Lymphatic drainage patterns in oral squamous cell carcinoma: findings of the ACOSOG Z0360 (Alliance) study

A single photodynamic priming protocol augments delivery of ⍺-PD-L1 mAbs and induces immunogenic cell death in head and neck tumors

Photodynamic priming (PDP) leverages the photobiological effects of subtherapeutic photodynamic therapy (PDT) regimens to modulate the tumor vasculature and stroma. PDP also sensitizes tumors to secondary therapies, such as immunotherapy by inducing a cascade of molecular events, including immunogenic cell death (ICD). We and others have shown that PDP improves the delivery of antibodies, among other theranostic agents. However, it is not known whether a single PDP protocol is capable of both inducing ICD in vivo and augmenting the delivery of immune checkpoint inhibitors. In this rapid communication, we show for the first time that a single PDP protocol using liposomal benzoporphyrin derivative (Lipo-BPD, 0.25 mg/kg) with 690 nm light (75 J/cm2 , 100 mW/cm2 ) simultaneously doubles the delivery of ⍺-PD-L1 antibodies in murine AT-84 head and neck tumors and induces ICD in vivo. ICD was observed as a 3-11 fold increase in tumor cell exposure of damage-associated molecular patterns (Calreticulin, HMGB1, and HSP70). These findings suggest that this single, highly translatable PDP protocol using clinically relevant Lipo-BPD holds potential for improving immunotherapy outcomes in head and neck cancer. It can do so by simultaneously overcoming physical barriers to the delivery of immune checkpoint inhibitors, and biochemical barriers that contribute to immunosuppression.

Sentinel lymph node biopsy in early oral cancers: are we ready for it yet? Results from a survey among Indian surgeons treating oral cancers

OBJECTIVE

Emerging evidence has shown that sentinel node biopsy (SNB) is an oncologically safe option in patients with early oral cancer compared with elective neck dissection (END). However, its use on a routine basis could be associated with many challenges.

STUDY DESIGN

This online survey was conducted among the Indian surgeons treating patients with oral cancer to understand and comprehend the incidence and patterns of usage of SNB in their practice, their approach toward the use of SNB, and the possible challenges they face or perceive in its routine use in patients with early oral cancer.

RESULTS

We received 352 responses with a response rate of 47.63%. Most of the respondents (82.6%) were managing N-zero necks with END, only 15.1% (n = 53) respondents practiced SNB currently. Most respondents believed that SNB offered the advantage of better shoulder function compared with END (76.4% [n = 269]). The deterrents considered for routine use of SNB in early oral cancer were additional costs (71.9% [n = 253]), the unavailability of necessary expertise and infrastructure (87.2% [n = 307]), SLNB being a more time-consuming treatment (58.8% [n = 207]), a higher false negative rate (74.1% [n = 261]), and the possible need of a second surgery (82.4% [n = 290]).

CONCLUSIONS

Though SNB presently could be considered as an alternative treatment option, there seem to be various issues that need to be addressed before it can be adopted as a standard of care across centers.

Single photon emission computed tomography-computed tomography visualization of sentinel lymph nodes for lymph flow guided nodal irradiation in oral tongue cancer

PURPOSE

To evaluate correlation of single photon emission computed tomography-computed tomography (SPECT-CT) data on lymph flow (LF) from oral tongue cancer (OC) and the topography of lymph nodes (LN) metastases; to determine the clinical value of lymph flow guided radiotherapy (LFGRT).

MATERIALS AND METHODS

SPECT-CT visualization of LF from the OC lesions was performed after peritumoral injection of 99mTc-phytate in 26 primary patients with clinical stage cT1-2N0M0 disease. We determined the individual drainage (unilateral/bilateral) from the tumor, and localization of sentinel LNs according to the neck levels. Metastases in LNs were verified with histology and a 2-year follow-up.

