Treatment of head and neck cancer

What therapy options are there?

 

The patient with early larynx cancer will be recommended to receive radiotherapy. This involves the making of an immobilising cast for the neck such that there is accuracy and reproducibility of therapy each day. Then, the patient attends daily for therapy (Monday to Friday in most centres) for up to seven weeks. During therapy he feels nothing as patient cannot feel x-rays whether being shone in diagnostic amounts or therapy dosages. However, by the last week or so of therapy the patient feels sore in the area. These are general remarks for radiotherapy for all head and neck sites.

 

For larynx cancer cases, the voice becomes more hoarse and he is advised to avoid smoking throughout therapy and also avoiding shouting and other insults to the larynx. At the end of radiotherapy the larynx appears red and sore, and there may still be a residual lesion on the vocal cord (the usual site of origin of larynx cancer), but this continues to rgress after therapy has ended and the doctor can only really assess the success or failure of the radiotherapy at the one to two month assessment point. Occasional patients with large and obstructing laryngeal tumours or those which are ulcerating into the laryngeal cartilages will be recommended to receive radical surgery (the larngectomy, which is the removal of the whole larynx, leaving the patient with the trachea opening out onto the front of the neck as a tracheostomy). The patient may learn to speak through oesophageal speech or via a valved/speaking tracheostomy tube.\

 

Patients with laryngeal cancer who relapse after radiotherapy in the original primary site are also considered for ‘salvage’ laryngectomy and this operation has a finite cure rate in these relapsing patients.

 

Where the patient develops neck nodal disease, it is usually in the chain of nodes (the deep cervical chain) that extends from the skull base down to the collar bone on the same side as the primary tumour (i.e. cancer arising on the right vocal cord will first spread to the right deep cervical node chain). In this situation, the doctor recommends a ‘Block dissection’ – an operation where he whole chain of nodes is dissected out. This serves the purpose of removing the obviously affected nodes, and also the next sites, which may already be harbouring microscopic disease. This operation may therefore effect salvage cure, and is an important one in therapy of this disease.

 

For the patient with oral cancer the choice of therapy is more contentious. For early cancer of the tongue, the results of surgery and those of radiotherapy, which sometimes involves the implantation of radioisotope activated needles or pins into the tumour for several days, having the advantages of brachytherapy – very intense dosage of radiation close to the tumour and fast falling dosage as distance increases away from the tumour (see prostate brachytherapy section), are very comparable and the patient is allowed to make an informed decision with the doctors as to which to choose.

 

Where there is relapse after one therapy then the other option is available but the objective, as in cancer therapy, is to maximise first time cure rates, even if this involves using both surgery and radiation in the first instance (e.g. where surgery is chosen but the margins of the operative specimen, when viewed microscopically, are too close for comfort and it is felt prudent to add radiotherapy). For cancer of the pharynx, the operation of pharyngectomy is so huge (and the complication rate so high) that the first choice of curative therapy for these patients is radiotherapy; this is carried out broadly as outlined above and over seven to eight weeks.

 

For patients with nasopharynx cancer the choice is also that of radical (curative) radiotherapy over a similar time period. In nasopharynx cancer, the neck nodes on both sides of the neck (i.e. both deep cervical chains) are included in the radiation portals, and this is often the case in the radiotherapy courses for other head and neck sites where there is a real chance of spread of the disease outside the primary site and is de rigeur in cases presenting with N1-3 disease. If nodal disease persists after the radiotherapy (and particularly where it is still positive on PET scanning) then a block dissection is called for, providing the primary cancer itself has been controlled. There is no definitive resection operation for the primary tumour in nasopharynx cancer and so great, if not entire, reliance is with radiotherapy.

 

In recent years, it has been realised that chemotherapy has a role in the management of head and neck cancer. At first it was found that regression could be temporarily achieved in patients relapsing after definitive surgery and radiotherapy. Then it was observed that ‘up front’ (also called neoadjuvant) chemotherapy, that is chemotherapy given before surgery of radiotherapy, could downsize and thereby maybe help the subsequent surgery or radiotherapy to effect cure. This remained contentious but next it was found that for squamous cancer at various sites (e.g anal cancer) the synchronous delivery of some chemotherapy regimens and radiotherapy could achieve greater cure rates than radiotherapy alone.

 

The drugs involved are usually cis-platinum, 5-fluorouracil and mitomycin-C and they are given prior to, together with and sometimes after the radical course of radiotherapy. They sensitise the tissues to the radiation and the radiotherapist to some extent loses his control of the radiation reaction that the patient will encounter. That is, the radiotherapist usually expects the patient to start getting sore at five weeks and this to be increased by seven weeks in a controlled fashion. However, with concomitant chemotherapy with these agents he may find patients with severe side effects at unusually early time points. It is not advisable to stop the radiotherapy course to allow nature to settle these but sometimes the soreness demands this.

 

The exact place of concomitant/synchronous chemotherapy and radiotherapy (also called chemo-raadiotherapy) in head and neck cancer is not yet fully evaluated, but it is almost always used in nasopharynx cancer (excepting the most early cases) and this disease is perceived to be the most chemosensitive of all squamous head and neck cancer.

 

In other primary head and neck cancer sites it is usually introduced in the more advanced cases and either as neoadjuvant therapy or synchronous chemo-radiotherapy.Many clinical trials are ongoing and the field should be better evaluated this coming decade.