Childhood cancer epidemiology in New Mexico's American Indians, Hispanic whites, and non-Hispanic whites, 1970-82

The statewide population-based New Mexico Tumor Registry identified 473 malignant tumors among children of ages 0-14 years, during the period 1970-82. There were 235 non-Hispanic whites (50%), 189 Hispanic whites (40%), 38 American Indians (8%), and 11 other nonwhites (2%). The average annual age-adjusted incidence rates per million for non-Hispanic whites were 138.6 for males and 108.3 for females; for Hispanic whites, the rates were 108.5 for males and 80.9 for females; for American Indians, the rates were 75.5 for males and 78.0 for females. The incidence rates for all sites of cancer combined were lower for Hispanics and American Indians than for New Mexico's non-Hispanic whites and U.S. whites. Leukemia was the most common cancer in all racial-ethnic groups. In comparison with U.S. whites, American Indians were at low risk for leukemias, lymphomas, central nervous system (CNS), sympathetic nervous system (SNS), and kidney tumors and were at high risk for retinoblastoma, bone, and sex organ tumors. Hispanics were at low risk for CNS, SNS, kidney, sex organ, and liver tumors. Hispanic and non-Hispanic white males both were at increased risk for melanoma.     

Survival of children and adolescents with acute lymphoid leukemia. A study of American Indians and Hispanic and non-Hispanic whites treated in New Mexico (1969 to 1986)

During the period 1969 to 1986, 196 American Indian and Hispanic and non-Hispanic white children and adolescents (ages, 0 to 19 years) were treated for acute lymphoid leukemia (ALL) at the University of New Mexico affiliated institutions. There were 28 American Indians (14%), 91 Hispanic whites (46%), and 77 non-Hispanic whites (39%). Median survivals for patients undergoing antileukemic therapy ranged from 8 months for American Indian boys to 140 months for non-Hispanic white girls. American Indian boys had the highest initial median leukocyte count (WBC) at 23.8 X 10(9)/l. Compliance problems occurred most commonly among American Indian children of both genders. Other clinical and pathologic features evaluated in this study were distributed similarly among the ethnic gender groups. Multi-variate analysis revealed that independent prognostic variables for survival included initial WBC, age, and gender. Ethnicity and compliance problems were possible, but confounded, prognostic variables. To the authors' knowledge this represents the most comprehensive study to date of ALL in American Indian patients.     

Lung cancer histology,stage, treatment,and survival in American Indians and Alaska Natives and whites

BACKGROUND:

Studies of lung cancer disparities between American Indians and Alaska Natives (AIANs) and whites have yielded mixed results. To the authors' knowledge, no studies to date have investigated whether race‐based differences in histology could explain survival disparities.

METHODS:

Data were obtained on AIANs and whites with lung cancer from the 17 population‐based cancer registries participating in the Surveillance, Epidemiology, and End Results (SEER) program from 1973 to 2006. Logistic regression was used to determine whether race and other covariates were associated with histology, stage at diagnosis, and receipt of surgery. Cox regression was used to determine the risk of death associated with race, after adjusting for histology, stage, and other covariates.

RESULTS:

Histology, but not race, was found to be associated with stage at diagnosis, and both race and stage were found to be associated with histology. AIANs were less likely to receive surgery than whites, after adjusting for patient and tumor characteristics. Survival improved for both AIANs and whites after 2000, compared with the 1973 through 1999 period, but survival was consistently shorter for AIANs. The association between AIAN race and decreased survival was strongest in the later time period.

CONCLUSIONS:

Lung cancer histology appears to be associated with tumor characteristics, treatment, and survival. AIAN race is associated with tumor histology, receipt of surgery, and survival. In the future, studies with access to smoking data, patient comorbidity information, and health systems‐level data will be able to identify factors responsible for the disparities observed in these analyses. Cancer 2010. © 2010 American Cancer Society.     