RESULTS

SPECT-CT detected bilateral LF in 10 (38.5%) of 26 patients; in 16 (61.5%) cases the drainage was unilateral. Histology revealed LNs metastases in three cases; regional recurrences were diagnosed in other four patients. In all seven observations metastases were located at the same site and level as the sentinel LNs. In eight (30.8%) of 26 patients sentinel LNs were visualized unilaterally at levels Ib-IIa; in five cases, unilaterally at levels I-IIa-III. In these patients, LFGRT demonstrated 59%-70% reduction of irradiated volume, and 26%-42% and 51%-70% decrease of the mean dose to the spinal cord and the contralateral parotid gland. In patients with a bilateral drainage the reduction of doses absorbed by the spinal cord and contralateral parotid gland was 19% and 6%, respectively.

CONCLUSION

Localization of sentinel LNs determined by SPECT-CT corresponds to the localization of metastatic LNs in terms of side and levels.

Clinician perspectives on the factors influencing prognostic stratification by the American Joint Commission on Cancer Head and Neck Cutaneous Squamous Cell Carcinoma Staging

BACKGROUND

The eighth edition of the American Joint Committee on Cancer Staging Manual includes a staging system for head and neck cutaneous squamous cell carcinoma for the first time. The pN categories for head and neck cutaneous squamous cell carcinoma and mucosal squamous cell carcinoma are identical, despite the vastly different biological behavior of these diseases. This study aimed to survey head and neck cancer specialists' views regarding the clinical utility of the American Joint Committee on Cancer Staging Manual for head and neck cutaneous squamous cell carcinoma and to identify avenues for improvement.

DESIGN

An electronic survey of 19 questions relating to the prognostic utility of the staging system was designed based on the findings of a literature review. The survey was distributed internationally to specialists managing head and neck cutaneous squamous cell carcinoma.

RESULTS

Literature review identified 9 articles describing primary research relevant to the performance of the American Joint Committee on Cancer Staging Manual for head and neck cutaneous squamous cell carcinoma, which recognized a lack of homogeneity, monotonicity, and distinctiveness in the pN staging system. One hundred and five survey responses were received: 71% indicated that mucosal and head and neck cutaneous squamous cell carcinoma require different nodal staging categories; 63% indicated that immunosuppression should be included in the staging system; 70% thought that soft tissue metastases portend a worse prognosis compared with extranodal extension; 38% almost never saw pN3a tumors; and 40% felt that the N stage is a poor predictor of survival.

CONCLUSION

The views of head and neck cancer specialists across disciplines and countries align with evidence suggesting that head and neck cutaneous squamous cell carcinoma merits a staging system distinct from mucosal squamous cell carcinoma, that immunosuppression should be considered in prognostication, and that the use of extranodal extension should be modified.

Sentinel-Lymph-Node Multicenter Trials

Well executed multicenter clinical trials often provide significant evidence and support for, or against, foundational aspects of clinical procedures perceived to improve clinical management of a medical condition. In this review, discussed are reports of multicenter clinical trials designed to investigate sentinel lymph node biopsy procedures in seven types of cancer: breast, melanoma, head and neck, gastric, colon, uterine, and vulvar-with focus on the most recent reports of the hypotheses, objectives, parameters, data, results, implications, and impacts of the included trials. Such trials generally enroll more subjects, in shorter time periods, than do single-center studies. Such studies generally also have greater diversities among investigator practitioners and investigative environments than do single-center studies. The greater number of subjects provides more power to statistical analyses performed in such studies. The more rapid accrual usually results in data being more consistently acquired. The diversities of practitioners and environments may produce results that are more conservative than might be obtained from more "focused" studies; however, diversities in a study often identify implicitly results that are more robust-that is results applicable by more practitioners and applicable in more environments.

