What are the other Names for this Condition? (Also known as/Synonyms)

• MASC of Salivary Glands
• Secretory Carcinoma of Salivary Glands (Mammary Analogue Subtype)

What is Mammary Analogue Secretory Carcinoma of Salivary Glands? (Definition/Background Information)

• Mammary Analogue Secretory Carcinoma (MASC) of Salivary Glands is a type of cancer involving the salivary glands inside the mouth. It is a newly-recognized condition
• It used to be diagnosed as one of various ‘other’ conditions with similar signs and symptoms; however, now it is recognized as a distinct condition based on certain genetic factors. These ‘other’ conditions were nearly always other cancers or tumors of the glands and soft tissues of the mouth and often mimic MASC of Salivary Glands
• They include, in a rough order of frequency according to the primary retrospective study on the condition, the following:
  • Adenoid cystic carcinoma
  • Acinic cell carcinoma
  • Cystadenocarcinoma of major or minor salivary glands
  • Salivary duct carcinoma
  • Mucoepidermoid carcinoma
• In the primary retrospective study to look at potential cases of Mammary Analogue Secretory Carcinoma of Salivary Glands, individuals of many ages including children and adults, developed the condition
• The cancer is found frequently in the parotid gland (a salivary gland); however, it can be found on any of the soft tissues (mucosae) lining the mouth. The tumor may be found on the roof of the mouth (hard palate) in one case
• Surgical treatment, with additional intervention for local and regional spread in some cases, is generally effective. The prognosis of Mammary Analogue Secretory Carcinoma of Salivary Glands depends on many factors, but it is better with early detection and treatment

Who gets Mammary Analogue Secretory Carcinoma of Salivary Glands? (Age and Sex Distribution)

• From certain limited studies, it is seen that Mammary Analogue Secretory Carcinoma of Salivary Glands is a relatively rare tumor, but with various common mimics. It affects similar populations to other salivary gland tumors, especially those of genetic origin
• It primarily affects adults, though it can affect children; individuals between 9 and 73 years are known to be affected
• No racial, gender, or geographic restriction is noted in presentation of Mammary Analogue Secretory Carcinoma

What are the Risk Factors for Mammary Analogue Secretory Carcinoma of Salivary Glands? (Predisposing Factors)

• Aside from genetic predisposition, no definite risk factors are known to increase an individual’s likelihood of developing Mammary Analogue Secretory Carcinoma of Salivary Glands
• If genetic changes are not observed, then the risk remains at the same baseline level as the risk for any individual to develop a cancer of the mouth

It is important to note that having a risk factor does not mean that one will get the condition.  A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors.  Some risk factors are more important than others.  

Also, not having a risk factor does not mean that an individual will not get the condition.  It is always important to discuss the effect of risk factors with your healthcare provider.  

What are the Causes of Mammary Analogue Secretory Carcinoma of Salivary Glands? (Etiology)

Mammary Analogue Secretory Carcinoma of Salivary Glands is caused, or at least accelerated by, a genetic change at the molecular level.

• The rearrangement is in the form of what is called a translocation between two genes on two different chromosomes, and it is called the ETV6-NTRK3 translocation
• The same genetic change is observed in some secretory cancers of the mammary gland (breast, in females, but is also reported occasionally in males), which explains the name
• The genetic rearrangement in the glandular cells allows them to divide uncontrollably, leading to tumor growth and cancer

What are the Signs and Symptoms of Mammary Analogue Secretory Carcinoma of Salivary Glands?

Signs and symptoms of Mammary Analogue Secretory Carcinoma of Salivary Glands are as follows:

• Often a slow-growing, painless lump is observed in the cheek or mouth
• Sometimes, the tumor can be more aggressive, presenting with faster growth, pain, altered salivation, invasion of surrounding skin tissue, inflammation of lymph glands in the neck, and/or breaking through the mucous lining of the mouth or the external surface of the skin

How is Mammary Analogue Secretory Carcinoma of Salivary Glands Diagnosed?