Reproductive history in relation to breast cancer risk among Hispanic and non-Hispanic white women

Objective To evaluate reproductive history risk factors in breast cancer among Hispanic (HISP) women in the U.S. southwest, a population with approximately 33% lower breast cancer incidence than non-Hispanic whites (NHW). Methods Population-based case–control study of HISP (796 cases, 919 controls) and NHW (1,525 cases, 1,596 controls) women. Results 19.3% of HISP women reported five or more births and had a reduced risk of breast cancer, adjusted odds ratio (OR) 0.70 (95% confidence interval (CI): 0.50, 0.98) compared to those with one or two births. Breast cancer risk for HISP increased with older age at first birth, p trend = 0.008. Parity and age at first birth associations were specific to ER positive tumors. HISP women who had given birth within five years had higher breast cancer risk than women with 16–25 years since a birth, OR 2.62 (95% CI: 1.44, 4.78); the trend with years since last birth was stronger than for NHWs, p interaction = 0.05. Conclusions Reproductive history influences on breast cancer risk among HISP were similar to associations reported for NHWs. Differences in the prevalence of reproductive risk factors would explain an estimated 6.6% lower breast cancer incidence for HISP compared to NHWs.     

Microsomal epoxide hydrolase polymorphisms and lung cancer risk in non-Hispanic whites

Microsomal epoxide hydrolase (mEPHX) is a critical metabolic enzyme involved in the activation and subsequent detoxification of specific tobacco carcinogens. mEPHX harbors polymorphisms in exon 3 and exon 4 that modulate enzymatic activity. The exon 3 polymorphism decreases mEPHX metabolic activity, whereas the exon 4 polymorphism increases activity. We hypothesized that the mEPHX polymorphisms modulate lung cancer risk. Using a case-control study design and restriction fragment length polymorphism polymerase chain reaction assay, we determined the mEPHX polymorphic genotypes of 181 lung cancer cases among non-Hispanic whites and 163 controls (matched for age, sex, ethnicity, and smoking history). Our results showed that the variant allele of mEPHX exon 4 increased the overall lung cancer risk by 56% (odds ratio [OR]=1.56, 95% confidence interval [CI]=0.99-2.46). Additionally, the risk estimates were elevated significantly for younger people (<64 yr) (OR=2.27, 95% CI=1.15-4.50) and current smokers (OR=2.22, 95% CI=1.06-4.65). The variant allele of mEPHX exon 3 had no effect overall (OR=0.88, 95% CI=0.56-1.38), but there was a 53% protective effect (OR=0.47, 95% CI=0.22-0.99) in younger people. When we analyzed the exon 3 and exon 4 polymorphisms together, those people with the high enzymatic activity genotype had an elevated lung cancer risk of 1.72 (95% CI=0.90-3.29). This elevated risk was also evident only in younger people. These findings suggest that these variant alleles of exon 3 and exon 4 of mEPHX modulates lung cancer risk.     

Gut microbiota differences in Island Hispanic Puerto Ricans and mainland non-Hispanic whites during chemoradiation for rectal cancer: A pilot study

PurposeTo investigate whether there are differences in diversity, taxonomic composition, and predicted functional pathways of the gut microbiome between Island Hispanic Puerto Ricans (HPR) and mainland non-Hispanic whites (NHW) measured before and at the end of chemo-radiation (CRT) for Rectal Cancer.MethodsFifty-six stool samples of newly diagnosed rectal cancer patients (25 HPR and 31 NHW) were amplicon-sequenced during chemo-radiotherapy. 16S rRNA gene data was analyzed using QIIME2, phyloseq, and LEfSe.ResultsWe observed similar within-sample alpha diversity for HPR and NHW participants during CRT. However, at the end of CRT, several taxa were present at significantly different abundances across both groups. Taxa enriched in the gut of HPR compared to NHW included Muribaculaceae, Prevotella 2 and 7, Gemella, Bacillales Family XI, Catenibacterium, Sutterella, Pasteurellales, and Pasteurellaceae genera, whereas over-represented taxa in NHW participants were Turicibacter and Eubacteriaceae. Significant differences in predicted HPR microbiota functions included pathways for synthesis of L-methionine and degradation of phenylethylamine and phenylacetate.ConclusionIn this pilot study, taxonomic analyses and functional predictions of the gut microbiomes suggest greater inflammatory potential in gut microbial functions among HPR rectal cancer patients undergoing CRT compared to that of NHW participants.     

