Cancers and precancers of the oral mucosa are notoriously challenging to treat and, according to one expert, a heightened vigilance spanning different specialties remains key in reducing the morbidity and mortality in patients.
New York - Cancers and precancers of the oral mucosa are notoriously challenging to treat and, according to one expert, a heightened vigilance spanning different specialties remains key in reducing the morbidity and mortality in patients.
“The early diagnosis of precancerous and cancerous lesions in the oral cavity is absolutely critical. Despite the advances in surgery, radiation and chemotherapy, these treatment approaches may only have a palliative effect in many cases and often prove to be too little, too late for a large majority of unfortunate patients,” says Marcia Ramos-e-Silva, M.D., Ph.D., associate professor and head, sector of dermatology, School of Medicine, Federal University of Rio de Janeiro.
Cancers of the oral cavity constitute 3 to 5 percent of all cancers and result in 50 percent mortality in five years, underscoring the importance for physicians to arrive at an accurate and early clinical diagnosis of suspicious lesions. In order to better understand the dynamic of oral cancers, it is paramount to diagnose premalignant conditions and premalignant lesions before they worsen, says Dr. Ramos-e-Silva, who spoke at the American Academy of Dermatology summer conference in New York.
Premalignant or precancerous lesions are morphologically altered tissue in which cancer occurs with a greater frequency than normal tissue. In the oral cavity, these include leukoplakia, erythroplakia, leukoplakia candidiasis, cutaneous horns, actinic cheilitis, compound and junctional nevi, and lentigo maligna.
In contrast, a premalignant condition is a generalized state that is significantly associated to an increased risk of cancer, including Plummer-Vinson syndrome, atrophic glossitis of tertiary syphilis, xeroderma pigmentosum (XP), lichen planus and lupus erythematosus. The latter two conditions remain controversial and a gray area, Dr. Ramos-e-Silva says, in terms of their potential to undergo malignant transformation.
Some conditions can be more serious than others in terms of their potential for malignancy, such as erythroplakia. According to Dr. Ramos-e-Silva, 91 percent of cases that are diagnosed as erythroplakia have already progressed to epithelial dysplasia, carcinoma in situ or invasive cancer.
Though still considered controversial as to whether they can undergo malignant transformation, Dr. Ramos-e-Silva says lichen planus - which can present as reticulate, linear or annular, atrophic, erosive or ulcerative, among other forms - is one common premalignant condition of which to be particularly wary. Up to 2.8 percent of all cases can turn malignant.
Similarly, up to 75 percent of patients with systemic lupus erythematosus and up to 25 percent of patients with discoid lupus erythematosus have oral lesions, Dr. Ramos-e-Silva says, and theoretically, any number of these lesions could turn malignant, further stressing the need for extreme vigilance in affected patients.
“As there is a potential for these diagnosed premalignant conditions to turn malignant, and surgery or other therapeutic modalities are often not the first choice of management, we strongly recommend that these patients be seen every six months for follow-up in order to hopefully diagnose any invasive tumor as early as possible,” Dr. Ramos-e-Silva says.
Leukoplakia is a common premalignant lesion, particularly among the elderly, and occurs in up to 5 percent of the general population. While 20 percent of cases can undergo spontaneous involution, up to 23 percent can progress to epithelial dysplasia, carcinoma in situ or invasive cancer. Therefore, Dr. Ramos-e-Silva recommends that patients with leukoplakia be treated and managed as if the lesions could turn malignant.
Regardless of the premalignant lesion or condition, the key is to initiate treatment as soon as possible, she says, which can range from local or oral corticosteroid therapy for conditions such as lichen planus, to electrocoagulation and curettage or even surgery for leukoplakia.
The most common cancer in the oral cavity by far is squamous cell carcinoma, constituting 90 percent of all malignant neoplasia of the mouth, followed by others cancers such as basal cell carcinoma (by contiguity), melanoma and distant metastases.
“The choice of treatment for oral cancer greatly varies from case to case. Particularly true for more advanced cases, anything you do will be mutilating in order to adequately remove the tumor with significant collateral damage to surrounding tissues, especially if the cancer is large,” she says. “So, the best approach is to step up our screening efforts and detect these lesions early in their development.
Physicians of different medical disciplines including dermatologists, GPs, head and neck surgeons, dentists, and ENT specialists could help by simply asking the patient of any suspicious lesion or problem they may have noticed in their mouth during a regular consultation or physical examination.
According to Dr. Ramos-e-Silva, 50 percent of lesions in the oral cavity are asymptomatic and it is possible that what the patient sees as “nothing” could turn out to be the beginning of a cancerous process.
“This is a multidisciplinary area and there are many specialists that patients see who could diagnose something in the patient’s mouth, and then refer them onwards to the appropriate specialist for further scrutiny and treatment of the lesion,” she says. “Asking the patient is all that it takes sometimes to help detect these lesions early.”
Disclosures: Dr. Ramos-e-Silva reports no relevant financial interests.