Abstract

Abstract 3160

Introduction:

Acute leukemias (AL) have a distinct incidence pattern in Hispanics versus Caucasians, with higher rates of B-cell acute lymphoblastic leukemia (ALL) and acute promyelocytic leukemia (APL), and lower rates of non-APL acute myeloid leukemia (AML). Despite the fact that incidence differentials between foreign- and native-born populations can inform the relative contributions of environmental and genetic factors in cancer etiology, no such investigation has been undertaken in Hispanics with AL.

Methods:

To better understand heritable genetic versus environmental contributors to occurrence patterns, we assessed AL incidence in a large population of California Hispanics according to birthplace. Cancer incidence data were obtained from the California Cancer Registry, part of the National Cancer Institute's Surveillance, Epidemiology, and End Results Program. Patients were included if they were living in California and diagnosed between 2000–2009 with AL. Population estimates were obtained from the 2000 Census Summary Files 3, and estimates by nativity were derived from the 20% Integrated Public-Use Microdata Sample of the censuses.

Results:

Compared to Caucasians, Hispanics had an increased incidence of B-cell ALL and APL, with incidence rate ratios (IRR) of 2.13 (95% confidence interval [CI] 1.93–2.35) and 1.33 (95% CI 1.12–1.57), respectively. There was no difference in B-cell ALL incidence by nativity, with an IRR for foreign- to native-born Hispanics of 1.07 (95% CI 0.85–1.34). However, foreign-born Hispanics had a greater incidence of APL than native-born Hispanics (IRR 1.79, 95% CI 1.11–2.94).

Conclusions:

Our findings suggest the increased B-cell ALL incidence for foreign-born Hispanics is influenced by heritable genetic factors. Furthermore, the increased incidence of APL for foreign-born Hispanics may result from environmental exposures currently not described and which require further epidemiologic investigation.

Table 1:

Age-adjusted incidence rates (per 100,000 person-years) of acute leukemias and incidence rate ratios (IRR) by race/ethnicity among non-Hispanic Whites and Hispanics, and nativity among Hispanics*, 2000–2004 and 2000–2009