Colorectal carcinoma screening among Hispanics and non-Hispanic whites in a rural setting

BACKGROUND: Colorectal carcinoma ranks as the second most common cancer and the second leading cause of cancer death in the United States. Hispanics are less likely than their non-Hispanic white counterparts to have ever received a fecal occult blood test (FOBT) or sigmoidoscopy/colonoscopy. Little is known about the barriers to screening in the Hispanic population. METHODS: The authors used baseline data from a community randomized trial of cancer prevention to compare screening prevalence and the associations between reported barriers and screening participation between Hispanics (n = 137) and non-Hispanic whites (n = 491) age > or = 50 years. RESULTS: Hispanics were less likely than non-Hispanic whites to have ever received an FOBT (P = 0.003) or sigmoidoscopy/colonoscopy (P = 0.001). No significant difference across ethnic groups was observed in the prevalence of recent screening using FOBT (29.8% for Hispanics vs. 34.5% for non-Hispanic whites; P = 0.41), but recent use of sigmoidoscopy/colonoscopy was lower for Hispanics (24.1% for Hispanics vs. 33.7% for non-Hispanic whites; P 0.06). Lacking health care coverage or having few years of education were directly associated with failure to ever receive an FOBT or sigmoidoscopy/colonoscopy. CONCLUSIONS: Interventions to improve adherence to colorectal carcinoma screening recommendations among Hispanics should target initial screening examinations, particularly among those lacking health care coverage or having low levels of education.     

Oral, injected and implanted contraceptives and breast cancer risk among U.S. Hispanic and non-Hispanic white women

Associations between oral contraceptive (OC) use and breast cancer have been reported, but few studies have considered associations in racial and ethnic minorities. Data regarding injected or implanted hormonal contraceptives are limited. In a case-control study of Hispanic (796 cases, 919 controls) and non-Hispanic white (1,522 cases, 1,596 controls) women in the U.S. southwest interviewed in 2000-2005, 49% of Hispanic controls and 66% of non-Hispanic white controls reported having used OC. Breast cancer odds ratios (OR) associated with OC use within the past 5 years were 1.22 (95% confidence interval (CI) 0.80, 1.84) among Hispanics, 1.28 (95% CI 0.93, 1.76) among non-Hispanic whites, 1.27 (95% CI 0.99, 1.63) for both ethnic groups combined and 1.53 (95% CI 0.98, 2.40) for estrogen receptor (ER) negative tumors. OC use for 20 years or longer was associated with ORs of 1.50 (95% CI 1.04, 2.17) for both ethnic groups combined, and 2.23 (95% CI 1.17, 4.25) for ER negative tumors. Hormonal contraceptive injections were used by 3.3% of Hispanic controls and 2.8% of non-Hispanic white controls, OR 1.23 (95% CI 0.88, 1.73). Fifteen cases and 2 controls reported use of a subdermal contraceptive implant, OR 8.59 (95% CI 1.92, 38.39). Associations between OC use and breast cancer in Hispanics are consistent with modestly increased risk among recent users and for ER negative tumors, as observed in other populations. Based on a small number of users of contraceptive implants, a significantly increased breast cancer risk was observed; continued surveillance of implant users may be warranted.     

Incidence of esophageal and gastric cancers among Hispanics,non-Hispanic whites and non-Hispanic blacks in the United States: subsite and histology differences

Objective We examined subsite- and histology-specific esophageal and gastric cancer incidence patterns among Hispanics/Latinos and compared them with non-Hispanic whites and non-Hispanic blacks. Methods Data on newly diagnosed esophageal and gastric cancers for 1998–2002 were obtained from 37 population-based central cancer registries, representing 66% of the Hispanic population in the United States. Age-adjusted incidence rates (2000 US) were computed by race/ethnicity, sex, anatomic subsite, and histology. The differences in incidence rates between Hispanics and non-Hispanics were examined using the two-tailed z-statistic. Results Squamous cell carcinoma accounted for 50% and 57% of esophageal cancers among Hispanic men and women, respectively, while adenocarcinoma accounted for 43% among Hispanic men and 35% among Hispanic women. The incidence rate of squamous cell carcinoma was 48% higher among Hispanic men (2.94 per 100,000) than non-Hispanic white men (1.99 per 100,000) but about 70% lower among Hispanics than non-Hispanic blacks, for both men and women. In contrast, the incidence rates of esophageal adenocarcinoma were lower among Hispanics than non-Hispanic whites (58% lower for men and 33% for women) but higher than non-Hispanic blacks (70% higher for men and 64% for women). Cardia adenocarcinoma accounted for 10–15% of gastric cancers among Hispanics, and the incidence rate among Hispanic men (2.42 per 100,000) was 33% lower than the rate of non-Hispanic white men (3.62 per 100,000) but 37% higher than that of non-Hispanic black men. The rate among Hispanic women (0.86 per 100,000), however, was 20% higher than that of non-Hispanic white women (0.72 per 100,000) and 51% higher than for non-Hispanic black women. Gastric non-cardia cancer accounted for approximately 50% of gastric cancers among Hispanics (8.32 per 100,000 for men and 4.90 per 100,000 for women), and the rates were almost two times higher than for non-Hispanic whites (2.95 per 100,000 for men and 1.72 per 100,000 for women) but about the same as the non-Hispanic blacks. Conclusion Subsite- and histology-specific incidence rates of esophageal and gastric cancers among Hispanics/Latinos differ from non-Hispanics. The incidence rates of gastric non-cardia cancer are almost two times higher among Hispanics than non-Hispanic whites, both men and women. The rates of gastric cardia cancer are lower among Hispanics than non-Hispanic whites for men but higher for women. The rates of esophageal and gastric cardia adenocarcinomas are higher among Hispanics than non-Hispanic blacks.     

