MD Anderson Cancer Center
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>> Welcome to Cancer News Line, a weekly podcast series from the University of Texas, M.D. Anderson Cancer Center. Cancer News Line helps you stay current with the news on cancer research, diagnosis, treatment and prevention, providing the latest information on reducing your family's cancer risk. I'm your host Lisa Garvin. Today, our guest is Dr. Michael Kupferman. He is an assistant professor of head and neck surgery here at M.D. Anderson and our subject today is salivary gland cancer which is a very rare cancer apparently. Dr. Kupferman, first of all let's have an anatomy lesson. Let's talk about how many salivary glands we have and where they're located.
>> Thank you Lisa. The salivary glands exist both in the cheek region, underneath the jaw and then throughout the mouth. And as you stated quite accurately these are very rare tumors and they can arise in any one of these structures. The salivary glands of the parotid gland are paired on either side of the cheeks and they sit in the region right in front of the ear. The submandibular glands sit just underneath the jaw bone. And then scattered throughout the oral cavity and in the back of the throat and the nose are small salivary glands that also can go on to develop tumors.
>> But from what I understand it's the parotid glands that are most likely to be the site of the cancer.
>> That's correct. The parotid gland is the most common site for salivary gland cancers and that's probably because they are the largest volume of salivary tissue that we have. And functionally they provide the mouth with the saliva and in order to bathe the mouth, keep the teeth healthy, and provide the various digestive enzymes that begin the process of digestion of food inside the mouth during chewing.
>> And we talked about the rarity, I had seen figures from the American Cancer Society, this says it's less than 1 percent of all cancers diagnosed in the US.
>> That's correct. These are very rare tumors and in fact, in the head and neck, they account for approximately 5 percent of the cancers that we see. And so the management of these various tumors is quite complex and because there is so little experience across the United States and the world in terms of managing these, these tumors are most often best managed by experienced clinicians.
>> And I would guess owing to the location that they are not often caught in the early stages.
>> You know it's interesting. Some patients will walk around with little bumps underneath their jawbone or in their parotid gland and oftentimes not necessarily have them addressed by a clinician. And so these tumors may in fact oftentimes remain at a very small size and they can for years stay at that size. And the majority of these tumors are benign and so there is in the community less of an urgency to manage these tumors. It's really only when patients notice that they begin to enlarge, they begin to cause pain or more ominously start leading toward nerve paralysis, do patients oftentimes seek attention.
>> And let's talk about some of the symptoms. What would a patient or a person typically experience?
>> As I stated earlier, for the most part most patients will oftentimes present with a nonspecific lump in the cheek region or just behind the ear or just underneath the jawbone. And it may be nontender. It may not cause them much discomfort. Occasionally, patients can have a bleeding episode into these small lesions. But as they continue to enlarge they begin to involve some of the surrounding structures. They may get inflamed and lead to a small localized infection. They may start to involve the nerve that controls the face, which can lead to limitations in motion of the face. When they exist in the oral cavity or in the nose or in the back of the throat they may cause very nonspecific symptoms such as a sore throat or the sensation that there is a lump in the back of the throat, sometimes a bloody nose or nasal congestion.
>> As with a lot of cancers there are usually nonspecific factors that lead to this cancer. Are there any risk factors for salivary gland cancer?
>> Well, obviously, like occurs in most cancers, the history of smoking is associated with the development of salivary gland cancers. There is a suggestion that there is an association between breast cancer as well as salivary gland cancers. The tumors sometimes under the microscope can look very similar and so there is a suggestion that they may have some of the same risk factors. There is an association with radiation exposure as well as some other occupational exposures which we tend not to have in this country but are primarily related to heavy metal exposures. It has to be distinguished from patients who have a history of skin cancers in which the skin cancer spread to the lymph nodes in and around the saliva glands which oftentimes are confused for being tumors of the saliva glands. And so whenever we see a patient who has a tumor in the saliva glands we're always careful to determine whether they have a history of the skin cancer as some of these skin cancers may spread to the same anatomic region.
>> But given its rare nature so it's not really a typical metastasis site, I mean, primary cancers don't typically metastasize to salivary glands.
>> Very uncommonly. However, there are some known tumors that do metastasize to this area and when the story does not make sense in terms of development of the tumor, we oftentimes think in the back of our minds that perhaps this may be the spread of the cancer from another site such as breast cancer, lymphoma may present in the lymph nodes and in and around the parotid gland, and cancers of the kidneys can also spread to the parotid gland.
>> I hate to bring this up because the evidence is so contradictory but let's talk cellphones as a risk factor. Is that--I know the evidence is maturing but--
>> I think at this time it's difficult to state definitively that cellphone use is associated directly with the development of salivary gland cancers. There is also been established associations with other tumors in and around the brain associated with cellphone use but at this point I think the jury is still out.
>> And let's talk about treatment. I assume that salivary gland--the primary front line treatment would be surgery?
