Santosh University Journal of Health Sciences

REVIEW ARTICLE
Year
: 2021  |  Volume : 7  |  Issue : 2  |  Page : 11--14

Significance of surgical margins assessment in head-and-neck squamous cell carcinoma: A surgeon's perspective


Sanjeev Tomar1, Upma Tomar2, Akshat Mediratta1, Manish Gupta3, Shivani Bhandari2,  
1 Department of Oral and Maxillofacial Surgery, Santosh Dental College and Hospital, Santosh Deemed to be University, Ghaziabad, Uttar Pradesh, India
2 Department of Oral and Maxillofacial Pathology and Microbiology, Santosh Dental College and Hospital, Santosh Deemed to be University, Ghaziabad, Uttar Pradesh, India
3 Department of Oral Medicine and Radiology, Santosh Dental College and Hospital, Santosh Deemed to be University, Ghaziabad, Uttar Pradesh, India

Correspondence Address:
Sanjeev Tomar
Department of Oral and Maxillofacial Surgery, Santosh Dental College and Hospital, Santosh Deemed to be University, Ghaziabad, Uttar Pradesh
India

Abstract

Head-and-neck squamous cell carcinoma (HNSCC) is the most common malignant tumor of the oral cavity. HNSCC can be treated by surgery, radiation therapy, chemotherapy and sometimes combinations of all these modalities, and among all these modalities, surgery is the most accepted line of treatment. The purpose of cancer surgery is achieving complete resection of the tumor, and its success depends on not leaving any residual neoplastic cell. Despite all the recent advances in the diagnosis and treatment of these patients, HNSCC is showing increasingly high recurrence rates. The surgical margins (SMs) or resection margins are the margins or boundaries of resection specimen, which is excised by the surgeon. The goal of this review was to evaluate the significance of SMs in adequate and proper treatment of HNSCC along with minimum recurrence.



How to cite this article:
Tomar S, Tomar U, Mediratta A, Gupta M, Bhandari S. Significance of surgical margins assessment in head-and-neck squamous cell carcinoma: A surgeon's perspective.Santosh Univ J Health Sci 2021;7:11-14


How to cite this URL:
Tomar S, Tomar U, Mediratta A, Gupta M, Bhandari S. Significance of surgical margins assessment in head-and-neck squamous cell carcinoma: A surgeon's perspective. Santosh Univ J Health Sci [serial online] 2021 [cited 2022 Jul 7 ];7:11-14
Available from: http://www.sujhs.org/text.asp?2021/7/2/11/331796


Full Text



 Introduction



Head-and-neck squamous cell carcinoma (HNSCC) is the eighth most common cancer of the oral cavity worldwide.[1],[4] HNSCC may be treated by surgery, radiation therapy, chemotherapy, or combinations of all these modalities,[1],[2] and in all of these modalities, surgery is the most accepted line of treatment. Complete resection of the tumor and success depends on not leaving any residual cancer cell.[3] Due to the anatomical complexity of the oral cavity, it is always difficult for surgeon to remove tumors with clear surgical margins during oncological surgery.[4]

 Types of Tumor Margin



Broadly, the margins of tumor have been categorized as:

Clinical margins

These are the margins of tumor on clinical examination and palpation, which are included during resection of tumor tissue.[5]

Resection margin or surgical margin

As defined by Hinni et al.[1] is any tissue plane where the surgeon's knife meets the patient. Along with the surface mucosa (at the edge of the tumor), it also include the sub-mucosal and deeper connective tissues, all around the tumor.[6],[7] SMs reflect the surgeons endeavor to excise all the neoplastic tissue along with preservation of adjacent unaffected anatomical structures, for the purpose of balancing the oncological as well as functional goals.[8] Microscopically, SMs can be subdivided into histological and molecular margins.

Histological margins

The pathologists screen the edges/margins of resection specimen for evidence of tumor cells.[3] The UK Royal College of Pathologist's guidelines for screening of margins propose that both the “mucosal margin” and “deep margin.”[4]

According to approximation of tumor cells, mucosal and deep margins are subdivided into clear, close, and involved.[5]

Clear/negative margin

Histological distance of >5 mm from the invasive carcinoma to SMs.

Close margin

Histological distance of 1–5 mm from the invasive carcinoma to SMs.

Involved/positive margin

Histological distance of <1 mm from the invasive carcinoma to SMs.