Melanoma among southwestern American Indians

All forms of skin cancer are uncommon among southwestern American Indians. The estimated average annual incidence of melanoma is approximately 1 per hundred thousand population or less than one tenth of that currently reported for Anglos (non-Hispanic whites) residing in the same region. This study correlates the clinical and pathologic features of melanoma in 18 American Indian patients. A marked predilection for palms, soles, and subungual locations was displayed. Additionally, three patients presented with mucous membrane primaries and two with ocular melanomas. Advanced disease stage at diagnosis was common. The protective influence of natural pigmentation in skin cancer is discussed.     

Mammography utilization after a benign breast biopsy among Hispanic and non-Hispanic women

BACKGROUND: In spite of the effectiveness of mammography screening for early detection of breast carcinoma, the use of screening mammography varies widely across racial and ethnic groups. Recently, concerns have been raised about the potential adverse effect a benign breast biopsy may have on subsequent mammography utilization, including subsequent use among minority women. METHODS: Computerized health care claims data for 1991 through 1997 from a managed care organization were used to compare mammography use among Hispanic and non-Hispanic women who had had a mammogram followed by an incisional or excisional benign breast biopsy to women who had had a mammogram and no biopsy. Through survival analysis methods, the time-to-next mammogram was compared among these three groups. RESULTS: The sample included 693 (3.2%) and 289 (1.3%) women who had had a mammogram followed by an incisional biopsy or an excisional biopsy, respectively, and 20,540 (95.4%) women who had had a mammogram and no biopsy. Both Hispanic and non-Hispanic women with a biopsy returned sooner for subsequent mammograms than women without a biopsy (P < 0.0001). Hispanic women without a biopsy returned later than non-Hispanic women without a biopsy (P < 0.0001). However, Hispanic women with an excisional biopsy returned sooner than non-Hispanic women (P < 0.05). CONCLUSIONS: Within a managed care organization, both Hispanic and non-Hispanic women who had had a mammogram followed by a benign breast biopsy returned sooner for a subsequent mammogram than women who had had a mammogram and no biopsy. However, ethnic differences in time-to-next mammogram were observed for women without a biopsy and those with an excisional biopsy. Hispanic women without a biopsy returned later for a subsequent mammogram than non-Hispanic women in similar groups, but those with an excisional biopsy returned sooner.     

Disparities in lung cancer stage, treatment and survival among American Indians and Alaskan Natives

Background

Disparities in lung cancer care and outcomes have been documented for blacks and Hispanics. Less is known about the care received by the American Indian and Alaskan Native population (AI/AN). We sought to evaluate lung cancer outcomes in this population and to asses if potential disparities in survival are explained by differences in stage of disease at diagnosis and type of treatment received.

Methods

We identified patients with potentially resectable (stages I-IIIA) non-small cell lung cancer (NSCLC) from the Surveillance, Epidemiology and End Results registry between 1988 and 2006. Kaplan-Meier curves were used to compare survival of AI/AN patients to those of other racial groups. Cox regression analysis was used to identify potential mediators of the association between AI/AN origin and worse survival.

Results

Five-year lung cancer survival was 47% for AI/AN, 56% for whites, 51% for blacks, 55% for Hispanics and 59% for individuals of other race (p < 0.0001). AI/AN were more likely to be diagnosed with stage IIIA (p < 0.0001) and less likely to undergo resection (p < 0.0001) than whites. In multivariable regression analyses, controlling for patient characteristics and histology, AI/AN race was associated with worse survival than white patients. When stage, treatment and surgery were added to the model, AI/AN origin was no longer significantly associated with worse outcomes.

