Laryngeal Cancer/Larynx (Voice box) Cancer

It is a cancer of the voice box or larynx. It usually occurs at the vocal cords or it may be above the vocal cords.

Cancer of the larynx, also known as laryngeal cancer is a common head and neck cancer in Singapore. It usually affects males who are smokers. Divided into three areas, the larynx comprises the glottis, supraglottis and subglottis. In Singapore, the two most common sites of laryngeal cancer are the supraglottis and glottis.

Laryngeal Cancer/Larynx (Voice box) Cancer is commonly associated with with smoking and alcohol consumption.

Often the patient complains of a change in the voice, throat pain or hoarseness. This is especially so if the lesion arises from the glottis. The hoarseness is persistent and will increase in severity. Occasionally, the patient is able to ignore the change in voice, which presents itself only during breathlessness.

Throat pain, or referred otalgia (pain originating outside the ear) is not a common symptom.

Dysphonia may occur.

The patient may have difficulty breathing if the larynx cancer is too big.

An examination of the larynx will reveal the lesion and diagnosis is confirmed by biopsy. This is performed under general anaesthesia. Staging of the cancer is performed by examining the tumour extent during biopsy as well as by imaging.

Most glottic tumours are discovered in the early stage of the disease because even the smaller tumours arising from the vocal cords will cause a change in voice quality. In comparison, supraglottic cancers are usually more advanced.

Treatment depends on the site as well as the stage of disease. It may be treated by radiation or surgery if early. Surgery can be performed by laser operation.

In advanced cancer of the voice-box, treatment is by chemotherapy and radiation.

However, some patients present with lymph node enlargement in the neck. These patients will have neck lumps. Good results can be obtained from both minimally invasive surgery to preserve voice or by radiation. Similarly, good results can be obtained for advanced tumours by surgery combined with radiation and/or chemotherapy.

Traditionally, treatment of these tumours is by radiation, with or without chemotherapy. The goal is to cure and preserve organ function, namely that of speech and swallowing.

Radiation has clearly been an effective treatment option for early cancers of the larynx. The 5-year survival rates for early cancers (Stage I and II) are in the range of above 80 percent when radiation is used. The voice quality remains good and swallowing is not significantly affected.

The side-effects of radiation vary, but often patients are disturbed by the dryness of mouth as well as ulcers, causing pain when swallowing food and fluids. With more recent techniques, such as intensity-modulated radiation therapy (IMRT), these side effects are reduced. Recurrences in these patients are usually treated by surgery rather than a second course of radiation.

Trans-oral laser resection of laryngeal cancers can also be used to treat newly diagnosed patients. As the laryngeal tumour is accessed and visualised via a laryngoscope, there is no external incision. It is excised using a carbon dioxide laser.

This modality is especially useful for small lesions on the vocal cords. Patients normally do not have to stay in the hospital more than two days. While the voice is poor initially, it recovers quickly and is largely intelligible. Swallowing can commence on the first day after operation. A tracheostomy, a surgical procedure to open a direct airway to the windpipe through an incision on the neck is not necessary in these patients.

The cure rate is similar to that attained by radiation and patients can return to work after two or three weeks.

Not every patient with early laryngeal cancer is suitable to undergo trans-oral laser resection. For patients who have a very anterior larynx, accessing and visualising the lesion may be extremely difficult. Tumours extended outside the larynx are not suitable for laser resection. As voice quality is dependent on the amount of tissue removed, this is expected to be poorer in patients with a larger volume of the disease.