April 2, 2018
DR JONATHAN CLARK: Brad's been diagnosed with a squamous cell cancer of the tongue base. Squamous cell cancers are the most common type of cancer that we see in the throat and back of the tongue. His cancer has spread from the tongue base to a single lymph node in the upper part of his neck.
The majority of these cancers in 2012 are viral cancers caused by the human papilloma virus and we think in Brad's case that this is one of those types of cancers.
Previously, the majority of cancers in the throat and tongue base were cancers induced by smoking.
The rate of smoking in countries such as Australia is reducing and we're seeing a dramatic change in the prevalence of cancers in this area with the majority now being viral cancers as opposed to cancers due to smoking.
CAROL DUNCAN: The cervical cancer vaccine which is now being provided to young girls is to protect them against HPV.
Yes, it's the same virus and the same type of that virus, type 16, which causes cancers both in the cervix and cancers in the throat - in particular the tonsil region.
We don't know why this type of cancer is increasing, lots of reasons are being speculated, and it's very important to be aware of this change because the prognosis from viral cancers in the throat is much better than cancers due to smoking.
Throat cancer is one of the most common types of cancers in the head and neck region, but having said that head and neck cancers as a group are relatively uncommon in Australia if we compared it to breast cancer or colo-rectal cancer.
In other areas of the world such as India, cancers of the mouth and in particular the cheek and tongue are very common, in fact one of the most common types of cancers. But in Australia, this is a relatively uncommon cancer.
CAROL DUNCAN: How common is the human papilloma virus?
Most people are exposed to HPV, however the majority of people don't develop cancers.
It will be very interesting to see what the impact of the HPV vaccine that's been introduced for girls has on the prevalence of throat cancers in the head and neck population.
At present* boys are not being vaccinated but we expect that with the vaccination of girls the actual rate of HPV in the population will reduce due to what's called 'herd immunity' where if there are less people without the virus in just one gender it will usually reduce the rate of the virus in the other gender. *Note: 2013 sees the introduction of a free, school-based vaccination scheme for boys in Australian schools.
Brad is going to be one of the first Australians having his throat cancer surgically removed with a 'robot', the Da Vinci Surgical System.
Traditionally cancers in the back of the throat were operated on using a very radical approach. We would have to cut the jaw bone and swing the jaw bone out to be able to get to the back of the tongue adequately to remove the cancer. Because of that there's been a shift in treatment away from surgery to using radiotherapy in combination with chemotherapy for cancers of the tongue base in particular.
More recently, with the introduction of robotic surgery which has become very popular for prostate cancer, we're able to access the back of the tongue without making any cuts on the lip or the face and get excellent visualisation of the area and be able to remove tumours that we were not previously able to do well without doing a radical operation.
The advantage here of using the robot is to be able to do things in what we would call a 'minimally invasive approach', and in his particular case, in Brad's particular case the advantage of chemo-radiation is it may be possible that he is able to avoid radiotherapy altogether, but more importantly we'll get additional pathological information which helps us to 'risk stratify' his cancer, or determine whether his cancer has a high chance of recurrence, a medium risk of recurrence, or low risk of recurrence.
In those patients who we feel have a low risk of recurrence we would aim to use the least aggressive form of treatment with the least amount of side effects and toxicity.
So, in general, if you can treat someone with one method of treatment - whether it be surgery or radiotherapy or chemotherapy - without combining the two or three together we would expect the side effects to be less.
However there are certainly people who need to have more aggressive treatment and combination treatment.
Our data at the moment suggests that the chances of cure if you combine radiotherapy with chemotherapy are equivalent to the combination of surgery and radiotherapy.
In using the robot to get that pathological information we can also potentially put Brad into a high risk group - hopefully that's not the case but if it was we would then be able to offer him triple-modality therapy which would involve surgery followed by radiotherapy and concurrent chemotherapy with the radiotherapy.
So, at the moment if he was to have radiotherapy it would be a fairly 'cookie-cutter' approach to that, that he would receive as a standard treatment receive radiotherapy combined with chemotherapy.
What we'd like to do in Brad's case is to individualise his treatment and risk-stratify the most appropriate treatment approach.
We still have a long way to go to optimise personal medicine, and HPV has been a very important bio-marker because of its better prognosis.
We still haven't really determined in an individual what the bio-markers are that mean that we can de-intensify their treatment, but we've got a number of standard pathological features that we could use to determine if someone falls into a low, intermediate or high-risk group.
CAROL DUNCAN: How confident do you feel about attempting this surgery using the Da Vinci robot?
We haven't done very many operations this way so there's always a degree of trepidation when you're embarking on something that you haven't done a hundred times but in the cases that we've done so far we've found that the robot gives you excellent visualisation of the area, much better than using traditional approaches.
The arms of the robot enable us to distract and pull tissue in ways that we're not able to do with approaches using trans-oral laser surgery, so that combination of better visualisation and being able to move the arms in free space that we were not able to do previously means that we've got a greater degree of confidence in tackling these types of tumours.
CAROL DUNCAN: What are you expecting with Brad's surgery?
There's two components to the operation. The first part is the removal of the tumour from the back of the tongue.
We're expecting that we'll be removing about one quarter of the base of the tongue area extending on to the tonsil. That operation we'd expect to take about 45 minutes.
We also need to do the second component which is removal of the lymph glands from the left hand side of the neck. We'll do that using the traditional approach of an incision of the neck which we expect to heal very well.
We need to remove the lymph glands from the upper part of the neck and a bit further down but be very careful of a whole host of important structures in that area that are important for movement of his arm and shoulder and for his speech and swallowing.