Treatment of primary skin cancer

Treatment of primary skin cancer is as follows:

(1) Surgical treatment: The ideal treatment method requires timely diagnosis, accurate estimation of the tumor range and invasion depth, and achieving satisfactory cosmetic and functional results while enabling the patient to return to the level of activity before treatment as soon as possible. Surgery can achieve this goal, and the greatest guarantee it provides is accurate diagnosis of the primary disease, satisfactory removal of the tumor, and the achievement of no recurrence.

If the surgical incision can be closed initially, excisional biopsy is the most ideal method, and diagnosis and treatment can be obtained at the same time. If the tumor remains at the edge after the first excision, the excision needs to be expanded to ensure complete excision of the tumor and effective treatment. The activity of the skin around the lesion determines the maximum range of lesion excision and whether the incision can be closed initially. The greater the activity of the skin around the lesion, the safer the lesion can be excised. Larger lesions often require flap transfer or free skin grafting to close the wound. In addition, patients who relapse after radiotherapy or electrocautery, or because the tumor invades the bone or cartilage, often need surgical treatment. Pathological controlled excision, also known as Mohs surgery, is used for skin cancer that recurs repeatedly or has no other effective methods. The method is to cut a thin piece of tissue at the edge of the incision with a knife during the operation for frozen section, and check for cancerous tissue under a microscope. This surgery has a high cure rate. It has been reported that 170 lesions in 148 patients were treated with this procedure, and the cure rate can reach 97.1%. Recently, there have been reports of the use of Mohs surgery combined with sentinel lymph node excision in the treatment of high-risk cutaneous squamous cell carcinoma of the metastasis, hoping to further improve the cure rate of this type of tumor.

(2) Radiotherapy: For primary skin cancer in the skin cancer area, if the tumor has not invaded the bone or cartilage and has not been treated with radiotherapy in the past, radiotherapy is often the most effective treatment method. Generally, squamous cell carcinoma is moderately sensitive to radiation, while basal cell carcinoma is sensitive to radiation and has a higher skin tolerance. Therefore, lesions occurring in exposed areas are prone to scar formation after surgical resection, which affects beauty and function. The elderly and frail people, and those with surgical contraindications (diabetes, kidney disease, heart disease, etc.) can all choose radiotherapy. However, lesions on scar tissue (burn scars), previous radiotherapy areas, poor blood supply, or tumors involving bones and cartilage, such as the scalp, fingers, nose, ears, etc., are not suitable for radiotherapy. The preferred radiation source is electron beam, followed by contact X-rays or shallow X-rays. The edge of the irradiation field should exceed the tumor by 0.5-1 cm. If the tumor boundary is unclear, the edge should be expanded by 3-4 cm. Vertical, tangential or multi-field irradiation is used according to the size of the tumor. The general tumor dose is 60-70GY/6-8 weeks, and the basal cell dose is slightly smaller. During treatment, the radiation field and dose should be adjusted according to the tumor shrinkage. If the tumor diameter is less than 1cm, X-ray contact treatment can be used, with a total of 60-70GY, 20-30GY each time, 3 days apart, for a total of 2-3 times, and care should be taken to protect the surrounding tissues.

(3) Chemosurgery: Mohs pioneered the chemosurgery technique. The method is to apply zinc oxide paste to the tumor. After the tumor is completely fixed, the fixed part is removed, frozen sections are examined, and the remaining part of the tumor is marked. Then the zinc oxide paste is repeatedly applied. This process of fixation with zinc oxide and frozen sections is repeated until the tumor is completely removed. For small primary lesions, the cure rate of chemosurgery is basically the same as that of surgical resection, radiotherapy, and electrosurgery. Chemosurgery is an ideal treatment for cases with extensive recurrence after combined surgery and radiotherapy.