Nasopharyngeal cancer is a common malignant tumor of the head and neck in China. Guangdong, Guangxi, Fujian and Hainan are the high incidence areas, with incidence rates reaching 20-30/100,000 people, and the incidence is also higher in various regions of Hubei Province. In the last decade, radiation therapy techniques have been revolutionized.
Radiation therapy is the main radical treatment for nasopharyngeal carcinoma and has been applied to the treatment of nasopharyngeal carcinoma for more than 80 years. By the end of last century, 5-year overall survival after nasopharyngeal cancer treatment has reached 60%, but conventional conventional radiation therapy has brought many treatment-related complications, such as severe dry mouth, difficulty in opening mouth, and nerve and brain damage ground, while curing some patients.
In the mid to late 1990s, Intensity-modulated Radiotherapy (IMRT) was introduced at Baylory College of Medicine in Houston, Texas, enabling the planning of high-dose radiotherapy treatments. IMRT allows the shape of the radiation treatment plan to match the shape of the tumor target area, thus better protecting the normal tissues and organs surrounding the tumor. Radiation therapy is the primary treatment for nasopharyngeal carcinoma, and the rate of tumor control is closely related to the radiation dose. Due to the special anatomical location of nasopharyngeal cancer, it often grows infiltratively and adjacent to or invades important surrounding tissues and organs, such as spinal cord, brainstem, optic nerve, temporal lobe, etc., which limits the increase of dose to the target area. In addition, nasopharyngeal carcinoma tumor growth is irregular in shape, so traditional irradiation methods cannot provide satisfactory dose distribution. Intensity-modulated conformal radiation therapy (IMRT) can solve these problems by improving the conformality of the high dose area to the tumor target area, and thus patients with nasopharyngeal carcinoma are one of the largest beneficiaries of IMRT. In 2002, our hospital was the first in central China to carry out intensity-modulated radiation therapy for nasopharyngeal carcinoma, which has significantly improved the local control rate and long-term survival of nasopharyngeal carcinoma, with a 5-year local control rate of over 90% and a 5-year overall survival of 80%.
Chemotherapy is another effective means of nasopharyngeal cancer treatment, and its combination with radiation therapy can further improve the effect of nasopharyngeal cancer treatment. Currently, chemotherapy and radiotherapy are used in the form of induction chemotherapy, synchronous radiotherapy and adjuvant chemotherapy after radiotherapy. For tumors with late T-stage and adjacent to surrounding normal tissues, 2-3 cycles of induction chemotherapy can be given before radiation therapy to reduce the size of the tumor in order to better protect the normal tissues. For patients with extensive lymph node metastasis and high risk of bloodway metastasis, induction chemotherapy can reduce the risk of distant metastasis. Synchronized radiotherapy is the standard treatment for locally advanced nasopharyngeal carcinoma. Several domestic and international studies have shown that synchronized chemotherapy given during radiation therapy can significantly improve the radiosensitivity of tumor tissues and increase the efficacy of radiotherapy. After the completion of radiation therapy, most units currently recommend 4-6 cycles of adjuvant chemotherapy to reduce the incidence of distant metastases.
Molecular targeted therapy is a breakthrough and revolutionary development in tumor treatment in the 21st century and represents the direction of tumor treatment. Epidermal growth factor receptor (EGFR) is an important proto-oncogene in head and neck tumorigenesis and is overexpressed in almost 100% of head and neck tumors. The results of in vitro studies and animal experiments have shown that anti-EGFR antibodies, after binding to tumor cells, can inhibit tumor cell proliferation, promote tumor cell apoptosis, inhibit tumor cell metastasis and inhibit tumor tissue neovascularization with significant anti-tumor effects. A multicenter, prospective and randomized study conducted by the American Society for Radiation Oncology (ASTRO) found that radiation therapy combined with anti-EGFR molecular targeting therapy can significantly improve the local control rate and survival rate of patients with locally advanced squamous head and neck cancer and prolong the survival time of patients.
In conclusion, nasopharyngeal carcinoma is a curable malignant tumor, and the combination of existing therapies has greatly improved the treatment effect. With the continuous development of radiation therapy technology, the introduction of molecular targeted drugs and the progress of chemotherapy drugs, the treatment prospect of nasopharyngeal carcinoma will definitely become brighter and brighter.