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CLINICAL GASTROENTEROLOGY AND HEPATOLOGY 2012;10:1179 –1180LETTERS TO THE EDITORReaders are encouraged to write letters to the editor concerning articles that have been published in CLINICAL GASTROENTEROLOGY ANDHEPATOLOGY. Short, general comments are also considered, but use of the Letters to the Editor section for publication of original data inpreliminary form is not encouraged. Letters should be typewritten and submitted electronically to http://www.editorialmanager.com/cgh.Challenges in Calculating the Risk for 1.01–3.0) with a median follow-up of 10 years. This is remark-Colorectal Cancer in Patients With able, because the similar range of SIRs across different geo- graphic areas—including now Eastern Europe—may supportUlcerative Colitis that chronic inﬂammation contributes in a similar, additiveDear Editor: manner to the initiation of carcinogenesis in the colon, irre- We read with interest the report by Jess et al1 on the meta- spective of the pre-existing baseline risk or geographic differ-analysis of the risk of colorectal cancer (CRC) in patients with ences. Second, previous studies have identiﬁed multiple riskulcerative colitis (UC) in population-based cohort studies. The factors for UC-associated CRC. In the study by Jess et al,1 malesmajor ﬁnding of the study was that the risk of UC in popula- (SIR, 2.6; 95% CI, 2.2–3.0 vs females: SIR, 1.9; 95% CI, 1.5–2.3)tion-based cohorts was increased. However, it was signiﬁcantly and patients with extensive colitis (SIR, 4.8; 95% CI, 3.9 –5.9)lower than previously reported in the landmark meta-analysis had a greater risk, similar to recent Swedish data. In the pop-by Eaden et al.2 In the present meta-analysis, an average of 1.6% ulation-based Hungarian cohort, the SIR was also increased inof patients with UC were diagnosed with CRC during the ﬁrst patients with extensive colitis (SIR, 4.1; 95% CI, 2.0 – 8.1), and a14 years of follow-up. The pooled standardized incidence ratio tendency of increased SIRs was seen in females and males.(SIR) was 2.4 (95% conﬁdence interval [CI], 2.1–2.7). Neverthe- Other potential risk factors include age at onset, disease dura-less, it is important to highlight potential limitations of the tion, primary sclerosing cholangitis, and medication historystudy before accepting the above general conclusion. One of the (including exposure to 5-aminosalicylates/azathioprine).most important possible confounders is the high percentage of In summary, communication of cancer risk in ulcerativeproctitis (45%– 60%) in about half of the cohorts. In addition, colitis and patient management strategies should be tailored tothe rate of colectomy was exceedingly high (16%–31%), espe- speciﬁc patients based on age, sex, disease extent, disease dura-cially compared with the relatively short median follow-up tion, geographic area, and presence of factors including age atperiod. Geographic imbalance is also apparent, with 5 out of 8 onset, disease duration, and primary sclerosing cholangitis.studies coming from the Nordic countries. Furthermore, al- PETER L. LAKATOS, MD, PhDthough authors interpreted the positive association between First Department of Medicinecohort size and CRC risk as a conﬁrmatory factor against Semmelweis Universitypublication bias, an alternative explanation is that the patient Budapest, Hungarypopulation in the study by Söderlund et al was signiﬁcantlydifferent from other cohorts included in this meta-analysis with LASZLO LAKATOS, MD, PhDonly 27% of patients having proctitis at diagnosis.3 Interest- Department of Medicineingly, other population-based cohorts from Scandinavia also Csolnoky F. Province Hospitalreported a lower percentage of proctitis at diagnosis, and com- Veszprem, Hungaryparable data (25.3%) were reported by our group from Eastern 1. Jess T, et al. Clin Hepatol Gastroenterol 2012;10:639 – 645.Europe.4 In addition, colectomy rates have shown large geo- 2. Eaden JA, et al. Gut 2001;48:526 –535.graphic variation with signiﬁcantly lower rates reported from 3. Söderlund S, et al. Gastroenterology 2009;136:1561–1567.the Mediterranean and Eastern Europe in previous studies. 4. Lakatos L, et al. Inﬂamm Bowel Dis 2006;12:205–211.Consequently, in contrast to the meta-analysis by Eaden et al,2the present meta-analysis potentially underestimated the actualCRC risk in UC. Generalizability of results is therefore ques-tionable, and geographic restrictions may also apply. Conﬂicts of interest Nevertheless, communicating only the overall SIR to the The authors disclose no conﬂicts.patients can be misleading because of at least 2 reasons. First, http://dx.doi.org/10.1016/j.cgh.2012.04.021there is substantial variation in the incidence of sporadic CRCworldwide. The incidence of sporadic CRC in the Western world Reply. We thank Drs Lakatos and Lakatos for commenting onis approximately 30 to 40 per 100,000. In contrast, correspond- our meta-analysis on risk of colorectal cancer (CRC) in patientsing numbers (eg, in Hungary) are 81 per 100,000 in males and with ulcerative colitis (UC).1 We agree that the results of our50 per 100,000 in females. This is one of the highest sporadic meta-analysis are different from those of the meta-analysis byCRC incidences reported worldwide. Therefore, a similar SIR Eaden and colleagues from 2001.2 We believe that this differ-may correspond to considerable different absolute CRC risk in ence is explained by the unselected nature of the cohort studiesdifferent geographic areas (eg, the cumulative risk of developing included in the present meta-analysis. Reassuringly for patients,CRC after a disease duration of 15 and 20 years was 2.6% and we observed a more modestly increased risk of CRC in UC than5.4% in the Hungarian cohort).4 After the original publication, in the former meta-analysis, which included selected patientSIR rates were calculated for the Hungarian UC patients. In series.2 Due to the strict inclusion criteria in the present meta-concordance with the results of the above meta-analysis, the analysis, we believe that our results are inherently more gener-overall SIR in this Eastern European cohort was 1.74 (95% CI, alizable to the broad spectrum of UC patients and especially to