by IPFSG category and 2-year progression- free survival and 3-year overall survival rates within each risk category were very similar to the IPFSG results. There were two toxic deaths with CDCT and none with HDCT. Overall, patients treated with CDCT plus HDCT had improved progression- free survival and overall survival. CONCLUSIONS: The IPFSG prognostic risk factors appeared valid in our patient population. The safety of HDCT with etoposide and carboplatin was confirmed. HDCT was associated with improved progression- free survival and overall survival outcomes, consistent with observations of the IPFSG group. Ideally, the value of optimal HDCT should be determined in comparison to optimal CDCT as first salvage therapy in men with metastatic germ cell tumour with a randomized trial.

Recombinant human erythropoietin in combination with chemotherapy increases breast cancer metastasis in preclinical mouse models.

PURPOSE: Erythropoiesis-stimulating agents (ESA) are used clinically for treating cancer-related anemia. Recent clinical trials have reported increased adverse events and reduced survival in ESA-treated breast cancer patients receiving chemotherapy, potentially related to erythropoietin (EPO)-induced cancer progression. However, minimal preclinical data are available about the impact of EPO on metastatic cell behavior and/or the metastatic process, and this was the goal of our study. EXPERIMENTAL DESIGN: Breast cancer cell lines were treated with recombinant human EPO (rHuEPO) and screened for expression of EPO receptors (EPOR). MDA-MB-231 and MDA-MB-435 cell lines were used for functional assays in vitro (two-dimensional/three-dimensional growth and survival) and in vivo (tumorigenicity and metastasis), in the presence or absence of EPO and/or cytotoxic agents. RESULTS: A large variation in EPOR expression across cell lines was observed. In vitro, rHuEPO had a protective effect on radiation-treated MDA-MB-435 cells (P < 0.05); however, rHuEPO treatment alone or combined with chemotherapy or hypoxia did not influence cell survival. In vivo, rHuEPO increased lung metastases in immunocompromised mice injected with MDA-MB-231 or MDA-MB-435 cells and treated with chemotherapy relative to mice treated with chemotherapy alone (P < 0.05). CONCLUSIONS: The lack of an in vitro effect of rHuEPO highlights the importance of in vivo studies to delineate the effects of EPO on the metastatic process. These studies may begin to uncover the underlying functional explanation for the observed EPO-related adverse events and decreased survival in ESA-treated metastatic breast cancer patients undergoing chemotherapy.

Deletion of the thrombin cleavage domain of osteopontin mediates breast cancer cell adhesion, proteolytic activity, tumorgenicity, and metastasis.

BACKGROUND: Osteopontin (OPN) is a secreted phosphoprotein often overexpressed at high levels in the blood and primary tumors of breast cancer patients. OPN contains two integrin-binding sites and a thrombin cleavage domain located in close proximity to each other. METHODS: To study the role of the thrombin cleavage site of OPN, MDA-MB-468 human breast cancer cells were stably transfected with either wildtype OPN (468-OPN), mutant OPN lacking the thrombin cleavage domain (468-ΔTC) or an empty vector (468-CON) and assessed for in vitro and in vivo functional differences in malignant/metastatic behavior. RESULTS: All three cell lines were found to equivalently express thrombin, tissue factor, CD44, αvß5 integrin and ß1 integrin. Relative to 468-OPN and 468-CON cells, 468-ΔTC cells expressing OPN with a deleted thrombin cleavage domain demonstrated decreased cell adhesion (p < 0.001), decreased mRNA expression of MCAM, maspin and TRAIL (p < 0.01), and increased uPA expression and activity (p < 0.01) in vitro. Furthermore, injection of 468-ΔTC cells into the mammary fat pad of nude mice resulted in decreased primary tumor latency time (p < 0.01) and increased primary tumor growth and lymph node metastatic burden (p < 0.001) compared to 468-OPN and 468-CON cells. CONCLUSIONS: The results presented here suggest that expression of thrombin-uncleavable OPN imparts an early tumor formation advantage as well as a metastatic advantage for breast cancer cells, possibly due to increased proteolytic activity and decreased adhesion and apoptosis. Clarification of the mechanisms responsible for these observations and the translation of this knowledge into the clinic could ultimately provide new therapeutic opportunities for combating breast cancer.

Opposing actions of the progesterone metabolites, 5alpha-dihydroprogesterone (5alphaP) and 3alpha-dihydroprogesterone (3alphaHP) on mitosis, apoptosis, and expression of Bcl-2, Bax and p21 in human breast cell lines.

Previous studies have shown that breast tissues and breast cell lines convert progesterone (P) to 5alpha-dihydroprogesterone (5alphaP) and 3alpha-dihydroprogesterone (3alphaHP) and that 3alphaHP suppresses, whereas 5alphaP promotes, cell proliferation and detachment. The objectives of the current studies were to determine if the 5alphaP- and 3alphaHP-induced changes in cell numbers are due to altered rates of mitosis and/or apoptosis, and if 3alphaHP and 5alphaP act on tumorigenic and non-tumorigenic cells, regardless of estrogen (E) and P receptor status. The studies were conducted on tumorigenic (MCF-7, MDA-MB-231, T47D) and non-tumorigenic (MCF-10A) human breast cell lines, employing several methods to assess the effects of the hormones on cell proliferation, mitosis, apoptosis and expression of Bcl-2, Bax and p21. In all four cell lines, 5alphaP increased, whereas 3alphaHP decreased cell numbers, [(3)H]thymidine uptake and mitotic index. Apoptosis was stimulated by 3alphaHP and suppressed by 5alphaP. 5alphaP resulted in increases in Bcl-2/Bax ratio, indicating decreased apoptosis; 3alphaHP resulted in decreases in Bcl-2/Bax ratio, indicating increased apoptosis. The effects of either 3alphaHP or 5alphaP on cell numbers, [(3)H]thymidine uptake, mitosis, apoptosis, and Bcl-2/Bax ratio, were abrogated when cells were treated simultaneously with both hormones. The expression of p21 was increased by 3alphaHP, and was unaffected by 5alphaP. The results provide the first evidence that 5alphaP stimulates mitosis and suppresses apoptosis, whereas 3alphaHP inhibits mitosis and stimulates apoptosis. The opposing effects of 5alphaP and 3alphaHP were observed in all four breast cell lines examined and the data suggest that all breast cancers (estrogen-responsive and unresponsive) might be suppressed by blocking 5alphaP formation and/or increasing 3alphaHP. The findings further support the hypothesis that progesterone metabolites are key regulatory hormones and that changes in their relative concentrations in the breast microenvironment determine whether breast tissues remain normal or become cancerous.