Laryngeal precancer: A review of the literature, commentary, and comparison with oral leukoplakia

Abstract

Laryngeal keratosis (LK) is a precancerous mucosal change with great similarity to oral leukoplakia. Its malignant transformation rate varies from 1% to 40%, with the highest rates being found in patients microscopically diagnosed as "keratosis with atypia" (KWA). Recent evidence indicates that even cases with only mild or moderate epithelial dysplasias are at increased risk for malignant transformation, with the highest rates occurring in patients with more severe dysplasia or carcinoma in situ. Approximately 81% of LK patients are men and the average age at diagnosis is 50 years, a decade younger than that for laryngeal carcinoma patients. A high proportion of LK patients are tobacco smokers (84%) and alcohol abusers (at least 35%). LK is almost always found on the true vocal cords and is usually bilateral (67%). Clinical signs of high risk include, in decreasing order of importance: erythroplakia, surface granularity, increased keratin thickness, increased size, recurrence after conservative removal, and long duration. The annual incidence of LK in the United States is 10.2 and 2.1 lesions per 100,000 males and females, respectively.

Association of laryngeal cancer with vocal cord leukoplakia and associated risk factors in 1,184 patients diagnosed in otorhinolaryngology practices in Germany

“…The proportion of male patients with vocal cord leukoplakia in the present study was 61.8%, which is at the lower end of the spectrum compared with the results of previous studies (6,25,26). In addition, the present study identified advanced age as a risk factor for the diagnosis of laryngeal carcinoma in patients with vocal cord leukoplakia.…”

“…In 1991, Bouquot and Gnepp published a review of studies on malignant transformation rates of various laryngeal precancerous lesions: Laryngeal keratosis (leukoplakia according to the authors' terminology), KWOA vs. KWA and laryngeal CIS (6). The studies revealed malignant transformation rates of 0.6-39.7% for laryngeal keratosis, 0.0-16% for KWOA, 5.6-40.0% for KWA and 3.5-90.0% for laryngeal CIS.…”

“…The association of vocal cord leukoplakia with laryngeal carcinoma has been the subject of numerous clinical studies and meta-analyses over the past decades, which have been mainly based on data from hospitals (3,6,7). The rates of carcinoma underlying leukoplakia at first diagnosis and the secondary malignant transformation rates in the later course of the disease vary widely between studies, which is due to a marked sampling or case selection bias of hospital-based studies when compared with the general population, selecting more severe cases and higher transformation rates in specialized centers (6).…”

“…The rates of carcinoma underlying leukoplakia at first diagnosis and the secondary malignant transformation rates in the later course of the disease vary widely between studies, which is due to a marked sampling or case selection bias of hospital-based studies when compared with the general population, selecting more severe cases and higher transformation rates in specialized centers (6). The only population-based study on vocal cord leukoplakia and laryngeal cancer with supposedly less biased data included a limited number of cases, only 108 over a period of 49 years (8).…”

Binary System of Grading Epithelial Dysplasia in Oral Leukoplakias

“…It has been suggested a possible correlation between clinical and histopathological features of OL [16]. Following this proposal, thin and flat OL would show hyperkeratosis, acanthosis, and occasional lymphocytes.…”