Clinical value of genetically diagnosed lymph node micrometastasis for patients with oral squamous cell carcinoma

Prognostic role of lymph node micrometastasis in oral and oropharyngeal cancer: A systematic review

BACKGROUND

An estimated 20% of patients with oral and oropharyngeal squamous cell carcinoma (OOSCC) have micrometastases (Mi) or isolated tumor cells (ITC) in the cervical lymph nodes that evade detection by standard histological evaluation of lymph node sections. Lymph node Mi and ITC could be one reason for regional recurrence after neck dissection. The aim of this study was to review the existing data regarding the impact of Mi on the survival of patients with OOSCC.

METHODS

PubMed and the Cochrane Library were searched for articles reporting the impact of Mi and ITC on patient survival. Two authors independently assessed the methodological quality of retrieved studies using the Downs and Black index. Data were also extracted on study type, number of included patients, mode of histological analysis, statistical analysis, and prognostic impact.

RESULTS

Sixteen articles with a total of 2064 patients were included in the review. Among the 16 included studies, eight revealed a statistically significant impact of Mi on at least one endpoint in the Kaplan-Meier and/or multivariate analysis. Three studies regarded Mi as Ma, while five studies found no impact of Mi on survival. Only one study demonstrated an impact of ITC on patient's prognosis in the univariate but not in the multivariate analysis.

CONCLUSION

The majority of cases included in the review were patients with oral cancer. The findings provide low-certainty evidence that Mi negatively impacts survival. Data on ITC were scarcer, so no conclusions can be drawn about their effect on survival. The lower threshold to discriminate between Mi and ITC should be defined for OOSCC since the existing thresholds are based on data from different tumors. The histological, immunohistological, and anatomical characteristics of Mi and ITC in OOSCC as well as the effect of radiotherapy on Mi should be further investigated separately for oral and oropharyngeal carcinomas.

Comparing the Diagnostic Accuracy of Ultrasonography, CT, MRI, and PET/CT in Cervical Lymph Node Metastasis of Oral Squamous Cell Carcinoma

(1) Background: In oral cancer staging, ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and 2-deoxy-2-[fluorine-18]fluoro-D-glucose (FDG) with positron emission tomography/computed tomography (PET/CT) are routinely used in clinical practice. The present study is a retrospective examination of the diagnostic accuracy of cervical lymph node metastasis using US, CT, MRI, and PET/CT, with histopathological diagnosis as a reference, to compare the different diagnostic imaging modalities. (2) Methods: The participants included 16 patients with oral squamous cell carcinoma who underwent US-, CT-, MRI-, and PET/CT-based preoperative diagnostic imaging and simultaneous primary lesion resection and neck dissection, including 82 level regions and 424 lymph nodes. We compared the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of each imaging modality based on the imaging results and the pathology results of metastasis. (3) Results: Of the four diagnostic imaging modalities, PET/CT exhibited the highest sensitivity but the lowest specificity and accuracy. US, CT, and MRI had high specificities. Comparing each level region and lymph node showed that differences were observed in PET/CT. (4) Conclusions: PET/CT to diagnose lymph node metastasis requires a comprehensive evaluation because it produces more false positives than other diagnostic imaging modalities. Using US, CT, and MRI, which have excellent spatial resolution, improves diagnostic accuracy at the lymph node level.

Postoperative radiotherapy is dispensable for OSCC patients with micrometastases in lymph nodes

Lymph node metastasis is a decisive factor for performing postoperative radiotherapy for oral squamous cell carcinoma (OSCC). However, whether OSCC patients with only micrometastasis need postoperative radiotherapy is unclear. In this study, OSCC patients (n = 311) with negative (n = 247), only micrometastasis (n = 44) and macrometastasis (n = 20) were detected and selected by HE staining. Micrometastasis was re-assessed using immunohistochemical staining of cytokeratin (CK) in HE-negative patients to find out the false negative cases. The results indicated that, among the negative lymph node cases (n = 247), the positive rate of CK was 4.94% (n = 12). Besides, the clinical features of the primary tumor in relation to the only micrometastatic status and the value of the postoperative radiotherapy on the only micrometastasis patients were evaluated. Patients with only micrometastasis had higher T stage and inferior worst pattern of invasion (WPOI) than patients without micrometastasis, but they had longer overall survival (OS), metastasis-free survival (MFS), and disease-free survival (DFS) than macrometastasis patients. However, the survival time of only micrometastasis patients with or without postoperative radiotherapy was comparable, even in patients with inferior WPOI. Radiotherapy, however, may only benefit patients with IV/V levels of micrometastasis. These data indicated that postoperative radiotherapy is dispensable for only micrometastasis OSCC patients.