Conclusions

AI/AN with potentially resectable NSCLC have survival rates comparable to other minority groups and worse than whites. These survival differences are partly explained by advanced stage at diagnosis, and lower rates of treatment.     

Decreasing rates of cervical cancer among American Indians and Hispanics in New Mexico (United States)

Minority women in New Mexico (United States)—including American Indian and Hispanic women—have shown disproportionately high incidence rates of invasive cervical cancer during the 1960s and 1970s. Several public health programs in New Mexico were directed toward early detection of cervical cellular abnormalities, particularly targeting the state's minority women. To evaluate the effectiveness of these programs, we examined the New Mexico Surveillance, Epidemiology, and End Results (SEER) data collected from 1969–92, and calculated average annual, age-specific, and age-adjusted incidence rates by ethnic group (American Indian, Hispanic, and non-Hispanic White) for five-year time intervals. We also calculated age-adjusted mortality rates for cervical cancer in the same ethnic groups using state vital records. Age-adjusted incidence rates for invasive cervical cancer show substantial temporal decreases, especially for minority women in the state. The age-adjusted incidence rate decreased by 66 percent, from 30.3 to 10.3 per 100,000 for American Indian women, and by 61 percent, from 26.1 to 10.2 per 100,000 for Hispanic women. A stage shift to earlier stages of cervical neoplasia occurred over the study period, with a substantially higher proportion of in situ compared with invasive cancers diagnosed in the most recent cf the most remote time period. The ratio of incidence rates of in situ to invasive cancers changed dramatically for both American Indian and Hispanic women. Cervical cancer mortality rates decreased steadily among Hispanic women from 1958 to 1992; the decrease among American Indian women was less stable and fluctuated due to small numbers. Ongoing targeted sceening programs should help to reduce cervical cancer incidence and mortality further in New Mexico.Drs Chao, Becker, Jordan, Darling, Gilliland, and Key are with the New Mexico Tumor Registry/Epidemiology and Cancer Control Program, Albuquerque, NM, USA. Dr Jordan and also Dr Key are with the Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM. Address correspondence to Dr Chao, New Mexico Tumor Registry, University of New Mexico Cancer Research and Treatment Center, 900 Camino de Salud NE, Albuquerque, NM, 87131-5306, USA.     

Differences in estrogen receptor subtype according to family history of breast cancer among Hispanic, but not non-Hispanic White women

BACKGROUND: Pathologic differences have been reported among breast tumors when comparing ethnic populations. Limited research has been done to evaluate the ethnic-specific relationships between breast cancer risk factors and the pathologic features of breast tumors. METHODS: Given that genetic variation may contribute to ethnic-related etiologic differences in breast cancer, we hypothesized that tumor characteristics differ according to family history of breast cancer among Hispanic and non-Hispanic White (NHW) women. Logistic regression models were used to compute odds ratios (OR) and 95% confidence intervals (95% CI) to assess this relationship in the population-based, case-control 4-Corners Breast Cancer Study (1,537 cases and 2,452 controls). RESULTS: Among Hispanic women, having a family history was associated with a 2.7-fold increased risk of estrogen receptor (ER) negative (95% CI, 1.59-4.44), but not ER positive tumors (OR, 1.04; 95% CI, 0.71-1.54) when compared with women without breast cancer. In contrast, there was an increased risk for ER positive (OR, 1.89; 95% CI, 1.50-2.38) and a marginally significant increased risk for ER negative tumors (OR, 1.41; 95% CI, 0.92-2.17) among NHW women. When comparing tumor characteristics among invasive cases, those with a family history also had a significantly higher proportion of ER negative tumors among Hispanics (39.2% versus 25.8%; P=0.02), but not among NHWs (16.3% versus 21.1%; P=0.13). CONCLUSIONS: These results may reflect ethnic-specific predisposing genetic factors that promote the development of specific breast tumor subtypes, and emphasize the importance of evaluating the relationship between breast cancer risk factors and breast tumor subtypes among different ethnic populations.     

Early referral to supportive care specialists for symptom burden in lung cancer patients: a comparison of non-Hispanic whites, Hispanics, and non-Hispanic blacks

BACKGROUND:

Effective management of symptoms in cancer patients requires early intervention. This study assessed whether the timing of referral to the Supportive Care Center (SCC) and symptom burden outcome varied by race or ethnicity in lung cancer patients who had been seen at a tertiary cancer center.

