INFORMED CONSENT STATUS IN OBSERVATIONAL STUDIES WITH RETROSPECTIVE DESIGN: A POOR SHOW
Objective: Informed consent is very important to protect the rights of patients and is obtained as a vital component of any clinical study. Requirement
of patient consent in retrospective research continues to stir controversy even today. Some of directions of regulatory authorities even waive off the
consent for retrospective studies, whereas few recommend that at least clearance from the Ethical Review Board may be taken or information to
patient may be given or oral consent must be given by patient for usage of the data in any retrospective study. The aim of this study was to analyze the
current status of informed consent procedures in observational studies with retrospective design.
Methods: This review was intended to find out the current status of procedures involved in informed consent in India and abroad. A total of 100
retrospective studies were searched for this objective from the internet and other literature sources.
Results: Data show that in 65% of studies neither informed consent/oral consent nor ethical clearance was taken. Only 1% of studies have been
conducted with informed consent as well as ethical clearance. Only 14% of studies were conducted with informed consent and 21% with ethical
Conclusion: The study reflects very poor status of informed consent in retrospective studies and noncompliance of ICH guidelines for clinical research
in relation to informed consent.
Keywords: Clinical research, Informed consent, Retrospective studies.
1. Bhowmik D, Chandira M, Chiranjib B. Emerging trends of scope and opportunities clinical trials in India. Int J Pharm Pharm Sci 2010;2(1):7-20.
2. Johnson J, Gupta NV. Recent advances in quality management of clinical trials. Int J Pharm Pharm Sci 2013;5(3):34-8.
3. Al-Shahi R, Vousden C, Warlow C; Scottish Intracranial Vascular Malformation Study (SIVMS) Steering Committee. Bias from requiring explicit consent from all participants in observational research: Prospective, population based study. BMJ 2005;331(7522):942.
4. Junghans C, Feder G, Hemingway H, Timmis A, Jones M. Recruiting patients to medical research: Double blind, randomised trial of â€œopt-inâ€ versus â€œopt-outâ€ strategies. BMJ 2005;331(7522):940-2.
5. WMA: The World Medical Association. Declaration on Ethical Considerations Regarding Health Databases; 2002. Available from: http://www.wma.net/e/policy/d1.html. [Last accessed on 2009 Jul 30].
6. CIOMS: Council for International Organizations of Medical Sciences. International Ethical Guidelines for Biomedical Research Involving Human Subjects. Available from: http://www.cioms.ch/frame_guidelines_nov_2002.html. [Last accessed on 2009 Aug 10].
7. Capron AM, Mauron A, Elger BS, Boggio A, Ganguli-Mitra A, Biller-Andorno N. Ethical norms and the international governance of genetic databases and biobanks: Findings from an international study. Kennedy Inst Ethics J 2009;19(2):101-24.
8. SAMS. Directive on Biobanks, Obtainment, Preservation and Utilisation of Human Biological Material. Basel: SAMS; 2006.
9. British Sociological Association. Statement of Ethical Practice. Durham: British Sociological Association Appendix; 2004.
10. Matsui Y, Kamiyama Y. Retrospective study in breast cancer patients supplemented with AHCC. Int J Integr Oncol 2009;3(2):12-6.
11. Bigler SA, Pound CR, Zhou X. A retrospective study on pathologic features and racial disparities in prostate cancer. Prostate Cancer 2011;2011:239460.
12. Eschle D, Wieser HG. Are antinuclear antibodies useful in neurologic patients? A retrospective analysis based on 545 cases. Schweiz Arch Neurol Psychiatr 2004;155(2);67-9.
13. Mathur A, Jain M, Shiva M, Navlakha M, Prabu, Kulkarni S. Tobacco habits and risk of oral cancer: A retrospective study in India. Iran J Blood Cancer 2009;1(3):111-6.
