Chemotherapy for bowel cancer
The four main reasons why chemotherapy is recommended for patients with large bowel cancer are:
Chemotherapy & biological therapies for bowel cancer:
In this situation chemotherapy is given to patient after their bowel cancer has been removed with surgery as an added insurance policy to reduce the chance of it returning in another part of the body in the future (most commonly the liver).
patients benefit? Those people
with tumours with features which suggest a higher risk of relapse:-
1. Tumour found in the lymph nodes near the bowel at the time - Duke's staging C.
2. Being young - although of course very subjective
3. Tumour looks aggressive down the microscope - poorly differentiated.
4. Cancer cells are seen invading the vessels of the tumour - vascular invasion
5. The depth the tumour has grown through the bowel wall - T stage
The strongest of these risk factors is the 1st (tumour in the lymph nodes). In other words the tumour had spread from the original site by the lymphatic system to the regional nodes.
How much do patients benefit? For an individual the benefit is relatively small - there is approximately a 10% greater chance of cure with chemotherapy than without. This means that 9 out of 10 people will have no benefit from chemotherapy either because they are cured anyway or the tumour will return despite chemotherapy. As bowel cancer is so common, however, if chemotherapy is given to all patient, over the country many lives will be saved every year.
Which chemotherapy for adjuvant treatment: A number of choices are available - Weekly 5FU is the most common in the UK, the Mayo regimen is also commonly used. Capecitabine has the advantage of oral administration and has been show to be as good but better tolerated than 5FU. Recent trials have also suggested that in patients with poor risk factors may have a better outcome with Oxaliplatin and 5FU regimens but these do carry an extra risk of damage to the nerves (peripheral neuropathy). The UK NICE committee have recently recommneded 5 FU, Capecitabine and FOLFOX (Oxaliplatin 5FU) xelox in the adjuvant setting.
For bowel cancer this is usually reserved for situations where the surgeon does not feel the tumour could be safely removed at operation. Chemotherapy is given first in an attempt to shrink the tumour to make it possible to operate or alternatively receive radiotherapy.
The aim is not to cure, but to control or shrink the tumour especially if it is causing a specific symptom. The aim of this treatment is to improve the quality of life; therefore the side effects from the chemotherapy should not outweigh the benefits of shrinking the tumour.
In these latter two categories, your oncologist would require a full re-assessment of your disease after two or three cycles, to check whether chemotherapy is working effectively. If not, the chemotherapy regime could be stopped or changed.
Chemotherapy to sensitive radiotherapy
This section mainly applied to rectal tumours. These can either be removed surgically (mesorectal excision) alone or proceded by radiotherapy and/or chemotherapy. The order in which these are given is decided by the team managing the patient and depends on a wide variety of patient and tumour related factors. They broadly can be put into the following sections:-
 Early stage T1, T2 no other risk factors - surgery alone
 Early stage with risk factors - located in the anterior tumour of the rectum, located in the lower third of the rectum, T3, but the surgeon believes the final pathological margins will be complete. - 5 fractions of radiotherapy (short course) without chemotherapy.
 More advanced rectal tumours particularly with positive nodes and tumour approaching the edge of the mesorectum - surgeon concerned that complete pathological margins are in doubt - 25 fractions of radiotherapy (long course) with chemo sensitisation with 5 FU or capecitabine.
 Very advanced un-resectable rectal tumours but no metastasis - If fit enough, full course of chemotherapy and radiotherapy
 Very advanced un-resectable rectal tumours with metastasis - palliative chemotherapy
Further general information Your doctors and specialist nurses are in an ideal position to give you relevant information on your disease and treatment as they know your individual circumstances. Cancerbackup has a help line (0808 800 1234) and a prize winning video available in English, Italian, Urdu, Bengali, Gujarati & Hindi explaining Radiotherapy & Chemotherapy. Cancernet.co.uk has over 500 pages describing cancer, its management, practical tips and tool which patients, their carers and their doctors have found helpful during the cancer journey.