METHODS:

Non‐Hispanic white (n = 752), Hispanic (n = 111), and non‐Hispanic black (n = 117) patients with nonsmall cell lung cancer comprised this sample. Data on sociodemographic factors, stage of disease, comorbid conditions, and symptom severity (pain, depressed mood, fatigue) served as potential predictor variables.

RESULTS:

Whereas the mean time (15 months; median = 7 months) from initial presentation at the cancer center to referral to the SCC did not vary by race or ethnicity, we found that Hispanics and non‐Hispanic blacks had higher symptom burden when they first presented at the cancer center than non‐Hispanic whites. Severe pain, depressed mood, and fatigue were significant predictors for early referral (<7 months) of non‐Hispanic whites, but only severe fatigue (P <.05) was predictive of early referral for Hispanics and non‐Hispanic blacks. Furthermore, while the proportion of non‐Hispanic white patients reporting severe pain, depressed mood, and fatigue significantly decreased (P <.001) at first follow‐up visit after referral to the SCC; among Hispanics, improvement was only observed for depressed mood. No improvement in any of these symptoms was observed for non‐Hispanic blacks.

CONCLUSIONS:

Whereas the timing of referral to supportive services did not vary by race, disparities in symptom burden outcomes persisted. Additional studies are needed to validate our findings. Cancer 2012;. © 2011 American Cancer Society.     

Cancer stage at diagnosis, treatment, and survival among American Indians and non-American Indians in Montana

BACKGROUND: The intent of the current study was to ascertain whether differences in cancer survival between Montana non-American Indians (non-AI) and Montana American Indians (AI) were related to differences in stage of disease at diagnosis or in the type of treatment received. METHODS: A case-control design was utilized using data from the Montana Central Tumor Registry and the Indian Health Service medical records. AIs diagnosed between January 1, 1984 and December 31, 1993 were the cases in the study, and non-AIs diagnosed in the same period were the controls. Chi-square tests and life table techniques were used to analyze the data. RESULTS: Five hundred twenty-two cases were matched with controls. The 5-year cancer survival rate for AIs was 36% and was 47% among non-AIs. The stage at the time of diagnosis was local in 34% of AIS and 36% of non-AIs. The stage was regional in 30% of AIs and 26% of non-AIs. Distant disease at the time of diagnosis was present in 25% of AIs and 24% of non-AIs, whereas an unknown extent of disease was present in 11% of AIs and 14% of non-AIs. AIs underwent surgery less frequently than non-AIs (79% vs. 86%), but this did not appear to contribute to the survival differences observed. CONCLUSIONS: The survival differences observed in the current study cannot be explained easily by differences in the cancer stage at diagnosis or the type of treatment received.     

Incidence rates of acute promyelocytic leukemia among Hispanics, blacks, Asians, and non-Hispanic whites in the United States.

Despite significant improvements in the prognosis of acute promyelocytic leukemia brought about by therapeutic advances, understanding of the epidemiology of acute promyelocytic leukemia remains limited. Earlier reports have suggested that Hispanics may have an increased incidence of acute promyelocytic leukemia, but no systematic analysis of national data has yet been reported. We performed a retrospective cohort study, using data from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute from 1992-2001 in order to compare leukemia incidence rates as a function of race and ethnicity. We identified 709 cases of acute promyelocytic leukemia and analyzed incidence rates by race and sex. Hispanics were not found to have greater lifetime incidence rates than whites, with an incidence relative rate (IRR) of 0.86 that of whites (P=0.17). The age distribution among Hispanics was significantly different from non-Hispanic whites, with greater incidence rates for children ages 1-19 years (IRR=1.9, P=0.02) and adult ages 20-44 years (IRR=1.6, P=0.004). Blacks had lower lifetime incidence rates than non-Hispanic whites (IRR=0.75, P=0.04), Hispanics (IRR=0.64, P=0.007), and Asians (IRR=0.67, P=0.03). Asians did not differ from non-Hispanic whites in lifetime or age-specific incidence rates. These results indicate that while US Hispanics do not have greater lifetime incidence rates of acute promyelocytic leukemia, blacks have lower incidence rates of acute promyelocytic leukemia than Hispanics, non-Hispanic whites, and Asians.