Nasopharynx cancer

A nasopharyngeal carcinoma, also called Epipharynxkarzinom or German nasopharyngeal cancer and often NPC for engl. Nasopharyngeal Carcinoma abbreviated, is a cancer of the nasopharynx ( nasopharynx or epipharynx or nasal pharyngeal Pars ). The nasopharyngeal cancer belongs to the group of head and neck tumors.

The nasopharynx is the upper part of the sub-divided into three areas of the throat ( pharynx Greek ).

Epidemiology

Cancers in the nasopharynx occurred in Central Europe and North America quite rare. The incidence is in the range of 0.5 to 1 in 100,000. This corresponds to a share of 0.2 % of all tumors. In some countries and regions, such as Taiwan, South China, Southeast Asia and parts of North Africa, the nasopharyngeal carcinoma is endemic with an incidence of 30 per 100,000. The proportion of nasopharyngeal carcinoma in Taiwan in all cancers is about 18%. There, the nasopharyngeal cancer is now the leading cause of death in young men. One reason seems to be the consumption of betel nuts.

While in Asia are affected in much middle-aged people, children make Africa a high proportion of new patients. The causes for the increased risk of disease in these countries is not yet fully understood.

Men are affected by the disease more often than women. The ratio is about 2:1.

Etiology

Possible causes or triggers of endemic nasopharyngeal carcinoma are the Epstein -Barr virus (EBV ), various environmental factors, diet and genetic characteristics of patients.

Since positive IgA antibody titers detected against EBV - Viruskapsidantigen and elevated IgG antibodies to the EBV early antigen in 80 to 90 % of people suffering from a nasopharyngeal carcinoma patient is epidemiologically a close link between infection with EBV and the nasopharyngeal carcinoma. Epstein -Barr virus (EBV) is also in the development of other types of cancer, such as Hodgkin's disease involved, Burkitt's lymphoma, and HIV-associated lymphomas.

In the dietary habits could in Asia, the consumption of salted dried fish, the relatively high levels of carcinogenic nitrosamines has partly be identified as a risk factor.

Well-differentiated nasopharyngeal whose cells are very similar histologically considered other squamous cell carcinoma of the head and neck region, can the standard risk factors for cancer, such as nicotine (tobacco smoke ), especially in combination with high alcohol, be assigned.

Classification and histology

The nasopharyngeal cancer is a malignant neoplasm (cancer), when it is about 90% of carcinomas. They are of epithelial origin ( squamous cell carcinoma ).

In the histology of nasopharyngeal cancer are three different subtypes:

• A keratinizing well differentiated squamous cell carcinoma by the WHO type 1 ( approximately 20% of nasopharyngeal carcinomas)
• Keratinizing squamous cell carcinoma from a non- WHO type 2 ( 30-40 %)
• An undifferentiated form of the WHO type 3 ( Schmincke Schmincke Regaud - tumor or tumor called ), a lymphoepithelial carcinoma, which typically contains non-malignant lymphocytes. This type can also still occur in the tonsils and in the hypopharynx. These undifferentiated form is most common ( 40-50 %) and can be seen in close connection with a previous infection with the Epstein- Barr virus.

Rarely, malignant lymphomas, adenocarcinomas or sarcomas be found. This article is confined mainly to the undifferentiated carcinomas and squamous cell carcinomas.

Symptoms

Nasopharyngeal cancer occurs in all age groups. A significant accumulation is in the age group in the 40 - to 60 -year-olds to watch. The tumors are usually discovered only in an already advanced stage of cancer very late due to their low symptomatology. Nosebleeds, difficulty in breathing through the nose and middle ear effusion or otitis media may be among the early symptoms. The disease is frequently to VI symptomatic only by metastases in the cervical lymph nodes or paralysis of the cranial nerves III by infiltration of the skull base. For this reason, the patients are the main symptom at the time of diagnosis of enlarged cervical lymph nodes in 60 %. Regional lymph nodes metastases are often found even at very small primary tumor. Distant metastases are found more frequently than in other ENT tumors in the bone, lung or liver.

Nasopharynx carcinomas usually develop from the side walls and the roof of the nasopharynx. From them off early in the nasal cavity, the paranasal sinuses and the cranial nerves there wide. In contrast, a metastasis via the blood is relatively rare. Distant metastases are diagnosed in only 30% of patients even in advanced stages of the disease.

Diagnosis

The standard examination is endoscopy of the nasopharynx. Biopsies from the nasopharynx can be removed in this way.

To assess the extent of the primary tumor and possible regional lymph node metastases, magnetic resonance imaging ( MRI) is a imaging technique the method of choice. In cases of suspected infiltration of the skull base, a computed tomography ( CT) should be performed in special bone window. In this case, the CT is superior in the assessment of tumor extent of MRI. Fernmetastasten in bone, liver and lungs can be diagnosed by bone scan or abdominal sonography ( ultrasound).

Therapy

The nasopharynx is extremely difficult to access surgically. In addition, the nasopharyngeal carcinoma is often so far advanced at diagnosis that an operation can not be performed.

Radiotherapy

The drug of choice for treatment of nasopharyngeal carcinoma is radiotherapy. Here, the tumor with locally very high doses of a total of about 70 Gy is irradiated in multiple sessions.

In the non- keratinizing and undifferentiated subtype of nasopharyngeal carcinoma during radiotherapy responses very well, whereas this is less the case in the keratinizing subtype.

Chemotherapy

In a recent study it was demonstrated that in locally advanced tumors concomitant chemotherapy with radiation therapy yielded a significant advantage for patients. Oxaliplatin was used as a chemotherapeutic agent with a dose of 70 mg/m2 per week.

Operation

The surgical removal of the primary tumor is ( " located beneath the mucous membrane " ) because of the frequent submucosal spread and difficult accessibility of the tumor usually does not make sense. Complete resection is hardly possible with this form of cancer.

A removal of all cervical lymph nodes, called a neck dissection must be carried out only rarely.

Forecast

Cure rates are, as with all malignant neoplasms, strongly dependent on the tumor stage. In patients with tumors in stage I, they are between 70 and 80%, are in the Schmincke Regaud tumor - not least because of its high sensitivity to radiation - with early detection, over 90 % successfully treatable. Stage IV between 20 to 40%.

The five- year survival rate of patients with non- keratinizing and undifferentiated nasopharyngeal carcinoma is at an appropriate therapy about 65%. Due to the high radiosensitivity of the malignant tissue, even when the disease has already set in regional lymph nodes, there are very good chances of recovery. However, the prognosis falls in keratinizing nasopharyngeal cancer much worse, since this form is considerably more resistant to irradiation.