Germline CHEK2 Gene Mutations in Hereditary Breast Cancer Predisposition – Mutation Types and their Biological and Clinical Relevance

Česká verze

Authors: Petra Kleiblová ^1,2; Lenka Stolařová ¹; Křížová Křížová ³; Filip Lhota ¹; Jan Hojný ¹; Petra Zemánková ¹; Ondřej Havránek ^4,5; Michal Vočka ⁶; Marta Černá ¹; Klára Lhotová ¹; Marianna Borecká ¹; Markéta Janatová ¹; Jana Soukupová ¹; Jan Ševčík ¹; Martina Zimovjanová ⁶; Jaroslav Kotlas ²; Aleš Panczak ^2,7; Kamila Veselá ²; Jana Červenková ⁸; Michaela Schneiderová ⁹; Monika Burócziová ³; Kamila Burdová ³; Viktor Stránecký ¹⁰; Lenka Foretová ¹; Eva Macháčková ¹¹; Spiros Tavandzis ¹²; Stanislav Kmoch ¹⁰; Libor Macůrek ³; Zdeněk Kleibl ¹
Authors place of work: Laboratoř onkogenetiky, Ústav biochemie a experimentální onkologie, 1. LF UK v Praze ¹; Ústav biologie a lékařské genetiky, 1. LF UK a VFN v Praze ²; Laboratoř biologie nádorové buňky, Ústav molekulární genetiky AV ČR v. v. i., Praha ³; BIOCEV, 1. LF UK v Praze 5 I. interní klinika 1. LF UK a VFN v Praze ⁴; Onkologická klinika 1. LF UK a VFN v Praze ⁶; Radiologická klinika 1. LF UK a VFN v Praze ⁷; Radioterapeutická a onkologická klinika FN Královské Vinohrady, Praha ⁸; I. chirurgická klinika 1. LF UK a VFN v Praze ⁹; Laboratoř pro studium vzácných nemocí, Klinika dětského a dorostového lékařství 1. LF UK a VFN v Praze ¹⁰; Oddělení nádorové epidemiologie, Masarykův onkologický ústav, Brno ¹¹; Oddělení lékařské genetiky, Laboratoře AGEL, Praha ¹²
Published in the journal: Klin Onkol 2019; 32(Supplementum2): 36-50
Category: Původní práce
doi: https://doi.org/10.14735/amko2019S36

Summary

Background: Hereditary mutations in the CHEK2 gene (which encodes CHK2 kinase) contribute to a moderately increased risk of breast cancer (BC) and other cancers. Large variations in the frequency of CHEK2 mutations and the occurrence of variants of unknown clinical significance (VUS) complicate estimation of cancer risk in carriers of germline CHEK2 mutations.

Patients and methods: We performed mutation analysis of 1,526 high-risk Czech BC patients and 3,360 Czech controls. Functional analysis was performed for identified VUS using a model system based on a human RPE1-CHEK2-KO cell line harboring biallelic inactivation of endogenous CHEK2.

Results: The frequency of ten truncating CHEK2 variants differed markedly between BC patients (2.26%) and controls (0.11%; p = 4.1 × 10⁻¹²). We also found 23 different missense variants in 4.5% patients and in 4.0% of controls. The most common was p.I157T, which was found in patients and controls with the same frequency. Functional analysis identified nine functionally deleterious VUS, another nine functionally neutral VUS, and four intermediate VUS (including p.I157T). We found that carriers of truncating CHEK2 mutations had a high BC risk (OR 8.19; 95% CI 4.11–17.75), and that carriers of functionally deleterious missense variants had a moderate risk (OR 4.06; 95% CI, 1.37–13.39). Carriers of these mutations developed BC at 44.4 and 50.7 years, respectively. Functionally neutral and functionally intermediate missense variants did not increase the BC risk. BC in CHEK2 mutation carriers was frequently ER-positive and of higher grade. Notably, carriers of CHEK2 mutations developed second cancers more frequently than BRCA1/BRCA2/PALB2/p53 or mutation non-carriers.

Conclusion: Hereditary CHEK2 mutations contribute to the development of hereditary BC. The associated cancer risk in mutation carriers increases with the number of affected individuals in a family. Annual follow-up with breast ultrasound, mammography, or magnetic resonance imaging is recommended for asymptomatic mutation carriers from the age of 40. Surgical prevention and specific follow-up of other tumors should be considered based on family cancer history.