Lymph Node Yield as a Predictor of Survival in Pathologically Node Negative Oral Cavity Carcinoma

Objective

Even after a pathologically node-negative (pN0) neck dissection for oral cavity squamous cell carcinoma (SCC), patients may develop regional recurrence. In this study, we (1) hypothesize that an increased number of lymph nodes removed (lymph node yield) in patients with pN0 oral SCC predicts improved survival and (2) explore predictors of survival in these patients using a multivariable model.

Study Design

Case series with chart review.

Setting

Administrative database analysis.

Subjects and Methods

The SEER database was queried for patients diagnosed with all-stage oral cavity SCC between 1988 and 2009 who were determined to be pN0 after elective lymph node dissection. Demographic and treatment variables were extracted. The association of lymph node yield with 5-year all-cause survival was studied with multivariable survival analyses.

Results

A total of 4341 patients with pN0 oral SCC were included in this study. The 2 highest lymph node yield quartiles (representing >22 nodes removed) were found to be significant predictors of overall survival (22-35 nodes: hazard ratio [HR] = 0.854, P = .031; 36-98 nodes: HR = 0.827, P = .010). Each additional lymph node removed during neck dissection was associated with increased survival (HR = 0.995, P = .022).

Conclusion

These data suggest that patients with oral SCC undergoing elective neck dissection may experience an overall survival benefit associated with greater lymph node yield. Mechanisms behind the demonstrated survival advantage are unknown. Larger nodal dissections may remove a greater burden of microscopic metastatic disease, diminishing the likelihood of recurrence. Lymph node yield may serve as an objective measure of the adequacy of lymphadenectomy.

Detection of Cervical Lymph Node Micrometastases in Patients with Squamous Cell Carcinoma of the Oral Cavity, Pharynx and Larynx

Background: The goal of this prospective study was to determine the frequency of micrometastases in patients with squamous cell carcinoma (SCC) of the oral cavity, pharynx and larynx in whom elective neck dissection was indicated (cN0). Patients and Methods: A total of 12 patients (10 males and 2 females) were enrolled in the study. The age ranged 42–73 years (median 62 years). Elective neck dissection was performed in all patients (8 ipsilateral, 4 bilateral) and a total of 256 lymph nodes were removed and sent for microscopic examination. Results: The presence of tumor cells in cervical lymph nodes was found in 5/12 (42%) patients. Micrometastases of SCC were found in two patients and isolated tumor cells (ITC) in two other patients. In the remaining one patient with oropharyngeal SCC, a micrometastasis of papillary thyroid carcinoma (PTC) was detected. Positive lymph nodes were localized in level II in three patients with SCC of larynx, hypopharynx and tongue base, respectively, in level I in one patient with SCC of oral tongue and in level III in one patient with PTC. Conclusion: Our results indicate that SCC of head and neck has a high potential for creating micrometastases which frequency is higher compared to clinically detected macrometastases. Therefore, elective neck dissection or radiotherapy of the neck should be considered in patients with high risk of occult metastases or micrometastases.

Current advances in diagnosis and surgical treatment of lymph node metastasis in head and neck cancer

Still today, the status of the cervical lymph nodes is the most important prognostic factor for head and neck cancer. So the individual treatment concept of the lymphatic drainage depends on the treatment of the primary tumor as well as on the presence or absence of suspect lymph nodes in the imaging diagnosis. Neck dissection may have either a therapeutic objective or a diagnostic one. The selective neck dissection is currently the method of choice for the treatment of patients with advanced head and neck cancers and clinical N0 neck. For oncologic reasons, this procedure is generally recommended with acceptable functional and aesthetic results, especially under the aspect of the mentioned staging procedure. In this review article, current aspects on pre- and posttherapeutic staging of the cervical lymph nodes are described and the indication and the necessary extent of neck dissection for head and neck cancer is discussed. Additionally the critical question is discussed if the lymph node metastasis bears an intrinsic risk of metastatic development and thus its removal in a most possible early stage plays an important role.

