Active surveillance is also known as watchful waiting or observation
and this is the least invasive treatment strategy for kidney cancer.
The term “active surveillance” is preferred as it is
most accurate regarding this process.
Active surveillance simply means that a physician
and a patient are working together to actively observe an identified
renal mass. Once a radiographic test has identified a kidney
lesion that is potentially kidney cancer, radiographic tests such
as a CT scan, MRI scan, or ultrasound are done at regular intervals
to observe the mass.
Active surveillance is a reasonable option for some
patients as small renal masses are generally reliable in their growth
rate and pattern. Studies have demonstrated that small renal masses
tend to grow at a rate of 0.1 to 0.8 cm per year. Some kidney masses
that are small and grow slowly can be observed and treated in a
delayed manner. Alternatively, kidney masses that grow more quickly
are suspicious for kidney cancer and should be treated.
Typically, after identifying a renal mass that is
suspicious for kidney cancer, follow-up radiographic imaging is
scheduled 3 to 6 months later. If there is no change in the mass,
you and your doctor can coordinate an individualized surveillance
schedule with which you are both comfortable. Typically, this involves
obtaining radiographic imaging every 6 to 12 months with consultation
at each time point.
Active surveillance is by definition an active process.
Coordinating the radiographic imaging with routine discussion with
your doctor is critical to the success of active surveillance. If
the kidney mass should grow or change in character, then intervention
may be required.
There are a number of important patient and tumor parameters that
are critical in deciding the type of treatment that is best for
a small renal mass. Considerations are numerous but include: the
size and general radiographic appearance of the mass, the local
anatomy of the mass, the overall age and health condition of the
patient, overall kidney function, the number of lesions in the kidney,
patient personal preference, etc.
Regarding characteristics of the renal mass, the smaller
the kidney mass, the better suited it is for observation. Smaller
kidney masses are less likely to be aggressive cancer and are also
less likely to spread (metastasize). Regarding patient characteristics,
the best candidates for active surveillance are older patients who
have medical problems. Older patients with medical problems are
at slightly higher risk of complications from surgery, and may benefit
from close radiographic monitoring of their kidney mass. If the
kidney mass remains the same size or has a minimal change in size,
then active surveillance is continued. Alternatively, if the mass
should grow, intervention with a minimally invasive management strategy
such as ablation, laparoscopic partial nephrectomy, or laparoscopic
radical nephrectomy can always be performed.
Advantages and disadvantages
of active surveillance:
The major advantage of active surveillance is that no procedure
is required. All procedures, no matter how “minor” or
minimally invasive, are associated with complications. Active surveillance
is not a procedure, and therefore does not have the risks of any
invasive procedure. Also, most kidney masses grow slowly at a reliable
rate so that the risk of a cancer growing rapidly and spreading
is quite small.
However, active surveillance is not for everyone.
Some patients are not comfortable with the idea of possibly having,
and just observing, a kidney cancer in their body. For some patients,
the idea of having a potential cancer under observation is very
anxiety producing. Additionally, while small renal masses are relatively
predictable in their growth rate, there is a small risk of tumor
spreading during the course of observation.