14. Kozanoglu I, Deniz Y, Buyukkurt N, Yeral M, Boga C, Ozdogu H. A retrospective study on patients with guillain-barrÃ© syndrome treated with therapeutic plasma exchange and other treatment options â€“ A centreâ€™s experience. Eur Neurol Rev 2015;10(1):81-4.
15. Zargar AH, Sofi FA, Laway BA, Masoodi SR, Shah NA, Dar FA. Profile of neurological problems in diabetes mellitus: Retrospective analysis of data from 1294 patients. Health Adm 2009;22:95-106.
16. Kumari KG, Sudhakar G, Ramesh M, Kalpana VL, Paddaiah G. Prognostic factors in cervical cancer: A hospital-based retrospective study from Visakhapatnam City, Andhra Pradesh. J Life Sci 2010;2(2):99-105.
17. Silva CA, Oliveira AC, Vilas-Boas L, Fink MC, Pannuti CS, Vidal JE. Neurologic cytomegalovirus complications in patients with AIDS: Retrospective review of 13 cases and review of the literature. Rev Inst Med Trop Sao Paulo 2010;52(6):305-10.
18. Cengiz N, Adibelli Z, YakupoÄŸlu YK, TÃ¼rker H. Neurological complications after renal transplantation: A retrospective clinical study. Arch Neuropsychiatry 2015;52:331-5.
19. Stockton D, Davies T, Day N, McCann J. Retrospective study of reasons for improved survival in patients with breast cancer in East Anglia: Earlier diagnosis or better treatment. BMJ 1997;314(7079):472-5.
20. Morris EJ, Penegar S, Whitehouse LE, Quirke P, Finan P, Bishop DT, et al. A retrospective observational study of the relationship between family history and survival from colorectal cancer. Br J Cancer 2013;108(7):1502-7.
21. Pishbijari HF, Rad MA, Ghofrani H, Shafaghi A, Toosi MN, Dolatshahi S, et al. A retrospective study of gastric cancers in Tehran. Med J Islam Repub Iran 2006;20(3):107-10.
22. Mercimek-Mahmutoglu S, Sidky S, Hyland K, Patel J, et al. Prevalence of inherited neurotransmitter disorders in patients with movement disorders and epilepsy: A retrospective cohort study. Orphanet J Rare Dis 2015;10:12.
23. Aggarwal S, Bogula VR, Mandal K, Kumar R, Phadke SR. Aetiologic spectrum of mental retardation and developmental delay in India. Indian J Med Res 2012;136(3):436-44.
24. Grapsa I, Pavlopoulos H, Dawson D, Gibbs JS, Nihoyannopoulos P. Retrospective study of pulmonary hypertensive patients: Is right ventricular myocardial performance index a vital prognostic factor? Hellenic J Cardiol 2007;48(3):152-60.
25. Mumford KG, Contant CK, Weissman J, Wolf J, Glanz K. Changes in physical activity and travel behaviors in residents of a mixed-use development. Am J Prev Med 2011;41(5):504-7.
26. Pr R, Hv A, Shivamurthy M. Anti hypertensive prescribing patterns and cost analysis for primary hypertension: A retrospective study. J Clin Diagn Res 2014;8(9):HC19-22.
27. Gupta SK, Nayak RP, Rahavi R, Kumar A. A cross-sectional retrospective study to assess the pattern of prescribing for inpatient hypertensive cases in a tertiary hospital and to find out the possible avenues for betterment of hypertension management. Arch Med Health Sci 2015;3(1):60-5.
28. Maan MA, Hussain F, Jamil M. Prevalence and risk factors of HIV in Faisalabad, Pakistan -A retrospective study. Pak J Med Sci 2014;30(1):32-5.
29. Madâ€™ar R, BenesovÃ¡ D, BrandejskÃ¡ D, CermÃ¡kovÃ¡ M, DvorkovÃ¡ A, GazÃ¡rkovÃ¡ O, et al. Vaccination of patients with diabetes mellitus â€“ A retrospective study. Cent Eur J Public Health 2011;19(2):98-101.