Prognostic biological features in neck dissection specimens

The superior prognostic value offered by routine histopathological staging of neck dissections, as compared to clinical staging using palpation and modern imaging techniques, is well established in the literature concerning the management of squamous cell carcinoma of the head and neck. In this review, we discuss the definitions and criteria used in standardised routine histopathological reporting and explore additional potential nodal prognostic features. In addition, we critically appraise the value of immunohistochemistry, histochemistry, molecular and other non-morphological techniques and suggest tumour and host features that merit further investigations.

Retrospective Study of Selective Submandibular Neck Dissection versus Radical Neck Dissection for N0 or N1 Necks in Level I Patients with Oral Squamous Cell Carcinoma

Objective. To evaluate the efficacy of selective submandibular neck dissection (SMND) in patients with oral squamous cell carcinoma (OSCC) with or without nodal metastasis. Patients. From a total of 384 patients with untreated OSCC who underwent radical excision, we identified 229 with clinically N0 necks and 68 with clinically N1 necks in level I. Main Outcome Measures. The Kaplan-Meier 5-year regional control and 5-year disease specific survival (DSS) were compared for SMND, radical neck dissection (RND), and modified radical neck dissection (MRND). Results. In clinically node-negative necks, the regional control rates were 85.2% with SMND and 83.3% with MRND (P = 0.89), and 5-year DSS rates were 86.5% and 87.0%, respectively, (P = 0.94). In clinically N1 necks, the regional control rates were 81.3% with SMND and 83.0% with RND (P = 0.72), and the DSS rates were 81.3% and 80.0%, respectively, (P = 0.94). Type of neck dissection was not significantly associated with regional control or DSS on either univariate or multivariate analysis using Cox's proportional hazard model. Conclusions. SMND can be effectively applied in elective and therapeutic management to patients with OSCC that are clinically assessed as N0 or N1 to level I of the neck.

Current potential and limitations of molecular diagnostic methods in head and neck cancer

Traditional diagnostic methods such as clinical assessment, histopathological examination and imaging techniques are limited in their capacity to provide information on prognosis and treatment choice of head and neck cancer. In recent years, molecular techniques have been developed that enabled us to get more insight into the molecular biological cellular pathways underlying tumor progression and metastasis. Correlation of these molecular changes with clinical events has been explored. However, consistently useful markers have not been identified yet, although many promising developments are in progress. It may be expected that in the near future, molecular markers will be useful for clinical purposes. In this paper, an overview will be given of the several molecular techniques that may have potential to be introduced in clinical practice in the management of head and neck squamous cell carcinoma.

Elective management of the neck in oral cavity squamous carcinoma: current concepts supported by prospective studies

The incidence of occult cervical metastasis in oral cavity cancer, even in early stages, is significant, necessitating elective treatment of the neck in a majority of cases. There is no method of imaging or other examination that will detect microscopic foci of metastatic disease in cervical lymph nodes. Immunohistochemical and molecular analysis of neck specimens reveals the incidence of occult metastases to be higher than revealed by light microscopy with ordinary hematoxylin and eosin staining. The neck may be treated electively by surgery or irradiation. Surgery has the advantage of permitting pathological staging of the neck, avoiding unnecessary radiation treatment and indicating cases where adjuvant therapy should be employed. As oral cavity cancer rarely metastasizes to level V, a radical or modified radical neck dissection of all five node levels is not necessary. Selective dissection of levels I-III ("supraomohyoid neck dissection") is the usual procedure of choice for elective dissection of the neck. Most of the relatively small number of isolated metastasis to level IV are from primary tumours of the tongue, which are known to produce "skip" metastases. Thus an "extended supraomohyoid neck dissection" of levels I-IV is recommended by some authors for elective treatment of the neck in tongue cancer. A number of recent prospective multi-institutional studies have demonstrated that sublevel IIB is rarely involved with isolated metastasis from oral cavity primary tumours, except from some tongue cancers. Thus it is justifiable to omit dissection of sublevel IIB in elective treatment of most cases of oral cavity cancer. Bilateral neck dissection should be performed in elective treatment of tumours involving midline structures, and in patients with ipsilateral neck metastasis.