Mammary Analogue Secretory Carcinoma of Salivary Glands is typically diagnosed in the following fashion:

• Clinical history and physical examination; clinical monitoring of the mass for slow-growing masses
• Tissue biopsy of the mass for examination under a microscope and evaluation of binding of certain antibodies to the tissue. This is often thought to be sufficient for a diagnosis; however, with some of the other similar cancers having a very similar appearance under the microscope, often further antibody testing and cytogenetic analysis (for the genetic alteration) must be done, with the same tissue biopsy specimen
• While certain other unique genetic rearrangements have been found in some cases of MASC of Salivary Glands, the ETV6-NTRK3 translocation is considered pathognomonic (confirming the diagnosis of the condition)
• Since surgery is often a mainstay in treatment, postoperative examination of the surgical specimen is also used

Many clinical conditions can have similar signs and symptoms.  Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.  

What are the possible Complications of Mammary Analogue Secretory Carcinoma of Salivary Glands?

Possible complications of Mammary Analogue Secretory Carcinoma of Salivary Glands include:

• Impaired salivation, taste, and swallowing
• Loss of part or all of a salivary gland or other structure in the mouth, such as hard palate, from surgical excision during treatment; this could lead to problems with articulating speech and swallowing
• Local spread of the tumor/progression of the condition
• Regional lymph gland swelling
• Distant metastasis (seeding of cancer elsewhere in the body)
• Other cancers due to adjuvant (additional) radiation therapy often employed in treatment

Complications may occur with or without treatment, and due to treatment also.  

How is Mammary Analogue Secretory Carcinoma of Salivary Glands Treated?

Mammary Analogue Secretory Carcinoma of Salivary Glands is usually treated, at least initially by a surgical approach:

• Partial or complete removal of the salivary gland is common, while attempting to clear all affected tissue within the specimen removed
• When removal of all the affected tissue is difficult, or the structure of the oral cavity has to be preserved, adjuvant (additional) radiation therapy to the region may be also used
• Dissection of lymph glands in the neck is also done in cases where the disease has spread or is spreading regionally, in order to try to prevent it from spreading farther
• Systemic (whole-body) chemotherapy is also sometimes used in treating MASC of Salivary Glands
• Research into using the genetic alteration as a target in treatment is underway
• Regular follow-up for monitoring for recurrence or disease progression is essential

How can Mammary Analogue Secretory Carcinoma of Salivary Glands be Prevented?

No firmly established guidelines exist for preventing Mammary Analogue Secretory Carcinoma of Salivary Glands, since it is a genetic condition.  

• Evidence is still emerging as to whether or not it is inherited, and thus whether prenatal genetic testing (of the fetus in the mother’s uterus during pregnancy) is of any value
• A family history could warrant preconception genetic counseling for the parents, but research is still being conducted to find more evidence, if any, to support this
• Active research is increasing into how genetic or other treatment could play a role in slowing or curing MASC of Salivary Glands
• Regular surveillance medical examinations are mandatory in those determined to be likely at increased risk for the tumor

What is the Prognosis of Mammary Analogue Secretory Carcinoma of Salivary Glands? (Outcomes/Resolutions)

• The prognosis of Mammary Analogue Secretory Carcinoma of Salivary Glands is still somewhat unknown due to the limited number of described cases, particularly with long-term follow-up
• It is typically treated as a less aggressive carcinoma with a generally good prognosis; for the most part, this appears to be yielding positive results
• The prognosis has so far consistently been better with treatment, usually initial surgical treatment with further treatment dependent on the case. However, in some cases it can be aggressive, since the cancer can spread to the regional lymph nodes or even beyond
• Genetics may play a role in the development of the condition, but it has not been shown that an individual’s genetic makeup renders him or her more or less resistant to treatment

Additional and Relevant Useful Information for Mammary Analogue Secretory Carcinoma of Salivary Glands:

The genetic, and thus, molecular staining differences often make certain the diagnosis of Mammary Analogue Secretory Carcinoma of Salivary Glands; however, some other genetic or molecular changes can cause very similar conditions or different presentations of the same condition.  Thus the importance of examination under a microscope and clinical correlation with the healthcare provider cannot be understated.