30. Macdonald A, Pritchard D, Tapadar P. The impact of multifactorial genetic disorders on critical illness insurance: A simulation study based on UK Biobank. Astin Bull 2006;36(2):311-46.
31. Tomatir AG, Demirhan H, Sorkun HC, KÃ¶ksal A, Ozerdem F, Cilengir N. Major congenital anomalies: A five-year retrospective regional study in Turkey. Genet Mol Res 2009;8(1):19-27.
32. Imam TS, Oyeyi TI. A retrospective study of pulmonary tuberculosis (Ptb) prevalence amongst patients attending infectious diseases hospital (IDH) in Kano, Nigeria. Bayero J Pure Appl Sci 2008;1(1):10-5.
33. Ojiezeh TI, Ogundipe OO, Adefosoye VA. A retrospective study on incidence of pulmonary tuberculosis and human immunodeficiency
Asian J Pharm Clin Res, Vol 10, Issue 3, 2017, 480-487
Gill et al.
virus co-infection among patients attending national tuberculosis and leprosy control programme, OWO Centre. The Pan Afr Med J 2015;20:345.
34. Biadglegne F, Anagaw B, Debebe T, Anagaw B, Tesfaye W, Tessema B, et al. A retrospective study on the outcomes of tuberculosis treatment in Felege Hiwot Referral Hospital, Northwest Ethiopia. Int J Med Med Sci 2013;5(2):85-91.
35. Myneedu VP, Visalakshi P, Verma AK, Behera D, Bhalla M. Prevalence of XDR TB cases â€“ A retrospective study from a tertiary care TB hospital. Indian J Tuberc 2011;58(2):54-9.
36. Kpanyen PN, Diouf G, Tokpa AF, Toe MW, Nie S. A retrospective study to determine the prevalence and outcome of tuberculosis among patients who visited the TB Annex Hospital in Congo Town, Monrovia, Liberia from July 2009 to July 2010. Glob J Health Sci 2011;3(1):110-8.
37. Jetan CA, Jamaiah I, Rohela M, Nissapatorn V. Tuberculosis: An eight year (2000-2007) retrospective study at the University of Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia. Southeast Asian J Trop Med Public Health 2010;41(2):378-85.
38. Singh SS, Mehra N, Hopkins L; Society of Obstetricians and Gynecologists of Canada. Surgical safety checklist in obstetrics and gynaecology. J Obstet Gynaecol Can 2013;35(1):82-5.
39. Eskandar M, Archibong EI, Sadek AA, Sobande AA. Ectopic pregnancy and seasonal variation: A retrospective study from the south western region of Saudi Arabia. Bahrain Med Bull 2002;24(2):63-5.
40. Pjetursson BE, Tan WC, Tan K, BrÃ¤gger U, Zwahlen M, Lang NP. A systematic review of the survival and complication rates of resin-bonded bridges after an observation period of at least 5 years. Clin Oral Implants Res 2008;19(2):131-41.
41. Pjetursson BE, Tan WC, Zwahlen M, Lang NP. A systematic review of the success of sinus floor elevation and survival of implants inserted in combination with sinus floor elevation. J Clin Periodontol 2008;35 8 Suppl:216-40.
42. Schropp L, Isidor F. Timing of implant placement relative to tooth extraction. J Oral Rehabil 2008;35 Suppl 1:33-43.
43. Christodoulides N, Nikolidakis D, Chondros P, Becker J, Schwarz F, RÃ¶ssler R, et al. Photodynamic therapy as an adjunct to non-surgical periodontal treatment: A randomized, controlled clinical trial. J Periodontol 2008;79(9):1638-44.
44. Chalasani N, Younossi Z, Lavine JE, Diehl AM, Brunt EM, Cusi K, et al. The diagnosis and management of non-alcoholic fatty liver disease: Practice guideline by the American association for the study of liver diseases, American college of gastroenterology, and the American gastroenterological association. Hepatology 2012;55(6):2005-23.
