Cancer incidence in kidney transplant recipients: a study protocol.
BACKGROUND
Different publications show an increased incidence of neoplasms in renal transplant patients. The objective of this study is to determine the incidence of cancer in the recipients of renal transplants performed in the A Coruña Hospital (Spain) during the period 1981-2007.


METHODS
During the study period 1967 kidney transplants were performed, corresponding to 1710 patients. Patients with neoplasms prior to the transplant will be excluded (n = 38). A follow-up study was carried out in order to estimate cancer incidence after transplantation.For each patient, information included donor and recipient characteristics, patients and graft survival and cancer incidence after transplantation. Incident cancer is considered as new cases of cancer after the transplant with anatomopathological confirmation. Their location will be classified according to the ICD-9.The analysis will be calculated using the indirect standardisation method. Age-adjusted cancer incidence rates in the Spanish general population will be obtained from the Carlos III Health Institute, the National Epidemiology Centre of the Ministry of Science and Technology. Crude first, second and third-year post-transplantation cancer incidence rates will be calculated for male and female recipients. The number of cases of cancer at each site will be calculated from data in the clinical records. The expected number of cancers will be calculated from data supplied by the Carlos III Health Institute. For each tumour location we will estimate the standardized incidence ratios (SIRs), using sex-specific cancer incidence rates, by dividing the incidence rate for the transplant patients by the rate of the general population. The 95% confidence intervals of the SIRs and their associated p-values will be calculated by assuming that the observed cancers follow a Poisson distribution. Stratified analysis will be performed to examine the variation in the SIRs with sex and length of follow-up.Competing risk survival analysis methods will be applied to estimate the cumulative incidence of cancer and to identify variables associated to its occurrence.


CONCLUSIONS
Information about cancer incidence in kidney transplant patients could be useful to adapt the guidelines on post-kidney transplant follow-up on tumour screening, and evaluate the impact of intervention measures for the prevention of cancer in these patients.
Pita-Fernandez
Salvador
S
Clinical Epidemiology and Biostatistics Unit, University Hospital Complex of A Coruña, Hotel de Pacientes 7a Planta, As Xubias, A Coruña, Spain. salvador.pita.fernandez@sergas.es
Valdes-Cañedo
Francisco
F
Pertega-Diaz
Sonia
S
Seoane-Pillado
Maria Teresa
MT
Seijo-Bestilleiro
Rocio
R
D002985:Clinical Protocols; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D009369:Neoplasms / Q000453:epidemiology* / Q000209:etiology; D012189:Retrospective Studies; D013030:Spain / Q000453:epidemiology
Liver Transpl Surg. 1999 Jan;5(1):46-9
9873092
Br J Dermatol. 2000 Sep;143(3):513-9
10971322
Lancet. 2007 Jul 7;370(9581):59-67
17617273
Am J Transplant. 2007 Sep;7(9):2140-51
17640312
Nephrol Dial Transplant. 2002;17 Suppl 4:31-6
12091640
J Am Acad Dermatol. 1999 Feb;40(2 Pt 1):177-86
10025742
Nephrol Dial Transplant. 2007 May;22 Suppl 1:i4-10
17456618
Transplant Rev (Orlando). 2008 Apr;22(2):141-9
18631867
Transplantation. 2009 Apr 27;87(8 Suppl):S19-22
19384182
Br J Cancer. 2003 Oct 6;89(7):1221-7
14520450
Am J Transplant. 2007 Apr;7(4):941-8
17331115
Am J Transplant. 2004 Jun;4(6):905-13
15147424
Am J Transplant. 2004 Jun;4(6):841-2
15147414
J Am Acad Dermatol. 1995 Aug;33(2 Pt 1):222-9
7622649
Transplantation. 2003 Nov 27;76(10):1448-51
14657684
Nefrologia. 2006;26(2):253-60
16808264
Nephrol Dial Transplant. 2002;17 Suppl 4:32, 34-6
12091641
Nature. 1999 Feb 11;397(6719):530-4
10028970
JAMA. 2006 Dec 20;296(23):2823-31
17179459
Nephrol Dial Transplant. 2002;17 Suppl 4:1-67
12484407
Lancet. 2000 May 27;355(9218):1886-7
10866449
Transplantation. 2005 Oct 15;80(2 Suppl):S254-64
16251858
Transpl Int. 2000;13 Suppl 1:S394-8
11112040
Lancet. 1995 Sep 23;346(8978):796-8
7674744
Transplantation. 2003 Aug 15;76(3):597-602
12923450
Clin J Am Soc Nephrol. 2008 Mar;3 Suppl 2:S87-S100
18309007
Nephrol Dial Transplant. 2002;17 Suppl 4:31-3, 35-6
12091638
Drugs. 2008;68 Suppl 1:11-9
18442297
Int J Cancer. 1995 Jan 17;60(2):183-9
7829213