SERVICIOS DE ESTOMATOLOGÍA

The potential of absolute alcohol and sclerosing agents to induce necrosis when injected into malignant tumours has been recognised for some time (Spiller and M isiewicz 1987). Endoscopic injection treatment is a promising new technique for the palliation of malignant dysphagia which involves the multiple injection of small aliquots of absolute alcohol or sclerosant using a standard variceal sclerotherapy needle into protruberant tumour tissue in order to induce its necrosis and sloughing.

Compared with other endoscopic treatments, injection therapy is

inexpensive, does not require special equipment and is technically simple and could therefore be performed in most gastroenterology units. It can be applied to exophytic tumours of the whole oesophagus and gastric cardia irrespective of their circumferential extent or severity of luminal obstruction. One of the

significant problems of the technique is judging the adequacy of treatment. Unlike laser or BICAP therapy, there is no immediate visual feedback of the extent of tissue damage induced leading to over or underinjection, which may result in complications or an inadequate symptomatic response.

Three recent prospective uncontrolled studies of alcohol injection therapy for the palliation of malignant dysphagia using similar methodology and

comprising 105 patients, report consistent results (Fiorini et al 1993,

Nkwokolo et al 1994, Chung et al 1994). The initial functional success rate for squamous cell carcinomas and adenocarcinomas was 81-95% and

symptomatic improvement was noted after one to two treatments. On average, patients improved from being able to swallow liquids only prior to treatment to eating at least some solid food. More than 80% of patients developed recurrent dysphagia after a mean of 35 days and required repeat treatment. As no detailed follow-up was provided, the long-term efficacy of the technique could not be evaluated. Treatment was well tolerated, most patients reporting only mild retrosternal discomfort. N o complications

occurred in the study of Nkwokolo and colleagues (1994), whereas Chung and coworkers (1994) reported the development of oesophago-respiratory fistulae and mediastinitis in 9% of patients who were subsequently successfully managed by endoscopic intubation.

In a randomised study of NdiYAG laser and injection therapy with 3% polidocanol in 34 patients with malignant dysphagia, approximately 80% in both groups could sw allow most solids after an average of three treatments (Angelini et al 1991). Successful long-term palliation with repeated

treatments was possible in a similar proportion of patients in both groups but those treated with the laser required significantly more procedures. Both treatments were w ell tolerated. Injection treatment resulted in oesophageal perforation in 7% of patients who were successfully managed by endoscopic intubation; no complications occurred after laser therapy.

Injection therapy may also have a role as an adjuvant to other endoscopic therapies. In a pilot study, alcohol injection given in combination with Nd:YAG laser therapy, reduced the amount laser energy required to complete recanalisation by 40% without an increase in complications (Banerjee et al 1993).

2.5 Comments

For the majority of patients with cancer of the oesophagus and gastric cardia considered unsuitable for surgery, the main aim of treatment is to palliate the progressive dysphagia, improve the quality of remaining life and prevent an unpleasant death. This aim needs to be achieved with minimum morbidity and inconvenience for the patient both during and after treatment. From an ethical point of view , the quality rather than the length of survival is more important especially if the latter is achieved at the cost of disabling side- effects. However, survival may well be prolonged by purely palliative treatments because of improved nutritional intake.

The increasing number of non-surgical palliative methods used in recent years fall into two broad categories: endoscopic techniques that maintain patency of the oesophageal lumen and radiotherapy or chemotherapy that in addition to relieving obstruction have the potential to alter the natural

history of the disease. A critical assessment of their use is necessary in order to recommend the best method or combination of methods for individual

patients. The important questions to be addressed are: What are the indications for treatment? What is the initial and long-term efficacy of

treatment and what is the time-scale of the response, that is how quickly will symptoms be relieved? Can treatment be repeated if dysphagia recurs? What is the treatment related morbidity and mortality? Does treatment improve quality of life? and lastly in an era of limited health budgets. Is the treatment cost-effective? The review of the literature presented in this chapter has attempted to answer these questions, define relative indications and advantages and identify problems for the various palliative treatments in current use. For some of the better studied treatments such as endoscopic intubation, laser therapy and external beam radiotherapy answers have been provided to most of these questions, although these are often incomplete and contradictory. For newer and promising treatments such as injection therapy, expanding metal stents and brachytherapy much more information is

required in order to establish their proper clinical role. Direct comparison between studies, is difficult because of patient selection, incomplete

documentation, different treatment end-points and variable assessment and analysis of results.

What is clear is that there is no ideal single palliative therapy and that treatment must be individualised, exploiting specific advantages of various techniques in different clinical situations. Best results will probably be

achieved by combinations of treatments, especially methods of intraluminal tumour debulking and external beam radiotherapy with or without

chemotherapy which may allow prolonged palliation and perhaps survival. Which treatment or combination of treatments is best for individual patients w ill be determined by w ell designed comparative trials detailing long-term outcome. In order to establish benefits and provide clinically meaningful answers, future studies must carefully and systematically gather data on quality of palliation using a clearly defined grading system for dysphagia, quality of life, survival and cost. The work in this thesis was designed to tackle some of these challenges and provide clinically relevant answers.

Chapter 3

P a llia tiv e m anagem ent o f rectosigm oid cancer :