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Xu et al. J Transl Genet Genom 2021;5:218-39 https://dx.doi.org/10.20517/jtgg.2021.20 Page 224

DISPARITIES IN SURVIVAL OF ALL PATIENTS
In this section, we summarize disparities in the overall survival rates of ALL patients, though we do not
review potential disparities in long-term outcomes, such as treatment-related morbidities, which have been
described elsewhere [103-106] .

Children
Among children, the survival of ALL is lowest in infants (< 1 year), highest in those aged 1-9 years, and
[83]
thereafter, decreases with increased age [5,83] . Girls have better survival than boys overall . Hispanic/Latino
children have inferior outcomes compared to NHWs [83-87] , with a 5%-15% difference in overall survival rate
being persistently seen in SEER data [84,85,87] . Furthermore, in Hispanics/Latinos, childhood ALL mortality has
[107]
been shown to differ by genetic ancestry . For instance, Hispanic/Latino children in general have a 2.27
times higher mortality compared to NHW children [mortality rate ratio (MRR) = 2.27 (95%CI: 1.68-3.06)],
with a MRR of 2.56 (95%CI: 1.93-3.40) in continental Hispanic/Latino children (Mexicans, Central
Americans, and South Americans) but with a MRR of only 1.23 (95%CI: 0.74-2.03) in Caribbean
[107]
Hispanic/Latino children (Puerto Ricans, Cubans, and Dominicans) , suggesting that higher Indigenous
American ancestry is associated with poorer overall survival.

In Black childhood ALL patients, improvement of 5-year survival lags behind compared to in other
[108]
races/ethnicities . The largest improvements of survival in Blacks occurred at much later diagnosis
periods (1995-2001 and 2002-2008) compared to those in NHWs and AI/ANs (1988-1994 and 1995-
[84]
2001) . Promisingly, SEER data have revealed a decreased inequality in ALL survival between Black and
NHW children [83,85,109] . From 1992-1995 to 2003-2007, 5-year relative survival rate improved faster in Black
children (APC = 3.01) than in NHW children (APC = 1.37) . In another study, from 1975-1983 to 2000-
[85]
2010, the difference in 5-year cumulative mortality of ALL between Black and NHW children reduced from
15% to 3%; compared with NHWs, the adjusted hazard ratio (HR) for Blacks dropped from 1.46 (95%CI:
1.09-1.94) to an insignificant 1.21 (95%CI: 0.74-1.96) .
[83]

API and AI/ANs also have significantly worse survival of childhood ALL compared to NHWs [83,84] , with the
5-year cumulative ALL mortality being 10% in APIs, and 19% in AI/ANs versus being 8% in NHWs at 2000-
2010 . Compared with NHW counterparts, APIs diagnosed at 1-9 years, and AI/ANs diagnosed at 10-19
[83]
[83]
years had about twice the ALL mortality HR . Further, in a stratified analysis for Asian subgroups, when
comparing to NHWs, East Asians in general (i.e., Chinese, Filipino, Korean, Japanese, Vietnamese and
other Southeast Asians combined) had significant inferior outcomes, with particularly worse survival for
Vietnamese [relative risk (RR) = 2.44 (95%CI: 1.50-3.97)] and Filipino [RR = 1.64 (95%CI: 1.13-2.38)]
patients, whereas the inferior outcomes for Koreans, Japanese and other Southeast Asians were non-
significant .
[84]

AYAs
A “survival cliff” has been observed for ALL in AYA patients at age 17 to 20 years, where the survival rate
drops considerably during just this 3-year difference in age, and accounts for nearly half of the total survival
[110]
decrease from childhood to older adults . This substantial drop of survival rate partly results from the
high frequency of the high-risk Ph-like B-ALL subtype among AYAs [95-99] . Based on data obtained from the
Texas Cancer Registry, among AYA ALL patients, the overall 5-year survival rate was better in females than
in males, and it has improved over time across all races/ethnicities in both sex groups . However,
[88]
improvement in the survival rate of Black AYA patients lags behind other racial/ethnic groups, similar to
the pattern seen in Black children. Among AYA patients, survival in Black males diagnosed in 2004-2012
[66.9% (95%CI: 64.0%-69.6%)] was significantly worse than in NHW [78.2% (95%CI: 77.2%-79.1%)] and in