Hematological Malignancy Race/Ethnicity or Nativity Male Female Male and Female 
Cases Incidence Rate* (95% CI) IRR (95% CI) Cases Incidence Rate* (95% CI) IRR (95% CI) Cases Incidence Rate* (95% CI) IRR (95% CI) 
B-Cell ALL White 478 0.78 (0.71–0.85) 1.00 (reference) 365 0.54 (0.48–0.60) 1.00 (reference) 843 0.65 (0.61–0.70) 1.00 (reference) 
 Hispanic 542 1.39 (1.26–1.54) 1.80 (1.57–2.06) 451 1.36 (1.23–1.50) 2.53 (2.19–2.94) 993 1.39 (1.30–1.49) 2.13 (1.93–2.35) 
Non–APL AML White 3118 4.87 (4.70–5.04) 1.00 (reference) 2480 3.17 (3.04–3.30) 1.00 (reference) 5598 3.91 (3.81–4.02) 1.00 (reference) 
 Hispanic 846 3.83 (3.54–4.14) 0.79 (0.72–0.86) 694 2.63 (2.42–2.84) 0.83 (0.76–0.91) 1540 3.13 (2.96–3.31) 0.80 (0.75–0.85) 
APL White 207 0.33 (0.28–0.38) 1.00 (reference) 162 0.24 (0.21–0.29) 1.00 (reference) 369 0.29 (0.26–0.32) 1.00 (reference) 
 Hispanic 134 0.36 (0.30–.044) 1.11 (0.87–1.42) 141 0.40 (0.33–0.47) 1.61 (1.26–2.06) 275 0.38 (0.33–0.43) 1.33 (1.12–1.57) 
B–Cell ALL** US-Born 91 1.28 (1.00–1.63) 1.00 (reference) 69 1.10 (0.83–1.42) 1.00 (reference) 160 1.24 (1.04–1.48) 1.00 (reference) 
 Foreign-Born 142 1.33 (1.07–1.65) 1.04 (0.75–1.45) 114 1.23 (0.99–1.50) 1.11 (0.80–1.57) 256 1.32 (1.15–1.52) 1.07 (0.85–1.34) 
Non–APL AML** US–Born 169 4.37 (3.66–5.18) 1.00 (reference) 147 3.16 (2.65–3.73) 1.00 (reference) 316 3.64 (3.22–4.10) 1.00 (reference) 
 Foreign-Born 224 3.95 (3.34–4.63) 0.90 (0.71–1.15) 189 2.72 (2.31–3.17) 0.86 (0.68–1.09) 413 3.21 (2.86–3.58) 0.88 (0.75–1.04) 
APL** US–Born 12 *** *** 21 0.29 (0.17–0.47) 1.00 (reference) 33 0.23 (0.15–400.34) 1.00 (reference) 
 Foreign-Born 40 0.41 (0.27–0.59) *** 42 0.42 (0.30–0.59) 1.44 (0.78–2.72) 82 0.41 (0.32–0.53) 1.79 (1.11–2.94) 
Hematological Malignancy Race/Ethnicity or Nativity Male Female Male and Female 
Cases Incidence Rate* (95% CI) IRR (95% CI) Cases Incidence Rate* (95% CI) IRR (95% CI) Cases Incidence Rate* (95% CI) IRR (95% CI) 
B-Cell ALL White 478 0.78 (0.71–0.85) 1.00 (reference) 365 0.54 (0.48–0.60) 1.00 (reference) 843 0.65 (0.61–0.70) 1.00 (reference) 
 Hispanic 542 1.39 (1.26–1.54) 1.80 (1.57–2.06) 451 1.36 (1.23–1.50) 2.53 (2.19–2.94) 993 1.39 (1.30–1.49) 2.13 (1.93–2.35) 
Non–APL AML White 3118 4.87 (4.70–5.04) 1.00 (reference) 2480 3.17 (3.04–3.30) 1.00 (reference) 5598 3.91 (3.81–4.02) 1.00 (reference) 
 Hispanic 846 3.83 (3.54–4.14) 0.79 (0.72–0.86) 694 2.63 (2.42–2.84) 0.83 (0.76–0.91) 1540 3.13 (2.96–3.31) 0.80 (0.75–0.85) 
APL White 207 0.33 (0.28–0.38) 1.00 (reference) 162 0.24 (0.21–0.29) 1.00 (reference) 369 0.29 (0.26–0.32) 1.00 (reference) 
 Hispanic 134 0.36 (0.30–.044) 1.11 (0.87–1.42) 141 0.40 (0.33–0.47) 1.61 (1.26–2.06) 275 0.38 (0.33–0.43) 1.33 (1.12–1.57) 
B–Cell ALL** US-Born 91 1.28 (1.00–1.63) 1.00 (reference) 69 1.10 (0.83–1.42) 1.00 (reference) 160 1.24 (1.04–1.48) 1.00 (reference) 
 Foreign-Born 142 1.33 (1.07–1.65) 1.04 (0.75–1.45) 114 1.23 (0.99–1.50) 1.11 (0.80–1.57) 256 1.32 (1.15–1.52) 1.07 (0.85–1.34) 
Non–APL AML** US–Born 169 4.37 (3.66–5.18) 1.00 (reference) 147 3.16 (2.65–3.73) 1.00 (reference) 316 3.64 (3.22–4.10) 1.00 (reference) 
 Foreign-Born 224 3.95 (3.34–4.63) 0.90 (0.71–1.15) 189 2.72 (2.31–3.17) 0.86 (0.68–1.09) 413 3.21 (2.86–3.58) 0.88 (0.75–1.04) 
APL** US–Born 12 *** *** 21 0.29 (0.17–0.47) 1.00 (reference) 33 0.23 (0.15–400.34) 1.00 (reference) 
 Foreign-Born 40 0.41 (0.27–0.59) *** 42 0.42 (0.30–0.59) 1.44 (0.78–2.72) 82 0.41 (0.32–0.53) 1.79 (1.11–2.94) 
*

Standardized to the 2000 US population age standard

□Age-adjusted incidence rates (per 100,000 person-years) of acute leukemias and incidence rate ratios (IRR) by race/ethnicity among non-Hispanic Whites and Hispanics age 3 20 in California, 2000–2009

**

Age-adjusted incidence rates (per 100,000 person-years) of hematological malignancies and incidence rate ratios by nativity among Hispanics >/= 20 in California, 2000–2004

***

Insufficient case counts to calculate rate

Disclosures:

No relevant conflicts of interest to declare.

Author notes

*

Asterisk with author names denotes non-ASH members.