By April Cheong

Helping cancer patients hear again

More than half of the people who undergo radiation for nose cancer lose their hearing to some degree.

One in 20 become deaf or almost deaf.

However, doctors at the Singapore General Hospital (SGH) recently found that these nose cancer patients who become deaf can regain their hearing after cochlear implants, something not previously studied and not usually done.

While such ear implants are not uncommon among children and adults who have hearing problems, there has been little research on using them on people whose hearing have been affected by cancer radiation treatment.

Nose cancer - or nasopharyngeal cancer - is not so common in the West and little work has been done in this area, said Associate Professor Low Wong-Kein, the director of the centre for hearing and ear implants at SGH.

However, in Singapore, there are 300 to 400 new nose cancer cases every year and it is the sixth most common cancer for men.

Radiation - the main form of treatment for nose cancer - can lead to some form of hearing loss years down the road in 55 per cent of the patients, said Prof Low.

The hearing loss becomes serious for one in 20.

While radiation to the head region kills the cancer cells, it may also damage other healthy tissue in the area, such as the cochlea.

Yet, very few here turn to cochlear implants to regain their hearing. SGH - with the biggest hearing implant centre here - has done about 10 cochlear implants for such patients over the last few years.

Other ear, nose and throat (ENT) doctors that Mind Your Body spoke to had either not come across such patients or had only heard of isolated cases.

Said Associate Professor Lynne Lim, an ENT senior consultant at the National University Hospital: "Many patients do not come forward readily to seek treatment for hearing rehabilitation as they tend to be grateful for their cancers being cured post-radiation and accept a reduced quality of life.

"Some fear that the cancers may recur, so hearing loss may not be one of their main concerns."

Prof Lim herself has not implanted the device in such patients before. For the cochlear implant to work, the hearing nerve of the patient has to be undamaged.

Prof Low said that radiotherapy is known to potentially damage the hearing nerve, so doubt has always existed as to whether a cochlear implant is feasible in such patients.

However, the recent findings by the SGH doctors have shown that such patients may be suitable candidates for the implants after all.

Observations and scans of the patients before and after their cancer treatment have indicated that their hearing nerves were largely undamaged post-radiation.

It was mainly the cochlea, which forms part of the inner ear, that was affected.

Even if the cochlear cells in these patients continue to deteriorate years on, it would make no difference because the device bypasses the cochlear region to transmit sounds directly to the nerve, said Prof Low.

However, there are other considerations when it comes to this group of patients.

After cancer treatment, they may have middle ear, pituitary gland or sinus problems. Their tissue will also be more susceptible to infection, said Prof Low.

So they will have to undergo a series of scans and tests to check if they are suitable for the implant, which costs $40,000.

Prof Lim said that the implants do not increase the chance of recurrence of cancer and improving hearing will significantly improve the patient's quality of life and social and work options.

aprilc@sph.com.sg

This article was first published in Mind Your Body, The Straits Times.