Subscribe to RSS
DOI: 10.4103/ijmpo.ijmpo_3_17
Role of Insulin-like Growth Factor, Insulin-like Growth Factor Receptors, and Insulin-like Growth Factor-binding Proteins in Ovarian Cancer
Financial support and sponsorship Nil.Abstract
Insulin and IGFs play an important role in cancer initiation and progression, including ovarian cancer (OC). Epithelial ovarian cancer (EOC) is the most frequent type of OC in women and it is the most lethal gynecological malignancy worldwide. Generally, insulin is associated with metabolism, whereas Insulin like growth factors (IGFs) are involved in cell proliferation. Hence, Insulin-like growth factor binding proteins (IGFBPs) determines the bioavailability of IGFs in circulation. The interplay between these molecules such as insulin, IGFs, IGFBPs and insulin-like growth factor receptor 1 (IGF1R) may be crucial for ovarian cancer cell biology and cancer progression. However, the IGF1R inhibitors exhibiting potent activity on IGF/IGF1R also demonstrated activity against OC cells. The combination therapy of drugs may prove to be beneficial in clinical management of OC. This review describes both molecular and clinical associations between insulin and IGF1 signaling pathways in ovarian cancer. The data was collected using PubMed search engine with the following key words such as ovarian cancer, IGFs, IGFBP, IGF1Rs and ovarian cancer.
Keywords
Insulin-like growth factor - insulin-like growth factor-binding proteins - insulin-like growth factor receptor - obesity - ovarian cancer - prognostic valuePublication History
Article published online:
06 July 2021
© 2017. Indian Society of Medical and Paediatric Oncology. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/.)
Thieme Medical and Scientific Publishers Pvt. Ltd.
A-12, 2nd Floor, Sector 2, Noida-201301 UP, India
-
References
- 1 Ferlay J, Steliarova-Foucher E, Lortet-Tieulent J, Rosso S, Coebergh JW, Comber H, et al. Cancer incidence and mortality patterns in Europe: Estimates for 40 countries in 2012. Eur J Cancer 2013;49:1374-403.
- 2 Swaminathan R, Shanta V. Population based Cancer Registry, Chennai Cancer Institute (WIA), Adyar, Chennai. Individual Registry Write-up: 2006-2008; 2010. p. 165-83.
- 3 Kaku T, Ogawa S, Kawano Y, Ohishi Y, Kobayashi H, Hirakawa T, et al. Histological classification of ovarian cancer. Med Electron Microsc 2003;36:9-17.
- 4 Jelovac D, Armstrong DK. Recent progress in the diagnosis and treatment of ovarian cancer. CA Cancer J Clin 2011;61:183-203.
- 5 Weroha SJ, Haluska P. The insulin-like growth factor system in cancer. Endocrinol Metab Clin North Am 2012;41:335-50, vi.
- 6 Forbes BE, McCarthy P, Norton RS. Insulin-like growth factor binding proteins: A structural perspective. Front Endocrinol (Lausanne) 2012;3:38.
- 7 Oosterhuis GJ, Vermes I, Lambalk CB, Michgelsen HW, Schoemaker J. Insulin-like growth factor (IGF)-I and IGF binding protein-3 concentrations in fluid from human stimulated follicles. Hum Reprod 1998;13:285-9.
- 8 Brokaw J, Katsaros D, Wiley A, Lu L, Su D, Sochirca O, et al. IGF-I in epithelial ovarian cancer and its role in disease progression. Growth Factors 2007;25:346-54.
- 9 Douglas JB, Silverman DT, Pollak MN, Tao Y, Soliman AS, Stolzenberg-Solomon RZ. Serum IGF-I, IGF-II, IGFBP-3, and IGF-I/IGFBP-3 molar ratio and risk of pancreatic cancer in the prostate, lung, colorectal, and ovarian cancer screening trial. Cancer Epidemiol Biomarkers Prev 2010;19:2298-306.
- 10 Burger AM, Leyland-Jones B, Banerjee K, Spyropoulos DD, Seth AK. Essential roles of IGFBP-3 and IGFBP-rP1 in breast cancer. Eur J Cancer 2005;41:1515-27.