MR evaluation of tongue carcinoma in the assessment of depth of invasion with histopathological correlation: A single center experience

Introduction

Magnetic resonance imaging (MRI) has become the cornerstone for pretreatment evaluation of carcinoma tongue and provides accurate information regarding the extent of the lesion and depth of invasion that helps the clinician to optimize treatment strategy. Aim of the study is to correlate MRI and histopathological findings, to evaluate the role of MRI in loco-regional tumor node metastasis (TNM) staging, and to assess the depth of invasion of tongue carcinoma.

Materials and Methods

This study was undertaken on 30 patients with clinical diagnosis of tongue carcinoma referred for MR imaging at a tertiary care hospital over the 2-year period between July 2017 and June 2019. MRI was performed with GE 1.5 Tesla scanner, neurovascular (NV) array coil. Clinical and MRI staging of tongue carcinoma was done preoperatively and correlated. Post-surgery, histopathological TNM staging was done and correlated with clinical and MRI TNM staging. The cutoff value of histopathological (HP) depth that could determine the existence of nodal metastasis was 5 mm.

Results

In 30 patients diagnosed with tongue carcinoma, the incidence was higher in males (92%). Moderate agreement (k = 0.512) was noted for T staging between clinical and MRI staging assessments. Fair agreement (k = 0.218) was noted for N stage between clinical and MRI staging assessments. There was good agreement (k = 0.871) for M stage between the clinical and MRI staging assessments. Good agreement (k = 0.822 and k = 0.767, respectively) was noted for both T staging and Nstaging between MRI and histopathology staging assessments. The agreement for the T stage was poor (k = 0.012) between the clinical and histopathology staging assessments. Agreement for the N stage was also poor (k = 0.091) between the clinical and histopathology staging assessments. Mean depth of invasion by histology and MRI was 14.22 mm and 16.12 mm, respectively. Moderate agreement (k = 0.541) was noted between clinical and pathological tumor depth and good agreement (k = 0.844) was noted between radiological and pathological tumor depth. As for the T1WGd MRI depth with a cutoff value of 5 mm, the nodal metastasis rate in the group with values >5 mm was 52%, and for those <5 mm was 24%, both of which were significantly different (P = 0.040). Pearson's correlation coefficient of HP depth and T1WGd MRI depth was 0.851 (P < 0.001) suggesting that HP depth shows a strong correlation with T1WGd MRI depth.

Conclusion

MRI is the imaging modality of choice for evaluation of tongue carcinoma as MRI helps in accurate staging of the tumor using TNM classification which is crucial for optimizing treatment options. The current study shows a high correlation between MRI and histopathological findings regarding thickness of tumor and depth of invasion. MRI and histopathology assessments of tumor spread were equivalent to within 0.5 mm DOI. Estimation of invasion depth using MRI as a preoperative study in oral tongue carcinoma is essential in planning surgical treatment strategies such as the extent of elective neck dissection. Invasion depth, which greatly affects occult node metastases, must be included in the TNM staging of oral tongue carcinoma.

Lymphoscintigraphy for Sentinel Node Mapping in Head and Neck Cancer

The aim of this comprehensive review is to describe and analyze the role of the sentinel node mapping in head and neck cancers. For this purpose, head and neck neoplasms have been categorized in cutaneous malignancies and neoplasms of the upper aerodigestive tract. A concise description of lymphatic drainage will be the "prelude" for each section, as well as the description of the injection techniques, when specific. Concisely, the attention has been focused on detection rate of the sentinel node by lymphoscintigraphy for each cancer, and for those patients in which the sentinel lymph node has been identified, true-positives rates, false-negative rates, and overall accuracy has been pointed out. Overall, in cutaneous neoplasms of the head and neck, the detection rate is higher than 90%, however the false-negative rate is still an issue, in particular in melanoma, inducing the need for newer developments. In fact, new tracers and techniques are already available, while prospective multicenter trials exploring the outcome impact are needed in the near future. For the upper aerodigestive tract and in particular oral cavity and oropharynx, sentinel lymph node identification by lymphoscintigraphy allows avoiding unnecessary neck dissection and/or node irradiation. Even in this case, the main limit remains the risk of false-negative rates. While, for patients affected by laryngeal and hypopharyngeal cancers the data seem very limited and, although the feasibility has been demonstrated, performances of this lymphoscintigraphy still need to be confirmed by multicenter studies.

