Elective neck dissection or “watchful waiting”: optimal management strategy for early stage N0 tongue carcinoma using decision analysis techniques

VEGF as a Key Actor in Recurrent Respiratory Papillomatosis: A Narrative Review

Recurrent respiratory papillomatosis (RRP) is a benign disease of the upper aerodigestive tract caused by human papillomavirus (HPV) types 6 and 11. The clinical course is unpredictable and some patients, especially younger children, experience a high rate of recurrence with a significant impact on their quality of life. The molecular mechanisms of HPV infection in keratinocytes have been extensively studied throughout the years, with particular regard to its role in causing malignant tumors, like cervical cancer and head and neck carcinomas. A minor but not negligible amount of the literature has investigated the molecular landscape of RRP patients, and some papers have studied the role of angiogenesis (the growth of blood vessels from pre-existing vasculature) in this disease. A central role in this process is played by vascular endothelial growth factor (VEGF), which activates different signaling cascades on multiple levels. The increased knowledge has led to the introduction of the VEGF inhibitor bevacizumab in recent years as an adjuvant treatment in some patients, with good results. This review summarizes the current evidence about the role of VEGF in the pathophysiology of RRP, the molecular pathways activated by binding with its receptors, and the current and future roles of anti-angiogenic treatment.

Sentinel Lymph Node Biopsy Using Preoperative Computed Tomographic Lymphography and Intraoperative Indocyanine Green Fluorescence Imaging in Patients With Localized Tongue Cancer

Importance

The indocyanine green method alone is unsuitable for sentinel lymph node biopsy in patients with oral cancer because of poor transcutaneous identification of the fluorescent signal through the platysma and sternocleidomastoid muscles.

Objective

To assess the utility of a novel sentinel lymph node biopsy technique using preoperative computed tomographic (CT) lymphography followed by the intraoperative indocyanine green fluorescence method.

Design, Setting, and Participants

In this prospective study performed at Akita University Hospital, Akita, Japan, participants comprised 18 patients with previously untreated cN0 tongue cancer (squamous cell carcinoma) were enrolled from November 2012 to November 2016. Median observer period was 38 (range, 14-62) months. Analysis was completed between January 10 and March 10, 2018.

Interventions

For preoperative sentinel lymph node mapping, CT lymphography was performed the day before sentinel lymph node biopsy. For sentinel lymph node biopsy, a minimum skin incision was made according to the predetermined location of sentinel lymph nodes. Sentinel lymph nodes were excised under indocyanine green fluorescence guidance.

Main Outcomes and Measures

Identification rate of preoperative sentinel lymph node mapping by CT lymphography and the number of sentinel lymph node successfully identified by the intraoperative indocyanine green fluorescence method.

Results

Among 18 patients (8 men, 10 women; median age, 65.5 [range, 40-83] years), sentinel lymph nodes could be mapped by preoperative CT lymphography in 16 patients (89%). At least 1 sentinel lymph node was successfully identified and excised in each of these 16 patients using intraoperative indocyanine green fluorescence. Among the 16 patients in whom sentinel lymph nodes were excised, metastases to sentinel lymph nodes were found in 5 patients (31%).

Conclusions and Relevance

The novel sentinel lymph node biopsy technique of preoperative CT lymphography mapping with intraoperative indocyanine green fluorescence has a high potential for identifying sentinel lymph nodes in patients with cN0 tongue cancer. Because the intraoperative indocyanine green method alone cannot identify sentinel lymph nodes in the neck region, this combined method has clinical potential as a sentinel lymph node biopsy technique that does not require radioisotopes.