- 11 Conover CA, Hartmann LC, Bradley S, Stalboerger P, Klee GG, Kalli KR, et al. Biological characterization of human epithelial ovarian carcinoma cells in primary culture: The insulin-like growth factor system. Exp Cell Res 1998;238:439-49.
- 12 Cheng AJ, Chen LC, Chien KY, Chen YJ, Chang JT, Wang HM, et al. Oral cancer plasma tumor marker identified with bead-based affinity-fractionated proteomic technology. Clin Chem 2005;51:2236-44.
- 13 Marks AG, Carroll JM, Purnell JQ, Roberts CT Jr. Plasma distribution and signaling activities of IGF-II precursors. Endocrinology 2011;152:922-30.
- 14 Kennedy SG, Wagner AJ, Conzen SD, Jordán J, Bellacosa A, Tsichlis PN, et al. The PI 3-kinase/Akt signaling pathway delivers an anti-apoptotic signal. Genes Dev 1997;11:701-13.
- 15 Pouysségur J, Volmat V, Lenormand P. Fidelity and spatio-temporal control in MAP kinase (ERKs) signalling. Biochem Pharmacol 2002;64:755-63.
- 16 Han J, Jogie-Brahim S, Harada A, Oh Y. Insulin-like growth factor-binding protein-3 suppresses tumor growth via activation of caspase-dependent apoptosis and cross-talk with NF-κB signaling. Cancer Lett 2011;307:200-10.
- 17 Peruzzi F, Prisco M, Dews M, Salomoni P, Grassilli E, Romano G, et al. Multiple signaling pathways of the insulin-like growth factor 1 receptor in protection from apoptosis. Mol Cell Biol 1999;19:7203-15.
- 18 Galvan V, Logvinova A, Sperandio S, Ichijo H, Bredesen DE. Type 1 insulin-like growth factor receptor (IGF-IR) signaling inhibits apoptosis signal-regulating kinase 1 (ASK1). J Biol Chem 2003;278:13325-32.
- 19 Yao JE, Yan M, Guan Z, Pan CB, Xia LP, Li CX, et al. Aurora-A down-regulates IkappaBalpha via Akt activation and interacts with insulin-like growth factor-1 induced phosphatidylinositol 3-kinase pathway for cancer cell survival. Mol Cancer 2009;8:95.
- 20 Shao M, Hollar S, Chambliss D, Schmitt J, Emerson R, Chelladurai B, et al. Targeting the insulin growth factor and the vascular endothelial growth factor pathways in ovarian cancer. Mol Cancer Ther 2012;11:1576-86.
- 21 Rho SB, Dong SM, Kang S, Seo SS, Yoo CW, Lee DO, et al. Insulin-like growth factor-binding protein-5 (IGFBP-5) acts as a tumor suppressor by inhibiting angiogenesis. Carcinogenesis 2008;29:2106-11.
- 22 Baron-Hay S, Boyle F, Ferrier A, Scott C. Elevated serum insulin-like growth factor binding protein-2 as a prognostic marker in patients with ovarian cancer. Clin Cancer Res 2004;10:1796-806.
- 23 Wolin KY, Carson K, Colditz GA. Obesity and cancer. Oncologist 2010;15:556-65.
- 24 Farghaly SA. Ovarian cancer in obese women: Risk and optimal medical and surgical treatment options. Womens Health (Lond) 2015;11:261-3.
- 25 Rose DP, Komninou D, Stephenson GD. Obesity, adipocytokines, and insulin resistance in breast cancer. Obes Rev 2004;5:153-65.
- 26 Benedetto C, Salvagno F, Canuto EM, Gennarelli G. Obesity and female malignancies. Best Pract Res Clin Obstet Gynaecol 2015;29:528-40.
- 27 Gunter MJ, Hoover DR, Yu H, Wassertheil-Smoller S, Manson JE, Li J, et al. Aprospective evaluation of insulin and insulin-like growth factor-I as risk factors for endometrial cancer. Cancer Epidemiol Biomarkers Prev 2008;17:921-9.
- 28 Endogenous Hormones and Breast Cancer Collaborative Group, Key TJ, Appleby PN, Reeves GK, Roddam AW. Insulin-like growth factor 1 (IGF1), IGF binding protein 3 (IGFBP3), and breast cancer risk: Pooled individual data analysis of 17 prospective studies. Lancet Oncol 2010;11:530-42.