45. Alimoghaddam K, Jalali A, Aliabadi LS, Ghaffari F, Maheri R, Eini E, et al. The outcomes of esophageal and gastric cancer treatments in a retrospective study, single center experience. Int J Hematol Oncol Stem Cell Res 2014;8(2):9-13.
46. Suryawala K, Soliman D, Mutyala M, Nageeb S, Boktor M, Seth A, et al. Gastric cancer in women: A regional health-center seven year retrospective study. World J Gastroenterol 2015;21(5):7805-13.
47. Afshinmajd S, Ghasemi H, Rajabi MT, Jalili M, Yarmohammadi ME. Clinical evaluation, prevalence and etiologic factors in patients with ophthalmoplegia. Iran J Ophthalmol 2011;23(1):48-54.
48. Lipscombe LL, LÃ©vesque L, Gruneir A, Fischer HD, Juurlink DN, Gill SS, et al. Antipsychotic drugs and hyperglycemia in older patients with diabetes. Arch Intern Med 2009;169(14):1282-9.
49. Parveen M, Pansi, Sonia C, Vani M, Ajay C. Spectrum of celiac disease at tertiary care center of Northeren India. Adv Res Gastroentero Hepatol 2015;1(2):555-8.
50. Richardson DB, Daniels RD, Gillies M, Cardis E, Oâ€™Hagan JA, Hamra GB, et al. Risk of cancer from occupational exposure to ionising radiation: Retrospective cohort study of workers in France, the United Kingdom, and the United States (INWORKS). BMJ 2015;351(6634):1-8.
51. Sakoda LC, Ferrara A, Achacoso NS, Peng T, Ehrlich SF, Quesenberry CP Jr, et al. Metformin use and lung cancer risk in patients with diabetes. Cancer Prev Res (Phila). 2015;8(2):174-9.
52. Castilho JL, Luz PM, Shepherd BE, Turner M, Ribeiro SR, Bebawy SS, et al. HIV and cancer: A comparative retrospective study of Brazilian and U.S. Clinical cohorts. Infect Agent Cancer 2015;10:4.
53. Mostafa MF, El-Etreby N, Awad N. Retrospective analysis evaluating ovarian cancer cases presented at the clinical oncology department, Alexandria University. Alex J Med 2012;48(4):353-60.
54. Das P, Thomas A, Kannan S, Deodhar K, Shrivastava SK, Mahantshetty U, et al. Human papillomavirus (HPV) genome status and cervical cancer outcome â€“ A retrospective study. Indian J Med Res 2015;142(5):525-32.
55. GervÃ¡sio OL, Dutra RA, Tartaglia SM, Vasconcellos WA, Barbosa AA, Aguiar MC. Oral squamous cell carcinoma: A retrospective study of 740 cases in a Brazilian population. Braz Dent J 2001;12(1):57-61.
56. Sharma S, Vijaykumar DK, Chitrathara K, Haji AG, George RC, Pavithran K. Neoadjuvant chemotherapy in advanced epithelial ovarian cancer: A retrospective study. Indian J Med Paediatr Oncol 2007;28(1):7-13.
57. Khaliq SA, Naqvi SB, Fatima A. Retrospective study of cancer types in different ethnic groups and genders at Karachi. Springerplus 2013;2(1):118.
58. A new prognostic system for hepatocellular carcinoma: A retrospective study of patients: The cancer of the liver Italian program (CLIP) investigators. Hepatology 1998;28(3):751-5.
59. Evans SM, Earnest A, Bower W, Senthuren M, McLaughlin P, Stirling R. Timeliness of lung cancer care in Victoria: A retrospective cohort study. Med J Aust 2016;204(2):e1-9.
60. Ismail H, Ho KM, Narayan K, Kondalsamy-Chennakesavan S. Effect of neuraxial anaesthesia on tumour progression in cervical cancer patients treated with brachytherapy: A retrospective cohort study. Br J Anaesth 2010;105(2):145-9.
