Research Summary
Dr. Polley’s primary research involves the design, conduct, and analysis of all phases of cancer clinical trials. She is the Head of the Statistics Division and Senior Statistician of the Brain Tumor Committee for NRG Oncology, a National Cancer Institute sponsored member of the national clinical trials network group. Previously, she served as the Director of the Biostatistics and Bioinformatics Core of the Mayo Clinic Breast Cancer Specialized Program of Research Excellence (SPORE). Dr. Polley had served on many scientific governing or advisory bodies including the National Cancer Institute Steering Committees (breast, lymphoma, head and neck cancer, and pediatric and adolescent solid tumor), the Scientific Program Committee of American Society of Clinical Oncology (ASCO) annual meetings, and the US Veterans Affairs (VA) Oncology A Study Section. Dr. Polley’s methodological interests include early-phase clinical trial designs, biomarker reproducibility, innovative group sequential methods for biomarker validation, prognostic and predictive modeling, design and analysis of biomarker-based clinical trials, and design and monitoring of late phase clinical trials.
clinical trials, cancer biomarker, prognostic modeling, biomarker reproducibility, breast cancer, brain cancer
  • Harvard University, Cambridge, Massachusetts, MA Statistics 06/1999
  • Columbia University, New York, New York, MS Biostatistics 05/2001
  • Columbia University, New York, New York, PhD Biostatistics 06/2006
Biosciences Graduate Program Association
Awards & Honors
  • 2001 - 2004 Merck & Co., Inc. Fellowship Columbia University
  • 2006 - The Joseph L. Fleiss Memorial Prize in Biostatistics for an Outstanding Dissertation Columbia University
  • 2008 - Travel Award - Biostatistics Workshop American Association for Cancer Research (AACR)
  • 2009 - Award for Excellence in Clinical Research The American Brain Tumor Association
  • 2009 - REAC Pilot Research Award in Basic and Clinical/Translational Sciences University of California San Francisco
  • 2012 - Distinguished Achievement Award Kelly Government Solutions, National Cancer Institute
  • 2017 - The Fraternal Order of Eagles Cancer Research Award Mayo Clinic Cancer Center
  • 2018 - Breast Cancer Specialized Program of Research Excellence - Developmental Research Program Award Mayo Clinic
  • 2021 - 2025 Appointee - Special Government Employee (SGE) member, Federal Advisory Committee Act (FACA) US Department of Veterans Affairs (VA)
  1. Rahman R, Ventz S, McDunn J, Louv B, Reyes-Rivera I, Polley MC, Merchant F, Abrey LE, Allen JE, Aguilar LK, Aguilar-Cordova E, Arons D, Tanner K, Bagley S, Khasraw M, Cloughesy T, Wen PY, Alexander BM, Trippa L. Leveraging external data in the design and analysis of clinical trials in neuro-oncology. Lancet Oncol. 2021 10; 22(10):e456-e465. View in: PubMed

  2. Polley MC, Dickler MN, Sinnwell J, Tenner K, de la Haba J, Loibl S, Goetz MP, Bergh J, Roberston J, Couch F, Ellis MJ, Martin M. A clinical calculator to predict disease outcomes in women with hormone receptor-positive advanced breast cancer treated with first-line endocrine therapy. Breast Cancer Res Treat. 2021 Aug; 189(1):15-23. View in: PubMed

  3. Carter JM, Polley MC, Leon-Ferre RA, Sinnwell J, Thompson KJ, Wang X, Ma Y, Zahrieh D, Kachergus JM, Solanki M, Boughey JC, Liu MC, Ingle JN, Kalari KR, Couch FJ, Thompson EA, Goetz MP. Characteristics and Spatially Defined Immune (micro)landscapes of Early-stage PD-L1-positive Triple-negative Breast Cancer. Clin Cancer Res. 2021 10 15; 27(20):5628-5637. View in: PubMed

  4. Polley MC. On the Quest of Risk Stratification in HER2-Positive Breast Cancer. J Natl Cancer Inst. 2022 03 08; 114(3):345-346. View in: PubMed

  5. Polley MC, Dignam JJ. Statistical Considerations in the Evaluation of Continuous Biomarkers. J Nucl Med. 2021 05 10; 62(5):605-611. View in: PubMed