- 29 Shimasaki S, Ling N. Identification and molecular characterization of insulin-like growth factor binding proteins (IGFBP-1, -2, -3, -4, -5 and -6). Prog Growth Factor Res 1991;3:243-66.
- 30 Hofmann J, Wegmann B, Hackenberg R, Kunzmann R, Schulz KD, Havemann K. Production of insulin-like growth factor binding proteins by human ovarian carcinoma cells. J Cancer Res Clin Oncol 1994;120:137-42.
- 31 Lin B, White JT, Wu J, Lele S, Old LJ, Hood L, et al. Deep depletion of abundant serum proteins reveals low-abundant proteins as potential biomarkers for human ovarian cancer. Proteomics Clin Appl 2009;3:853-61.
- 32 Fowler DJ, Nicolaides KH, Miell JP. Insulin-like growth factor binding protein-1 (IGFBP-1): A multifunctional role in the human female reproductive tract. Hum Reprod Update 2000;6:495-504.
- 33 Sugita S, Morishita Y, Kano J, Furuya S, Shiba-Ishii A, Noguchi M. IGFBP-1 is expressed specifically in ovarian clear cell adenocarcinoma. Histopathology 2011;58:729-38.
- 34 Lee EJ, Mircean C, Shmulevich I, Wang H, Liu J, Niemistö A, et al. Insulin-like growth factor binding protein 2 promotes ovarian cancer cell invasion. Mol Cancer 2005;4:7.
- 35 Flyvbjerg A, Mogensen O, Mogensen B, Nielsen OS. Elevated serum insulin-like growth factor-binding protein 2 (IGFBP-2) and decreased IGFBP-3 in epithelial ovarian cancer: Correlation with cancer antigen 125 and tumor-associated trypsin inhibitor. J Clin Endocrinol Metab 1997;82:2308-13.
- 36 Wang H, Rosen DG, Wang H, Fuller GN, Zhang W, Liu J. Insulin-like growth factor-binding protein 2 and 5 are differentially regulated in ovarian cancer of different histologic types. Mod Pathol 2006;19:1149-56.
- 37 Karasik A, Menczer J, Pariente C, Kanety H. Insulin-like growth factor-I (IGF-I) and IGF-binding protein-2 are increased in cyst fluids of epithelial ovarian cancer. J Clin Endocrinol Metab 1994;78:271-6.
- 38 Kanety H, Kattan M, Goldberg I, Kopolovic J, Ravia J, Menczer J, et al. Increased insulin-like growth factor binding protein-2 (IGFBP-2) gene expression and protein production lead to high IGFBP-2 content in malignant ovarian cyst fluid. Br J Cancer 1996;73:1069-73.
- 39 Torng PL, Lin CW, Chan MW, Yang HW, Huang SC, Lin CT. Promoter methylation of IGFBP-3 and p53 expression in ovarian endometrioid carcinoma. Mol Cancer 2009;8:120.
- 40 Chen X, Ferry RJ Jr. Novel actions of IGFBP-3 on intracellular signaling pathways of insulin-secreting cells. Growth Horm IGF Res 2006;16:41-8.
- 41 Tonin P, Ehrenborg E, Lenoir G, Feunteun J, Lynch H, Morgan K, et al. The human insulin-like growth factor-binding protein 4 gene maps to chromosome region 17q12-q21.1 and is close to the gene for hereditary breast-ovarian cancer. Genomics 1993;18:414-7.
- 42 Durai R, Davies M, Yang W, Yang SY, Seifalian A, Goldspink G, et al. Biology of insulin-like growth factor binding protein-4 and its role in cancer (review). Int J Oncol 2006;28:1317-25.
- 43 Dikshit A, Gao C, Small C, Hales K, Hales DB. Flaxseed and its components differentially affect estrogen targets in pre-neoplastic hen ovaries. J Steroid Biochem Mol Biol 2016;159:73-85.
- 44 Mosig RA, Lobl M, Senturk E, Shah H, Cohen S, Chudin E, et al. IGFBP-4 tumor and serum levels are increased across all stages of epithelial ovarian cancer. J Ovarian Res 2012;5:3.