61. Hussain MA, Pati S, Swain S, Prusty M, Kadam S, Nayak S. Pattern and trends of cancer in odisha, India: A retrospective study. Asian Pac J Cancer Prev 2012;13(12):6333-6.
62. Zeng WJ, Hu WQ, Wang LW, Yan SG, Li JD, Zhao HL, et al. Long term follow up and retrospective study on 533 gastric cancer cases. BMC Surg 2014;14(12):29.
63. Ajuzieogu OV, Ezike HA, Amucheazi AO, Enwereji J. A retrospective study of the outcome of cesarean section for women with severe pre-eclampsia in a third world setting. Saudi J Anaesth 2011;5(1):15-8.
64. Karaman S, Karaman T, Dogru S, Sahin A, Arici S, Tapar H, et al. Retrospective evaluation of Anesthesia approaches for lumbar disc surgery. J Anesth Clin Res 2014;5(4):1-3.
65. Parekh N, Husaini SW, Russell IF. Caesarean section for placenta praevia: A retrospective study of anaesthetic management. Br J Anaesth 2000;84(6):725-30.
66. Weinger MB, Slagle J, Jain S, Ordonez N. Retrospective data collection and analytical techniques for patient safety studies. J Biomed Inform 2003;36(1-2):106-19.
67. Divatia JV, Ambulkar R. Anesthesia and cancer recurrence: What is the evidence? J Anaesthesiol Clin Pharmacol 2014;30(2):147-50.
68. Sokhal N, Rath GP, Chaturvedi A, Dash HH, Bithal PK, Chandra PS. Anaesthesia for awake craniotomy: A retrospective study of 54 cases. Indian J Anaesth 2015;59(5):300-5.
69. Isais-Agdeppa AT, Bravo L. A five-year retrospective study on the common microbial isolates and sensitivity pattern on blood culture of pediatric cancer patients admitted at the Philippine general hospital for febrile neutropenia. PIDSP J 2005;9(2):19-24.
70. Aruna DS, Prasad KV, Shavi GR, Ariga J, Rajesh G, Krishna M. Retrospective study on risk habits among oral cancer patients in Karnataka Cancer Therapy and Research Institute, Hubli, India. Asian Pac J Cancer Prev 2011;12(6):1561-6.
71. Anis R, Gaballah K. Oral cancer in the UAE: A multicenter, retrospective study. Libyan J Med 2013;8:21782.
72. Sassi LM, Cervantes O, Schussel JL, Stramandinoli RT, Guebur MI, Ramos GH. Incidence of second primary oral cancer tumors: A retrospective study. Rev Odontol CiÃªn 2010;25(4):367-70.
73. Pompa G, Saccucci M, Di Carlo G, Brauner E, Valentini V, Di Carlo S, et al. Survival of dental implants in patients with oral cancer treated by surgery and radiotherapy: A retrospective study. BMC Oral Health 2015;15:5.
74. Munde AD, Karle RR, Wankhede PK, Shaikh SS, Kulkurni M. Demographic and clinical profile of oral lichen planus: A retrospective study. Contemp Clin Dent 2013;4(2):181-5.
75. Da Silva AJ, Rocha AC, Vasti AR, Cury R, Cury M, Cury SE. Retrospective study of the frequency of oral squamous cell carcinoma in the population of volta Redonda, Rio de Janeiro, Brazil. WebmedCentral Oncol 2013;4(11):WMC004446.
76. Deen JF, Krieger EV, Slee AE, Arslan A, Arterburn D, Stout KK, et al. Metabolic syndrome in adults with congenital heart disease. J Am Heart Assoc 2016;5(2):e001132.
77. Bhateja S. High prevalence of cardiovascular diseases among other medically compromised conditions in dental patients: A retrospective study. J Cardiovasc Dis Res 2012;3(2):113-6.
