Gestational trophoblastic neoplasia in American Indians.
OBJECTIVE
To analyze gestational trophoblastic neoplasia (GTN) trends among American Indians (AI) using population-based data.


METHODS
GTN incidence, by race and age, was calculated using data collected by the New Mexico Tumor Registry over 29 years (1973-2001). Live birth, pregnancy and women at risk were tabulated using data derived from the state's vital record annual reports and from the registry. Statistical methods included trends analysis and Poisson regression. There is no national registry in the United States for all GTN. Therefore, the Surveillance, Epidemiology and End Results (SEER) database was used to identify choriocarcinoma cases in American Indians between 1973 and 1999.


RESULTS
Within New Mexico, 1,082 cases of GTN were identified among 752,374 live births and 904,831 pregnancies, with ratios of 1:695 and 1:836, respectively, affecting 234 AI, 355 non-Hispanic whites (NHW), 463 Hispanic whites (HW) and 30 other nonwhites. Ratios per live births (pregnancy), respectively, were significantly higher in AI (AI 1:439 [1:487], NHW 1:739 [1:949], HW 1:783 [1:903]), as was age-adjusted incidence per 100,000 woman-years (AI 10.62, NHW 3.53, HW 5.15; all P<.0001). Using Poisson models with live birth and woman-year denominators, AI were found to be at increased risk for all GTN histologic subsets (complete, partial and invasive hydatidiform mole and choriocarcinoma). Of 524 total gestational choriocarcinoma cases identified within SEER, 8 (1.8%) affected American Indians; of them, 7 were from New Mexico.


CONCLUSIONS
In New Mexico, AI continue to be at higher risk of GTN than are other groups. Given the rarity of choriocarcinoma within SEER, especially among AI, the New Mexico dataset provides the best available estimate of trends in U.S. AI GTN risk.
Smith
Harriet O
HO
New Mexico Tumor Registry, Department of Obstetrics and Gynecology, University of New Mexico Health Sciences Center, Albuquerque 87131-5286, USA. hsmith@salud.unm.edu
Qualls
Clifford R
CR
Hilgers
Robert D
RD
Verschraegen
Claire F
CF
Rayburn
William F
WF
Cole
Laurence W
LW
Padilla
Luis A
LA
Key
Charles R
CR
D001741:Black or African American / Q000706:statistics & numerical data; D000367:Age Factors; D001213:Asian / Q000706:statistics & numerical data; D002822:Choriocarcinoma / Q000453:epidemiology / Q000208:ethnology*; D005260:Female; D031901:Gestational Trophoblastic Disease / Q000453:epidemiology / Q000208:ethnology*; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D007198:Indians, North American / Q000706:statistics & numerical data*; D009516:New Mexico / Q000453:epidemiology; D011247:Pregnancy; D012042:Registries; D018426:SEER Program; D014594:Uterine Neoplasms / Q000453:epidemiology / Q000208:ethnology*; D044465:White People / Q000706:statistics & numerical data