KANSER TEKAK

Kanser tekak lebih tepat dikenali sebagai kanser laring (larynx) dari segi istilah perubatan. Anatomi laring melibatkan kawasan peti suara yang juga berdekatan saluran pemakanan iaitu esofagus (esophagus).
Di dalam kajian National Cancer Registry tahun 2006 terdapat 1.1 kes per 100,000 populasi di Malaysia di mana kaum lelaki mencatatkan kekerapan lebih 5 kali ganda berbanding kaum wanita. Ia juga menunjukkan peningkatan kes bagi pesakit yang berumur 40 tahun ke atas dengan yang tertinggi di kalangan pesakit yang berumur 60-69 tahun.

Kawasan tekak (larynx) melibatkan khususnya organ peti suara (glottis), supraglottis dan subglottis

Gejala kanser tekak seringkali timbul sebagai perubahan suara, suara garau atau masalah menelan makanan dan minuman. Pesakit juga kadangkala berasa seperti ada 'sesuatu yang sangkut' di bahagian tekak. Perubahan suara kerapkali merupakan gejala sakit tekak biasa yang disebabkan oleh jangkitan kuman. Akan tetapi sekiranya perubahan suara itu berlarutan lebih dari 2 minggu, pesakit seharusnya mendapatkan pemeriksaan tekak yang lebih terperinci.

Gejala-gejala lain yang berkaitan kanser tekak adalah bengkak pada leher yang disebabkan oleh kelenjar limpa, batuk berdarah, sesak pernafasan atau pernafasan berbunyi terutamanya di kalangan mereka yang merokok.

PEMERIKSAAN KLINIKAL

Pesakit yang mempunyai gejala- gejala tersebut perlu diperiksa dengan lebih lanjut menggunakan peralatan endoskopi semasa sesi rawatan di dalam klinik pakar. Sekiranya pemeriksaan endoskopi menunjukkan ketumbuhan di kawasan tekak pesakit perlu menjalani pemeriksaan selanjutnya.

Ketumbuhan pada tekak boleh disebabkan oleh pelbagai penyakit seperti tuberkulosis (batuk kering), polip, granuloma selain dari kanser. Untuk mengenalpasti punca sebenar sedikit tisu perlu diambil dari ketumbuhan tersebut. Kerapkali ini melibatkan pembedahan kecil.

Pesakit juga perlu menjalani pemeriksaan CT scan (computed tomography) untuk mengetahui sejauh mana kanser tersebut telah merebak.

RISIKO KANSER TEKAK

Terdapat beberapa faktor yang merupakan risiko tinggi untuk kanser tekak:
Faktor umur- Risiko meningkat semakin pesakit berumur
Alkohol- Tabiat pengambilan alkohol atau minuman keras merupakan faktor risiko yang tinggi terutamanya jika pesakit juga mengamalkan tabiat merokok
Merokok- Perokok tegar yang bertahun-tahun lamanya mempunyai risiko yang amat tinggi
Pesakit kanser tekak di kalangan ahli keluarga terdekat terutamanya ibubapa atau adik-beradik
Human papillomavirus- Jangkitan virus ini juga meningkatkan risiko kanser tekak
Faktor lain seperti Asid reflux, pencemaran Bahan kimia, Diet yang kurang sihat

RAWATAN KANSER TEKAK

Pelan rawatan penyakit kanser perlu pertimbangan antara pesakit dan doktor pakar bedah bersama pakar onkologi. Rawatan kanser tekak yang disyorkan oleh doktor pakar bergantung kepada tahap kanser tersebut.

Sekiranya tahap penyakit kanser tekak masih di peringkat awal rawatan secara pembedahan atau radioterapi perlu dijalankan. Ketumbuhan kanser yang lebih besar terutamanya yang melibatkan kelenjar limpa perlu kedua-dua pembedahan dan radioterapi. Kadangkala kemoterapi juga diperlukan bagi tahap kanser tekak yang lebih lanjut. Pelan rawatan penyakit kanser adalah khusus bagi setiap pesakit setelah mengambil kira tahap kanser, keadaan kesihatan pesakit dan jenis sel kanser.

