Surgical margins in head and neck cancer: Intra- and postoperative considerations.

OBJECTIVE: To provide a perspective on the significance of recent reports for optimizing cancer free surgical margins that have challenged standard practices. METHODS: We conducted a review of the recent literature (2012-2018) using the keywords surgical margin analysis, frozen and paraffin section techniques, head and neck cancer, spectroscopy and molecular markers. RESULTS: Of significance are the reports indicating superiority of tumor specimen directed sampling of margins compared to patient directed (tumor bed) sampling for frozen section control of oral cancers. With reference to optimal distance between tumor and the surgical margin, recent reports recommended cutoffs less than 5mm. Employment of new technologies such as light spectroscopy and molecular analysis of tissues, provide opportunities for a "real time" assessment of surgical margins. CONCLUSIONS: The commonly practiced method of patient directed margin sampling involving previous studies raises concern over conclusions made regarding the efficacy of frozen section margin control. The recent studies that challenge the optimal distance for clear surgical margins are retrospective and address patient cohorts with inherently confounding factors. The use of novel ancillary techniques require further refinements, clinical trial validation, and justification based on the additional resources.

HPV and CSC in HNSCC cisplatin resistance.

Cisplatin (DNA intercalator), a standard chemotherapy drug often used to treat head and neck squamous cellular carcinoma (HNSCC) has very low response rates in recurrent disease of HNSCC, this is a major clinical problem today. However, a valuable window to look in to the underlying molecular aspects of a favorable and unfavorable cisplatin response is offered by a distinct disease entity in HNSCC - HPV+ OPSCC. It responds far more favorably to cisplatin than non-HPV driven HNSCC. Another intriguing aspect of head and neck cancer biology is the emergence of the CD44+ cancer stem cell - the tumor initiating population that in all likelihood is the root cause of therapeutic resistance. The critical question is, are there any differences between the CD44+ CSC population of an HPV+ OPSCC and a non-HPV HNSCC? In this regard, the inverse relation between EGFR levels and HPV status in OPSCC may be a common thread that connects the better response rates of HPV+ OPSCC with the contribution of CD44+ stem cells of HNSCC to chemoresistance.

Delphian node metastasis in head and neck cancers--oracle or myth?

Delphian node (DN) refers to the pre-laryngeal or pre-cricoid nodal tissue often identified during laryngeal or thyroid surgery. The original nomenclature is based on the assumption that metastasis to this node was predictive of aggressive disease and poor outcome for patients. In this article, we review the existing literature on the topic to determine the significance of DN metastasis in laryngeal, hypopharyngeal and thyroid cancers.

Planned neck dissection for patients with complete response to chemoradiotherapy: a concept approaching obsolescence.

The question of efficacy of "planned" neck dissection following complete response to chemoradiation of head and neck cancer is discussed. There is general agreement that preemptive neck dissection in patients who present initially with low volume (N1) neck disease is not necessary. However, routine performance of planned neck dissection for patients who present initially with high volume (> or =N2) disease remains controversial. The authors reviewed a large number of studies reported in the recent literature and discuss how they affect this debate.Twenty-four of the reviewed studies indicate a benefit in regional control obtained by "planned" neck dissection among patients who had bulky neck disease pretreatment. All these studies are retrospective, they do not assess treatment response prior to surgery, although they do show very good regional control rates. Twenty-six studies demonstrate no benefit from "planned" neck dissection after complete clinical response. The reasons for these different conclusions include the development of more effective chemoradiation regimens which have improved the initial locoregional control rates of patients undergoing primary chemoradiation treatment, and improvements in diagnostic technology which have increased ability to detect low volume persistent tumor in the post treatment period. When neck dissection is necessary for persistent or recurrent disease, recent studies have shown that selective or superselective neck dissection may produce results therapeutically equivalent to those obtained with more extensive procedures, with less morbidity.There is now a large body of evidence, based on long-term clinical outcomes, that patients who have achieved a complete clinical (including radiologic) response to chemoradiation have a low rate of isolated neck failure, and the continued use of planned neck dissection for these patients cannot be justified.