Detection of lymph node micrometastases in patients with squamous carcinoma of the head and neck

While the significance of large cervical node metastases in patients with head and neck squamous carcinomas is well established, the import of a finding of regional nodal micrometastases (where a micrometastasis is defined as a metastatic deposit greater than 0.2 mm and not greater than 2.0 mm in greatest dimension) or isolated tumor cells in those patients is less clearly understood. Some earlier investigators have suggested that finding micrometastases does not have an impact on prognosis; some later investigators, however, have taken issue with this position, arguing that finding either micrometastases or isolated tumor cells might portend a poorer prognosis for head and neck cancer patients. At this juncture, it is difficult to advance a single recommendation for handling a finding of micrometastases or isolated tumor cells. It would be helpful if two courses of action were followed: first, while the detection of micrometastases and isolated tumor cells remains an investigatory practice, data should be collected and analyzed with an eye to discerning whether such findings are indeed of significance to the individual head and neck cancer patient. Second, rigorous definitions of micrometastases and isolated tumor cells (such as the definitions suggested here) should be developed and widely employed so as to permit ready comparison between the results as they are reported by different investigators.

Sentinel lymph nodes in cancer of the oral cavity: is central step-sectioning enough?

BACKGROUND

Extended histopathologic work-up has increased the detection of micrometastasis in sentinel lymph nodes in malignant melanoma and breast cancer. The aim of this study was to examine if (A) step-sectioning of the central 1000 microM at 250 microM levels with immunostaining were accurate when compared with (B) step-sectioning and immunostaining of the entire sentinel lymph node at 250 microM levels.

METHODS

Forty patients with T1/T2 cN0 oral cancer were enrolled. Three patients were excluded. In one patient no sentinel lymph node was identified. The remaining two had unidentified sentinel lymph nodes due to lymphoscintigraphic and surgical sampling error. The central 1000 microM of 147 sentinel lymph nodes were step-sectioned in 250-microm intervals and stained with hematoxylin and eosin and CK-KL1. All lymph nodes were recorded as negative or positive for macrometastases or micrometastases. After inclusion of the last patient the residual tissue of the lymph nodes was totally step-sectioned at 250-microm intervals and re-classified. The tumor deposits were divided into macrometastases and micrometastases and ITC.

RESULTS

Method (A) upstaged 17 lymph nodes and 11 patients compared with method (B), which upstaged 22 lymph nodes and 11 patients. Seven of the patients with positive lymph nodes did not change stage. However, four lymph nodes changed from micrometastases to macrometastases. One patient changed from a micrometastasis to four micrometastases. One pN2c patient with bilateral micrometastases did not change stage, but an additional ipsilateral lymph node with a micrometastasis was identified.

CONCLUSION

Larger tumor deposits and more metastases are identified by more extensive sectioning of the sentinel lymph nodes. None of the patients was false-negative due to histopathologic sampling error, but the results indicate that central step-sectioning of the central 1000 microM cannot completely be relied upon for accurate staging of the patients.

Micrometastases in cervical lymph nodes from patients with squamous carcinoma of the head and neck: should they be actively sought? Maybe

Techniques are now being developed, which allow ever smaller metastatic deposits in regional lymph nodes to be detected; the question is, should they be sought, or does their presence convey no additional information for treatment of head and neck carcinoma patients at this time? Preliminary findings have suggested that the presence of micrometastases may carry with it some prognostic information, and as a consequence, the search for micrometastases would, for the foreseeable future, appear to be a fertile ground for investigation. To bring some uniformity to this project, it is suggested that these definitions be adopted: a micrometastasis measures greater than 0.2 mm but less than 2.0 mm in diameter, and smaller deposits should be designated as isolated tumor cells, which, in turn, are subdivided into those isolated tumor cells detected by light microscopy, immunohistochemistry, or molecular methods. At this juncture, the import of such micrometastases remains in the realm of the clinical investigator--it remains an open question whether the identification of micrometastases (however they may ultimately come to be defined) will prove to have an impact on the care of head and neck cancer patients.

