Nasopharyngeal Cancer

21.03.2024

DIAGNOSIS AND TREATMENT OF NASOPHARYNX CANCER

Nasopharyngeal cancer is a type of cancer that develops in the upper part of the nasal cavity and the area at the back of the throat, called the nasopharynx. This cancer has been associated with Epstein-Barr virus (EBV) infection and is particularly common in Southeast Asia and North Africa. Nasopharyngeal cancer usually does not show obvious symptoms initially and is often diagnosed in the late stages. Therefore, early diagnosis can be difficult. Symptoms may include nasal congestion, fluid buildup in the ear, a mass or swelling in the head and neck area, hearing loss, sore throat, and sometimes bloody saliva or runny nose. Treatment usually includes radiotherapy and chemotherapy and gives more successful results in the early stages. The importance of this type of cancer is high due to its subtle initial symptoms and potentially serious consequences. Regular screening and paying attention to risk factors play an important role in early diagnosis.

WHAT ARE THE RISK FACTORS?

Numerous risk factors for nasopharyngeal cancer (nasopharyngeal carcinoma) have been identified. These risk factors include genetic, environmental and lifestyle factors. The most important risk factors are:

Epstein-Barr Virus (EBV) Infection: Infection with EBV has a strong association with the development of nasopharyngeal cancer. Although it is not fully understood how EBV causes cancer, the presence of the virus's DNA in tumor cells supports this relationship.

Ethnicity and Geographic Factors: This type of cancer is more common in Southeast Asia and North Africa. The risk is increased in people living in or coming from these regions.

Family History: A family member with nasopharyngeal cancer may increase the risk for other family members.

Gender and Age: This type of cancer is more common in men and is usually seen in middle-aged and older individuals.

Salty Foods and Nitrosamines: Nitrosamines, found in some foods such as salted fish and fermented foods, may increase the risk of nasopharyngeal cancer. Cancer is more common in regions where consumption of such foods is high.

Smoking and Alcohol Use: Smoking and excessive alcohol consumption may increase the risk of nasopharyngeal cancer, especially in EBV-infected individuals.

Occupational Exposures: Workplace exposure to certain chemicals and dusts (such as formaldehyde) may increase the risk.

Genetic Factors: Having certain genetic structures may increase the risk of nasopharyngeal cancer.

Understanding the risk factors for nasopharyngeal cancer is important for the prevention and early diagnosis of this type of cancer. Individuals at risk are advised to have regular health checks, especially if they have symptoms or a family history.

Image 1: Cancer of the nasopharynx is a type of cancer that develops in the upper part of the nasal cavity and the area behind the throat.

HOW DOES IT OCCUR?

The mechanisms of development of nasopharyngeal cancer involve a complex interaction of genetic, environmental and viral factors. One of the most important factors is infection with the Epstein-Barr Virus (EBV). EBV is a virus often found in nasopharyngeal cancer cells and can cause these cells to grow and divide abnormally. The integration of the virus into the DNA of cells and causing genetic changes plays an important role in the development of cancer. Additionally, genetic predisposition is associated with higher risk, especially in certain ethnic groups. Environmental factors, especially foods containing carcinogenic substances such as nitrosamines and cigarette smoke, may also contribute to the development of cancer. The combination of these factors leads to abnormal cell growth in the nasopharynx tissue, resulting in the development of cancer. This process involves various biological changes at the cellular level, such as DNA damage, changes in gene expression, and disruption of the cells' normal control mechanisms. Our understanding of exactly how nasopharyngeal cancer develops is constantly evolving, and a better understanding of these complex interactions will contribute to the development of more effective prevention and treatment strategies.

WHAT ARE THE SYMPTOMS?

Nasopharyngeal cancer may not cause obvious symptoms in its initial stages, or symptoms can often be confused with other more common health problems. However, some obvious findings may occur in the future. These findings may include:

Ear Problems: A feeling of congestion in the ear, hearing loss, or sometimes fluid accumulation in one ear may be observed.

Nasal Congestion or Nose Bleeding: There may be unilateral nasal congestion or abnormal nosebleeds.

Sore throat: Difficulty swallowing or sore throat may be significant, especially if these symptoms are unilateral.

Mass or Swelling in the Head and Neck Area: Swelling or masses may be seen in the lymph nodes in the neck area.

Voice Changes: Hoarseness or changes in speech may be detected.

Bloody Saliva or Phlegm: Blood may come from the mouth or nose.

Headache: Continuous or severe headaches may occur.

Vision Problems: There may be eye problems such as vision loss or double vision.

Neurological Symptoms: Neurological symptoms, such as facial numbness or signs of paralysis, may occur.

Any of these symptoms could be a sign of nasopharyngeal cancer, but they can also be caused by other more common health problems. If you have such symptoms, and especially if the symptoms persist, it is important to consult a physician. Early diagnosis can significantly increase the treatment success of nasopharyngeal cancer.