The work was supported by grants from the Czech Health Research Council of the Ministry of Health of the Czech Republic NR 15-28830A, 16-29959A, NV19-03-00279, projects of the PROGRES Q28/LF1, GAUK 762216, SVV2019 / 260367, PRIMUS/17/MED/9, UNCE/MED/016, Progress Q26, LQ1604 NPU II and project AVČR Qualitas. The analysis of a set of unselected controls was made possible by the existence and support of the scientific infrastructure of the National Center for Medical Genomics (LM2015091) and its project aimed at creating a reference database of genetic variants of the Czech Republic (CZ.02.1.01/0.0/0.0/16_013/0001634).

The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study.

The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.

Submitted: 2. 4. 2019

Accepted: 14. 5. 2019

Keywords:

breast cancer – CHEK2 – hereditary mutations – variants of unknown significance – functional analysis

Zdroje

1. Kleibl Z, Kristensen VN. Women at high risk of breast cancer: Molecular characteristics, clinical presentation and management. Breast 2016; 28: 136–144. doi: 10.1016/j.breast.2016.05.006.

2. Foretová L, Macháčková E, Palácová M et al. Doporučení rozšíření indikačních kriterií ke genetickému testování mutací v genech BRCA1 a BRCA2 u hereditárního syndromu nádorů prsu a ovarií. Klin Onkol 2016; 29 (Suppl 1): 9–13.

3. Petráková K, Palácová M, Schneiderová M et al. Syndrom hereditárního karcinomu prsu a ovarií. Klin Onkol 2016; 29 (Suppl 1): 14–21. doi: 10.14735/amko2016S14.

4. Janatová M, Borecká M, Soukupová J et al. PALB2 jako další kandidátní gen pro genetické testování u pacientů s hereditárním karcinomem prsu v České republice. Klin Onkol 2016; 29 (Suppl 1): 31–34. doi: 10.14735/amko2016S31.

5. Pohlreich P, Kleibl Z, Kleiblova P et al. Klinický význam analýz genů středního rizika pro hodnocení rizika vzniku karcinomu prsu a dalších nádorů v České republice. Klin Onkol 2012; 25 (Suppl): 59–66. doi: 10.14735/amko20121S59.

6. Cybulski C, Gorski B, Huzarski T et al. CHEK2 is a multiorgan cancer susceptibility gene. Am J Hum Genet 2004; 75 (6): 1131–1135. doi: 10.1086/426403.

7. Matsuoka S, Rotman G, Ogawa A et al. Ataxia telangiectasia-mutated phosphorylates Chk2 in vivo and in vitro. Proc Natl Acad Sci USA 2000; 97 (19): 10389–10394. doi: 10.1073/pnas.190030497.

8. Zannini L, Delia D, Buscemi G. CHK2 kinase in the DNA damage response and beyond. J Mol Cell Biol 2014; 6 (6): 442–457. doi: 10.1093/jmcb/mju045.

9. Hu C, Zhang S, Gao X et al. Roles of Kruppel-associated Box (KRAB) -associated Co-repressor KAP1 Ser-473 Phosphorylation in DNA Damage Response. J Biol Chem 2012; 287 (23): 18937–18952. doi: 10.1074/jbc.M111.313262.

10. Meijers-Heijboer H, van den OA, Klijn J et al. Low-penetrance susceptibility to breast cancer due to CHEK2 (*) 1100delC in noncarriers of BRCA1 or BRCA2 mutations. Nat Genet 2002; 31 (1): 55–59. doi: 10.1038/ng879.

11. Weischer M, Bojesen SE, Ellervik C et al. CHEK2*1100delC genotyping for clinical assessment of breast cancer risk: meta-analyses of 26,000 patient cases and 27,000 controls. J Clin Oncol 2008; 26 (4): 542–548. doi: 10.1200/JCO.2007.12.5922.

12. Yang Y, Zhang F, Wang Y et al. CHEK2 1100delC variant and breast cancer risk in Caucasians: a meta-analysis based on 25 studies with 29,154 cases and 37,064 controls. Asian Pac J Cancer Prev 2012; 13 (7): 3501–3505.

