This insidious disease can be hard to spot. Its early symptoms can be as nondescript as a stuffy nose, headaches and frequent ear blockage. Other symptoms include nose bleeds, blood in the saliva or a lump in the neck caused by a swollen lymph node.

Add to that the difficulty in inspecting the nasopharynx - the upper part of the throat behind the nose - and diagnosis is often delayed. Hence, the tumours are often detected late, when the disease is already quite advanced.

Cho (name changed for patient confidentiality reasons) was lucky that he was diagnosed before the cancer had spread to other parts of his body, which nasopharyngeal carcinomas are prone to do.

Therefore, he was given radiation therapy to kill the cancer cells, followed by chemotherapy to stop the disease in its tracks.

But the cancer was resilient. Cho started to suffer nose blocks and nose bleeds not long after his treatment ended. The carcinoma had returned.

An endoscopy and biopsy confirmed that a tumour was again growing in Cho's nasopharynx, smack in the middle of his head. At 2cm, the lesion was too large to be removed by either the endoscope or by a minimally invasive, robot-assisted alternative.

Against such an aggressive cancer, dramatic measures were needed, and Professor William Ignace Wei, head of Hong Kong Sanatorium and Hospital's surgical department, stepped in.

Two decades ago, Wei had pioneered a surgical technique that enabled access to the centre of the head using a 'maxillary swing approach'. Essentially, he had figured out how to open up the face, take tumours out of the nasopharynx, and put the face back together. Cho was going to need this radical surgery to save his life.

First, Wei drilled holes in the facial bone. A special plate would later be screwed to these holes to hold Cho's face together afterwards. Next, using an oscillating saw, he cut into Cho's face from the ear to the bridge of the nose, just under the eye. He then made an incision down the middle of the face and then cut towards the back of Cho's throat before slicing back towards the ear. That part of the facial bone and structure was now completely severed from the rest of the skull, and held to the head by the skin and muscle of the face.

Wei then folded back the dislodged quarter of Cho's face to reveal the nasopharynx - and the tumour. With a clear view of the lesion, Wei could completely and precisely remove the offending growth without damaging the vital carotid artery, which provides the main blood supply to the brain. The artery passes nearby on its way to the brain.

He also cut into the healthy tissue around the tumour and had it microscopically analysed immediately for cancer cells, and kept cutting until the tissue came back clear of abnormal cells.

Wei says cutting open the face is the easy part of the operation, but removing the tumour entirely without damaging the surrounding tissue and organs is often the greater challenge.

Once the cancerous tissue was removed, Wei started to put Cho's face back together. The flap of his face that had been swung open was returned into position. Mini-plates and screws were used to hold the piece of bone in place, and sutures stitched the skin back together.

For the next 10 days, Cho had to rely on intravenous feeding, then slowly started to ingest food normally as the wounds healed.

Cho later found that he could not open his mouth as wide as before. The trauma to the face and jaw muscles from the surgery restricted the range of his jaw's movement, but this minor inconvenience only meant that he had to take smaller bites of food than he used to.

Six months later, only faint lines show where the incisions on Cho's face had been, and the casual observer might not even notice. More importantly, eight years on, Cho remains cancer-free.