P5-20-01: Patient Valuation of Reduced Risk of Side Effects during Treatment for Metastatic Breast Cancer

Background

Chemotherapy treatment for metastatic breast cancer (MBC) has shown significant benefits in survival for breast cancer patients. However, chemotherapy is associated with several side effects that have a significant impact on patients’ quality of life. The objective of this analysis was to quantify the value patients with MBC place on reduced risk of treatment side effects.

Methods: A willingness to pay (WTP) survey was developed to assess metastatic breast cancer patients’ willingness to pay for a reduction in the risk of breast cancer treatment side effects. The survey assessed patients’ WTP for a 25%, 50% and 100% reduction in the risk of all side effects. Patients were also asked to select the side effect they would pay the most to avoid. Additionally, the survey collected demographic information such as treatment regimen, age, race/ethnicity, region, employment status, and insurance type.

Results: The survey was completed by 202 metastatic breast cancer patients. Most survey respondents were white (94%), married (62%), and over the age of 51 (78%). Most patients were covered by private insurance (67%) or Medicare (24%). Of the 58% of respondents who remembered paying out of pocket for their last treatment, the average out of pocket payment was $459. Survey respondents were willing to pay an extra $1,886, $3,837 and $7,794 for a 25%, 50% and 100% reduction in the risk of all side effects, respectively. Hair loss (28%), pain (17%) and nausea (15%) were selected most often as the side effect respondents would pay the most to avoid.

Discussion: Chemotherapy for MBC is associated with several adverse events that patients would like to avoid or reduce such as hair loss, pain, nausea and neutropenia. This analysis demonstrates patients with MBC place a significant value on reducing the risk of side effects and are willing to pay 4.2 times for a treatment devoid of side effects as compared to a treatment with a 25% reduction in the risk of treatment side effects.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-20-01.

The financial implications of a conversion from enoxaparin to dalteparin as the LMWH of choice at a comprehensive cancer center

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Background: To assess the financial implications of a conversion from enoxaparin to dalteparin as the low molecular weight heparin (LMWH) of choice at a large, comprehensive cancer center. Methods: A full class review of LMWH's was conducted in September of 2007 resulting in dalteparin replacing enoxaparin as the LMWH of choice. The Pharmacy and Therapeutics Committee approved automatic substitution with notification of the prescribing physician. The one exception to the policy was conversion if the patient was on enoxaparin at home, the policy would allow for continuation of therapy. Once the policy was approved, laminated dosing conversion cards and pre-printed order sets were developed. Multiple in-services were held prior to the official conversion date of October 15, 2007, to address any issues and to facilitate the conversion. Cost comparisons were made within individual settings adjusting for utilization levels. Results: In the fiscal year prior to the conversion from enoxaparin to dalteparin the cancer center purchased nearly $360,000 of enoxaparin for the inpatient and infusion center settings. In the year following the LMWH change, the total projected cost for LMWHs is $244,000, resulting in a 32% cost savings of $115,000. Conclusions: The change from enoxaparin to dalteparin resulted in significant cost savings for the cancer center. Additional studies are underway to examine the clinical outcomes of the LMWH change.

No significant financial relationships to disclose.

Expression of monocyte chemoattractant protein-1 in the bovine corpus luteum around the time of natural luteolysis

Monocyte chemoattractant protein (MCP-1) is a specific chemoattractant for monocytes/macrophages that could have a role in the influx of macrophages into the corpus luteum (CL) during structural luteolysis. In this study, reverse transcription-polymerase chain reaction and in situ hybridization were used to investigate MCP-1 mRNA expression in CL collected from 18 heifers between Days 15 and 20 of the estrous cycle. There was expression of mRNA encoding MCP-1 in luteal tissue from all cows; however, expression was greater in animals that had undergone luteolysis at the time of CL collection as compared to animals in which the CL was still functional. Similarly, in situ hybridization showed greater expression of mRNA encoding MCP-1 in CL after functional luteolysis. There was also evidence of increased MCP-1 mRNA expression in an animal with a functional CL where the systemic concentration of prostaglandin F2alpha metabolite was high at the time of tissue collection. T lymphocyte populations, identified by immunohistochemistry, had a distribution similar to that of cells expressing MCP-1 mRNA within the CL, but other cell types were also involved. These results demonstrate an increase in MCP-1 mRNA after functional luteolysis in the cow, which may be related to the influx of macrophages that occurs at this time.