- 45 Zhu W, Shiojima I, Ito Y, Li Z, Ikeda H, Yoshida M, et al. IGFBP-4 is an inhibitor of canonical Wnt signalling required for cardiogenesis. Nature 2008;454:345-9.
- 46 Zhang C, Lu L, Li Y, Wang X, Zhou J, Liu Y, et al. IGF binding protein-6 expression in vascular endothelial cells is induced by hypoxia and plays a negative role in tumor angiogenesis. Int J Cancer 2012;130:2003-12.
- 47 Yang Z, Bach LA. Differential effects of insulin-like growth factor binding protein-6 (IGFBP-6) on migration of two ovarian cancer cell lines. Front Endocrinol (Lausanne) 2015;5:231.
- 48 Bahrani-Mostafavi Z, Tickle TL, Zhang J, Bennett KE, Vachris JC, Spencer MD, et al. Correlation analysis of HOX, ErbB and IGFBP family gene expression in ovarian cancer. Cancer Invest 2008;26:990-8.
- 49 Gunawardana CG, Kuk C, Smith CR, Batruch I, Soosaipillai A, Diamandis EP. Comprehensive analysis of conditioned media from ovarian cancer cell lines identifies novel candidate markers of epithelial ovarian cancer. J Proteome Res 2009;8:4705-13.
- 50 Lin TM, Halbert SP, Spellacy WN. Measurement of pregnancy-associated plasma proteins during human gestation. J Clin Invest 1974;54:576-82.
- 51 Conover CA, Oxvig C, Overgaard MT, Christiansen M, Giudice LC. Evidence that the insulin-like growth factor binding protein-4 protease in human ovarian follicular fluid is pregnancy associated plasma protein-A. J Clin Endocrinol Metab 1999;84:4742-5.
- 52 Mazerbourg S, Overgaard MT, Oxvig C, Christiansen M, Conover CA, Laurendeau I, et al. Pregnancy-associated plasma protein-A (PAPP-A) in ovine, bovine, porcine, and equine ovarian follicles: Involvement in IGF binding protein-4 proteolytic degradation and mRNA expression during follicular development. Endocrinology 2001;142:5243-53.
- 53 Hourvitz A, Kuwahara A, Hennebold JD, Tavares AB, Negishi H, Lee TH, et al. The regulated expression of the pregnancy-associated plasma protein-A in the rodent ovary: A proposed role in the development of dominant follicles and of corpora lutea. Endocrinology 2002;143:1833-44.
- 54 Juengel JL, Haydon LJ, Mester B, Thomson BP, Beaumont M, Eckery DC. The role of IGFs in the regulation of ovarian follicular growth in the brushtail possum (Trichosurus vulpecula). Reproduction 2010;140:295-303.
- 55 Mazerbourg S, Bondy CA, Zhou J, Monget P. The insulin-like growth factor system: A key determinant role in the growth and selection of ovarian follicles? a comparative species study. Reprod Domest Anim 2003;38:247-58.
- 56 Spicer LJ. Proteolytic degradation of insulin-like growth factor binding proteins by ovarian follicles: A control mechanism for selection of dominant follicles. Biol Reprod 2004;70:1223-30.
- 57 Laursen LS, Overgaard MT, Weyer K, Boldt HB, Ebbesen P, Christiansen M, et al. Cell surface targeting of pregnancy-associated plasma protein A proteolytic activity. Reversible adhesion is mediated by two neighboring short consensus repeats. J Biol Chem 2002;277:47225-34.
- 58 Laursen LS, Kjaer-Sorensen K, Andersen MH, Oxvig C. Regulation of insulin-like growth factor (IGF) bioactivity by sequential proteolytic cleavage of IGF binding protein-4 and -5. Mol Endocrinol 2007;21:1246-57.
- 59 Monget P, Mazerbourg S, Delpuech T, Maurel MC, Manière S, Zapf J, et al. Pregnancy-associated plasma protein-A is involved in insulin-like growth factor binding protein-2 (IGFBP-2) proteolytic degradation in bovine and porcine preovulatory follicles: Identification of cleavage site and characterization of IGFBP-2 degradation. Biol Reprod 2003;68:77-86.