  6. Polley MC, Leon-Ferre RA, Leung S, Cheng A, Gao D, Sinnwell J, Liu H, Hillman DW, Eyman-Casey A, Gilbert JA, Negron V, Boughey JC, Liu MC, Ingle JN, Kalari K, Couch F, Carter JM, Visscher DW, Nielsen TO, Goetz MP. A clinical calculator to predict disease outcomes in women with triple-negative breast cancer. Breast Cancer Res Treat. 2021 Feb; 185(3):557-566. View in: PubMed

  7. Nielsen TO, Leung SCY, Rimm DL, Dodson A, Acs B, Badve S, Denkert C, Ellis MJ, Fineberg S, Flowers M, Kreipe HH, Laenkholm AV, Pan H, Penault-Llorca FM, Polley MY, Salgado R, Smith IE, Sugie T, Bartlett JMS, McShane LM, Dowsett M, Hayes DF. Assessment of Ki67 in Breast Cancer: Updated Recommendations From the International Ki67 in Breast Cancer Working Group. J Natl Cancer Inst. 2021 07 01; 113(7):808-819. View in: PubMed

  8. Fernandez-Martinez A, Krop IE, Hillman DW, Polley MY, Parker JS, Huebner L, Hoadley KA, Shepherd J, Tolaney S, Henry NL, Dang C, Harris L, Berry D, Hahn O, Hudis C, Winer E, Partridge A, Perou CM, Carey LA. Survival, Pathologic Response, and Genomics in CALGB 40601 (Alliance), a Neoadjuvant Phase III Trial of Paclitaxel-Trastuzumab With or Without Lapatinib in HER2-Positive Breast Cancer. J Clin Oncol. 2020 12 10; 38(35):4184-4193. View in: PubMed

  9. Polley MC, Cheung YK. Early-Phase Platform Trials: A New Paradigm for Dose Finding and Treatment Screening in the Era of Precision Oncology. JCO Precis Oncol. 2019; 3. View in: PubMed

  10. Polley MC, Korn EL, Freidlin B. Phase III Precision Medicine Clinical Trial Designs That Integrate Treatment and Biomarker Evaluation. JCO Precis Oncol. 2019; 3. View in: PubMed

  11. Korpics MC, Polley MY, Bhave SR, Redler G, Pitroda SP, Luke JJ, Chmura SJ. A Validated T Cell Radiomics Score Is Associated With Clinical Outcomes Following Multisite SBRT and Pembrolizumab. Int J Radiat Oncol Biol Phys. 2020 09 01; 108(1):189-195. View in: PubMed

  12. Schöder H, Polley MC, Knopp MV, Hall N, Kostakoglu L, Zhang J, Higley HR, Kelloff G, Liu H, Zelenetz AD, Cheson BD, Wagner-Johnston N, Kahl BS, Friedberg JW, Hsi ED, Leonard JP, Schwartz LH, Wilson WH, Bartlett NL. Prognostic value of interim FDG-PET in diffuse large cell lymphoma: results from the CALGB 50303 Clinical Trial. Blood. 2020 06 18; 135(25):2224-2234. View in: PubMed

  13. Baughn LB, Li Z, Pearce K, Vachon CM, Polley MY, Keats J, Elhaik E, Baird M, Therneau T, Cerhan JR, Bergsagel PL, Dispenzieri A, Rajkumar SV, Asmann YW, Kumar S. The CCND1 c.870G risk allele is enriched in individuals of African ancestry with plasma cell dyscrasias. Blood Cancer J. 2020 03 16; 10(3):39. View in: PubMed

  14. Norton N, Youssef B, Hillman DW, Nassar A, Geiger XJ, Necela BM, Liu H, Ruddy KJ, Polley MC, Ingle JN, Couch FJ, Perez EA, Liu MC, Carter JM, Leon-Ferre RA, Boughey JC, Somers EB, Kalari KR, Visscher DW, Goetz MP, Knutson KL. Folate receptor alpha expression associates with improved disease-free survival in triple negative breast cancer patients. NPJ Breast Cancer. 2020; 6:4. View in: PubMed

  15. Page DB, Bear H, Prabhakaran S, Gatti-Mays ME, Thomas A, Cobain E, McArthur H, Balko JM, Gameiro SR, Nanda R, Gulley JL, Kalinsky K, White J, Litton J, Chmura SJ, Polley MY, Vincent B, Cescon DW, Disis ML, Sparano JA, Mittendorf EA, Adams S. Two may be better than one: PD-1/PD-L1 blockade combination approaches in metastatic breast cancer. NPJ Breast Cancer. 2019; 5:34. View in: PubMed