78. Cazzola M, Calzetta L, Bettoncelli G, Cricelli C, Romeo F, Matera MG, et al. Cardiovascular disease in asthma and COPD: A population-based retrospective cross-sectional study. Respir Med 2012;106(2):249-56.
Asian J Pharm Clin Res, Vol 10, Issue 3, 2017, 480-487
Gill et al.
79. Sari I, Altuntas F, Hacioglu S, Kocyigit I, Sevinc A, Sacar S, et al. A multicenter retrospective study defining the clinical and hematological manifestations of brucellosis and pancytopenia in a large series: Hematological malignancies, the unusual cause of pancytopenia in patients with brucellosis. Am J Hematol 2008;83(4):334-9.
80. Girmenia C, Pagano L, Martino B, Dâ€™Antonio D, Fanci R, Specchia G, et al. Invasive infections caused by Trichosporon species and Geotrichum capitatum in patients with hematological malignancies: A retrospective multicenter study from Italy and review of the literature. J Clin Microbiol 2005;43(4):1818-28.
81. Desalu OO, Oluwafemi JA, Ojo O. Respiratory diseases morbidity and mortality among adults attending a tertiary hospital in Nigeria. J Bras Pneumol 2009;35(8):745-52.
82. Alamoudi OS. Prevalence of respiratory diseases in hospitalized patients in Saudi Arabia: A 5 years study 1996-2000. Ann Thorac Med 2006;1(2):76-80.
83. Al Balushi KA, Al-Shibli S, Al-Zakwani I. Drug utilization patterns in the emergency department: A retrospective study. J Basic Clin Pharm 2013;5(1):1-6.
84. Shawky H, Tawfik H. Primary Gastrointestinal Non-Hodgkinâ€™s Lymphoma: A Retrospective Study with Emphasis on Prognostic Factors and Treatment Outcome. J Egypt Natl Canc Inst 2008;20(4):330-41.
85. Arora N, Manipadam MT, Pulimood A, Ramakrishna BS, Chacko A, Kurian SS, et al. Gastrointestinal lymphomas: Pattern of distribution and histological subtypes: 10 years experience in a tertiary centre in South India. Indian J Pathol Microbiol 2011;54(4):712-9.
86. de Silva IL, Mehr SS, Tey D, Tang ML. Paediatric anaphylaxis: A 5 year retrospective review. Allergy 2008;63(8):1071-6.
87. Shah JM, Shah FR, Atit NB, Kakadiya SR. Interpretation of upper gastrointestinal tract endoscopic biopsies - A retrospective study. Inter J Sci Res 2015;4(9):56-8.
88. Padhi S, Paul TR, Challa S, Prayaga AK, Rajappa S, Raghunadharao D, et al. Primary extra nodal non Hodgkin lymphoma: A 5 year retrospective analysis. Asian Pac J Cancer Prev 2012;13(10):4889-95.
89. Abdull Gaffar B. Gastrointestinal stromal tumors and extra-gastrointestinal tract neoplasms. South Med J 2010;103(10):1004-8.
90. Agerholm-Larsen B, Nordestgaard BG, Steffensen R, SÃ¸rensen TI, Jensen G, Tybjaerg-Hansen A. ACE gene polymorphism: Ischemic heart disease and longevity in 10,150 individuals. A case-referent and retrospective cohort study based on the Copenhagen City Heart Study. Circulation 1997;95(10):2358-67.
91. Daikeler T, Labopin M, Ruggeri A, Crotta A, Abinun M, Hussein AA, et al. New autoimmune diseases after cord blood transplantation: A retrospective study of EUROCORD and the Autoimmune Disease Working Party of the European Group for Blood and Marrow Transplantation. Blood 2013;121(6):1059-64.
92. Simon M, Hahn T, Ford LA, Anderson B, Swinnich D, Baer MR, et al. Retrospective multivariate analysis of hepatic veno-occlusive disease after blood or marrow transplantation: Possible beneficial use of low molecular weight heparin. Bone Marrow Transplant 2001;27(6):627-33.
