Page 20 - New epidemiological and PSMA-expression based paradigms in salivary gland tumors

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Chapter 1
example, mutations have been shown in parts of SGPAs that showed malignant behavior. But the complete process of malignant transformation at a genetic level, had never been shown yet in a single patient. In Chapter 4 we present the first case showing this process as a proof of principle of malignant transformation of a pleomorphic adenoma.
Since literature suggests that women have a higher risk of developing SGPA than men, a hormonal role was suspected. Other arguments add to this thought, such as the presence of hormone receptors on SGPA and salivary gland malignancies. In patient care, clinicians in our hospital had earlier noted a sequence of events where women had bot a salivary gland tumor and breast cancer at some point in time. A local study suggested a correlation between the tumors and we wondered whether our nationwide cohorts of patients with either SGPA of salivary gland cancer would show an increased risk of breast cancer. Chapter 5 aims to provide the answer to that question.
The developments in imaging of a particular molecule in a field in medicine can sometimes provide a new paradigm regarding a process in another specialty. It is as if a curtain is opened and one can see the view outside the window. Molecular imaging of the prostate specific membrane antigen (PSMA) is used for detection and follow-up of prostate cancer. Other tissues show up on these prostate patient scans as well, such as salivary glands, but these had not been systematically described yet. In order to be able to distinguish metastasized prostate cancer in the neck region from salivary gland tissue, we aimed to systematically describe uptake of the radioactive tracer (PSMA-ligand) for imaging with positron emission tomogram (PET) / computed tomography (CT) in the glands in the head and neck region in Chapter 6.
The technique of depicting salivary and seromucous glands can theoretically be used to assess and guide head and neck irradiation in head and neck cancer patients. We aimed to present cases to illustrate and discuss this idea in Chapter 7. The images of the PSMA PET/CT scans consistently suggested a collection of (salivary) gland tissue in the dorsolateral nasopharynx, near the auditory tube entrance. Although a higher density of microscopic minor glands had been described before, these large glandular tissue collections did not seem to fit in the existing picture of up to a thousand mainly spread out glands in the aerodigestive tract. Could it be that these are highly concentrated collections are present in all humans, both male and female? And if so, could they be of clinical relevance