A meta-analysis and trial
sequential analysis of randomized controlled trials is planned which would
comprehensively summarize the current evidence of effect of bisphosphonates on
For a cancer patient, every day is a
challenge and survival is the ultimate victory! And to make matters worse,
sometimes the same cancer could possibly come
back where it first started or somewhere else in the body. This is known as
recurrence, and for some this second cancer diagnosis could cause more shock
and distress than the first one. Bisphosphonates are drugs used to slow the
progression of or prevent bone damage in conditions such as osteoporosis
and are often prescribed to prevent bone loss
caused by malignancies. Drugs belonging to this group include alendronate,
risedronate, ibandronate, pamidronate, clodronate and zoledronic acid. Several
studies have indicated that bisphosphonates may also prevent recurrence of
cancer, as well as spread of cancer to the bone (bone metastasis).
Even though several meta-analyses conducted in the
past have assessed the role of bisphosphonates in reducing risk of
cancer recurrences, they only studied a particular type of cancer and many
studies have evaluated only a particular type of bisphosphonate. In addition to this, it is currently unclear whether
the effects hold true for less common cancers and whether they differ at
different follow-up time etc.
A meta-analysis is a
statistical study that combines data from several clinical trials. The
meta-analysis that has been planned will include patients diagnosed with any
primary cancer and without evidence of any relapse before follow-up in original
studies. Two reviewers will independently extract data from each study with
uniform electronic forms specifically created for this study.
primary outcomes of the study will include any cancer recurrence and bone
events. Secondary outcomes will include events of local
recurrence, regional recurrence or non-skeletal distant metastasis,
disease-free survival as well as overall survival.
Online databases such as
MEDLINE, EMBASE and CENTRAL (Cochrane Central Register of Controlled Trials)
will be systematically searched. Other sources of information will include reference
sections, citation lists of the reviewed literature, and the websites ClinicalTrials.gov and the
Clinicaltrialsregister.eu. The statistical methods that will be used have also
One of the possible limitations of this study would be that
currently most of the randomized trials have studied effect of bisphosphonates
in early breast cancer
and multiple myeloma and there
are very limited studies on other forms of cancer.
The authors state that the findings of this
meta-analysis would be submitted for publication in a peer-reviewed journal and
also presented at relevant national and international conferences.