3 Basal Cell Carcinoma Treatment
The treatment of BCC is generally divided into two categories: surgery and non-hand Surgical therapy.
3.1 Surgical therapy
These include scraping (surgery to stop bleeding after scraping the tumor), cryopreservation (liquid nitrogen), conventional surgical resection, and Mohs microsurgery. The cure rate of traditional surgery, curettage and cryotherapy can reach 95% and above. However, the freezing method can not provide tissue histological examination; the healing time caused by freezing and scraping is longer than the surgical treatment; and the scraping method cannot provide Sufficient tissue determines whether there is residual cancer tissue at the edge of the tumor, so the scraping method is not suitable for large, recurrent, morphea BCC or mid-surface risk areas.
The main advantage of surgical resection is that the resection edge can be histologically examined to determine if the edge is cut. At present, complete resection of early surgery is still the preferred treatment for BCC. However, since BCC occurs mostly on the head and face and is exposed, it is necessary not only to eliminate tumor cells, but also to take care of cosmetic problems and avoid unnecessary effects on the appearance. The surgeon is required to combine the basic principles of tumor surgery, plastic surgery and dermatology. Take full consideration. Large-scale dissection of malignant tumors is unobjectionable, but the pathological limitations of BCC and the minimally metastatic nature of BCC should be considered. It is not possible to emphasize the expansion of the surgical area. Then, it is necessary to completely remove the tumor, avoid recurrence, and minimize the impact of surgery on the appearance. How to determine the scope of surgery has always been a concern of plastic surgeons. For superficial, nodular and pigmented BCC, it is usually considered that the lesion is more limited and less invasive. Normally, it is feasible to remove from 4 to 5 mm from the edge of the tumor. The pathological basis for resection of borders is rare in foreign countries, but it has not been reported in China. For the morphea BCC, because of its deep and wide invasion, the boundary with normal tissues is unclear, and there are many opportunities for proliferation, which does not apply to the above principles.
Advocated by Dr Fredrick Mohs in 1930, Mohs micrographic surgery (MMS) is a surgical procedure that combines dermatology techniques with special frozen tissue sections (horizontal section staining). The key is to cut and control the edge and depth of the specimen in the same plane, accurately locate the tumor infiltration through the microscope, and then re-cut if necessary. This method maximizes the protection of normal tissues while achieving a high cure rate, and creates favorable conditions for subsequent repair of the wound surface. It provides an important and reliable method for the treatment of skin cancer, especially facial skin cancer. Especially suitable for large, invasive or recurrent tumors. The cure rate of MMS for primary tumors is 99%, and the cure rate for recurrent tumors is also above 95%. After years of development, Mohs microsurgery technology has matured. Generally, recurrent cancer has an increased degree of malignancy compared with the primary cancer. The cure rate of the primary tumor is higher than that of the recurrent tumor. The freezing and scraping method is not suitable for recurrent tumors. The 5-year cure rate for the treatment of recurrent BCC by scraping is about 60%.Therefore, for recurrent, plaque-like, and dangerous sites of BCC, Mohs microsurgery should be the treatment of choice.
3.2 Non-surgical treatment including radiation therapy, photodynamic therapy, medication
3.2 .1 radiation therapy
Generally used in elderly patients, when the lesion is large and not suitable for surgery. However, it is not suitable for young patients because the subsequent plastic surgery is not as good as surgery. The 5-year cure rate is about 90%.
3.2.2 Photodynamic therapy (PDT)
Clinically, photodynamic therapy usually refers only to photodynamic therapy, and photodynamic diagnosis is called photody namic diagnosis (PDD). The so-called photodynamic reaction means that the endogenous or exogenous photosensitive substance in the biological tissue absorbs the photon energy when it is irradiated by the corresponding wavelength (visible light, near-infrared light or ultraviolet light), and changes from the ground state to the excited state. The stimulating process can produce fluorescence, and the fluorescence spectrum can be used to diagnose the disease; the chemical de-excitation process can generate a large amount of reactive oxygen species, and the reactive oxygen species can interact with various biological macromolecules to produce cytotoxicity, which leads to cell damage or even death. , thus producing a therapeutic effect. Its three main elements are: photosensitizers, light sources and oxygen in tissues. The two prerequisites for photodynamic effects that can be used for disease treatment are that specific diseased tissues can ingest and retain photosensitizers more and the target sites are more susceptible to light irradiation.
3.2.3 Medical Treatment
It was thought that the application of 1.5% fluorouracil ointment was better in treating the trunk and multiple superficial BCC in the extremities. However, topical application of fluorouracil will heal the epidermis of the skin lesions, but there will be extensive metastasis under the skin, so it can not be used as a local treatment for basal cell carcinoma. Biological modification factor: topical application of 5% imiquimod cream, can induce interferon production in vivo, thereby eradicating superficial BCC and SCC. The clearance rate for BCC is between 70% and 100%, depending on the frequency of use. The long-term recurrence rate has not been reported. The same effect was achieved by injection of recombinant α-2b interferon, with a cure rate of approximately 67% in 3 years.
BCC is the most common malignant tumor of the skin, and its incidence is on the rise globally. Risk factors for BCC include skin type, juvenile freckles, sunburn during adolescence, family history of skin cancer, immunosuppressive therapy, and arsenic intake. The occurrence of BCC is the result of the interaction of genes and environment, especially ultraviolet light, and its exact mechanism remains to be further explored. Patients with BCC have an increased risk of recurrent BCC and other malignancies. BCC treatment includes various surgical treatments, radiotherapy, photodynamic therapy, topical fluorouracil, and imiquimod. The use of the new method works well for beauty and reducing recurrence. Encourage people to reduce sun exposure and prevent BCC from happening.
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