Histopathological prognosticators in oral and oropharyngeal squamous cell carcinoma

Incidence and Sites of Distant Metastases from Head and Neck Cancer

Squamous cell carcinoma of the oral tongue (SCCOT) is one of the most prevalent tumors of the head and neck region. Despite advances in treatment, the survival of patients with SCCOT has not significantly improved over the past several decades. Most frequently, treatment failure takes the form of local and regional recurrences, but as disease control in these areas improves, SCCOT treatment failures are occurring more often as distant metastasis. The presence of cervical lymph node metastasis is the most reliable adverse prognostic factor in patients with SCCOT, and extracapsular spread (ECS) of cervical lymph nodes metastasis is a particularly reliable predictor of regional and distant recurrence and death from disease. Decisions regarding the elective and therapeutic management of cervical lymph node metastases are made mainly on clinical grounds as we cannot always predict cervical lymph node metastasis from the size and extent of invasion of the primary tumors. Therefore, the treatment of these metastases in the management of SCCOT remains controversial. The promise of basing treatment decisions on biomarkers has yet to be fully realized because of our poor understanding of the mechanisms of regional and distant metastases of SCCOT. Here we summarize the current status of investigations of SCCOT metastases and the potential of these studies to have a positive impact on the clinical management of SCCOT in the future.

Metastasis of squamous cell carcinoma of the oral tongue

INTRODUCTION. The presence of nodal metastases remains the most significant predictive factor for regional recurrence and survival in patients treated for squamous cell carcinoma of the head and neck. Survival rates are further decreased in patients with nodal metastases that have spread beyond the lymph node capsule, or extracapsular spread (ECS). To the authors' knowledge, this is the first report on the impact of ECS in a large series of patients treated for squamous cell carcinoma of the oral tongue (SCCOT) at a single institution using surgery as the primary treatment modality. METHODS. The authors retrospectively reviewed the medical records of all patients treated for SCCOT with resection of the primary and neck dissection at a single institution between 1980 and 1995. RESULTS. Two hundred sixty-six patients were included in the study. Of that number, 146 patients (55%) were pathologically node-negative (pN0), 75 patients (28%) were pathologically node-positive (pN+) without ECS (pN+/ECS-), and 45 patients (17%) were pN+ with ECS (pN+/ECS+). The 5-year disease-specific and overall survival rates for pN0 patients were 88% and 75%; for pN+/ECS- patients, 65% and 50%; and 48% and 30% for pN+/ECS+ patients. The patterns of failure for the pN0, pN+/ECS- and, pN+/ECS+ groups showed overall recurrence rates of 19.8%, 34.2%, and 51.1% with regional failure rates of 11.5%, 19.2%, and 28.9%, respectively, and distant metastases rates of 3.3%, 8.2%, and 24.4%. CONCLUSIONS. ECS is the most significant predictor of both regional recurrence and development of distant metastasis accounting for decreased survival of patients with SCCOT in the current study. Therefore, intensive regional and systemic adjuvant therapy may be indicated for patients with ECS. Future studies should focus on identifying molecular mediators involved in ECS to determine targets for adjuvant therapies in this subset of patients.

Extracapsular spread. A significant predictor of treatment failure in patients with squamous cell carcinoma of the tongue.

The incidence of oral squamous cell carcinoma remains high. Oral and oro-pharyngeal carcinomas are the sixth most common cancer in the world. Several clinicopathological parameters have been implicated in prognosis, recurrence and survival, following oral squamous cell carcinoma. In this retrospective analysis, clinicopathological parameters of 115 T1/T2 OSCC were studied and compared to recurrence and death from tumour-related causes. The study protocol was approved by the Joint UCL/UCLH committees of the ethics for human research. The patients' data was entered onto proformas, which were validated and checked by interval sampling. The fields included a range of clinical, operative and histopathological variables related to the status of the surgical margins. Data collection also included recurrence, cause of death, date of death and last clinic review. Causes of death were collated in 4 categories (1) death from locoregional spread, (2) death from distant metastasis, (3) death from bronchopulmonary pneumonia, and (4) death from any non-tumour event that lead to cardiorespiratory failure. The patients' population comprised 65 males and 50 females. Their mean age at the 1st diagnosis of OSCC was 61.7 years. Two-thirds of the patients were Caucasians. Primary sites were mainly identified in the tongue, floor of mouth (FOM), buccal mucosa and alveolus. Most of the identified OSCCs were low-risk (T1N0 and T2N0). All patients underwent primary resection ± neck dissection and reconstruction when necessary. Twenty-two patients needed adjuvant radiotherapy. Pathological analysis revealed that half of the patients had moderately differentiated OSCC. pTNM slightly differed from the cTNM and showed that 70.4% of the patients had low-risk OSCC. Tumour clearance was ultimately achieved in 107 patients. Follow-up resulted in a 3-year survival of 74.8% and a 5-year survival of 72.2%. Recurrence was identified in 23 males and 20 females. The mean age of 1st diagnosis of the recurrence group was 59.53 years. Most common oral sites included the lateral border of tongue and floor of mouth. Recurrence was associated with clinical N-stage disease. The surgical margins in this group was evaluated and found that 17 had non-cohesive invasion, 30 had dysplasia at margin, 21 had vascular invasion, 9 had nerve invasion and 3 had bony invasion. Severe dysplasia was present in 37 patients. Tumour clearance was achieved in only 8 patients. The mean depth of tumour invasion in the recurrence group was 7.6 mm. An interesting finding was that 5/11 patients who died of distant metastasis had their primary disease in the tongue. Nodal disease comparison showed that 8/10 patients who died of locoregional metastasis and 8/11 patients who died from distant metastasis had clinical nodal involvement. Comparing this to pathological nodal disease (pTNM) showed that 10/10 patients and 10/11 patients who died from locoregional and distant metastasis, respectively, had nodal disease. All patients who died from locoregional and distant metastasis were shown to have recurrence after the primary tumour resection. Squamous cell carcinoma of the oral cavity has a poor overall prognosis with a high tendency to recur at the primary site and extend to involve the cervical lymph nodes. Several clinicopathological parameters can be employed to assess outcome, recurrence and overall survival.

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Clinicopathological parameters, recurrence, locoregional and distant metastasis in 115 T1-T2 oral squamous cell carcinoma patients

Distant metastases (DMs) occurred in 83 (11.4%) of 727 retrospectively studied head and neck cancer patients. Primary tumor location and initial treatment did not influence DM development; larger primaries (P < .04) or more extensive neck disease (P < .007) more often caused DMs. Initial diagnosis to DMs averaged 11.7 months (range, 0 to 60 months), with 84% diagnosed within 24 months. With the exception of laryngeal primaries, no facet of tumor, host, or initial treatment influenced where or how rapidly DMs developed. Lung was the most common DM site (83.4%), then bone (31.1%) and liver (6.0%). Survival with DMs averaged 4.3 months (range, 1 day to 2.7 years); 86.7% died within 1 year. This report yields the following conclusions: 1. Initial tumor size and neck disease are the only predictors of DMs. 2. DMs usually occur within 2 years of the initial diagnosis. 3. Lung is the most common DM site, making chest x-ray the most effective DM screen. 4. Survival with DMs is usually less than a year.

Paul Fulmer

Papers

Distant metastases from head and neck squamous cell carcinomas.