- 60 Laursen LS, Overgaard MT, Søe R, Boldt HB, Sottrup-Jensen L, Giudice LC, et al. Pregnancy-associated plasma protein-A (PAPP-A) cleaves insulin-like growth factor binding protein (IGFBP)-5 independent of IGF: Implications for the mechanism of IGFBP-4 proteolysis by PAPP-A. FEBS Lett 2001;504:36-40.
- 61 Ning Y, Schuller AG, Conover CA, Pintar JE. Insulin-like growth factor (IGF) binding protein-4 is both a positive and negative regulator of IGF activity in vivo. Mol Endocrinol 2008;22:1213-25.
- 62 Overgaard MT, Boldt HB, Laursen LS, Sottrup-Jensen L, Conover CA, Oxvig C. Pregnancy-associated plasma protein-A2 (PAPP-A2), a novel insulin-like growth factor-binding protein-5 proteinase. J Biol Chem 2001;276:21849-53.
- 63 Boldt HB, Conover CA. Overexpression of pregnancy-associated plasma protein-A in ovarian cancer cells promotes tumor growth in vivo. Endocrinology 2011;152:1470-8.
- 64 Thomsen J, Hjortebjerg R, Espelund U, Ørtoft G, Vestergaard P, Magnusson NE, et al. PAPP-A proteolytic activity enhances IGF bioactivity in ascites from women with ovarian carcinoma. Oncotarget 2015;6:32266-78.
- 65 Becker MA, Haluska P Jr., Bale LK, Oxvig C, Conover CA. A novel neutralizing antibody targeting pregnancy-associated plasma protein-a inhibits ovarian cancer growth and ascites accumulation in patient mouse tumorgrafts. Mol Cancer Ther 2015;14:973-81.
- 66 Kalli KR, Chen BK, Bale LK, Gernand E, Overgaard MT, Oxvig C, et al. Pregnancy-associated plasma protein-A (PAPP-A) expression and insulin-like growth factor binding protein-4 protease activity in normal and malignant ovarian surface epithelial cells. Int J Cancer 2004;110:633-40.
- 67 Lukanova A, Lundin E, Toniolo P, Micheli A, Akhmedkhanov A, Rinaldi S, et al. Circulating levels of insulin-like growth factor-I and risk of ovarian cancer. Int J Cancer 2002;101:549-54.
- 68 Peeters PH, Lukanova A, Allen N, Berrino F, Key T, Dossus L, et al. Serum IGF-I, its major binding protein (IGFBP-3) and epithelial ovarian cancer risk: The European Prospective Investigation into Cancer and Nutrition (EPIC). Endocr Relat Cancer 2007;14:81-90.
- 69 King SM, Modi DA, Eddie SL, Burdette JE. Insulin and insulin-like growth factor signaling increases proliferation and hyperplasia of the ovarian surface epithelium and decreases follicular integrity through upregulation of the PI3-kinase pathway. J Ovarian Res 2013;6:12.
- 70 Sasaki H, Hayakawa J, Terai Y, Kanemura M, Tanabe-Kimura A, Kamegai H, et al. Difference between genomic actions of estrogen versus raloxifene in human ovarian cancer cell lines. Oncogene 2008;27:2737-45.
- 71 Walker G, MacLeod K, Williams AR, Cameron DA, Smyth JF, Langdon SP. Insulin-like growth factor binding proteins IGFBP3, IGFBP4, and IGFBP5 predict endocrine responsiveness in patients with ovarian cancer. Clin Cancer Res 2007;13:1438-44.
- 72 Irie HY, Shrestha Y, Selfors LM, Frye F, Iida N, Wang Z, et al. PTK6 regulates IGF-1-induced anchorage-independent survival. PLoS One 2010;5:e11729.
- 73 Zhang W, Zong CS, Hermanto U, Lopez-Bergami P, Ronai Z, Wang LH. RACK1 recruits STAT3 specifically to insulin and insulin-like growth factor 1 receptors for activation, which is important for regulating anchorage-independent growth. Mol Cell Biol 2006;26:413-24.
- 74 Martin-Belmonte F, Perez-Moreno M. Epithelial cell polarity, stem cells and cancer. Nat Rev Cancer 2011;12:23-38.
- 75 Shen X, Xi G, Maile LA, Wai C, Rosen CJ, Clemmons DR. Insulin-like growth factor (IGF) binding protein 2 functions coordinately with receptor protein tyrosine phosphatase ß and the IGF-I receptor to regulate IGF-I-stimulated signaling. Mol Cell Biol 2012;32:4116-30.