>> That's correct. These tumors are very well treated with surgery. And that's part in due to the ability to control the tumor locally. It's also due in part to the side effects related to some of the other treatment modalities and the inability of these tumors to oftentimes respond to nonsurgical treatment such as radiation or chemotherapy. And so, for the most part tumors of the parotid gland and the salivary gland--parotid gland as well as the submandibular glands are best treated with surgery, oftentimes followed by radiation depending on the type of tumor. And the real problem with salivary gland tumors is that despite the rarity of these tumors, despite how infrequent they are and their location. They actually represent a very broad array of tumor types when you look at them under the microscope. And so, we really just can't classify all tumors just as salivary gland tumors. There is a very broad spectrum of tumor behaviors ranging from very benign, noncancerous or low risk cancers in the salivary glands to those that have a very high rate of spread to the lymph nodes. And so, that further challenges us in terms of how we best treat these patients.
>> As far as minimally invasive procedures, I'm not sure whether--is the chance for a facial disfigurement high when--with your surgical techniques or are we using minimally invasive methods?
>> So for salivary gland cancers we obviously attempt to utilize an approach that gives us the greatest access to the tumor but at the same time we try to achieve minimization of cosmetic and functional issues. And so we place our incisions when we're approaching these tumors in normal skin creases. So for instance, for tumors of the parotid gland we utilize the same incision that in general is used for a face lift. However, these incisions oftentimes need to be sizable that we can gain adequate access to these tumors, remove them, and at the same time preserve the critical structures such as the facial nerve, the nerve that controls the tongue, and the nerve that controls the shoulder. When these tumors exist in the oral cavity or the back of the throat or in the nasal cavity, we certainly can utilize less invasive approaches that don't necessarily require facial or neck incisions. And so, for instance, tumors in this region are oftentimes very amenable to surgical removal with say a robotic based approach which we have a lot of experience here at M.D. Anderson as well as minimally invasive endoscopic techniques using telescopes to address these tumors by removal through the nose without any facial incisions.
>> What is life like after--when you remove the salivary glands? Do they have to rely on artificial saliva? Do the other salivary glands kick in or how does that work post treatment?
>> The major issue related to salivary gland cancers from the functional standpoint relates to whether or not the patient has received radiation as part of their treatment package. When a patient has a single parotid gland removed or a single submandibular gland removed, that generally doesn't impact the overall saliva flow and the ability to maintain a hygienic oral cavity. However, it's when patients receive radiation for their tumors is when they begin to develop some of the long term issues related to poor saliva, dry mouth and associated dental and swallowing complications. In terms of the cosmetic issues, obviously, when we remove the parotid gland, it does lead to some shallowing out of the cheek region, some reconstructive techniques are utilized here in order to limit some of the cosmetic issues that patients may face. And so, working in conjunction with our plastic surgeons we make every attempt to provide patients with not only a very good functional outcome but also an excellent cosmetic outcome.
>> Is it like immediate reconstruction? Is it done the same time as the surgery to remove the tumor or is that usually a later procedure? That really just depends on the tumor type, for instance, the extent of the tumor may warrant a reconstruction at the time of surgery. And it often--on the other hand, if the tumors have limited size they don't necessarily need a reconstruction upfront. And it's important to remember that while cosmetic issues play an important role we don't want to compromise our ability to monitor these tumors and so, if we put in some artificial tissue or some tissue from another location into these regions it can make it more challenging for us to monitor these tumors over the long term and so it's a very delicate balance in terms of who gets reconstructed and why. And so, we really try to provide a personalized approach to all patients with these types of tumors.
>> Have you amassed enough of a patient volume here at M.D. Anderson to do any research into new treatments?
>> I would say that here at M.D. Anderson we have probably one of the largest experiences in the United States if not in the world in the world in dealing with these tumors. We see a lot of patients in second opinion, we see a lot of patients who have been previously treated who still require further treatment and we see patients who oftentimes come in with their tumor untreated. And so, looking back at our experience over the last 20 or 30 years we've been able to draw some fairly substantial conclusions about the treatment of these tumors both in the adult as well as the pediatric population. And one interesting thing that we've recently identified is that there is a specific sub type of salivary gland tumors called salivary ductile cancer which is one of those cancers that I'd mentioned that have very similar behavior and appearance into the microscope to breast cancer. And what we found is that patients who have a particular receptor embedded in the tumor which is the same receptor that is used for prediction for patients with breast cancer, when patients are treated with a particular type of agent that targets that receptor they tend to have a much better outcome than those who did not receive the treatment and many of your listeners may have heard of this drug called Herceptin. Herceptin is one of the most commonly used chemotherapies for patients with breast cancer and it specifically targets the HER2 receptor. And because of the commonalities that salivary ductile cancers have with breast cancers in this regard, we've began testing all patients who have salivary ductile cancers for the presence of this receptor and if they do, they will oftentimes go on and receive this type of therapy and our limited experience seems to suggest that it offers patients for a better outcome.
>> Great! Thank you very much. If you have questions about anything you've heard today on Cancer News Line, contact Ask MD Anderson at 1877-MDA-6789 or online at www.mdanderson.org/ask. Thank you for listening to this episode of Cancer News Line. Tune in next week for the next podcast in our series.
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