Discussion
This study describes BS as a promising component in the fertility
sparing treatment for patients who have early EC. This is the first
study discussing this topic in the local setting, and one of the few
studies worldwide describing using BS in this context.
Morbid obesity is the underlying biological factor that drives the
development of endometroid EC in young patients in the reproductive age
group. Addressing this underlying factor with BS is a logical treatment
strategy that can potentially improve the regression rates and reduce
recurrence rates of EC. Indeed, we see two patients who had EC
previously and had cancer regression with hormonal therapy. They had
recurrence a few years after treatment. Another patient had a long
treatment period with hormonal therapy, without regression of EC. This
could possibly be because obesity, as the underlying driving factor for
cellular proliferation and carcinogenesis, had not been addressed. Long
term follow-up and data is necessary to demonstrate if weight loss
induced by BS results in reduced EC recurrence and survival benefit.
In addition, weight loss induced by BS improves the chances of
fertility, both via natural conception or via ART, reduces maternal and
fetal complications antenatally and reduces risks in the peri-partum
period. We see that one of the patients had successfully conceived with
IVF and had no maternal or fetal complications during the antenatal
follow up period. Once the other patients pass the first 12 months after
BS, where weight loss is rapid and extensive, they would be counselled
to undergo ART to aid in conception.
The improvement in physical and psychological health after BS provides
additional benefit to this group of patients. Total weight loss is
between 25 to 30%, which is consistent with other large-scale studies.
We also saw resolution of obesity related comorbidities, which could
lead to improved health outcomes and reduced complications from
cardiovascular diseases in the long term (12, 27).
The limitations of this case series include the retrospective nature of
the study design, the lack of a control group, the short follow-up time
and the small number of patients in the study group. The retrospective
nature of the study design makes it prone to selection and measurement
bias. The patients included in this study are only those that are
treated in the centers in which the authors are based. In addition, the
early cancer regression in this group of patient who chose to undergo BS
may be due to other factors like higher compliance to the fertility
sparing treatment or increased health seeking behavior. Measurement bias
can also result from incomplete or heterogeneous data from a lack of
standard study protocol. This is partially mitigated by the fact that
all the treatment received by the patient (both fertility sparing
treatment for EC and BS) were according to a standard pathway, and all
data collected were from the same comprehensive EMR system used in both
public healthcare institutions. The outcomes measured were also
objective in nature e.g. histology proving that EC has regressed and
weight loss measured in the outpatient clinic during follow-up
appointments. The lack of a control group prevents us from inferring a
causal relationship between EC regression and BS. We are also unable to
draw any conclusions about the longevity of the cancer regression due to
the short follow-up period.