The fundamentals of medicine involve a thorough history and examination in order to come to a differential diagnosis (a list of possible problems). The reason we do special investigations is to confirm or deny our clinical suspicions. Head and Neck cancer is no different, but in addition to that, we also need to stage cancers.
Cancer staging is about gathering as much information as possible to accurately predict how well we think someone is going to do, i.e., their prognosis. It is not primarily for determining what treatment we are going to recommend, but it certainly guides us.
What are the most common special investigations required in order to manage head and neck cancers? I divide them into two broad categories. Investigations to assess the tumour and investigations to assess the patient.
Investigations for the tumour mainly involve a biopsy of some sort and imaging to assess the tumour where it starts and where it might spread to. Biopsies can be performed as incision, excision, fine needle or trucut biopsies. Where there is an ulcer or proliferative lesion, incision biopsies are most common. Suturing the wound is not necessary. When there are neck swellings or deep organ lesions, then fine needle or trucut biopsies are most often recommended, usually under ultrasound or CT scan guidance for the best results. The goal is to get the most representative specimen with the least possible risk, discomfort and cost. Excision biopsies of neck masses are not recommended as first line options.
Radiology is the most common tool to asses the extent of primary disease and possible spread. Most commonly head and neck cancers spread to the neck nodes and only into the blood stream if they are very advanced. There are of course exceptions. Ultrasounds of neck masses are usually the first test requested. CT is excellent for assessing a tumour’s growth as well as for bone invasion and neck node involvement. MRI can assess soft tissue well, especially for salivary glands, nerves, eyes and the brain. PET CT is excellent for assessing metastatic spread (into the blood stream) but is not done routinely for early disease.
Patient assessment is primarily about assessing risk before patients undergo treatment, whether that is surgery, radiation, chemotherapy or a combination of all of them. Because of co-morbidities, patients sometimes need to be assessed by physicians, cardiologists, pulmonologists or intensivists, requiring blood, lung function or cardiac tests. Certain blood tests impact healing and are sometimes required like HIV, glucose or albumin. Few head and neck cancers have tumour markers that require testing before treatment, but in some like thyroid cancer and nasopharynx cancer tumour markers can be used in surveillance.
All this crucial information is requested or performed by the head and neck surgeon or the referring doctor and discussed at a multidisciplinary meeting with recommendations being made to the patient regarding what we feel the best course of treatment is and the risks associated. Each member of the multidisciplinary team that may need to be involved may also require special investigations to assess the impact the treatment may have on the patient, for example, dental imaging, swallowing studies, nutritional assessment, etc.
In order not to waste time and money, if a referral colleague is unsure of the tests indicated, then early referral to the head and neck surgeon is the best course of action.