HOW IS IT DIAGNOSED?

The diagnosis of nasopharyngeal cancer is made by various clinical and laboratory tests. The first step is usually an evaluation of the patient's symptoms and medical history. A physical examination by an ear, nose, and throat (ENT) specialist helps detect abnormalities in the nasopharynx area. In this examination, endoscopic instruments are used to provide a more detailed look at the nasopharynx region. If cancer is suspected, a biopsy is performed; In this procedure, a small sample of suspicious tissue is taken and examined under a microscope. Imaging tests are also used to support the diagnosis; these include magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography (PET) scans. These tests help evaluate the size of the tumor, its spread, and whether it has spread to lymph nodes or other organs. Blood tests may also be performed to look for signs of infection with the Epstein-Barr Virus (EBV). All together, these tests allow for an accurate diagnosis of nasopharyngeal cancer.

WHAT ARE THE PATHOLOGICAL TYPES OF CANCER?

Nasopharyngeal cancer is divided into different pathological types according to their histological features. Each of these types is based on the microscopic structure and cellular characteristics of the cancer.

The main pathological types of nasopharyngeal cancer are:

Keratinizing Squamous Cell Carcinoma: This type of nasopharynx cancer consists mostly of cells that show keratinization (accumulation of keratin, a protein).

Non-Keratinizing Squamous Cell Carcinoma: This type consists of non-keratinized squamous cells and is a more common form of nasopharyngeal cancers. The non-keratinized form generally has a better prognosis and is more frequently associated with Epstein-Barr Virus (EBV) infection.

Basaloid Squamous Cell Carcinoma: This type shows squamous and basaloid cell characteristics and can follow an aggressive course.

Lymphoepithelioma Type (Undifferentiated Carcinoma):This type can also be classified as a subtype of non-keratinizing squamous cell carcinoma. It has a strong association with Epstein-Barr Virus and is usually seen in younger patients. This type is the most common type of nasopharyngeal cancer and usually responds well to radiotherapy.

Adenocarcinoma and Other Rare Types: These types constitute a small percentage of nasopharyngeal cancers and show different cellular characteristics.

Each pathological type can affect the behavior of the disease and its response to treatment. Therefore, accurate histopathological diagnosis plays an important role in determining an effective treatment plan.There are some important receptors and molecular markers that should be examined in the treatment and prognostic evaluation of nasopharynx cancer. In this type of cancer, markers related to the Epstein-Barr Virus (EBV), especially EBV DNA load and serological EBV antibodies, are important for monitoring the activity of the disease and response to treatment. Additionally, Epidermal Growth Factor Receptor (EGFR) levels on the surface of tumor cells can determine the course of the disease and response to some targeted therapies. Mutations of some tumor suppressor genes such as p53 and expression of oncogenes can provide information about the aggressiveness and prognosis of the disease. Analysis of these markers through immunohistochemical stains and molecular tests is used to better understand the biological behavior of the tumor and develop personalized treatment strategies. Especially in advanced stage nasopharyngeal cancers, the importance of this molecular profiling increases even more. However, the comprehensive list and importance of markers and receptors to be examined in nasopharyngeal cancer is constantly updated and expanded with new research.

Image 2: In the development of nasopharynx cancer, different complaints such as shortness of breath, decreased hearing and blurred vision may be observed.

HOW IS TUMOR STAGING DONE?

Tumor staging of nasopharynx cancer is a system used to determine the extent of disease spread and treatment options. This staging evaluates how far the cancer has progressed locally, whether it has spread to nearby lymph nodes, and whether it has metastasized to other parts of the body. The commonly used staging system for nasopharyngeal cancer is the TNM (Tumor, Lymph Node, Metastasis) system adopted by the Union for International Cancer Control (UICC) and the American Cancer Society (ACS). In this system:

T (Tumor): It indicates how much the tumor has grown as the main mass in the nasopharynx. It varies from T0 to T4, as the number increases, the size and spread of the tumor increases.

N (Lymph Node): It indicates spread to nearby lymph nodes. It is classified from N0 to N3. As the number increases, the degree and number of spread to lymph nodes increases.

M (Metastasis): It shows whether there is metastasis (spread) to distant organs. M0 means no metastasis; M1 indicates metastasis to distant organs.

As a result of these evaluations, nasopharyngeal cancer is divided into stages from 0 to IV:

Stage 0 (In Situ): The tumor is localized only within the nasopharynx.

Stage I: Small, localized tumor and no spread to lymph nodes.

Stage II: There is a slightly larger tumor.

Stage III: The tumor has grown larger or more lymph nodes have been affected.

Stage IV: Wide spread of the tumor; involves involvement in lymph nodes or distant metastasis.

