ReviewCurrent concepts in management of oral cancer – Surgery
Introduction
Cancer of the head and neck is a relatively uncommon human cancer. The term “head and neck cancer” covers a large number of neoplasms with diverse natural history arising in one anatomic region. Under the common term of “head and neck cancer” are included; tumors of the mucosa of the upper aerodigestive tract including oral cavity, pharynx, larynx, and sinuses. Also included are tumors of the salivary glands, thyroid, soft tissue and bone tumors and skin cancers. This special issue of Oral Oncology is dedicated to “multidisciplinary approaches in head and neck cancer”. However, it will largely emphasize on oral cancer management. Thus, this article will address the role of surgery in the contemporary management of oral cancer, but will briefly include the role of surgery and the surgeon in other sites in the head and neck such as pharynx, larynx, sinuses, salivary glands, thyroid, as well as skin, soft tissue and bone tumors. While broad philosophical issues in the surgical management of these other sites will be discussed here, it is not possible to cover the details of the surgical aspects of management of neoplasia arising in these other sites in this manuscript.
Oral cancer is the sixth most common cancer worldwide. Lifestyle, habits and demographic as well as genetic factors influence geographic variations in the incidence of oral cancer.1 For example, oral cancer is the most common cancer in India and accounts for 35% of all newly diagnosed cancers in men. The etiology of oral cancer is well established in most instances with consumption of tobacco in any form and alcohol being the most common etiologic agents.2 Recently, however, exposure to the human papilloma virus has been implicated in young patients with oral carcinoma. The exact mechanism of carcinogenesis in this setting still remains to be elucidated.
Surgery is the most well established mode of initial definitive treatment for a majority of oral cancers, with a longstanding history of being the accepted method of treatment for well over a century (Fig. 1). Introduction of ionizing radiation, following the discovery of radium, became an important means of non-surgical treatment of oral carcinoma. However, in the majority of patients with advanced cancer, radiotherapy is employed in conjunction with surgery, most often offered as post-operative treatment. Chemotherapy in the management of oral carcinoma was considered palliative in the 1950’s, 60’s and 70’s. However with the introduction of Cis-platinum, clinical trials of induction chemotherapy demonstrated that response to chemotherapy was observed in a significant number of patients. However, unlike other sites in the head and neck area, the response to induction chemotherapy did not translate into long term control of primary oral squamous cell carcinomas.3 Targeted therapies with EGFR inhibitors are an active area of investigation at this time. Immunotherapy and gene therapy are also areas of research where further work needs to be done.
Section snippets
Factors affecting choice of treatment
The factors that influence the choice of initial treatment are those related to the characteristics of the primary tumor, those related to the patient and those related to the treatment team. Thus, they are categorized under (1) tumor factors, (2) patient factors; (3) physician factors. In selection of optimal therapy for oral carcinoma one should consider these three sets of parameters in initial treatment planning. The ultimate goal of treatment of cancer of the oral cavity is to eradicate
Tumor factors
The tumor factors that affect the choice of initial treatment of oral cancer are primary site, size (T Stage), location (anterior versus posterior), proximity to bone (mandible or maxilla), status of cervical lymph nodes, previous treatment, and histology (type, grade and depth of invasion).4
The biological behavior of primary cancers in the oral cavity is different at various sites. Lip cancer, for example, behaves in a fashion similar to skin cancer with an excellent potential for long term
Patient factors
Several factors relative to patient characteristics are crucial in the selection of initial treatment for oral cancer. These are the patient’s age, general medical condition, tolerance of treatment, occupation of the patient, acceptance and compliance by the patient, lifestyle (smoking and drinking) and other socioeconomic considerations. In general, older age is not a contra-indicator for implementation of appropriate surgical treatment.7, 8 However, advancing age, intercurrent disease due to
Physician factors
The factors related to the treatment delivery team are also important in making the selection of initial definitive treatment for oral cancer. Expertise in various disciplines including surgery, radiotherapy, chemotherapy, rehabilitation services, dental and prosthetic support, and psycho-social support are all crucial in bringing about a successful outcome of the therapeutic program. Management of cancer of the oral cavity is a multidisciplinary team effort, and technical capabilities and
Surgical approaches
The factors that influence the choice of a particular surgical approach for primary tumors of the oral cavity are the size of the primary tumor, its depth of infiltration, the site of the primary tumor (that is anterior versus posterior location), and proximity of the tumor to mandible or maxilla. In addition to pre-operative clinical assessment of the primary tumor, examination under anesthesia is often indicated to accurately delineate the extent of the tumor. The proximity of the tumor to
Management of the mandible
Adequate assessment of the mandible for invasion by primary tumors of the oral cavity is crucial to accurate surgical treatment planning. The mandible is considered at risk when the primary tumor overlies the mandible, is adherent to the mandible, or is in proximity to the mandible. The mechanism for spread of oral cancers to the mandible has been well studied.11 Primary carcinomas of the oral cavity extend along the floor of the mouth or the buccal mucosa to approach the attached lingual or
Reconstructive surgery
Reconstructive surgery following resection for oral cancer is considered when there is functional or aesthetic loss of structures in the oral cavity. Thus loss of a significant part of the tongue, floor of mouth or buccal mucosa, and loss of a segment of the mandible following resection of the primary tumor would be indicators for reconstructive surgery. Superficial surgical defects of the mucosa and underlying soft tissues can be adequately reconstructed using simply a split thickness skin
Osseointegrated dental implants
The optimal rehabilitation of patients undergoing reconstructive surgery of the mandible following resection for oral cancer is restoration of permanent teeth. Osseointegrated dental implants can be considered in reconstruction of the lower or upper jaw with an osseus or osteocutaneous free flap. The selection of immediate insertion of implants or delayed placement of implants is a matter of personal preference of the surgical team. The pros and cons of both methods are heavily debated in the
Outcomes of surgical treatment of oral cancer
The most important factor which affects long term outcome following initial treatment of cancer of the oral cavity is the stage of disease at the time of presentation. Early staged tumors offer excellent cure rates, however once regional lymph node metastases have taken place a significant drop in the cure rate is to be expected. The five year overall and cause specific survival rates for squamous cell carcinomas of the oral cavity by stage of disease are depicted in Fig. 5.
Early diagnosis and
Conflict of interest statement
None declared.
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