Laryngeal cancer is a malignant tumor that can affect vocal cords and adjacent structures. 99% of cancers of the larynx originate in the mucosa. The etiology of laryngeal cancer is unknown although several factors have been clearly and clearly identified: tobacco and alcohol .
In the upper airway, tobacco acts as a carcinogenic substance and, by itself, is capable of inducing the transformation of the normal mucosa into cancer. In fact, laryngeal cancers occur almost exclusively in smokers , and are exceptional in non-smokers. The risk of developing cancer in smokers is 60% - 160% higher compared to non-smokers.
Although alcohol is not carcinogenic per se, the effect of both is synergistic, facilitating the action of tobacco , especially in cancers of supraglottis (above the vocal cords). There is also some genetic predisposition and viral infections (herpes simplex virus, human papilloma virus).
On the other hand, consumption of fruits , vegetables and foods containing carotene could reduce the risk. Gastroesophageal reflux and chronic vocal trauma are hypotheses proposed in a classical way, but there is no convincing evidence of their responsibility for oncogenesis.
Frequency of laryngeal cancer
The incidence of laryngeal cancer ranges in Central Europe between 9 and 10 new occurrences per 100,000 inhabitants. In Spain, this incidence varies according to provinces or regions, ranging from 15 to 25 new cases per year per 100,000 inhabitants. Specifically between 1997 and 2005, it is estimated that in our country the annual incidence of laryngeal cancer was 4,557 new cases. As can be deduced, Spain is among the countries with a higher rate of laryngeal cancer. The average age at presentation is 60 years , with an interval from the fourth to the eighth decade of life. For every eight to nine men a woman is affected, although in other countries, such as the United States, that ratio is four to one.
Symptoms of laryngeal cancer
Dysphonia typically appears in a larval form, progressively worsening. Fortunately, voice change allows early diagnosis. The involvement of supraglottis (false bands or epiglottis) may occur with a clinic of swallowing and / or voice alteration depending on the exact location of the tumor. Swallowing discomfort, such as pain , feeling of foreign body when swallowing or continued clearing are usually mild at first. Although the vocal cords are not affected at first, the occupation of the space above them can produce a more nasal voice. Persistent irritative cough or cough with bloody sputum , as well as more severe swallowing and breathing disorders, difficulty feeding and consequent weight loss may occur later. Occasionally, pain may be referred to the ear on the same side.
The palpation of the neck allows to evaluate the presence in the thyroid cartilage of some deformation or painful point, together with the presence (or not) of lymph nodes in the neck. The most commonly used radiological analysis in laryngeal cancer is computed tomography (CT), which allows the delimitation of the size and extension, as well as the depth of growth. Nuclear magnetic resonance imaging (MRI) is used as an additional method of investigation, in cases in which there is an early extralaringous growth or to evaluate the cartilage. Cartilage in general is very resistant to tumor invasion due to its low vascularization.
The use of positron emission tomography (PET) is still very limited but many studies have already highlighted its great sensitivity and specificity for the early detection of ganglion metastasis. Another of its main indications is the early detection of relapses after radio and / or chemotherapy treatment, better than classic imaging techniques. Ultrasound or ultrasound are safe and allow to delimit lymph nodes in the neck with high precision.
The so - called lymph node aspiration in the neck, under ultrasound control, consisting of puncturing the ganglion and aspirating cells that can then be analyzed under the microscope, allows to fine-tune if it is metastatic nodes in the neck. This scan is especially indicated in lymph nodes of uncertain origin, for example when no primary tumor is observed but there is a suspicion that the lymph node is a metastasis.