P53 expression in squamous cell carcinomas of the supraglottic larynx and its lymph node metastases: new results for an old question

BACKGROUND

Although p53 overexpression is frequent in head and neck squamous cell carcinomas (HNSCCs), controversy remains regarding the prognostic significance of that overexpression. The objective of this study was to investigate the expression pattern and prognostic significance of p53 expression in HNSCC of the same location, treated in the same way, and with long-term follow-up.

METHODS

P53 expression was determined by immunohistochemistry in paraffin-embedded tissue specimens from 107 consecutive patients (107 primary squamous cell carcinomas of the supraglottic larynx and 46 matched lymph node metastases). All patients underwent surgical resection and bilateral neck dissection.

RESULTS

A strong correlation was observed between p53 expression in the primary tumor and in the matched lymph node metastases (P=.0001). P53 overexpression in the lymph nodes was an independent predictor of regional recurrence (P=.027). Likewise, expression of p53 in the lymph nodes correlated significantly with disease-specific survival (P=.018). Five years after treatment, 70% of patients with p53-negative, metastatic lymph nodes remained alive, whereas only 30% of patients with p53-positive lymph nodes remained alive. In multivariate analysis, lymph node status and p53 expression in the lymph nodes remained associated with survival.

CONCLUSIONS

The current data suggested that, although p53 overexpression is common in supraglottic carcinomas, its expression in the primary tumor is of limited clinical significance. However, the results supported the role of p53 in the lymph node metastases as an independent predictor of regional failure and a poor prognosis in patients with HNSCC. A prospective trial is indicated to validate these findings.

Preliminary multi-institutional prospective pathologic and molecular studies support preservation of sublevel IIB and level IV for laryngeal squamous carcinoma with clinically negative neck

Level II-IV selective neck dissection, often performed bilaterally, has become the procedure of choice for elective dissection of the clinically negative (N0) neck in the treatment of laryngeal cancer. The most significant morbidity of this procedure is dysfunction of the accessory nerve, incurred by the necessity of mobilization and retraction of the nerve in order to remove the contents of sublevel IIB. Other morbidity includes possible injury to the phrenic nerve and chylous fistula. These complications are associated with the dissection of level IV. A number of prospective multi-institutional studies of the distribution of cervical lymph node metastases in the neck indicate that lymph nodes in sublevel IIB and level IV are rarely involved in cases of laryngeal cancer with N0 neck. Information was obtained by the study of neck dissection specimens by conventional light microscopy, and by molecular analysis of the specimens. Molecular analysis reveals a significant number of metastases that are not discovered by light microscopy, and is thus essential for this type of evaluation. The authors conclude that these preliminary studies indicate that it is safe and appropriate to eliminate dissection of sublevel IIB and level IV from the elective neck dissection performed for laryngeal cancer with N0 neck. This practice will reduce both operating time and morbidity, particularly accessory nerve dysfunction, without compromising the oncologic result. Further prospective studies are needed to confirm these conclusions.

Importance of molecular analysis in detecting cervical lymph node metastasis in head and neck squamous cell carcinoma

BACKGROUND

Because of the impact of nodal status on treatment and survival in squamous cell carcinoma of the head and neck, accurate staging of cervical lymph nodes is critical. This article explores the value of molecular analyses in the detection of cervical lymph node metastasis.

METHODS

A review of the literature was carried out and combined with our own experience regarding the role of molecular analyses in detecting cervical lymph node metastasis.

RESULTS

Few studies have demonstrated the diagnostic and prognostic relevance of molecular analysis in detecting tumor cells in lymph nodes. Nodal staging was improved by the use of molecular techniques; when compared with histopathologic examination, however, the small sample size of these studies did not allow definitive conclusions.

CONCLUSIONS

Molecular analysis is exquisitely sensitive in detecting very small cancer deposits within lymph nodes. It provides an oncologic basis that may be used to guide therapy and influence outcomes. It should be recommended for diagnostic use in controlled studies of patients without evidence of lymph node metastasis on routine hematoxylin-eosin-stained sections. The clinical significance of these types of metastases, however, must be determined with carefully designed and controlled prospective clinical trials.