  16. Taparra K, Liu H, Polley MY, Ristow K, Habermann TM, Ansell SM. Bleomycin use in the treatment of Hodgkin lymphoma (HL): toxicity and outcomes in the modern era. Leuk Lymphoma. 2020 02; 61(2):298-308. View in: PubMed

  17. Muss HB, Polley MC, Berry DA, Liu H, Cirrincione CT, Theodoulou M, Mauer AM, Kornblith AB, Partridge AH, Dressler LG, Cohen HJ, Kartcheske PA, Perez EA, Wolff AC, Gralow JR, Burstein HJ, Mahmood AA, Sutton LM, Magrinat G, Parker BA, Hart RD, Grenier D, Hurria A, Jatoi A, Norton L, Hudis CA, Winer EP, Carey L. Randomized Trial of Standard Adjuvant Chemotherapy Regimens Versus Capecitabine in Older Women With Early Breast Cancer: 10-Year Update of the CALGB 49907 Trial. J Clin Oncol. 2019 09 10; 37(26):2338-2348. View in: PubMed

  18. Blum KA, Polley MY, Jung SH, Dockter TJ, Anderson S, Hsi ED, Wagner-Johnston N, Christian B, Atkins J, Cheson BD, Leonard JP, Bartlett NL. Randomized trial of ofatumumab and bendamustine versus ofatumumab, bendamustine, and bortezomib in previously untreated patients with high-risk follicular lymphoma: CALGB 50904 (Alliance). Cancer. 2019 10 01; 125(19):3378-3389. View in: PubMed

  19. Bartlett NL, Wilson WH, Jung SH, Hsi ED, Maurer MJ, Pederson LD, Polley MC, Pitcher BN, Cheson BD, Kahl BS, Friedberg JW, Staudt LM, Wagner-Johnston ND, Blum KA, Abramson JS, Reddy NM, Winter JN, Chang JE, Gopal AK, Chadburn A, Mathew S, Fisher RI, Richards KL, Schöder H, Zelenetz AD, Leonard JP. Dose-Adjusted EPOCH-R Compared With R-CHOP as Frontline Therapy for Diffuse Large B-Cell Lymphoma: Clinical Outcomes of the Phase III Intergroup Trial Alliance/CALGB 50303. J Clin Oncol. 2019 07 20; 37(21):1790-1799. View in: PubMed

  20. Yang ZZ, Kim HJ, Villasboas JC, Price-Troska T, Jalali S, Wu H, Luchtel RA, Polley MC, Novak AJ, Ansell SM. Mass Cytometry Analysis Reveals that Specific Intratumoral CD4+ T Cell Subsets Correlate with Patient Survival in Follicular Lymphoma. Cell Rep. 2019 02 19; 26(8):2178-2193.e3. View in: PubMed

  21. Peterson JF, Rowsey RA, Marcou CA, Pearce KE, Williamson CM, Frederick LA, Greipp PT, Ketterling RP, Kumar S, Viswanatha DS, Polley MY, Fink JM, Reichard KK, Van Dyke DL, Baughn LB. Hyperhaploid plasma cell myeloma characterized by poor outcome and monosomy 17 with frequently co-occurring TP53 mutations. Blood Cancer J. 2019 02 19; 9(3):20. View in: PubMed

  22. Baughn LB, Pearce K, Larson D, Polley MY, Elhaik E, Baird M, Colby C, Benson J, Li Z, Asmann Y, Therneau T, Cerhan JR, Vachon CM, Stewart AK, Bergsagel PL, Dispenzieri A, Kumar S, Rajkumar SV. Differences in genomic abnormalities among African individuals with monoclonal gammopathies using calculated ancestry. Blood Cancer J. 2018 10 10; 8(10):96. View in: PubMed

  23. Leon-Ferre RA, Polley MY, Liu H, Gilbert JA, Cafourek V, Hillman DW, Elkhanany A, Akinhanmi M, Lilyquist J, Thomas A, Negron V, Boughey JC, Liu MC, Ingle JN, Kalari KR, Couch FJ, Visscher DW, Goetz MP. Impact of histopathology, tumor-infiltrating lymphocytes, and adjuvant chemotherapy on prognosis of triple-negative breast cancer. Breast Cancer Res Treat. 2018 01; 167(1):89-99. View in: PubMed