13. Liu C, Wang Y, Wang QS et al. The CHEK2 I157T variant and breast cancer susceptibility: a systematic review and meta-analysis. Asian Pac J Cancer Prev 2012; 13 (14): 1355–1360.

14. Walsh T, Casadei S, Coats KH et al. Spectrum of mutations in BRCA1, BRCA2, CHEK2, and TP53 in families at high risk of breast cancer. JAMA 2006; 295 (12): 1379–1388. doi: 10.1001/jama.295.12.1379.

15. Desrichard A, Bidet Y, Uhrhammer N et al. CHEK2 contribution to hereditary breast cancer in non-BRCA families. Breast Cancer Res 2011; 13 (6): R119. doi: 10.1186/bcr3062.

16. Le Calvez-Kelm F, Lesueur F, Damiola F et al. Rare, evolutionarily unlikely missense substitutions in CHEK2 contribute to breast cancer susceptibility: results from a breast cancer family registry case-control mutation-screening study. Breast Cancer Res 2011; 13 (1): R6. doi: 10.1186/bcr2810.

17. Dufault MR, Betz B, Wappenschmidt B et al. Limited relevance of the CHEK2 gene in hereditary breast cancer. Int J Cancer 2004; 110: 320–325. doi: 10.1002/ijc.20073.

18. Bell DW, Kim SH, Godwin AK et al. Genetic and functional analysis of CHEK2 (CHK2) variants in multiethnic cohorts. Int J Cancer 2007; 121 (12): 2661–2667. doi: 10.1002/ijc.23026.

19. Leedom TP, LaDuca H, McFarland R et al. Breast cancer risk is similar for CHEK2 founder and non-founder mutation carriers. Cancer Genet 2016; 209 (9): 403–407. doi: 10.1016/j.cancergen.2016.08.005.

20. Couch FJ, Shimelis H, Hu C et al. Associations between cancer predisposition testing panel genes and breast cancer. JAMA Oncol 2017; 3 (9): 1190–1196. doi: 10.1001/jamaoncol.2017.0424.

21. Fan Z, Ouyang T, Li J et al. Identification and analysis of CHEK2 germline mutations in Chinese BRCA1/2-negative breast cancer patients. Breast Cancer Res Treat 2018; 169 (1): 59–67. doi: 10.1007/s10549-018-4673-6.

22. Hauke J, Horvath J, Gross E et al. Gene panel testing of 5589 BRCA1/2-negative index patients with breast cancer in a routine diagnostic setting: results of the German Consortium for Hereditary Breast and Ovarian Cancer. Cancer Med 2018; 7 (4): 1349–1358. doi: 10.1002/cam4. 1376.

23. Young EL, Feng BJ, Stark AW et al. Multigene testing of moderate-risk genes: be mindful of the missense. J Med Genet 2016; 53 (6): 366–376. doi: 10.1136/jmedgenet-2015-103398.

24. Espenschied C, Kleiblova P, Richardson M et al. Classifying variants in the CHEK2 gene: the importance of collaboration. Eur J Cancer 2017; 72 (Suppl 1): S25. doi: 10.1016/S0959-8049 (17) 30161-2.

25. Soukupova J, Zemankova P, Lhotova K et al. Validation of CZECANCA (CZEch CAncer paNel for Clinical Application) for targeted NGS-based analysis of hereditary cancer syndromes. PLoS One 2018; 13 (4): e0195761. doi: 10.1371/journal.pone.019576.

26. Soukupová J, Zemanková P, Kleiblová P et al. CZECANCA: CZEch CAncer paNel for Clinical Application – návrh a příprava cíleného sekvenačního panelu pro identifikaci nádorové predispozice u rizikových osob v České republice. Klin Onkol 2016; 29 (Suppl 1): 46–54. doi: 10.14735/amko2016S46.

27. Kleiblova P, Stolarova L, Krizova K et al. Identification of deleterious germline CHEK2 mutations and their association with breast and ovarian cancer. Int J Cancer 2019. doi: 10.1002/ijc.32385.

28. Walsh T, Mandell JB, Norquist BM et al. genetic predisposition to breast cancer due to mutations other than BRCA1 and BRCA2 founder alleles among Ashkenazi Jewish women. JAMA Oncol 2017; 3 (12): 1647–1653. doi: 10.1001/jamaoncol.2017.1996.