Alternative splicing of the prolactin receptor gene generates a 1.7 kb RNA transcript that is linked to prolactin function in the red deer testis

A cDNA encoding a putative non-membrane bound prolactin receptor was amplified by RT-PCR from red deer (Cervus elaphus) testis. Sequence analysis suggests that the testicular cDNA is generated by alternative splicing resulting in the deletion of exons 7 and 8, which code for: (a) the final 53 aa of the extracellular domain of the receptor including the fifth conserved cysteine residue and the WS x WS motif, (b) the entire transmembrane domain, (c) the first three cytoplasmic amino acid residues, and (d) two nucleotides of the fourth cytoplasmic amino acid codon. The resultant RNA would encode a putative protein of 174 aa due to a single bp frame shift and a premature stop codon. Northern blot analysis confirmed that the PCR-amplified cDNA is encoded by a specific 1.7 kb RNA transcript whereas the membrane bound receptor is encoded by transcripts of 3.5 and 2.5 kb. HPLC studies using media from 293 cells transfected with the 1.7 kb cDNA failed to detect any specific binding for prolactin. These data suggest that: (a) the deletion in the 1.7 kb transcript alters the structure of the prolactin binding domain in the putative protein encoded by the 1.7 kb transcript, and (b) alternative splicing of the prolactin receptor gene toward the 1.7 kb transcript is a means of down-regulating the expression of the full length prolactin receptor and hence may modify the role of prolactin in the testis of seasonally breeding mammals such as red deer. The sequence reported in this paper has been deposited in the Genbank/EMBL data base with accession number Y14753.

Protein kinase C- and Ca2+ ionophore-stimulated production of reactive oxygen species in mechanically dispersed isolated bovine luteal cells

We measured the production of reactive oxygen species (ROS) using luminol-horseradish peroxidase-induced chemiluminescence in mechanically dispersed cell suspensions from bovine corpus luteum (CL). Since other cell types besides luteal cells were present in crude cell suspensions from CL, cell preparations were purified by centrifugation on Percoll. Only cell suspensions that gave no significant response when stimulated with formyl-methionyl-leucyl-phenylalanine, a potent stimulator of ROS production by phagocytes, were used routinely. Basal ROS production by purified bovine luteal cell preparations was low but could be stimulated rapidly and in a dose-dependent manner by nanomolar concentrations of the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA), though only in cells purified by fractionation on Percoll. Luteal ROS responses to PMA were quenched by returning bovine erythrocytes to purified luteal cells, or by exogenous catalase or superoxide dismutase. The magnitude of the response to PMA varied markedly from one luteal cell preparation to another but appeared to be unrelated to the stage of the luteal phase of the CL from which the cells were prepared. The luteal ROS response to PMA was blocked by staurosporine, an inhibitor of PKC. Although the inactive phorbol ester (4alpha-phorbol didecanoate; 4alphaPDD) alone had little or no effect on luteal ROS production, 4alphaPDD significantly potentiated the effects of submaximal concentrations of PMA in a dose-dependent manner. ROS production could also be stimulated by the Ca2+ ionophore A23187. This response was rapidly abolished by treatment with EDTA or EGTA. A23187 also augmented the response to submaximal PMA levels: however, pretreatment with 4alphaPDD did not significantly enhance the ROS response to A23187. In conclusion, we have shown that isolated bovine luteal cell suspensions are capable of generating a marked acute ROS response triggered by activation of PKC and/or elevation of cytosolic calcium.

Contrasting effects of 17 beta-estradiol on the growth of human ovarian carcinoma cells in vitro and in vivo

A human ovarian adenocarcinoma cell line (PE04) has been established as a xenograft in nude mice. In vitro, this cell line is estrogen receptor (ER)-positive and its growth is stimulated by 17 beta-estradiol at concentrations between 10(-12) and 10(-6) M. When xenografted, PE04 cells remain ER-positive and also possess progesterone receptors (PR); treatment with 17 beta-estradiol reduces the concentration of ER and increases levels of PR. Growth of the xenograft is reduced in ovariectomized animals while implantation of estrogen pellets also results in growth inhibition. Similar treatment with estrogen does not inhibit the ER-negative HOX 60 ovarian xenograft, and stimulates growth of the ER-positive ZR-75-I breast carcinoma xenograft. Serum measurements of 17 beta-estradiol confirm that ovariectomy reduces the level of 17 beta-estradiol while implantation of estrogen pellets results in raised levels of the hormone. Tamoxifen inhibits growth of the PE04 xenograft but not that of the HOX 60 xenograft, consistent with ER status. These results indicate that ER-positive PE04 ovarian cancer cells are sensitive to 17 beta-estradiol in vivo but that the response may be of a different type from the in vitro response. This lends further support to the concept that ovarian cancer may be hormone-sensitive and potentially responsive to endocrine therapy.