  24. Polley MC. Power estimation in biomarker studies where events are already observed. Clin Trials. 2017 Dec; 14(6):621-628. View in: PubMed

  25. Polley MY, Leung SC, Gao D, Mastropasqua MG, Zabaglo LA, Bartlett JM, McShane LM, Enos RA, Badve SS, Bane AL, Borgquist S, Fineberg S, Lin MG, Gown AM, Grabau D, Gutierrez C, Hugh JC, Moriya T, Ohi Y, Osborne CK, Penault-Llorca FM, Piper T, Porter PL, Sakatani T, Salgado R, Starczynski J, Lænkholm AV, Viale G, Dowsett M, Hayes DF, Nielsen TO. An international study to increase concordance in Ki67 scoring. Mod Pathol. 2015 Jun; 28(6):778-86. View in: PubMed

  26. Ionan AC, Polley MY, McShane LM, Dobbin KK. Comparison of confidence interval methods for an intra-class correlation coefficient (ICC). BMC Med Res Methodol. 2014 Nov 22; 14:121. View in: PubMed

  27. Polley MY, Polley EC, Huang EP, Freidlin B, Simon R. Two-stage adaptive cutoff design for building and validating a prognostic biomarker signature. Stat Med. 2014 Dec 20; 33(29):5097-110. View in: PubMed

  28. Sharon E, Polley MY, Bernstein MB, Ahmed M. Immunotherapy and radiation therapy: considerations for successfully combining radiation into the paradigm of immuno-oncology drug development. Radiat Res. 2014 Aug; 182(2):252-7. View in: PubMed

  29. McShane LM, Cavenagh MM, Lively TG, Eberhard DA, Bigbee WL, Williams PM, Mesirov JP, Polley MY, Kim KY, Tricoli JV, Taylor JM, Shuman DJ, Simon RM, Doroshow JH, Conley BA. Criteria for the use of omics-based predictors in clinical trials: explanation and elaboration. BMC Med. 2013 Oct 17; 11:220. View in: PubMed

  30. Polley MY, Leung SC, McShane LM, Gao D, Hugh JC, Mastropasqua MG, Viale G, Zabaglo LA, Penault-Llorca F, Bartlett JM, Gown AM, Symmans WF, Piper T, Mehl E, Enos RA, Hayes DF, Dowsett M, Nielsen TO. An international Ki67 reproducibility study. J Natl Cancer Inst. 2013 Dec 18; 105(24):1897-906. View in: PubMed

  31. Polley MY, Freidlin B, Korn EL, Conley BA, Abrams JS, McShane LM. Statistical and practical considerations for clinical evaluation of predictive biomarkers. J Natl Cancer Inst. 2013 Nov 20; 105(22):1677-83. View in: PubMed

  32. McShane LM, Cavenagh MM, Lively TG, Eberhard DA, Bigbee WL, Williams PM, Mesirov JP, Polley MY, Kim KY, Tricoli JV, Taylor JM, Shuman DJ, Simon RM, Doroshow JH, Conley BA. Criteria for the use of omics-based predictors in clinical trials. Nature. 2013 Oct 17; 502(7471):317-20. View in: PubMed

  33. McShane LM, Polley MY. Development of omics-based clinical tests for prognosis and therapy selection: the challenge of achieving statistical robustness and clinical utility. Clin Trials. 2013 Oct; 10(5):653-65. View in: PubMed

  34. Bodelon C, Polley MY, Kemp TJ, Pesatori AC, McShane LM, Caporaso NE, Hildesheim A, Pinto LA, Landi MT. Circulating levels of immune and inflammatory markers and long versus short survival in early-stage lung cancer. Ann Oncol. 2013 Aug; 24(8):2073-9. View in: PubMed

  35. Freidlin B, McShane LM, Polley MY, Korn EL. Randomized phase II trial designs with biomarkers. J Clin Oncol. 2012 Sep 10; 30(26):3304-9. View in: PubMed