PERINGATAN
Peringatan yang paling penting ialah pesakit harus cepat mendapatkan pemeriksaan lanjutan sekiranya mengalami gejala-gejala di atas. Kerana pemeriksaan awal dapat mengesan ketumbuhan pada peringkat awal. Sekiranya kanser tersebut dapat dikenalpasti pada peringkat awal, sudah tentu rawatannya kurang rumit dan peratusan kebarangkalian sembuh adalah amat tinggi.

NASOPHARYNGEAL CARCINOMA

Nasopharyngeal carcinoma (NPC) is a tumour of the nasopharynx which is situated at the deep end of the nose. It has the highest incidence amongst the Chinese of Southeastern region and Hong Kong.  It is one of the top 5 cancers affecting both male and female in Malaysia apart from breast, colorectal (bowel), lung and cervical cancer. The Malaysian National Cancer Registry in 2006 noted an incidence of 7.5 per 100,000 for males and 2.4 per 100,000 for females. Chinese men had the highest incidence rate of 15.9 per 100,000. The age specific incidence increased after 30 years old. 

The nasopharynx is situated at the deep end of the nose which makes it a blind spot to normal clinical examination. Tumors or the nasopharynx also often present late because of this anatomical position.

This disease has a multifactorial origin and is a result of interplay between genetic susceptibility, environmental factors and Epstein Barr virus. There is evidence to suggest that abnormalities in specific chromosomes may play a role in the pathogenesis. Cultural factors linked to NPC which have been observed include consumption of dried salted fish in childhood.

CLINICAL FEATURES

The symptoms of NPC are usually non obvious and only apparent when the tumor has spread, due to the anatomical location of the nasopharynx. More commonly patients present with neck swelling in 50-70% of cases followed by unilateral ear block or tinnitus and nasal obstruction. Other less common symptoms include blood stained nasal discharge or saliva and headache. Advanced disease may present with cranial nerve palsies, altered conscious level or distant tumour spread.

DIAGNOSIS

The diagnosis of NPC requires visualization of the nasopharynx region using nasal endoscopy. This endoscopic facility is readily available as an outpatient procedure in ENT clinics. The neck is also palpated to assess for enlarged lymph nodes. Patients with neck swelling and unilateral ear symptoms coupled with high risk ethnicity should always be examined with nasal endoscopy. Endoscopic examination findings in NPC would show as a growth/mass, swelling or obliteration of the Fossa of Rosenmuller. The diagnosis of NPC is confirmed by biopsy and examination of the tissue in the histopathological laboratory. In rare instances, nasal endoscopy may be normal. In these highly suspicious cases the ENT surgeon may suggest examination under general anaesthesia with deep multiple biopsies.

TUMOR STAGING

When diagnosis is confirmed, the tumour is then staged by imaging studies. The rationale for tumour staging is to give a true picture of the tumour extension and its related prognosis. Imaging studies include computed tomography (CT) scan of the head and neck area, chest radiograph, abdominal ultrasound and bone scan.

TREATMENT

The mainstay of treatment for NPC is radiotherapy with without concurrent chemotherapy.  Early small tumours will do well with radiotherapy alone. Often the radiotherapy is combined with chemotherapy. The oncologist will devise the treatment plan after discussing with the patient.

Nowadays advanced forms of radiotherapy such as intensity modulated radiation therapy (IMRT) can better target the tumour volume thus reducing radiation exposure to normal tissues. The side effects that patients may experience with radiotherapy include skin pigmentation and desquamation, oral ulcers and dryness, tiredness, restricted mouth movements, taste disturbance and hearing changes. These side effects would gradually occur during the course of the treatment and will slowly get better. However some of the side effects such as dry mouth and hearing changes are long term.

FOLLOW UP AFTER TREATMENT

After completing the treatment for NPC, the patient is reassessed to ensure good response to the treatment given. Patient is again reviewed by medical history, physical examination along with nasal endoscopy and imaging studies are performed to make sure that the tumour has been eradicated. These clinic reviews are also important to assess for tumour recurrence (return of the tumour), metastasis (distant spread of the disease) and any ongoing problems that the patient may have following treatment. The follow up consultation may be frequent, 3-4 monthly, in the first 2 years and then becomes a 6-12 monthly visit after that.

Useful links

National Cancer Society Malaysia 

National Cancer Registry 2006