29. Apostolou P, Fostira F, Mollaki V et al. Characterization and prevalence of two novel CHEK2 large deletions in Greek breast cancer patients. J Hum Genet 2018; 63 (8): 877–886. doi: 10.1038/s10038-018-0466-3.

30. Consortium CBCC-C. CHEK2*1100delC and susceptibility to breast cancer: a collaborative analysis involving 10,860 breast cancer cases and 9,065 controls from 10 studies. Am J Hum Genet 2004; 74 (6): 1175–1182. doi: 10.1086/421251.

31. Chekmariova EV, Sokolenko AP, Buslov KG et al. CHEK2 1100delC mutation is frequent among Russian breast cancer patients. Breast Cancer Res Treat 2006; 100 (1): 99–102. doi: 10.1007/s10549-006-9227-7.

32. Kleibl Z, Novotny J, Bezdickova D et al. The CHEK2 c.1100delC germline mutation rarely contributes to breast cancer development in the Czech Republic. Breast Cancer Res Treat 2005; 90 (2): 165–167. doi: 10.1007/s10549-004-4023-8.

33. Choi DH, Cho DY, Lee MH et al. The CHEK2 1100delC mutation is not present in Korean patients with breast cancer cases tested for BRCA1 and BRCA2 mutation. Breast Cancer Res Treat 2008; 112 (3): 569–573. doi: 10.1007/s10549-007-9878-z.

34. Cybulski C, Wokołorczyk D, Jakubowska A et al. Risk of breast cancer in women with a CHEK2 mutation with and without a family history of breast cancer. J Clin Oncol 2011; 29 (28): 3747–3752. doi: 10.1200/JCO.2010.34.0778.

35. Kleibl Z, Havranek O, Novotny J et al. Analysis of CHEK2 FHA domain in Czech patients with sporadic breast cancer revealed distinct rare genetic alterations. Breast Cancer Res Treat 2008; 112 (1): 159–164. doi: 10.1007/s10549-007-9838-7.

36. Havranek O, Kleiblova P, Hojny J et al. Association of Germline CHEK2 gene variants with risk and prognosis of non-Hodgkin lymphoma. Plos One 2015; 10 (10): e0140819. doi: 10.1371/journal.pone.0140819.

37. Roeb W, Higgins J, King MC. Response to DNA damage of CHEK2 missense mutations in familial breast cancer. Hum Mol Genet 2012; 21 (12): 2738–2744. doi: 10.1093/hmg/dds101.

38. Delimitsou A, Fostira F, Kalfakakou D et al. Functional characterization of CHEK2 variants in a Saccharomyces cerevisiae system. Hum Mutat 2019; 40 (5): 631–648. doi: 10.1002/humu.23728.

39. ClinVar. [online]. Available from: www.ncbi.nlm.nih.gov/clinvar?term=CHEK2.

40. Li J, Williams BL, Haire LF et al. Structural and functional versatility of the FHA domain in DNA-damage signaling by the tumor suppressor kinase Chk2. Mol Cell 2002; 9 (5): 1045–1054.

41. Falck J, Mailand N, Syljuasen RG et al. The ATM-Chk2-Cdc25A checkpoint pathway guards against radioresistant DNA synthesis. Nature 2001; 410 (6830): 842–847. doi: 10.1038/35071124.

42. Lek M, Karczewski J, Minikel EV et al. Analysis of protein-coding genetic variation in 60,706 humans. Nature 2016; 536 (7616): 285–291. doi: 10.1038/nature19057.

43. Margolin S, Eiberg H, Lindblom A et al. CHEK2 1100delC is prevalent in Swedish early onset familial breast cancer. BMC Cancer 2007; 7: 163. doi: 10.1186/1471-2407-7-163.

44. Lee A, Mavaddat N, Wilcox AN et al. BOADICEA: a comprehensive breast cancer risk prediction model incorporating genetic and nongenetic risk factors. Genet Med 2019. doi: 10.1038/s41436-018-0406-9.

45. Pelttari LM, Kiiski J, Nurminen R et al. A Finnish founder mutation in RAD51D: analysis in breast, ovarian, prostate, and colorectal cancer. J Med Genet 2012; 49 (7): 429–432. doi: 10.1136/jmedgenet-2012-100852.

