Hematopoietic Stem Cell Transplantation and Secondary Primary Malignancies in Taiwan

Abstract

AbstractAbstract 4219 ObjectivesHematopoietic stem cell transplantation (HSCT) is a curative strategy for many hematological disorders. The improvement of HSCT may lead to longer overall survival of patients with catastrophic illness and the risk of secondary cancer development become an emerging issue in long-term survivors. Patients and MethodsWe conducted a nationwide population-based study of 1,881 patients with hematologic diseases undergoing HSCT between January, 1997 and January, 2007 using Taiwan's National Health Insurance Research database. Performing HSCT to treat non-hematological diseases were excluded. All patients were followed until solid cancer development, death, or the end of 2010. We did not put hematological malignancies as endpoint because solid tumors and hematological malignancies might have different carcinogensis mechanism. We used standardized incidence ratios (SIRs) to compare patterns of cancer incidence in patients with those of the general population. Multivariate analysis was undertaken using Cox proportional-hazards regression using a forward selection, likelihood ratio model to identify independent predictors of cancer development among patients after HSCT. ResultsWe observed a total of 8,753.87 person-years in this study. Patients received HSCT had a significant increased risk of developing any kind of cancer (SIR 1.77, 95% confidence interval [CI] 1.15 – 2.62; p = 0.011). Specifically, patients after HSCT had increased cancer incidence of head and neck cancer (SIR 3.96, 95% CI 1.90 – 7.29; p < 0.001) and bone and soft tissue sarcomas (SIR 10.08, 95% CI 1.22 – 36.42; p = 0.035). In subgroup analyses, cancers were more likely to develop in patients aged 0 – 19 years (SIR 22.31, 95% CI 4.60 – 65.20; p < 0.001), and those who survived more than 5 years after HSCT (SIR 3.30, 95% CI 1.96 – 5.22; p < 0.001). ConclusionOur study demonstrates an increased incidence of cancer development in patients after HSCT, especially malignancies of head and neck and also bone and soft tissue sarcomas. Patients aged 0 – 19 years and those survived more than 5 years after HSCT have a higher incidence of developing cancer comparing to normal population. HSCT long-term survivors should therefore be monitored more carefully for cancer development and targeted with preventive intervention strategies.Table 1Characteristics of patients received hematopoietic stem cell transplantationTotalMaleFemaleNo. of patients1,8811,060821Person-years at risk8,753.874,748.264,005.61Median follow-up, years (interquartile range)4.41 (0.55–7.72)4.23 (0.52–7.54)4.65 (0.61–7.96)Median age, years (interquartile range)30.47 (19.63–41.76)30.32 (19.62–42.16)30.66 (19.68–41.10)Age at diagnosis, years0–1949427821620–3984246337940–5951930421560–79251510≥ 80101Table 2Standardized incidence ratios (SIRs) according to age at diagnosis, gender and duration after hematopoietic stem cell transplantationCharacteristicsTotalMaleFemaleObservedExpectedSIR (95% CI)ObservedExpectedSIR (95% CI)ObservedExpectedSIR (95% CI)All cancers2514.091.77 (1.15–2.62)167.992.00 (1.14–3.25)96.101.48 (0.67–2.80)Age at diagnosis, years0–1930.1322.31 (4.60–65.20)30.0742.42 (8.75–123.96)00.060.00 (0.00–57.88)20–3972.502.80 (1.12–5.77)31.092.74 (0.57–8.01)41.412.84 (0.77–7.28)40–59149.801.43 (0.78–2.40)105.661.77 (0.85–3.25)44.140.97 (0.26–2.48)≥6011.660.60 (0.02–3.35)01.170.00 (0.00–3.15)10.492.03 (0.05–11.29)Duration0–112.000.50 (0.01–2.79)01.100.00 (0.00–3.35)10.901.11 (0.03–6.21)1–566.650.90 (0.33–1.96)53.721.35 (0.44–3.14)12.930.34 (0.01–1.90)≥ 5185.453.30 (1.96–5.22)113.183.46 (1.73–6.20)72.273.08 (1.24–6.35)SIR Standardized incidence ratio; CI confidence intervalTable 3Standardized incidence ratios (SIRs) for specific cancer types among patients received hematopoietic stem cell transplantationTotalSite of cancersObservedExpectedSIR (95% CI)All cancers2514.091.77 (1.15–2.62)Head and neck102.523.96 (1.90–7.29)Digestive64.661.29 (0.47–2.80)Lung and mediastinum21.081.86 (0.22–6.70)Bone and Soft tissue20.2010.08 (1.22–36.42)Skin00.190.00 (0.00–19.56)Breast02.230.00 (0.00–1.66)Genitourinary11.890.53 (0.01–2.95)Thyroid10.651.55 (0.04–8.63)All Others30.694.37 (0.90–12.77)SIR Standardized incidence ratio; CI confidence interval Disclosures:No relevant conflicts of interest to declare.