Controversies in relation to neck management in N0 early oral tongue cancer

The standard local treatment for early-stage tongue cancer with no clinical lymph node metastases is partial glossectomy. The frequency of occult lymph node metastasis is ~20-30%. Thus, whether prophylactic neck dissection with glossectomy or glossectomy alone should be performed has been a controversial issue since the 1980s. Both treatments have advantages and disadvantages; however, especially in cases involving prophylactic neck dissection, surgical invasion and complications including the cosmetic disadvantage caused by neck skin incision, accessory nerve paralysis or facial nerve (mandibular marginal branch) paralysis, stiffness of the shoulder or neck and a feeling of neck tightness have been considered issues that could be solved by providing less-invasive treatment to the 70-80% of patients without occult lymph node metastasis. A more accurate preoperative diagnosis and strict follow-up are required to provide minimally invasive treatment while ensuring the therapeutic effect. It is also necessary to narrow down the target based on the risk-benefit balance. The depth of invasion should be considered in cases involving oral cavity malignancies. This was also taken into account in recent revisions of eighth edition of the TNM Classification of Malignant Tumors and it is an important factor for N0 neck management. This review article summarizes previous and recent reports on neck management, focusing on the risk-benefit and future perspectives of the diagnosis and treatment of early-stage oral tongue cancer. This effort is an attempt to establish treatment from the patient's point of view, with the patient's quality of life taken into account.

Elective neck dissection in oral squamous cell carcinoma: Past, present and future

In 1994 a decision analysis, based on the literature and utility ratings for outcome by a panel of experienced head and neck physicians, was presented which showed a threshold probability of occult metastases of 20% to recommend elective treatment of the neck. It was stated that recommendations for the management of the cN0 neck are not immutable and should be reconfigured to determine the optimal management based on different sets of underlying assumptions. Although much has changed and is published in the almost 25 years after its publication, up to date this figure is still mentioned in the context of decisions on treatment of the clinically negative (cN0) neck. Therefore, we critically reviewed the developments in diagnostics and therapy and modeling approaches in the context of decisions on treatment of the cN0 neck. However, the results of studies on treatment of the cN0 neck cannot be translated to other settings due to significant differences in relevant variables such as population, culture, diagnostic work-up, follow-up, costs, institutional preferences and other factors. Moreover, patients may have personal preferences and may weigh oncologic outcomes versus morbidity and quality of life differently. Therefore, instead of trying to establish "the" best strategy for the cN0 neck or "the" optimal cut-off point for elective neck treatment, the approach to optimize the management of the cN0 neck would be to develop and implement models and decision support systems that can serve to optimize choices depending on individual, institutional, population and other relevant variables.

Clinical relevance of copy number profiling in oral and oropharyngeal squamous cell carcinoma

Current conventional treatment modalities in head and neck squamous cell carcinoma (HNSCC) are nonselective and have shown to cause serious side effects. Unraveling the molecular profiles of head and neck cancer may enable promising clinical applications that pave the road for personalized cancer treatment. We examined copy number status in 36 common oncogenes and tumor suppressor genes in a cohort of 191 oropharyngeal squamous cell carcinomas (OPSCC) and 164 oral cavity squamous cell carcinomas (OSCC) using multiplex ligation probe amplification. Copy number status was correlated with human papillomavirus (HPV) status in OPSCC, with occult lymph node status in OSCC and with patient survival. The 11q13 region showed gain or amplifications in 59% of HPV-negative OPSCC, whereas this amplification was almost absent in HPV-positive OPSCC. Additionally, in clinically lymph node-negative OSCC (Stage I–II), gain of the 11q13 region was significantly correlated with occult lymph node metastases with a negative predictive value of 81%. Multivariate survival analysis revealed a significantly decreased disease-free survival in both HPV-negative and HPV-positive OPSCC with a gain of Wnt-induced secreted protein-1. Gain of CCND1 showed to be an independent predictor for worse survival in OSCC. These results show that copy number aberrations, mainly of the 11q13 region, may be important predictors and prognosticators which allow for stratifying patients for personalized treatment of HNSCC.

Novel diagnostic modalities for assessment of the clinically node-negative neck in oral squamous-cell carcinoma

Oral squamous-cell carcinomas arise in mucosal linings of the oral cavity and frequently metastasise to regional lymph nodes in the neck. The presence of nodal metastases is a determinant of prognosis and clinical management. The neck is staged by palpation and imaging, but accuracy of these techniques to detect small metastases is low. In general, 30-40% of patients will have occult nodal disease and will develop clinically detectable lymph-node metastases when the neck is left untreated. The choice at present is either elective treatment or careful observation followed by treatment of the neck in patients who develop manifest metastases. These unsatisfying therapeutic options have been the subject of debate for decades. Recent developments in staging of the neck, including expression profiling and sentinel lymph-node biopsy, will allow more personalised management of the neck.