46. Mavaddat N, Michailidou K, Dennis J et al. Polygenic risk scores for prediction of breast cancer and breast cancer subtypes. Am J Hum Genet 2019; 104 (1): 21–34. doi: 10.1016/j.ajhg.2018.11.002.

47. Muranen TA, Greco D, Blomqvist C et al. Genetic modifiers of CHEK2*1100delC-associated breast cancer risk. Genet Med 2017; 19 (5): 599–603. doi: 10.1038/gim.2016.147.

48. Muranen TA, Blomqvist C, Dork T et al. Patient survival and tumor characteristics associated with CHEK2: p.I157T – findings from the Breast Cancer Association Consortium. Breast Cancer Res 2016; 18 (1): 98. doi: 10.1186/s13058-016-0758-5.

49. Liu C, Chang H, Li XH et al. Network meta-analysis on the effects of DNA damage response-related gene mutations on overall survival of breast cancer based on TCGA database. J Cell Biochem 2017; 118 (12): 4728–4734. doi: 10.1002/jcb.26140.

50. Weischer M, Nordestgaard BG, Pharoah P et al. CHEK2*1100delC heterozygosity in women with breast cancer associated with early death, breast cancer-specific death, and increased risk of a second breast cancer. J Clin Oncol 2012; 30 (35): 4308–4316. doi: 10.1200/JCO.2012.42. 7336.

51. Zlowocka-Perlowska E, Narod SA, Cybulski C. CHEK2 alleles predispose to renal cancer in poland. JAMA Oncol 2019. doi: 10.1001/jamaoncol.2019. 0022.

52. Huzarski T, Gorecka-Szyld B, Huzarska J et al. Screening with magnetic resonance imaging, mammography and ultrasound in women at average and intermediate risk of breast cancer. Hered Cancer Clin Pract 2017; 15: 4. doi: 10.1186/s13053-017-0064-y.

53. Macklin S, Gass J, Mitri G et al. The role of screening MRI in the era of next generation sequencing and moderate-risk genetic mutations. Fam Cancer 2018; 17 (1): 167–173. doi: 10.1007/s10689-017-0007-9.

54. Huijts PE, Hollestelle A, Balliu B et al. CHEK2*1100delC homozygosity in the Netherlands-prevalence and risk of breast and lung cancer. Eur J Hum Genet 2014; 22 (1): 46–51. doi: 10.1038/ejhg.2013.85.

55. Nurmi A, Muranen TA, Pelttari LM et al. Recurrent moderate-risk mutations in Finnish breast and ovarian cancer patients. Int J Cancer 2019. doi: 10.1002/ijc.32309.

56. Girard E, Eon-Marchais S, Olaso R et al. Familial breast cancer and DNA repair genes: Insights into known and novel susceptibility genes from the GENESIS study, and implications for multigene panel testing. Int J Cancer 2019; 144 (8): 1962–1974. doi: 10.1002/ijc.31921.

57. Decker B, Allen J, Luccarini C et al. Rare, protein-truncating variants in ATM, CHEK2 and PALB2, but not XRCC2, are associated with increased breast cancer risks. J Med Genet 2017; 54 (11): 732–741. doi: 10.1136/jmedgenet-2017-104588.

58. Slavin TP, Maxwell KN, Lilyquist J et al. The contribution of pathogenic variants in breast cancer susceptibility genes to familial breast cancer risk. NPJ Breast Cancer 2017; 3: 22. doi: 10.1038/s41523-017-0024-8.

59. Schmidt MK, Hogervorst F, van Hien R et al. Age-and tumor subtype-specific breast cancer risk estimates for CHEK2*1100delC carriers. J Clin Oncol 2016; 34 (23): 2750–2760. doi: 10.1200/JCO.2016.66.5844.

60. Southey MC, Goldgar DE, Winqvist R et al. PALB2, CHEK2 and ATM rare variants and cancer risk: data from COGS. J Med Genet 2016; 53 (12): 800–811. doi: 10.1136/jmedgenet-2016-103839.

61. Liu Y, Liao J, Xu Y et al. A recurrent CHEK2 p.H371Y mutation is associated with breast cancer risk in Chinese women. Hum Mutat 2011; 32 (9): 1000–1003. doi: 10.1002/humu.21538.

