Tonsil cancer is a very common oropharyngeal malignancy.
The prevalence of tonsil cancer is rising in association with the growing incidence of human papillomavirus (HPV)-induced cancers.
Both surgical and other oncological approaches are used for tonsil cancer management.
However, medical researchers are giving an effort to discover optimal treatment regimens through ongoing research.
Etiology
Epidemiological studies stated that tonsil is the most common location of oropharyngeal cancer and comprises 23.1% of all cancer development in this anatomical site.
The overall incidence rate is cases per 100,000.
The rate of tonsil and oropharyngeal cancers is a medical concern because of the increased rate of incidence in the last forty years.
Classification
World Health Organization (WHO) has changed its approach in the head and neck tumor classification in the fourth edition to reflect the recent understanding of the disease.
Tonsil cancer is categorised under oropharyngeal cancers instead of oral cancer due to the presence of lymphoepithelial tissues present within the tonsils.
Tonsil cancers are a type of squamous cell carcinomas.
But WHO classified tonsil cancers as HPV positive and HPV negative based on two distinct morphological groups.
Sign, symptoms, and risk factors
The clinical history of tonsillar cancers is variable.
Patients may have the following symptoms:
- Sore throat.
- Unilateral nostalgia.
- The sensation of a mass in the throat.
- weight loss.
- odynophagia.
- dysphagia.
- persistent hoarseness.
In certain cases, tonsil cancer is asymptomatic at the initial phase.
However, a common sign is asymmetrical tonsils and trismus being a concerning sign of local invasion.
The rich lymphatic supply of tonsil may cause an occult lesion with enlarged cervical nodes within the jugulodigastric region and create tumors.
Some lifestyle factors increase the risk of tonsil cancer like the history of smoking, increased alcohol consumption and intravenous drug abuse, etc.
Prognosis and complication
The treatment prognosis of tonsil cancer depends upon the HPV status of the tumor.
It has been found that HPV-positive tumors showed a 5-year overall survival of 71% compared to 46% in HPV-negative disease in one study.
However, the survival rate negatively impacted smoking habits.
Presence of smoking, with death rates being significantly higher in HPV-positive smokers compared to non-smokers.
The prognosis and survival rate of tonsil cancer varies, depending upon the factors like tumor volume, nodal disease, age of the patient, comorbid status, and tumor invading lymphocytes.
Untreated tonsil cancer leads to steady growth of the malignancy and gradually invades adjoining organs.
Spreading of tonsil cancer can impact the lateral pterygoid muscle, pterygoid plates, lateral nasopharynx, skull base, and encasement around the carotid.
Invasion of the skull base and vertebral tissues due to tonsil cancer spreading can impede emerging nerves that cause Horner’s syndrome and palsies of the brachial plexus and phrenic nerve.
Encasement of the carotid artery can cause a life-threatening carotid blow-out.
It is necessary to mention that the management options of tonsil cancer can also carry significant complications.
Treatment options
Surgical Management
Surgical intervention is a usual treatment recommendation for early-stage tonsil cancer.
Transoral robotic surgery (TORS) and transoral laser microsurgery (TLM) are two widely used modern surgical methods that are usually preferable techniques.
Both of these treatments outcomes provide comparable oncological outcomes.
Transoral robotic surgery is gaining popularity because of the reduced time requires for surgery, shorter hospital stay, and improved swallowing recovery compared to conventional invasive techniques. However, persistent severe dysphagia can occur as a post-surgical complication.
Transoral laser microsurgery is a comparatively less commonly adopted technique.
In this process, the tumor is removed in several pieces, and that causes difficulty in histological examination of margins.
Regardless of the method of surgical intervention, it is recommended to eliminate both tonsils at the time of surgery due to a small rate of bilateral synchronous tonsillar cancers.
Oncological Management
Radiotherapy is also recommended for early staged tonsil cancer and provides better treatment outcomes and survival rates.
It is advised to treat contralateral nodes with bilateral radiotherapy to achieve a low rate of recurrence and improved rates of radiation toxicity.
Chemoradiotherapy is a treatment choice for the management of advanced tonsil cancer.
This treatment approach avoids the requirement for widespread surgery that carries substantial long-term morbidity.
However, chemoradiotherapy is also recommended as post-operative management.
Radiotherapy and concurrent platinum-based cisplatin chemotherapy is the most widely used regime.
The monoclonal antibody cetuximab is being used as an equally effective alternative for patients with cisplatin contraindicated conditions like renal impairment and hearing loss.
Reference:
https://www.ncbi.nlm.nih.gov/books/NBK537238/
