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Several groups have pursued local excision as a curative procedure for early rectal cancer in order to reduce procedure related morbidity and mortality. Tumours up to 8cm from the anal verge can be removed by peranal excision but more proximal tumours usually require an open procedure such as the Kraske sacral approach.

A recent series from the Mayo clinic (Diggers 1986) reviewed 234 patients with adenocarcinoma of the rectum treated locally. One hundred and eighty eight underwent local excision and 46 were treated with other local methods (Fulguration, cryosurgery, laser and radiation). No clear difference in survival was noted in patients treated by these techniques. The average size of the tumours was 2.3cm (range 0.5-8cm). Results were excellent. Ninety three patients had in situ disease and in this group survival was no different to matched controls from the general population. One hundred and forty one had invasive cancers. Overall survival in this group was not as good as those with in-situ disease. The five year survival in those with well differentiated lesions was 70% against 50% moderately or poorly differentiated lesions. Patients with lesions smaller than 3 cm in diameter survived longer. The authors conclude that patients with in-situ cancer and those with well differentiated tumours less than 3 cm in diameter are best managed by local excision.

Similar results with 82 patients undergoing local excision were achieved by a German group (Heberer 1987). The criteria for patient selection were low grade tumour < 3cm, confined to rectal wall, with histologically free excisional margins. Twenty six patients were found not to fully meet the criteria after local resection and 20 went on to radical surgery. Five year survival of those treated only by local excision was 84% which was better than that of patients from the same unit undergoing anterior resection or A-P excision (76% of 354 and 73% of 317 respectively). Post operative complications were seen in 20-30% of patients undergoing a radical procedure and only 5% of those undergoing local excision. Post operative mortality was 7.3% for A-P resection 3.5% for anterior resection and zero for local excision. The locoregional recurrence rate was 7.1% (3 patients) for patients treated with local excision. Other groups (Gall 1983, Nothinger 1985 and Lock 1978) have achieved similar results in highly selected patients.

Heberer (1987) also published their results for cryosurgery in 268 patients over the same period of time (1973-1985). The technique was employed primarily for palliation in patients with advanced disease or at high risk for surgery. Thus the patient group is similar to those treated in most of the published Nd YAG laser studies. The technique is normally applied with local anaesthetic only. It is not safe to treat lesions above the peritoneal reflection. Results were divided according to the indication. Seventy seven percent of thirty one patients with small carcinomas showed a complete response to treatment. In 217 patients with advanced disease with or without métastasés colostomy was still required in 20% which is considerably higher than that seen using laser. Bleeding was controlled in 2/3 of the patients in this group but perineal pain only responded in 50%. There were 3 deaths in this series from perforation sustained during treatment.

2.2.3 C om m ents

In the radiotherapy studies the average age of patients treated (particularly the early ones) was lower than in laser trials and there was often a significant proportion of early lesions or anastomotic recurrences which are likely to be smaller and respond better to treatment. Some of the studies using local techniques have specifically selected cases with early lesions in whom "cure" is aimed at (particularly the electrocoagulation and local excision studies). In general however, patients referred for laser treatment are a particularly poor prognosis group in whom other approaches have either failed or been rejected. Patients who survive for long periods in all these studies are almost exclusively those with small tumours treated aggressively with the modality concerned. It is likely that such patients include the group with early tumours in whom tumour eradication can be achieved with laser with far lower risk of serious treatment complications. It is however likely that radical external beam radiotherapy can achieve 'cure' in some patients with disease too extensive to be eradicated with laser using present technology.

Open surgery remains the treatment of choice for rectosigmoid cancer in most patients. For elderly patients with extensive local disease in whom curative surgery is not possible palliative surgery carries a very high risk and a minimally invasive treatment is appropriate. In those with distant métastasés or concurrent medical conditions precluding open surgery, a minimally invasive approach is also appropriate. We have cited considerable published evidence to support the use of Nd YAG laser in these groups as a treatment which provides valuable cost effective palliation with very low morbidity and negligible mortality. It is likely that a combination of a local treatment such as Nd YAG laser with external beam radiotherapy for selected patients with advanced rectal cancer may offer superior palliation than either treatment alone and studies exploring such an approach are appropriate.

We have also cited considerable evidence that early cancers can potentially be cured by any of these techniques. The challenge is to be sure that there is no tumour involvement beyond the rectal wall. Most surgeons would advise open surgery for such lesions and this is probably the correct approach providing the individual is fit for and agrees to such an operation. Clearly if a patient is not fit for open surgery or refuses such treatment any of the minimally invasive methods discussed may be appropriate. The excellent results achieved in large numbers of patients with small lesions treated with electrocoagulation required regular systematic follow up. Such an approach is essential if any of these techniques are to be used with disease eradication in mind.

CHAPTER 3

COMBINED LASER AND EXTERNAL BEAM RADIOTHERAPY FOR PALLIATION OF MALIGNANT DYSPHAGIA : A PILOT STUDY