Squamous Cell Carcinoma Treatment - Professional Information
There are several effective approaches to cure SCC: surgery and cryosurgery, curettage, electrodessication and radiation therapy. Each method may be more or less useful for specific clinical situations. In deciding what is best for the patient, the first goal is complete eradication of the carcinoma, and the next is preservation of form and function; the cost of treatment is a subsidiary, but not insignificant, factor. Of all treatment methods available, Mohs micrographic surgery has the highest 5-year cure rate for both primary and recurrent tumors.
This is the treatment of choice for tumors when primary closure, a simple graft or a flap can make good the defect. The palpable margin of the tumor should be outlined before any local anaesthetic is injected, and at least 3-5 mm clearance allowed beyond it. Surgical removal is quick and the wound heals in 2 weeks. The specimen provides better material for the pathologist than a biopsy or curettings. Mohs micrographic surgery has the highest cure rate of all surgical treatments. This method uses microscopic control to evaluate the extent of tumor invasion. Surgery is also the best treatment for lesions that have invaded bone or cartilage or when lymphnode metastases have developed. It is usually employed on cases that have recurred after other treatment has been given or on sclerosing tumors with ill-defined margins.
Cryosurgery is used for clinically well defined in situ tumors and in patients with medical conditions that preclude other types of surgery. Liquid nitrogen is used to either chill a cryoprobe continuously or to spray on a surface. It allows the local destruction of tissue to quite a considerable and calculable depth. The technique is simple, it requires no local anaesthetic and complications are rare. However, the successful treatment of malignant tumors requires adequate freezing of the tumor and the margin all round it, which is not always accomplished. The cytotoxic effect of freezing and thawing can be enhanced if the tumor is refrozen once or twice. Collagen, cartilage and bone are less sensitive than dermal cells to injury by freezing.
Curettage and electrodessication
Treatment by curettage and cauterization or diathermy is a quick method for destroying the tumor, but the adequacy of treatment cannot be assessed immediately since the surgeon cannot visually detect the depth of microscopic tumor invasion. These methods should be reserved for very small primary tumors.
Radiotherapy is particularly indicated for poorly differentiated squamous cell carcinoma that has not spread to bone or cartilage, nor metastasized. Its main use is in tumors of the head and neck.This treatment leaves rather fragile scars on the hand and forearm, and it may be followed by radionecrosis on the trunk. It is usually preferred by very elderly patients (who form a considerable proportion of cases). The quality of the scar following superficial X-ray therapy depends, to a considerable extent, upon the number of doses into which the total treatment dose is divided and the time taken to complete the treatment. In many centres, a total dose of 5000cGy is given in 10 doses over a period of 2 weeks. Large lesions, especially when situated on the trunk, require more protracted treatment, lasting for tip to 6 weeks. In a number of situations, especially where a curved area has to be treated, radium or radioactive cobalt applied as a surface mould gives excellent results. Interstitial radiation from radium needles, gold grain or iridium wire is a convenient and effective way of treating mobile areas, such as the lip and tongue, or curved surfaces. Electron-beam therapy can be used in areas, such as over nasal cartilage, where conventional radiation might result in radionecrosis. The planning of radiotherapy requires cooperation between the clinician and the physicist.
Carbon dioxide laser
This method may be helpful in the management of selected squamous cell carcinoma in situ. It may be considered when a bleeding diathesis is present, since bleeding is unusual when this laser is used.
Clinical trials are ongoing regarding the curative effects of intralesionally applied interferon alfa in squamous cell carcinoma. The results should be available in several years.
Treatment of lesions at special sites
The dorsum of the hand should not be treated by radiotherapy. Most tumors in this area are quite small, and curettage or excision gives good results.
The lip may be treated by any of the methods. Extensive superficial lesions are suitable for lipshave or curettage and cautery; radiotherapy of a large area leaves considerable scarring, and surgical excision calls for plastic repair. Smaller tumors may be excised by wedge excision, which is a relatively simple operation but leaves the lip shorter and thus changes the shape of the mouth. Poorly differentiated and invasive tumors of the lip should be irradiated unless they invade the mandible, when an extensive surgical removal is required.
The face can be treated by any of the methods according to the general considerations already mentioned.
Small tumors of the ear not involving the cartilage can be treated by any of the techniques. Involvement of cartilage is an indication for surgery, and lesions on the helix can be excised with a wedge of cartilage. If it is important to preserve the symmetry of the ears, a wedge from the other ear of up to 1cm in length at the helix can be used as a free graft.