  36. Phillips JJ, Huillard E, Robinson AE, Ward A, Lum DH, Polley MY, Rosen SD, Rowitch DH, Werb Z. Heparan sulfate sulfatase SULF2 regulates PDGFRa signaling and growth in human and mouse malignant glioma. J Clin Invest. 2012 Mar; 122(3):911-22. View in: PubMed

  37. Polley MY, Lamborn KR, Chang SM, Butowski N, Clarke JL, Prados M. Conditional probability of survival in patients with newly diagnosed glioblastoma. J Clin Oncol. 2011 Nov 01; 29(31):4175-80. View in: PubMed

  38. Butowski N, Chang SM, Lamborn KR, Polley MY, Pieper R, Costello JF, Vandenberg S, Parvataneni R, Nicole A, Sneed PK, Clarke J, Hsieh E, Costa BM, Reis RM, Hristova-Kazmierski M, Nicol SJ, Thornton DE, Prados MD. Phase II and pharmacogenomics study of enzastaurin plus temozolomide during and following radiation therapy in patients with newly diagnosed glioblastoma multiforme and gliosarcoma. Neuro Oncol. 2011 Dec; 13(12):1331-8. View in: PubMed

  39. Pejavar S, Polley MY, Rosenberg-Wohl S, Chennupati S, Prados MD, Berger MS, Banerjee A, Gupta N, Haas-Kogan D. Pediatric intracranial ependymoma: the roles of surgery, radiation and chemotherapy. J Neurooncol. 2012 Jan; 106(2):367-75. View in: PubMed

  40. Polley MY. Practical modifications to the time-to-event continual reassessment method for phase I cancer trials with fast patient accrual and late-onset toxicities. Stat Med. 2011 Jul 30; 30(17):2130-43. View in: PubMed

  41. Mueller S, Yang X, Sottero TL, Gragg A, Prasad G, Polley MY, Weiss WA, Matthay KK, Davidoff AM, DuBois SG, Haas-Kogan DA. Cooperation of the HDAC inhibitor vorinostat and radiation in metastatic neuroblastoma: efficacy and underlying mechanisms. Cancer Lett. 2011 Jul 28; 306(2):223-9. View in: PubMed

  42. Sanai N, Polley MY, McDermott MW, Parsa AT, Berger MS. An extent of resection threshold for newly diagnosed glioblastomas. J Neurosurg. 2011 Jul; 115(1):3-8. View in: PubMed

  43. Prasad G, Sottero T, Yang X, Mueller S, James CD, Weiss WA, Polley MY, Ozawa T, Berger MS, Aftab DT, Prados MD, Haas-Kogan DA. Inhibition of PI3K/mTOR pathways in glioblastoma and implications for combination therapy with temozolomide. Neuro Oncol. 2011 Apr; 13(4):384-92. View in: PubMed

  44. Parvataneni R, Polley MY, Freeman T, Lamborn K, Prados M, Butowski N, Liu R, Clarke J, Page M, Rabbitt J, Fedoroff A, Clow E, Hsieh E, Kivett V, Deboer R, Chang S. Identifying the needs of brain tumor patients and their caregivers. J Neurooncol. 2011 Sep; 104(3):737-44. View in: PubMed

  45. Li Y, Lupo JM, Polley MY, Crane JC, Bian W, Cha S, Chang S, Nelson SJ. Serial analysis of imaging parameters in patients with newly diagnosed glioblastoma multiforme. Neuro Oncol. 2011 May; 13(5):546-57. View in: PubMed

  46. Clark AJ, Butowski NA, Chang SM, Prados MD, Clarke J, Polley MY, Sughrue ME, McDermott MW, Parsa AT, Berger MS, Aghi MK. Impact of bevacizumab chemotherapy on craniotomy wound healing. J Neurosurg. 2011 Jun; 114(6):1609-16. View in: PubMed

  47. Essock-Burns E, Lupo JM, Cha S, Polley MY, Butowski NA, Chang SM, Nelson SJ. Assessment of perfusion MRI-derived parameters in evaluating and predicting response to antiangiogenic therapy in patients with newly diagnosed glioblastoma. Neuro Oncol. 2011 Jan; 13(1):119-31. View in: PubMed

  48. Tate MC, Kim CY, Chang EF, Polley MY, Berger MS. Assessment of morbidity following resection of cingulate gyrus gliomas. Clinical article. J Neurosurg. 2011 Mar; 114(3):640-7. View in: PubMed