Failure to detect gonadotrophin-releasing hormone receptors in human benign and malignant breast tissue and in MCF-7 and MDA-MB-231 cancer cells

We have measured the binding of radiolabelled analogues of gonadotrophin-releasing hormone (GnRH) to homogenates of human breast cancer and benign breast tissue, and to MCF-7 and MDA-MB-231 cell lines. Although incubation of breast cancer homogenates with the 125I-labelled GnRH agonist analogues, buserelin [(D-Ser tBU6)GnRH 1-9 ethylamide] and tryptorelin [(D-Trp6) GnRH 1-9 ethylamide] appeared to show significant though low, specific GnRH agonist binding in a high proportion of breast cancers (32/42 for buserelin; 15/32 for tryptorelin) and benign breast tissues (13/16 for buserelin; 10/12 for tryptorelin), after correction for displaceable binding in control assay tubes, GnRH agonist binding to breast tissue was no longer apparent. The lack of specific binding was not due to inactivation of GnRH agonist tracers, as > 86% of the unbound tracer was still capable of rebinding to fresh placental membranes after incubation with breast cancer homogenates. GnRH agonist did not bind to MCF-7 and MDA-MB-231 cells, however GnRH agonist tracer inactivation following exposure to these cells was very high. We have shown recently that human placental receptors bound salmon GnRH and chicken GnRH II as well as GnRH agonists, but not other isoforms of GnRH. However, no isoform of GnRH bound significantly to human breast tumour tissue. In summary, we could not confirm the presence of specific GnRH binding sites in homogenates and membranes from human breast tissues in this study. Low levels of apparently specific binding of GnRH agonist tracers could be accounted for entirely by displacement of tracer from assay tubes. Inability to demonstrate specific binding was not due to extensive inactivation of GnRH tracers (although this may be a factor in the failure to demonstrate GnRH binding to MCF-7 and MDA-MB-231 cell lines).

The effect of recombinant bovine somatotropin on ovarian function in heifers: follicular populations and peripheral hormones

The objective of this study was to investigate the possible effect of recombinant bovine somatotropin (BST) on ovarian folliculogenesis and ovulation rate. Twelve Hereford x Friesian heifers received daily injections of either 25 mg BST (6 heifers) or vehicle (6 heifers) for a period of two estrous cycles until slaughter. Blood samples were collected three times a week for measurements of peripheral growth hormone (GH), insulin-like growth factor I (IGF-I), FSH, LH, estradiol, and progesterone. Serial blood samples were also taken every 10 min for 8 h on Days 12 and 19 of the second estrous cycle to monitor GH, IGF-I, FSH, and LH profiles. At the end of treatment (Day 7 of the third estrous cycle), the heifers were killed and their ovaries were collected. Ovulation rate was determined by counting the number of fresh corpora lutea (CL). All antral follicles greater than or equal to 2 mm in diameter were dissected to assess antral follicle populations. Granulosa and thecal cells from the three largest follicles and CL from each heifer were collected for FSH and LH binding measurements. All heifers had a single ovulation. The treated heifers had significantly more antral follicles (60.2 +/- 6.7) than did the animals in the control group (33.2 +/- 3.2) (p less than 0.001). When follicles were grouped according to diameter, the mean numbers of follicles greater than 10 mm, 5-10 mm, and 2-5 mm in diameter were 0.8 +/- 0.2, 6.8 +/- 1.4, and 52.5 +/- 6.5 for the treated group, and 0.8 +/- 0.2, 6.5 +/- 1.0, and 25.8 +/- 2.7 for controls.(ABSTRACT TRUNCATED AT 250 WORDS)

The binding of epidermal growth factor to the human uterus and leiomyomata in women rendered hypo-oestrogenic by continuous administration of an LHRH agonist

The binding of epidermal growth factor (EGF) to human myometrium and leiomyomata was assessed in a group of women rendered hypo-oestrogenic with the LHRH agonist Zoladex (ICI 118630). The results were compared with those obtained with tissues from women with normal cycles. In normal women, the specific binding of radiolabelled [125I] EGF to both myometrial and fibroid homogenates did not vary during the menstrual cycle, but the specific binding of [125I] EGF to fibroid in women treated with LHRH agonist was significantly less than in the untreated group. Since the hypo-oestrogenic state induced by the agonist is associated with a decrease in fibroid size, the results suggest that the effect of oestrogen on fibroid tissue may partly be mediated by EGF.