The treatment also had extremely high efficacy in all four trials. It must be considered that HER-2
positive Metastatic Breast Cancer has extremely poor prognosis, as seen from the data in the
introduction (Gonzales, et al., 2009). The overall response rates of the illness to the combination of
drugs was 98.1%, 68.75%, 52%, and 83.3% in studies by Cortes, et al., Martin, et al., Chia, et al., and
Stickeler, et al. respectively. The median overall survival rate is also reported to be significantly high
in the four studies. Cortes, et al. reported the median OS to be as high as 61.4 months, whereas Martin,
et al., and Stickeler, et al. reported it to be 34.2 months and 16.23 months respectively. Chia, et al.
reported that the survival rate after 1 year is 76.9%. The cancer was extremely responsive to the
combination of drugs used, and the survival rate was also quite high, considering the poor prognosis
of advanced breast cancer.
The overall response rate of each of the studies is stated by their respective authors to be within range
of other studies with similar designs. Chia, et al (2006) mentioned that their overall response rate
(52%) was on the lower side of this range, but it was compensated by their higher median Progression
Free Survival rate (12 months). Also, we see an extremely high overall response rate in the study by
Cortes, et al., but the reason for this is not known.
In summation, these results show us that when doxorubixin is used in its newly developed liposomal
formulation along with trastuzumab, the combination yields great results. This combination was once
vastly discouraged due to the obvious severe cardiotoxicity (Rayson, et al., 2008). However, recent
clinical trials (such as the ones discussed in this review) show us that there is promise for the use of
this combination in treatment for advanced breast cancer. In the introduction, we discussed that the
systemic side effects of liposomal drugs should be lower due to reduced systemic distribution
(Deshpande, et al., 2013 & Ferrari, 2005). The data received from the four clinical trials supports this
point.
4.2. Limitations of the Study
There are several limitations in this systematic review. Firstly, only 4 studies were included in the
review. This was because not many clinical trials have been published on the administration of a
combination of liposomal doxorubicin and trastuzumab for the treatment of advanced breast cancer.
The liposomal formulation of doxorubicin is a relatively new technology, and hence its concerted use
with trastuzumab is yet to be tested completely. Secondly, our resources were extremely limited, as
we had access to only free publications. This is the reason why we could not access the clinical trials
in Cochrane Library.
4.3. Future Research
The review evaluates four trials and shows that the concerted use of trastuzumab with liposomal
doxorubicin was extremely effective and safe in the treatment of advanced breast cancer. Future