Validation of a gene expression signature for assessment of lymph node metastasis in oral squamous cell carcinoma

PURPOSE

Current assessment of lymph node metastasis in patients with head and neck squamous cell carcinoma is not accurate enough to prevent overtreatment. The aim of this study was validation of a gene expression signature for distinguishing metastasizing (N+) from nonmetastasizing (N0) squamous cell carcinoma of the oral cavity (OSCC) and oropharynx (OPSCC) in a large multicenter cohort, using a diagnostic DNA microarray in a Clinical Laboratory Improvement Amendments/International Organization for Standardization-approved laboratory.

METHODS

A multigene signature, previously reported as predictive for the presence of lymph node metastases in OSCC and OPSCC, was first re-evaluated and trained on 94 samples using generic, whole-genome, DNA microarrays. Signature genes were then transferred to a dedicated diagnostic microarray using the same technology platform. Additional samples (n=222) were collected from all head and neck oncologic centers in the Netherlands and analyzed with the diagnostic microarray. Human papillomavirus status was determined by real-time quantitative polymerase chain reaction.

RESULTS

The negative predictive value (NPV) of the diagnostic signature on the entire validation cohort (n=222) was 72%. The signature performed well on the most relevant subset of early-stage (cT1-T2N0) OSCC (n=101), with an NPV of 89%.

CONCLUSION

Combining current clinical assessment with the expression signature would decrease the rate of undetected nodal metastases from 28% to 11% in early-stage OSCC. This should be sufficient to enable clinicians to refrain from elective neck treatment. A new clinical decision model that incorporates the expression signature is therefore proposed for testing in a prospective study, which could substantially improve treatment for this group of patients.

Who are the low-risk patients that could benefit from watch-and-wait regarding the neck?

CONTEXT AND OBJECTIVE

The management of clinically negative neck is controversial, with an ongoing debate on the indication criteria and prognostic impact of different types of therapy. The aim here was to compare the results from neck dissection and watch-and-wait, among oral cancer patients who, clinically, did not show any evidence of neck metastasis.

DESIGN AND SETTING

Retrospective analysis in a tertiary cancer center hospital.

METHODS

Patients with epidermoid oral carcinoma were assessed. The inclusion criteria were: primary tumor restricted to the oral/oropharyngeal cavity, no previous treatment, surgical treatment as the first option, clinical/radiological stage N0 and no distant metastasis.

RESULTS

Two hundred and sixty-two patients were analyzed. The length of follow-up ranged from four to 369.6 months and, at the end, 118 patients were alive, 53 had died due to cancer, 84 had died from other causes and 7 had died after the operation. Among the patients who underwent neck dissection, lymphatic vascular embolization (P = 0.009) and tumor thickness (P = 0.002) were significant for regional recurrence, while for the watch-and-wait group, only tumor thickness was significant (P = 0.018). Through recursive partitioning, the patients without adverse prognostic factors and tumor thickness < 2 mm presented compatible results in the two groups.

CONCLUSION

Elective neck dissection seems to be the best treatment option. Patients who are eligible for watch-and-wait constitute a small group that, ideally, is categorized according to the postoperative pathological findings.

Management of the clinically negative neck in early-stage head and neck cancers after transoral resection

The decision regarding treatment of the clinically negative neck has been debated extensively. This is particularly true with early-stage tumors for which surgery is the treatment of choice, and the tumor has been resected transorally without a cervical incision. Elective neck dissection in this situation is an additional procedure with potential associated morbidity. The alternative strategy for the clinically negative neck is to "wait and watch." Both an elective neck dissection policy and a "watchful waiting" policy have their proponents. The purpose of this article was for us to review the literature about this subject to try to answer the following question: if the tumor has been resected transorally, should an elective treatment of the neck be performed or is a "watchful waiting" policy safe and adequate? We conclude that, currently, the best available evidence suggests that elective neck dissection does not seem to be superior to the policy of observation without neck surgery, with regard to survival and control of neck disease. This review highlights the need for further well-designed prospective studies that will provide more reliable answers to the debatable issue of the management of the clinically negative neck in such cases.