This staging plays an important role in determining the treatment plan and prognosis of the disease. Various medical tests, such as physical examination, biopsy, magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography (PET) scans, are used for staging.

HOW IS TREATMENT DONE ACCORDING TO STAGES?

Treatment of nasopharyngeal cancer is determined by the stage of the disease and usually requires a multidisciplinary approach.

Common treatment methods according to stages:

Stage 0 (In Situ)

Surgery: Early-stage nasopharyngeal cancers are rare, but at this stage, when the cancer is localized only in the inner part of the nasopharynx, the tumor can be removed by surgical intervention.

Stage I and II (Early Stage)

Radiotherapy: The main treatment method for early-stage nasopharyngeal cancer is usually radiotherapy. Cancer cells are targeted and destroyed using high-energy rays.

Combined Treatment: In some cases, chemotherapy may be used in addition to radiotherapy, especially in cases where the tumor has spread to the lymph nodes.

Stage III and IVa (Locally Advanced Stage)

Combined Radio-Chemotherapy: In these stages, chemotherapy is usually applied together with radiotherapy. Chemotherapy can increase the effectiveness of radiotherapy and reduce the risk of spread to lymph nodes or distant organs.

Surgery: In some cases, surgery may be required to reduce the size of the tumor.

Stage IVb (Metastatic)

Systemic Chemotherapy: If there is distant metastasis, systemic chemotherapy is administered to control the cancer and relieve symptoms.

Palliative Care: At this stage, palliative care becomes important to improve the patient's quality of life and relieve symptoms.

Targeted Therapy and Immunotherapy: In some cases, drugs with molecular targets or immunotherapy may be used.

General Approach

Regular Monitoring and Support: Regular monitoring at all stages and psychological or social support should be provided when necessary.

Clinical Trials: In addition to existing treatments, some patients may choose to participate in clinical trials that test new treatment approaches.

In the treatment of nasopharynx cancer, a personalized treatment plan is created by taking into account factors such as the patient's general health condition, the characteristics of the cancer and the patient's preferences. A teamwork consisting of oncologists, radiation oncologists, surgeons and other physicians is important in determining the treatment plan.

Image 3: Surgery, radiotherapy and chemotherapy can be used in the treatment of nasopharynx cancer.

WHAT ARE THE DRUGS USED IN TREATMENT?

There are various drugs and treatment methods used in the treatment of nasopharynx cancer. These include chemotherapy, targeted therapies (smart drugs) and immunotherapies. Hormonal treatments are not a common option for nasopharyngeal cancer.

Some of these treatments are:

Chemotherapy drugs:

Cisplatin: It is the most commonly used chemotherapy drug and is often given along with radiotherapy.

Carboplatin: It is another platinum-based drug with similar effects to cisplatin.

5-Fluorouracil (5-FU): It is often used together with cisplatin.

Docetaxel: In some cases, it may be added to other chemotherapy drugs.

Gemcitabine: Can be used for advanced nasopharyngeal cancer.

Epidermal Growth Factor Receptor (EGFR) Inhibitors: EGFR can be used as a target in some nasopharynx cancers. For example, drugs such as Cetuximab target this receptor.

Immunotherapies:

PD-1/PD-L1 Inhibitors: Drugs such as Pembrolizumab and Nivolumab can increase the effectiveness of the immune system against tumor cells by targeting PD-1 or PD-L1.

General Approach

Combination Therapies: Chemotherapy, targeted therapies and immunotherapies are often used in combination with other treatment methods.

Personalized Treatment: Treatment options are personalized based on factors such as the patient's general health status, characteristics of the cancer, and genetic profiling.

These drugs and treatment methods in the treatment of nasopharyngeal cancer are used to control the disease and improve the patient's quality of life. A team effort consisting of oncologists, radiation oncologists and other healthcare professionals is important in determining the treatment plan. Additionally, because treatment options and combinations are rapidly evolving, it is important to seek medical advice for the most up-to-date information.

HOW SHOULD FOLLOW-UP BE DONE AFTER RECOVERY?

Regular follow-up after recovery from nasopharyngeal cancer is vital to detect recurrence of the disease early and manage possible side effects. Post-recovery follow-up is often customized based on the patient's medical history and the characteristics of the cancer being treated. This follow-up process usually includes regular medical examinations, every 3-4 months for the first two years after treatment, and at least once a year thereafter. During these examinations, physical examination, nasopharyngeal endoscopy and, if necessary, imaging tests (for example, MRI or PET-CT) are performed. It is also important for patients to report any new symptoms or changes in the head, neck, and ear area to their doctors. During the recovery process, patients are encouraged to maintain healthy lifestyle habits, such as a balanced diet and regular exercise, to support their overall health. Psychological and social support are also important as part of the recovery process. This comprehensive approach is designed to ensure optimal management of patients' health after treatment for nasopharyngeal cancer.