  49. Srinivasan R, Phillips JJ, Vandenberg SR, Polley MY, Bourne G, Au A, Pirzkall A, Cha S, Chang SM, Nelson SJ. Ex vivo MR spectroscopic measure differentiates tumor from treatment effects in GBM. Neuro Oncol. 2010 Nov; 12(11):1152-61. View in: PubMed

  50. Cloyd JM, Acosta FL, Polley MY, Ames CP. En bloc resection for primary and metastatic tumors of the spine: a systematic review of the literature. Neurosurgery. 2010 Aug; 67(2):435-44; discussion 444-5. View in: PubMed

  51. Chang EF, Clark A, Smith JS, Polley MY, Chang SM, Barbaro NM, Parsa AT, McDermott MW, Berger MS. Functional mapping-guided resection of low-grade gliomas in eloquent areas of the brain: improvement of long-term survival. Clinical article. J Neurosurg. 2011 Mar; 114(3):566-73. View in: PubMed

  52. Mueller S, Polley MY, Lee B, Kunwar S, Pedain C, Wembacher-Schröder E, Mittermeyer S, Westphal M, Sampson JH, Vogelbaum MA, Croteau D, Chang SM. Effect of imaging and catheter characteristics on clinical outcome for patients in the PRECISE study. J Neurooncol. 2011 Jan; 101(2):267-77. View in: PubMed

  53. Khayal IS, Polley MY, Jalbert L, Elkhaled A, Chang SM, Cha S, Butowski NA, Nelson SJ. Evaluation of diffusion parameters as early biomarkers of disease progression in glioblastoma multiforme. Neuro Oncol. 2010 Sep; 12(9):908-16. View in: PubMed

  54. Polley MY, Lamborn KR, Chang SM, Butowski N, Clarke JL, Prados M. Six-month progression-free survival as an alternative primary efficacy endpoint to overall survival in newly diagnosed glioblastoma patients receiving temozolomide. Neuro Oncol. 2010 Mar; 12(3):274-82. View in: PubMed

  55. Butowski N, Chang SM, Lamborn KR, Polley MY, Parvataneni R, Hristova-Kazmierski M, Musib L, Nicol SJ, Thornton DE, Prados MD. Enzastaurin plus temozolomide with radiation therapy in glioblastoma multiforme: a phase I study. Neuro Oncol. 2010 Jun; 12(6):608-13. View in: PubMed

  56. Schiffman JD, Hodgson JG, VandenBerg SR, Flaherty P, Polley MY, Yu M, Fisher PG, Rowitch DH, Ford JM, Berger MS, Ji H, Gutmann DH, James CD. Oncogenic BRAF mutation with CDKN2A inactivation is characteristic of a subset of pediatric malignant astrocytomas. Cancer Res. 2010 Jan 15; 70(2):512-9. View in: PubMed

  57. McBride SM, Perez DA, Polley MY, Vandenberg SR, Smith JS, Zheng S, Lamborn KR, Wiencke JK, Chang SM, Prados MD, Berger MS, Stokoe D, Haas-Kogan DA. Activation of PI3K/mTOR pathway occurs in most adult low-grade gliomas and predicts patient survival. J Neurooncol. 2010 Mar; 97(1):33-40. View in: PubMed

  58. Sanai N, Polley MY, Berger MS. Insular glioma resection: assessment of patient morbidity, survival, and tumor progression. J Neurosurg. 2010 Jan; 112(1):1-9. View in: PubMed

  59. Liu R, Solheim K, Polley MY, Lamborn KR, Page M, Fedoroff A, Rabbitt J, Butowski N, Prados M, Chang SM. Quality of life in low-grade glioma patients receiving temozolomide. Neuro Oncol. 2009 Feb; 11(1):59-68. View in: PubMed

  60. Polley MY, Cheung YK. Two-stage designs for dose-finding trials with a biologic endpoint using stepwise tests. Biometrics. 2008 Mar; 64(1):232-41. View in: PubMed

  61. Dai B, Polley MC. Two-Stage Adaptive Design for Prognostic Biomarker Signatures With a Survival Endpoint. Statistics in Biopharmaceutical Research. 2020.::::

  62. Cunanan, KM; Polley MY. A simulation based evaluation of sample size methods for biomarker studies. Int J Stat Med Res. 2018; 4(7):106-116.::::