- 76 Shen X, Xi G, Wai C, Clemmons DR. The coordinate cellular response to insulin-like growth factor-I (IGF-I) and insulin-like growth factor-binding protein-2 (IGFBP-2) is regulated through vimentin binding to receptor tyrosine phosphatase ß (RPTPß). J Biol Chem 2015;290:11578-90.
- 77 Seto KK, Andrulis IL. Atypical protein kinase C zeta: Potential player in cell survival and cell migration of ovarian cancer. PLoS One 2015;10:e0123528.
- 78 Berchuck A, Iversen ES, Lancaster JM, Pittman J, Luo J, Lee P, et al. Patterns of gene expression that characterize long-term survival in advanced stage serous ovarian cancers. Clin Cancer Res 2005;11:3686-96.
- 79 Murphy SK, Huang Z, Wen Y, Spillman MA, Whitaker RS, Simel LR, et al. Frequent IGF2/H19 domain epigenetic alterations and elevated IGF2 expression in epithelial ovarian cancer. Mol Cancer Res 2006;4:283-92.
- 80 Li T, Chen H, Li W, Cui J, Wang G, Hu X, et al. Promoter histone H3K27 methylation in the control of IGF2 imprinting in human tumor cell lines. Hum Mol Genet 2014;23:117-28.
- 81 Foekens JA, Portengen H, Janssen M, Klijn JG. Insulin-like growth factor-1 receptors and insulin-like growth factor-1-like activity in human primary breast cancer. Cancer 1989;63:2139-47.
- 82 Wiley A, Katsaros D, Chen H, Rigault de la Longrais IA, Beeghly A, Puopolo M, et al. Aberrant promoter methylation of multiple genes in malignant ovarian tumors and in ovarian tumors with low malignant potential. Cancer 2006;107:299-308.
- 83 Huang YF, Cheng WF, Wu YP, Cheng YM, Hsu KF, Chou CY. Circulating IGF system and treatment outcome in epithelial ovarian cancer. Endocr Relat Cancer 2014;21:217-29.
- 84 Tas F, Karabulut S, Serilmez M, Ciftci R, Duranyildiz D. Clinical significance of serum insulin-like growth factor-1 (IGF-1) and insulinlike growth factor binding protein-3 (IGFBP-3) in patients with epithelial ovarian cancer. Tumour Biol 2014;35:3125-32.
- 85 Sayer RA, Lancaster JM, Pittman J, Gray J, Whitaker R, Marks JR, et al. High insulin-like growth factor-2 (IGF-2) gene expression is an independent predictor of poor survival for patients with advanced stage serous epithelial ovarian cancer. Gynecol Oncol 2005;96:355-61.
- 86 Wang Q, Bian CE, Peng H, He L, Zhao X. Association of circulating insulin-like growth factor 1 and insulin-like growth factor binding protein 3 with the risk of ovarian cancer: A systematic review and meta-analysis. Mol Clin Oncol 2015;3:623-8.
- 87 Levine ME, Suarez JA, Brandhorst S, Balasubramanian P, Cheng CW, Madia F, et al. Low protein intake is associated with a major reduction in IGF-1, cancer, and overall mortality in the 65 and younger but not older population. Cell Metab 2014;19:407-17.
- 88 Fan C, Huang YX, Bao YL, Sun LG, Wu Y, Yu CL, et al. Virtual screening of specific insulin-like growth factor 1 receptor (IGF1R) inhibitors from the National Cancer Institute (NCI) molecular database. Int J Mol Sci 2012;13:17185-209.
- 89 Janssen JA, Varewijck AJ. IGF-IR targeted therapy: Past, present and future. Front Endocrinol (Lausanne) 2014;5:224.
- 90 Pan H, Hanada S, Zhao J, Mao L, Ma MZ. Protein secretion is required for pregnancy-associated plasma protein-A to promote lung cancer growth in vivo. PLoS One 2012;7:e48799.
- 91 Mitsuhashi A, Kiyokawa T, Sato Y, Shozu M. Effects of metformin on endometrial cancer cell growth in vivo: A preoperative prospective trial. Cancer 2014;120:2986-95.