On the basis of the following histological criteria, Looser et al.[1],[3] suggested a classification of positive margins as:

Margin closeness (tumor within 0.5 mm)Premalignant change in marginIn situ cancer in marginInvasive microscopic cancer in the margin.[1],[3]

Molecular margins

The histologically normal margins may harbor genetic changes.[4] Thus, various molecular markers have been recently employed to detect these fields of genetically altered cells.[5]

Hence, anatomical site, clinical stage, and pathological features of the primary tumor are the essential elements to guide HNSCC treatment.[3] During surgical removal, the visible neoplastic area must be resected with a threshold of normal tissue, whose edge represents the mucosal margin.[5]

 Discussion



Margin inadequacy: Deep tissues versus mucosal tissues

Surgeons are always encounter difficulties in achieving adequate surgical margins (SMs) for deeper connective tissue planes as compared with mucosal margins. Anatomic constraints may also limit the surgeon's ability to achieve adequate deep resection margins. Another factor by which explaining the higher incidence of inadequate deep soft-tissue margins may be that on the mucosal surface the tumor is visible while during excision of the tumor in the soft tissues, the tumor is not visible but only palpable when one attempts an “en bloc” resection.[2] However, the factors such as perineural and lymphovascular invasion and infiltrative growth patterns are primary factor for inadequate deep soft-tissue margins.

Intraoperative margin surveillance

Some surgeons ink the different resection margin planes with different colors and also keep carefully the records which are an additional component of mapping (e.g., red ¼ superior).[2] Different inking is particularly important whenever a section will include more than 1 margin (i.e., deep and ventral) on the slide. After orienting, mapping, and inking the resection specimen, the pathologist closely observes the resection planes by cutting into the specimen at 2- to 4-mm intervals perpendicular to the resection margin plane. This gross assessment gives important primary information. After which, surgeon may decide to return to the defect at this time to excise more tissue on the basis of the gross examination result, as slides are being processed. This is followed by microscopic examination, which further refines the information. Sometimes, “Defect disorientation” can limit the surgeon's capability to accurately relocate the site of inadequate margin margins. This disorientation can be anticipated and rectified by marking the various margin points within the surgical defect by using of clips or sutures, before bringing the resection specimen to the frozen section suite. A false-negative frozen section report is usually the result of sampling error; sometimes, carcinoma may be absent in the actual frozen section slide but appears in the permanent sections after deeper cutting into the formalin-fixed paraffin-embedded block.{Figure 1}{Figure 2}{Figure 3}

Bone margins

Due to, its high mineral content and need for decalcification, bone is not advisable to rapid tissue analysis.[2] Osseous margins have therefore been always determined before surgery by analyze imaging. However, the need for a more definitive and immediate histologic intraoperative evaluation of bone margins for residual tumor is obvious and has been the subject of several studies.[3] Instead of frozen section, surgeons used intraoperative cytology assessment of bone marrow scrapings to predict margin status. This procedure proved to be easy, cost-effective, and reliable.

Management of positive margins

There seems to be little consensus on the treatment of positive margins other than perhaps avoiding them in the first place. For tumors from oral and oro-pharyngeal sites which are accessible for open or transoral surgery and excised with inadequate final margins, many surgeons will opt to re-excise the tissue if feasible, especially if this would abrogate the need for adjuvant chemotherapy or radiotherapy.

 Conclusion



Inadequate surgical resection margins may contribute to increased chances of local recurrence and morbidity rates, decreased survival rates, and hence increased cost to society. It might commit patients to adjuvant chemotherapy or radiotherapy, which may not have been necessary otherwise. Therefore, surgeons need to obtain adequate resection margins whenever possible. Currently, there is no uniformity in the definitions of adequate SMs. However, we do recommend that margin distance must be measured in millimeters and recorded on the surgical pathology report. Within the oral cavity, 5 mm represents the most commonly used margin standard. Positive margins should be surgically cleared whenever possible. If this is not feasible, chemotherapy and radiotherapy are superior to adjuvant radiotherapy alone. Other tumor features such as lymphovascular invasion, perineural spread, and high-risk status are also involved in the risk assessment for local recurrence and impact the decision for adjuvant treatment. Head-and-neck surgeons and pathologists should work together toward standardizing margin assessment from a multidisciplinary and multi-institutional perspective.

Hence, achieving adequate resection margin is always “operator dependent” with respect to oncosurgeons and pathologists. The appropriate surgical management of HNSCC would greatly benefit from a more accurate and standardized approach to resection margins. The goal of this review was to summarize the debates regarding the SMs, analyze the literature, provide evidence or a rationale for consensus and standardization, and finally, whenever possible, suggest a standard practice for marginal surveillance.

In conclusion, achieving adequate resection margins at the time of surgery is good practice. This has the potential to eliminate the requirement for additional surgery or adjuvant therapy.[9],[10],[11],[12],[13],[14],[15],[16]

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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