Study results shows that, survivors of allogeneic hematopoietic cell transplantation
who underwent high-dose total body irradiation incurred nearly 8 times
the risk for subsequent malignant neoplasms compared to general
population.
Results showed the association to be strongly dose- and fractionation-dependent,
and total body irradiation doses for nonmyeloablative conditioning
posed no increased risk above that of myeloablative chemotherapy-only
based regimens.
“The
big takeaway is that people need to be aware of this risk,” Scott
Baker, MD, director of the Fred Hutch survivorship program at Fred
Hutchinson Cancer Research Center, said in a press release. “For those
patients who received high-dose radiation, they need to be especially
vigilant about following all the standard cancer prevention and
screening recommendations. And younger patients, especially women,
should talk to their doctor about starting screening for some cancers,
such as breast, at an earlier age than recommended for this general
population.”
In
the retrospective study, Baker and colleagues evaluated 4,905 patients
(57.4% men; 91.8% white) who underwent HSCT between 1969 and 2014 and
had survived at least 1 year without subsequent malignant neoplasms.
Patients had undergone the transplants for hematologic malignancies (n = 4,500) or nonmalignant conditions (n = 405). Median age at time of transplantation was 34.5 years (range 0.3-78.9),
Risk
factors assessed by the researchers included sex, race, age at first
transplant, diagnosis for transplant, stem cell source, regimen
(including dose and fractionation) and development of graft-versus-host
disease as a time-dependent covariate.
Eleven
percent of the HSCT recipients (n = 499) developed a total of 581
subsequent malignant neoplasms at a median 10.3 years (range, 1-39.7)
after HSCT.
With a median follow-up of 12.5 years (range, 1-42.11) among 1,709 surviving patients,
observed a 22% cumulative incidence of subsequent malignant neoplasms at 30 years post-HSCT.
Compared
with SEER population rates matched for age, sex and calendar year,
results showed a 2.8-fold (95% CI 2.6-3.1) increase in the standardized
incidence ratio of subsequent malignant neoplasms.
The
highest SIRs were for subsequent malignant neoplasms in the bones
(28.8), oral cavity (13.8), skin (7.3), central nervous system (6) and
endocrine organs (4.9).
(EARs) for subsequent malignant
neoplasms per 1,000 person-years were seen in cancers of the breast (EAR
= 2.2; 95% CI, 1.4-3), oral cavity (EAR = 1.5; 95% CI, 1.2-2) and skin
(EAR = 1.5; 95% CI, 1.5-2).
Survivors
exposed to either unfractionated (600 cGy-1,200 cGy-1,200 cGy) or
high-dose fractionated (1,440 cGy-1750 cGy) total body irradiation had
the highest incidence of subsequent malignant neoplasms. Those who
received low-dose total body irradiation (200 cGy-450 cGy) demonstrated
risk comparable to that of chemotherapy alone, albeit still twice that
of the general population.
Patients
aged 20 years and younger at the time of transplant had the highest
risk for subsequent malignant neoplasms compared with age-matched
members of the general population, although this risk decreased with
longer follow-up in relation to transplant.
Patients
aged 50 and older at the time of transplant showed sustained elevated
SIRs over time, although follow-up beyond 20 years for these patients
could not be accessed. Those aged 20 years or younger at the time of
transplantation had a 2.28-times (95% CI, 1.31-3.96; P = 0.003) higher risk for subsequent malignant neoplasms than patients aged 50 years and older.
Risk for subsequent malignant neoplasms also appeared significantly higher among recipients of cord blood
(HR = 3.02, 95% CI, 1.29-7.09) and peripheral blood stem cells (HR =
1.55; 95% CI, 1.16-2.07) vs. bone marrow, including after adjustment for
acute and chronic GVHD.
“The
ultimate goal for the transplant world is to find effective,
nonradiation conditioning regimens, especially for children,” Baker said
in the press release.
Get to know more about Hematology/ Oncology at World Hematology 2019
No comments:
Post a Comment