Introduction:
Nasopharyngeal cancer is rare among head and neck cancers. It develops due to the abnormal multiplication and accumulation of abnormal cells that line the nasopharynx. It was first described in the year 1921. It accounts for one-third of all nasopharyngeal carcinomas occurring in childhood. It is commonly found in the Chinese and Tunisian populations. It is also common in Southeast Asia, the Mediterranean basin, and Alaska. It is rare in childhood. It is commonly found between the ages of 15 and 19.
What Is Nasopharynx?
It is the backward continuation of the nose which opens on either side into the ears. It is located in the upper part of the throat. It is part of the pharynx that acts like a connection between the windpipe and lungs that allows the man to breathe. It is 2 to 3 centimeters wide and 3 to 4 centimeters long.
What Is Nasopharyngeal Carcinoma?
It is the most common cancer developing in the nasopharynx and rare among all head and neck cancers. It is different from other cancers occurring in the head and neck region, attributing to its signs and symptoms, and causes, and also displays a distinguishing difference in treatment required. The clinical features of this cancer differ according to geographical location. Nasopharyngeal carcinoma develops due to abnormal proliferation of cells that line the nasopharynx. It is found in two age groups, one in early childhood and the other in the elderly. Males are more likely to develop this cancer when compared to females.
What Is the Cause for Nasopharyngeal Carcinoma?
The cause of the nasopharyngeal carcinoma is yet to be determined. It occurs due to multiple factors.
They are:
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Viral Causes: Epstein-Barr virus is considered a causative agent for nasopharyngeal carcinoma. It is one of the most common viruses. This virus can affect the cells that line the nasopharynx, capable enough to develop cancer. EBV spreads very fast, and it is present worldwide.
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Genetic Susceptibility: Individuals with immediate relatives with this cancer and cytogenetic abnormalities are identified as causative agents for this cancer.
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Environmental Factors: Geographical location, bimodal age distribution (early childhood and elderly age groups), and preserved food also play a role in causing this cancer.
Also, few studies are underway if chronic sinusitis can cause nasopharyngeal cancer.
What Are the Signs and Symptoms of Nasopharyngeal Carcinoma?
Nasopharyngeal carcinoma is difficult to identify as its signs and symptoms are similar to other conditions too. It cannot be detected till it reaches the regional lymph nodes. Most of the time, the patient can be without any symptoms till the cancer has reached its advanced stage.
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Congestion (Nose Block): It is due to the growing tumor mass in the nasopharynx.
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Nasal Discharge: Infections cause a runny nose due to mucus formation.
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Bleeding: Growing tumors damage adjacent tissues leading to a bleeding nose.
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Trismus: It is also called lockjaw. When there is spam in the jaw muscles, it will be difficult to open the mouth.
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Otitis Media: It is an infection of the middle ear.
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Tinnitus: It is the ringing sound in one or both ears. This sound is not there; others cannot hear the sound except for the affected individual.
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Headache: If there is a headache, it could be due to intracranial tumor invasion.
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Hearing Problems: There are hearing problems like ringing ears (tinnitus) or issues in hearing soft-pitched or high-pitched sounds.
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Hoarseness of Voice: A voice that sounds to be very strained and of very less volume.
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Paresis: It is a muscular weakness leading to impaired movements. Ears and mouth are commonly affected.
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Neck Swelling: A lump on the back of the neck causes neck swelling. These lumps are not painful but can be in advanced stages where cancer has already spread to regional lymph nodes. Swelling of the lymph nodes may be the initial presentation of cancer.
How Can Nasopharyngeal Carcinoma Be Diagnosed?
After checking for the signs and symptoms, if the doctor doubts the presence of nasopharyngeal cancer, further tests shall be conducted, that includes blood tests and imaging studies.
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Blood Tests: Blood tests checks for liver enzymes, complete blood count, and uric acid levels.
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Epstein-Barr Virus Titres: These titers may explain the tumor burden that helps in understanding the infection.
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Biopsy: In order to study the tumor mass, a small amount of tissue is collected from the tumor with the help of a needle. This procedure is performed under anesthesia. The sample is then sent to the laboratory for investigation.
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Nasendoscopy: A thin, flexible tube that has a camera is inserted into the nose and passed down into the throat to look for any abnormalities. To avoid discomfort, the doctor may perform this procedure under anesthesia.
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Panendoscopy: In this series of rigid tubes are sent into the throat via the nose under anesthesia.
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Imaging Studies: Scans like magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography (PET) are performed to locate and estimate the size of tumors. These studies also help to determine if the cancer is spread to adjacent areas.
What Is the Treatment for Nasopharyngeal Carcinoma?
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Chemotherapy: It uses drugs to treat cancer. But it is used along with radiotherapy. Drugs like Cisplatin and 5-Fluorouracil are used along with radiotherapy for better results. Similarly, Cisplatin and Gemcitabine, when given along with radiotherapy, gave good results in advanced nasopharyngeal carcinoma.
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Radiotherapy: It is the most common choice of treatment for nasopharyngeal cancers. Radiotherapy alone can treat early-stage cancers. A combination of chemotherapy and radiotherapy is generally prescribed for advanced-stage cancers. In advanced cancers, intensity-modulated radiation therapy (IMRT) is performed. IMRT, along with platinum-based chemotherapy, stands as a backbone of treatment for advanced nasopharyngeal carcinomas.
Recently, there were studies conducted to bring out a better treatment modality that would give a favorable prognosis. It was proved that induction chemotherapy followed by concurrent chemotherapy significantly controlled the disease, thereby increasing the survival rate.
Induction Chemotherapy (IC): Several studies were conducted recently, displaying promising results in treating nasopharyngeal carcinoma. It improved the quality of life of the patient, was cost-effective, and also showed a favorable prognosis. Initially, there were eight regimens in induction chemotherapy with concurrent chemoradiotherapy (CCRT). They are as follows:
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Docetaxel + Cisplatin (DC).
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Cisplatin + Epirubicin + Paclitaxel (PET).
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Gemcitabine + Carboplatin + Paclitaxel (GCP).
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Docetaxel + Cisplatin + Fluorouracil (TPF).
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Mitomycin + Epirubicin + Cisplatin + Fluorouracil + Leucovorin (MEPFL).
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Cisplatin + Fluorouracil (PF).
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Cisplatin + Capecitabine (PX).
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Gemcitabine + Cisplatin (GP).
Of these eight regimens of induction chemotherapy, the most appropriate one is yet to be identified, though it gave a better chance to patients than earlier, good quality of life. DC, GP, and PX have shown promising results during studies on the overall survival rate. These three regimens, however, showed positive results in the disease-free and overall survival rate of cancer. One of the studies also proved that the gap between induction chemotherapy and radiotherapy should not be more than 30 days. Patients treated with induction chemotherapy had rapid clearance for EBV from the body. Depending on the recurrence risk and treatment-related toxicologies, a careful clinical judgment has to be made. At last, it has been proved that the most effective induction chemotherapy regimens are DC, GP, and PX.
Conclusion:
Nasopharyngeal carcinoma cannot be prevented totally. Studies are still being conducted to obtain a favorable prognosis. The outcome depends on the stage of cancer, age, and other health factors of the patient. About 50 people out of 100 can survive for five years after the diagnosis. Radiotherapy can be used as the first line of treatment if the cancer is detected in its early stages. But a combination of chemotherapy and radiotherapy in advanced cancers showed much better disease outcomes. For now, induction chemotherapy can be assumed as the most effective treatment for nasopharyngeal carcinoma.