Tumours of nose, nasal passage and sinus
Sinonasal cancers arise from the nasal cavity and paranasal sinuses, and can involve the anterior skull base, which forms the junction between the nasal cavity and brain. The lateral skull base is affected primary by cancers of the temporal bone, external ear or middle ear. These are difficult tumours to treat and require a lot of multidisciplinary expertise (surgery, radiotherapy, medical oncology, pathology and radiology) for appropriate treatment, while avoiding injury to the critical structures in the vicinity, such as large blood vessels to the brain, eye, facial nerve and brain.
How common is it?
Tumours of the nasal cavity, paranasal sinuses and skull base are rare but challenging tumours to treat. Less than 1 in every 100,000 people in the population will develop this kind of cancer. However the diagnostic challenge lies in the fact that very often these tumours mimic benign nasal polyps or sinuses resulting in delayed and inappropriate treatment.
What are the symptoms?
Nasal symptoms include nasal stuffiness or block, watery discharge, bleeding, pain, headache or loss of smell. If the orbit (bony cavity in which the eye is situated) is involved, symptoms include reduced vision, double vision or watering of the eye. Other symptoms that can occur are difficulty opening the mouth, altered sensation or numbness in the face, loosening of teeth and a bulge in the palate. Cancers involving the lateral skull base can present with ear pain, reduced hearing, unilateral discharge or a lump in the neck.
What causes it?
The causative agents are not strongly established as they are with other cancers. Some of the associations are industrial pollutants like nickel, chromium and formaldehyde exposure. Exposure to wood and leather dust in factories is also believed to play a role. Some types are linked to tobacco and alcohol exposure.
How do you diagnose it?
Evaluation of these cancers involves two parts. The first biopsy of the tumour, which is performed under short general anaesthesia with endoscopic guidance. The second part is imaging of the cancer CT, MRI or PET scans. As these are a diverse group of cancers with many different subtypes, additional testing may be needed on the biopsy, called immunohistochemistry. These are a group of special stains that help identify what kind of tissue the cancer originates from. Based on the biopsy and the imaging, the best possible treatment for your cancer is determined.
How do you treat it?
Most of these tumours are best treated with surgery initially, however this can only be confirmed after the biopsy results. The goal of surgery is to completely remove the cancer with a rim of uninvolved tissue (known as a ‘margin’). As this is a delicate and confined space achieving margins may be difficult. Some tumours are suitable for an endoscopic approach – here the tumour is removed through endoscopes placed in the nose, avoiding a facial incision altogether. If the neck nodes are involved these also need to be removed. If the tumour involves the meninges (fibrous coverings of the brain), reconstruction is essential to ensure that there is no leak of cerebrospinal fluid in to the nose. Most tumours require additional treatment in the form of radiotherapy or chemotherapy. When tumours cannot be removed completely with surgery, radiotherapy with or without chemotherapy is the preferred treatment option.
Is it curable?
The type of cancer is a major determinant of survival in these patients. Low-grade cancers are less aggressive and respond well to treatment. Early stage and low-grade cancers that are removed completely have a high likelihood of cure. Advanced stage cancers have a high risk of recurrence and lower chance of cure. However each patient is different; it does not mean that patients with advanced disease do not survive. To maximize chances of survival, early diagnosis and appropriate and complete treatment from qualified specialists are of vital importance.
What does the road to recovery look like?
The extent of your treatment will determine how long it takes you to recover. Surgery for an early tumour may take two weeks to recover from while a major surgery following by radiotherapy and chemotherapy may take months to completely recover from. It is important to think of your treatment as a marathon rather than a sprint, and take help from those around you, whether they are medical professionals, or friends and family. The team involved in your rehabilitation may include the speech and swallowing therapist, the dental team, the physical therapist and the pain specialists. Follow-up after treatment is crucial – this is to not only assess your recovery, but also to check for recurrence. Your treating team needs considerable expertise in these cancers to offer you the best chance of cure. Endoscopic surgery when possible avoids facial scars and quicker recovery.