62. Weischer M, Bojesen SE, Tybjaerg-Hansen A et al. Increased risk of breast cancer associated with CHEK2*1100delC. J Clin Oncol 2007; 25 (1): 57–63. doi: 10.1200/JCO.2005.05.5160.

63. Vahteristo P, Bartkova J, Eerola H et al. A CHEK2 genetic variant contributing to a substantial fraction of familial breast cancer. Am J Hum Genet 2002; 71 (2): 432–438. doi: 10.1086/341943.

64. Liang M, Zhang Y, Sun C et al. Association between CHEK2*1100delC and breast cancer: a systematic review and meta-analysis. Mol Diagn Ther 2018; 22 (4): 397–407. doi: 10.1007/s40291-018-0344-x.

65. Han FF, Guo CL, Liu LH. The effect of CHEK2 variant I157T on cancer susceptibility: evidence from a meta-analysis. DNA Cell Biol 2013; 32 (6): 329–335. doi: 10.1089/dna.2013.1970.

66. Zhang B, Beeghly-Fadiel A, Long J et al. Genetic variants associated with breast-cancer risk: comprehensive research synopsis, meta-analysis, and epidemiological evidence. Lancet Oncol 2011; 12 (5): 477–488. doi: 10.1016/S1470-2045 (11) 70076-6.

67. AlDubayan SH, Pyle LC, Gamulin M et al. association of inherited pathogenic variants in checkpoint kinase 2 (CHEK2) with susceptibility to testicular germ cell tumors. JAMA Oncol 2019. doi: 10.1001/jamaoncol.2018.6477.

68. Obazee O, Archibugi L, Andriulli A et al. Germline BRCA2 K3326X and CHEK2 I157T mutations increase risk for sporadic pancreatic ductal adenocarcinoma. Int J Cancer 2019; 145 (3): 686–693. doi: 10.1002/ijc.32127.

69. Hallamies S, Pelttari LM, Poikonen-Saksela P et al. CHEK2 c.1100delC mutation is associated with an increased risk for male breast cancer in Finnish patient population. BMC Cancer 2017; 17 (1): 620. doi: 10.1186/s12885-017-3631-8.

70. Carlo MI, Mukherjee S, Mandelker D et al. Prevalence of germline mutations in cancer susceptibility genes in patients with advanced renal cell carcinoma. JAMA Oncol 2018; 4 (9): 1228–1235. doi: 10.1001/jamaoncol.2018.1986.

71. Pritchard CC, Mateo J, Walsh MF et al. Inherited DNA-repair gene mutations in men with metastatic prostate cancer. N Engl J Med 2016; 375 (5): 443–453. doi: 10.1056/NEJMoa1603144.

72. Siolek M, Cybulski C, Gasior-Perczak D et al. CHEK2 mutations and the risk of papillary thyroid cancer. Int J Cancer 2015; 137 (3): 548–552. doi: 10.1002/ijc.29426.

73. Wang Y, Dai B, Ye D. CHEK2 mutation and risk of prostate cancer: a systematic review and meta-analysis. Int J Clin Exp Med 2015; 8 (9): 15708–15715.

74. Hale V, Weischer M, Park JY. CHEK2 (*) 1100delC mutation and risk of prostate cancer. prostate cancer 2014; 2014: 294575. doi: 10.1155/2014/294575.

75. Ma X, Zhang B, Zheng W. Genetic variants associated with colorectal cancer risk: comprehensive research synopsis, meta-analysis, and epidemiological evidence. Gut 2014; 63 (2): 326–336. doi: 10.1136/gutjnl-2012-304 121.

76. Liu C, Wang QS, Wang YJ. The CHEK2 I157T variant and colorectal cancer susceptibility: a systematic review and meta-analysis. Asian Pac J Cancer Prev 2012; 13 (5): 2051–2055. doi: 10.7314/apjcp.2012.13.5.2051.

77. Weischer M, Heerfordt IM, Bojesen SE et al. CHEK2*1100delC and risk of malignant melanoma: Danish and German studies and meta-analysis. J Invest Dermatol 2012; 132 (2): 299–303. doi: 10.1038/jid.2011.303.

78. Xiang HP, Geng XP, Ge WW et al. Meta-analysis of CHEK2 1100delC variant and colorectal cancer susceptibility. Eur J Cancer 2011; 47 (17): 2546–2551. doi: 10.1016/j.ejca.2011.03.025.