Abstract

Abstract 4219

Objectives

Hematopoietic 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 Methods

We 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.

Results

We 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).

Conclusion

Our 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 1.

Characteristics of patients received hematopoietic stem cell transplantation

TotalMaleFemale
No. of patients 1,881 1,060 821 
Person-years at risk 8,753.87 4,748.26 4,005.61 
Median 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, years    
0–19 494 278 216 
20–39 842 463 379 
40–59 519 304 215 
60–79 25 15 10 
≥ 80 
TotalMaleFemale
No. of patients 1,881 1,060 821 
Person-years at risk 8,753.87 4,748.26 4,005.61 
Median 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, years    
0–19 494 278 216 
20–39 842 463 379 
40–59 519 304 215 
60–79 25 15 10 
≥ 80 
Table 2.

Standardized incidence ratios (SIRs) according to age at diagnosis, gender and duration after hematopoietic stem cell transplantation

CharacteristicsTotalMaleFemale
ObservedExpectedSIR (95% CI)ObservedExpectedSIR (95% CI)ObservedExpectedSIR (95% CI)
All cancers 25 14.09 1.77 (1.15–2.62) 16 7.99 2.00 (1.14–3.25) 6.10 1.48 (0.67–2.80) 
Age at diagnosis, years 
0–19 0.13 22.31 (4.60–65.20) 0.07 42.42 (8.75–123.96) 0.06 0.00 (0.00–57.88) 
20–39 2.50 2.80 (1.12–5.77) 1.09 2.74 (0.57–8.01) 1.41 2.84 (0.77–7.28) 
40–59 14 9.80 1.43 (0.78–2.40) 10 5.66 1.77 (0.85–3.25) 4.14 0.97 (0.26–2.48) 
≥60 1.66 0.60 (0.02–3.35) 1.17 0.00 (0.00–3.15) 0.49 2.03 (0.05–11.29) 
Duration 
0–1 2.00 0.50 (0.01–2.79) 1.10 0.00 (0.00–3.35) 0.90 1.11 (0.03–6.21) 
1–5 6.65 0.90 (0.33–1.96) 3.72 1.35 (0.44–3.14) 2.93 0.34 (0.01–1.90) 
≥ 5 18 5.45 3.30 (1.96–5.22) 11 3.18 3.46 (1.73–6.20) 2.27 3.08 (1.24–6.35) 
CharacteristicsTotalMaleFemale
ObservedExpectedSIR (95% CI)ObservedExpectedSIR (95% CI)ObservedExpectedSIR (95% CI)
All cancers 25 14.09 1.77 (1.15–2.62) 16 7.99 2.00 (1.14–3.25) 6.10 1.48 (0.67–2.80) 
Age at diagnosis, years 
0–19 0.13 22.31 (4.60–65.20) 0.07 42.42 (8.75–123.96) 0.06 0.00 (0.00–57.88) 
20–39 2.50 2.80 (1.12–5.77) 1.09 2.74 (0.57–8.01) 1.41 2.84 (0.77–7.28) 
40–59 14 9.80 1.43 (0.78–2.40) 10 5.66 1.77 (0.85–3.25) 4.14 0.97 (0.26–2.48) 
≥60 1.66 0.60 (0.02–3.35) 1.17 0.00 (0.00–3.15) 0.49 2.03 (0.05–11.29) 
Duration 
0–1 2.00 0.50 (0.01–2.79) 1.10 0.00 (0.00–3.35) 0.90 1.11 (0.03–6.21) 
1–5 6.65 0.90 (0.33–1.96) 3.72 1.35 (0.44–3.14) 2.93 0.34 (0.01–1.90) 
≥ 5 18 5.45 3.30 (1.96–5.22) 11 3.18 3.46 (1.73–6.20) 2.27 3.08 (1.24–6.35) 

SIR Standardized incidence ratio; CI confidence interval

Table 3.

Standardized incidence ratios (SIRs) for specific cancer types among patients received hematopoietic stem cell transplantation

Total
Site of cancersObservedExpectedSIR (95% CI)
All cancers 25 14.09 1.77 (1.15–2.62) 
Head and neck 10 2.52 3.96 (1.90–7.29) 
Digestive 4.66 1.29 (0.47–2.80) 
Lung and mediastinum 1.08 1.86 (0.22–6.70) 
Bone and Soft tissue 0.20 10.08 (1.22–36.42) 
Skin 0.19 0.00 (0.00–19.56) 
Breast 2.23 0.00 (0.00–1.66) 
Genitourinary 1.89 0.53 (0.01–2.95) 
Thyroid 0.65 1.55 (0.04–8.63) 
All Others 0.69 4.37 (0.90–12.77) 
Total
Site of cancersObservedExpectedSIR (95% CI)
All cancers 25 14.09 1.77 (1.15–2.62) 
Head and neck 10 2.52 3.96 (1.90–7.29) 
Digestive 4.66 1.29 (0.47–2.80) 
Lung and mediastinum 1.08 1.86 (0.22–6.70) 
Bone and Soft tissue 0.20 10.08 (1.22–36.42) 
Skin 0.19 0.00 (0.00–19.56) 
Breast 2.23 0.00 (0.00–1.66) 
Genitourinary 1.89 0.53 (0.01–2.95) 
Thyroid 0.65 1.55 (0.04–8.63) 
All Others 0.69 4.37 (0.90–12.77) 

SIR Standardized incidence ratio; CI confidence interval

Disclosures:

No relevant conflicts of interest to declare.

Author notes

*

Asterisk with author names denotes non-ASH members.