| Ch 7 | Page 4 / 12 | |
| Cancer surgery |
Diagnostic surgery | |
The biopsy technique varies according to the organ concerned and the type of cancer. Several quality criteria should be respected.
The biopsy
- uses an instrument which does not cause any crush nor coagulation of the sampled tissue (cold lancet, biopsy forceps),
- should be pertinent and should represent the whole tumour,
- suould avoid haemorrhaging, necrotic or infected zones,
- should concern junction zones between healthy tissue and tumour (for instance the implantation foot of polyp tumours),
- Should avoid any bleeding or abscess which would slow down further treatment,
- Should provide sufficient tissue to allow a good quality histological study,
- Should allow the study of other biological criteria necessary for a quality classification:
(tumour differentiation,
histological grading,
importance of vascularisation,
importance of stromal reaction,
presence of lymph or venous emboli,
research of hormone receptors by immunochemistry,
research of growth factor receptors by immunochemistry,
research of oncogenes by in situ hybridisation,
ploidy study by flow cytometry).
If the histological response is uncertain, we should not hesitate to repeat the biopsy in order not to reject the hypothesis of cancer or, on the contrary, to propose mutilating surgery without formal proof of malignancy.
If the biopsy is to be followed by excision, the surgical approach should be direct in order to allow the performance of the excision without any risk of healthy tissue contamination by cancer cells.
A node biopsy with complete removal of the node is necessary for the diagnosis of lymphoma in order to study node morphology. When dealing with node metastases (from another primitive tumour), partial sampling may be sufficient (for instance Tru-cut forceps biopsy), particularly if the node is fixed to neighbouring tissue (the excision could become traumatic).
Its popularity is currently on the increase; a great number of excisions are now performed using an endoscopic approach. However, one should consider that safe cancer surgery should consist of a complete excision, with healthy limits and no tumour spreading due to tumour manipulation. Such precautions are not always easy to take during laparoscopy.
Laparoscopic colon surgery is a technique whereby the colon can be removed using several small incisions. The use of smaller incisions leads to less pain after surgery, less time in the hospital, and a quicker return to work and full activity. However, this specialized procedure cannot be performed on all patients who need colon surgery.
Laparoscopy is also often performed for inventory surgery (such as second look laparotomy or laparoscopy in ovarian carcinoma).
Some surgeons fear the constitution of tumour implants on the various sites in contact with the trocars necessary for laparoscopic surgery: a carbon dioxide overpressure is instituted inside the abdomen which might favour tumour dissemination towards less resistant zones such as trocar holes.
An extra-peritoneal laparoscopy can be performed for laparoscopic radical prostatectomy. The urologist makes several small incisions (around 1cm long) in the patient’s abdomen. A laparoscope – a long, thin, lighted telescope – is then inserted through one of the incisions.
Tiny surgical instruments, held by robotic arms, are inserted into the other incisions. The surgeon uses the robot to control their movements. Mini-cameras on the instruments send images to video monitors. These images are larger than life, magnified many times, allowing the surgery to be extremely precise.
Its role has declined in relation to the increasing value of diagnostic techniques such as scanner, RMI or PetScan.
However, even if the tumour extension seems beyond any therapy, a diagnostic biopsy should always be performed (some non tumour pathologies can mimic cancer, at least macroscopically). If the tumour can also be treated by other therapies (such as chemotherapy for ovarian carcinoma), a voluntarist but reasonable excision should be attempted.
In contrast, a precise description of the lesions is necessary for tumour classification and to evaluate the effectiveness of new treatment (ovary, colon).
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