Sentinel node theory helps tracking of primary lesions of cancers of unknown primary

Background

Sentinel lymph node is the first stop of lymphatic spreading of cancer with known primary. The lymph node metastasis pattern of cancer of unknown primary (CUP) is unclear and has been presumed to follow the same pathway. To test this hypothesis, data of all 716 patients clinically diagnosed as CUP in our center were collected.

Methods

Diagnoses of lymph node metastasis were established by ¹⁸F-FDG PET-CT and/or biopsy pathology. Three hundred and forty-seven cases meeting the criteria were divided into three groups: pathology-confirmed primary with invasive biopsy or surgery of the suspicious lesion (group A, n = 64), primary still unknown even with invasive biopsy or surgery of the suspicious lesion (group B, n = 204), and others with no suspicious lesion or lesions who had not been sampled due to medical or other reasons (group C, n = 79). We assessed the clinicopathological features between these groups, and the relationship between lymph node metastasis pattern and confirmed primary site.

Results

In group A, the primary sites of 61 cases were compatible with sentinel node theory, resulting in a positive predictive value of 95%. No significant differences in age, sex, bone metastasis, or visceral metastasis observed between group A and group B, except that group A had a higher ratio of differentiated carcinoma (94% vs. 77%, P = 0.003).

Conclusion

To our knowledge, this is the first evidence indicating that the majority of clinical CUP cases follow the sentinel node theory to spread in lymph nodes, which helps tracking the primary, especially for differentiated carcinoma.

Prediction of cervical metastasis and survival in cN0 oral cavity cancer using tumour 18F-FDG PET/CT functional parameters

PURPOSE

Oral cavity squamous cell carcinoma (OCC) can spread to the neck without apparent lymphadenopathy. Pretreatment detection or prediction of occult metastasis might contribute to proper management of clinically node-negative (cN0) OCC. We examined the role of tumour quantitative 18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) measurements for predicting OCC occult metastasis and survival.

METHODS

This study included 130 cN0 OCC patients who underwent ¹⁸F-FDG PET/CT scanning and subsequent curative surgery and neck dissection. Maximum, peak, and mean standardized uptake value (SUV_max, SUV_peak, and SUV_mean), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) were measured on pretreatment ¹⁸F-FDG PET/CT. Binary logistic regression was used to identify factors predicting occult cervical metastasis. Univariate and multivariate Cox proportional hazard regression were used to find factors associated with overall survival (OS).

RESULTS

Pathological cervical metastasis (pN +) was found in 29 (22.3%) patients. Age, tumour differentiation, lymphovascular invasion, and T classification were significantly associated with pN + (all P < 0.05). After adjustment for these factors, MTV and TLG independently predicted pN + (P < 0.05). Invasion depth, lymphovascular invasion, T and N classifications, and overall TNM stage were significantly associated with OS. After adjustment for these factors, SUV_max and TLG independently predicted OS (all P < 0.05). Patients with TLG > 9.3 g had a 5.7-fold increased risk of overall mortality.

CONCLUSIONS

Tumour ¹⁸F-FDG PET/CT parameters might predict occult metastasis and survival in cN0 OCC patients.