93. Cherif H, Kronvall G, BjÃ¶rkholm M, Kalin M. Bacteraemia in hospitalised patients with malignant blood disorders: A retrospective study of causative agents and their resistance profiles during a 14-year period without antibacterial prophylaxis. Hematol J 2003;4(6):420-6.
94. Shenoi R, Devrukhkar V, Chaudhuri, Sharma BK, Sapre SB, Chikhale A. Demographic and clinical profile of oral squamous cell carcinoma patients: A retrospective study. Indian J Cancer 2012;49(1):21-6.
95. Labib NA, Elraghi HA, Shoman TH, Othman FH. Epidemiology of oral and pharyngeal cancer at the national cancer institute, Cairo. Med J Cairo Univ 2012;80(1):85-91.
96. Krempels K, Somlyai I, Gyongyi Z, Ember I, Balog K, Abonyi O, et al. A retrospective study of survival in breast cancer patients undergoing deuterium depletion in addition to conventional therapies. J Cancer Res Ther 2013;1(8):194-200.
97. Eltawel M, Abdulmoula M. Malignant skin tumours in Misurata Cancer Center during 2011-2014. MMSJ 2015:2(2);123-6.
98. Mohammad EA, Mansour M, Parichehr K, Farideh D, Amirhossein R, Ahmad SA. Assessment of clinical diagnostic accuracy compared with pathological diagnosis of basal cell carcinoma. Indian Dermatol Online J 2015;6(4):258-62.
99. Al-Maghrabi JA, Al-Ghamdi AS, Elhakeem HA. Pattern of skin cancer in Southwestern Saudi Arabia. Saudi Med J 2004;25(6):776-9.
100. Bomm L, Carvalho RV, Lima FF, Oliveira LN, Tolstoy F, LobÃ£o D. Retrospective analysis of melanocytic lesions in children at the National Cancer Institute-RJ. An Bras Dermatol 2014;89(2):369-71.
101. Ã–vermark M, Koskenmies S, PitkÃ¤nen S. A retrospective study of treatment of squamous cell carcinoma in situ. Acta Derm Venereol 2016;96(1):64-7.
102. Krishnatreya M, Kataki AC, Sharma JD, Lahkar K. A retrospective analysis of occupational exposure to pesticides as a possible risk factor for non-melanoma skin cancers. South Asian J Cancer 2015;4(1):47-8.
103. Brar BK, Sethi N, Khanna E. An epidemiological review of skin cancers in Malwa belt of Punjab India: A 3- year clinicopathological study. Sch J Appl Med Sci 2015;3(9D):3405-8.
104. Ochicha O, Edino ST, Mohammed AZ, Umar AB. Dermatological malignancies in kano, Northern Nigeria: A histopathological review. Ann Afr Med 2004;3(4):188-91.
105. LipozenÄiÄ‡ J, JurakiÄ‡-TonÄiÄ‡ R, RadoÅ¡ J, CeliÄ‡ D. Epidemiology of nonmelanoma and melanoma skin cancer in Zagreb, Croatia. Acta Dermatovenerol Croat 2008;16(4):193-203.
106. Patil R, Makdani M, Gunjalia A, Gandhi K, Pate H. Retrospective study of papulonodular skin lesions and their clinopathological correlation. Int J Med Sci Public Health 2015;4(5):612-6.
107. Chan A, Morey A, Brown B, Hastrich D, Willsher P, Ingram D. A retrospective study investigating the rate of HER2 discordance between primary breast carcinoma and locoregional or metastatic disease. BMC Cancer 2012;12:555.
108. Committee on Publication Ethics (COPE) Guidelines on Good Publication Practice. The COPE Report; 1999.
109. Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly Work in Medical Journals. Available from: http://www.icjme.org. [Last updated on 2015].
The publication is licensed under CC By and is open access. Copyright is with author and allowed to retain publishing rights without restrictions.