Schoot RA, Taselaar P, Scarzello G, Kolb F, Coppadoro B, Horst ST, Mandeville H, Ferrari A, Hladun R, Helfre S, Ferman S, Kelsey A, Hol MLF, Devalck C, Ben-Arush M, Orbach D, Chisholm J, Jenney M, Minard-Colin V, Bisogno G, Merks JHM.
Head Neck. 2024 Nov 15. doi: 10.1002/hed.27994. Online ahead of print.
PMID: 39545397
The parameningeal (PM) localization is a known adverse prognostic factor
in rhabdomyosarcoma (RMS) management. The PM sites are difficult to
reach by surgery, and due to its proximity to the meninges, tumor cells may
more easily spread to the central nervous system (CNS). The PM
localization consists of several subsites and in the past decades PM RMS
have been classified according to this subsite classification. A previous
analysis (by COG and EpSSG) defined adverse prognostic risk factors and
revealed that specific subsites had poorer outcome.
In this manuscript, we describe the treatment and outcome for patients with
PM RMS, treated within the EpSSG RMS 2005 study. Secondary aims of
this study were to investigate the validity of the previously defined risk
factors with a specific focus on the prognostic value of PM sites, and to
investigate whether PM tumor site should be defined by the originating site
or the site with the highest risk in which the tumor is extending.
Despite the application of radiotherapy in a higher percentage of patients
(94% of patients), the outcome for the 381 patients in this cohort appeared
similar to the outcome presented in previous historical studies. However,
such comparisons should be made with caution as they are performed post
hoc and biased by differences in design. Risk factors such as MI and age at
diagnosis and PM site (by highest risk extension) remained of prognostic
value, and in addition, tumor invasiveness was associated with event free
survival. Classification of PM sites appeared to be an academic endeavor,
with misclassifications in 22% of evaluated imaging reports. No sites could
be identified as individual poor risk localization, potentially because of the
large number of subgroups and inherent small numbers per subgroup that
were identified.
in rhabdomyosarcoma (RMS) management. The PM sites are difficult to
reach by surgery, and due to its proximity to the meninges, tumor cells may
more easily spread to the central nervous system (CNS). The PM
localization consists of several subsites and in the past decades PM RMS
have been classified according to this subsite classification. A previous
analysis (by COG and EpSSG) defined adverse prognostic risk factors and
revealed that specific subsites had poorer outcome.
In this manuscript, we describe the treatment and outcome for patients with
PM RMS, treated within the EpSSG RMS 2005 study. Secondary aims of
this study were to investigate the validity of the previously defined risk
factors with a specific focus on the prognostic value of PM sites, and to
investigate whether PM tumor site should be defined by the originating site
or the site with the highest risk in which the tumor is extending.
Despite the application of radiotherapy in a higher percentage of patients
(94% of patients), the outcome for the 381 patients in this cohort appeared
similar to the outcome presented in previous historical studies. However,
such comparisons should be made with caution as they are performed post
hoc and biased by differences in design. Risk factors such as MI and age at
diagnosis and PM site (by highest risk extension) remained of prognostic
value, and in addition, tumor invasiveness was associated with event free
survival. Classification of PM sites appeared to be an academic endeavor,
with misclassifications in 22% of evaluated imaging reports. No sites could
be identified as individual poor risk localization, potentially because of the
large number of subgroups and inherent small numbers per subgroup that
were identified.