Assessment of the contralateral facial artery pedicle nasolabial island flap for buccal defect repair

The facial artery pedicle nasolabial island flap (FAPNIF) is widely used for oral and maxillofacial reconstruction. However, its use in reconstruction after malignant tumour resection is limited by the possibility of ipsilateral cervical lymph node metastasis along the facial artery. Through fine dissection, it was found that the contralateral FAPNIF can be used to repair the defect after buccal carcinoma resection. The aim of this study was to evaluate the clinical outcomes of the contralateral FAPNIF for buccal defect repair. From 2013 to 2016, 30 patients underwent the repair of a buccal defect with a contralateral FAPNIF after tumour resection. Clinical outcomes and complications were recorded and quality of life was evaluated preoperatively and at 3, 6, and 12 months postoperative. The flaps survived in all 30 cases. Mean mouth opening was 2.50±0.14cm at 1 month, 3.22±0.25cm at 6 months, and 3.35±0.23cm at 12 months postoperative. With regard to patient quality of life, adverse effects included impaired aesthetics, pain, and difficulty eating; these usually subsided within 1year after surgery. The contralateral FAPNIF is easily harvested and is a safe and effective option for the repair of medium-sized buccal defects after the resection of carcinoma.

The EANM practical guidelines for sentinel lymph node localisation in oral cavity squamous cell carcinoma

Purpose

Sentinel lymph node biopsy is an essential staging tool in patients with clinically localized oral cavity squamous cell carcinoma. The harvesting of a sentinel lymph node entails a sequence of procedures with participation of specialists in nuclear medicine, radiology, surgery, and pathology. The aim of this document is to provide guidelines for nuclear medicine physicians performing lymphoscintigraphy for sentinel lymph node detection in patients with early N0 oral cavity squamous cell carcinoma.

Methods

These practice guidelines were written and have been approved by the European Association of Nuclear Medicine (EANM) and the International Atomic Energy Agency (IAEA) to promote high-quality lymphoscintigraphy. The final result has been discussed by distinguished experts from the EANM Oncology Committee, and national nuclear medicine societies. The document has been endorsed by the Society of Nuclear Medicine and Molecular Imaging (SNMMI).

These guidelines, together with another two focused on Surgery and Pathology (and published in specialised journals), are part of the synergistic efforts developed in preparation for the “2018 Sentinel Node Biopsy in Head and Neck Consensus Conference”.

Conclusion

The present practice guidelines will help nuclear medicine practitioners play their essential role in providing high-quality lymphatic mapping for the care of early N0 oral cavity squamous cell carcinoma patients.

Topographical distribution of sentinel nodes and metastases from T1-T2 oral squamous cell carcinomas

OBJECTIVE

The objective is to investigate the topographical distribution of sentinel nodes (SNs) and lymph node metastases in T1-2cN0 oral squamous cell carcinomas (OSCCs).

METHODS

The study entailed a prospective enrolment of 220 patients with clinical T1-2N0 OSCCs who underwent preoperative lymphoscintigraphy (LSG) followed by gamma probe-guided sentinel lymph node biopsy (SLNB). Patients with positive SNs were treated with completion neck dissection. Excised lymph nodes were grouped into the neck level according to the international guidelines.

RESULTS

The SN detection rate by LSG was 99.1%. Patients with midline tumours had bilateral lymphatic drainage on LSG in 15/21 (71.5%). There were 45/199 (22.6%) patients with lateralised tumours that had unexpected bilateral or contralateral drainage patterns on LSG. Fifty-five patients (25.0%) were SLNB positive, and metastases were found in 72/781 (9.2%) of the excised SNs. Metastatic involvement of neck level IV was rare and only observed in patients with anterior tongue cancer. No patients had level V involvement. Eleven patients developed isolated cervical recurrences, with no new primary tumour as origin. The SLNB procedure ensured an overall sensitivity of 83.3% and a negative predictive value of 93.3%.

CONCLUSION

Completion neck dissection of level I-III in SLNB-positive patients might be sufficient in most patients with OSCC except patients with anterior tongue cancer, but further studies are needed to support this potential therapeutic algorithm. Our study showed that SLNB was helpful in clarifying unexpected bilateral or contralateral metastatic drainage patterns. In our cohort, 8/55 patients with occult metastasis would have been missed by elective neck dissection of the ipsilateral neck.