The trial is a single-center, non-randomized feasibility study aiming to evaluate the feasibility of ex-vivo tissue analysis using differential mobility spectrometry (DMS) of tissue smoke generated by the use of an electrosurgical instrument.

Patients recruited in the trial receive standard-of-care oral squamous cell carcinoma tumor excision surgery.

Oral squamous cell carcinoma is the sixth common carcinoma and the cause of 1-2% of cancer related deaths in the world. The incidence of oral squamous cell carcinoma was 255 cases in Finland and 742 270 cases worldwide in year 2015. The number of cases per year has been increasing. The approximate age of tumor occurrence is usually between 60 - 70 years. The 5-year survival rate of all diagnosed oral squamous cell carcinoma cases in Finland during the years between 2014 and 2016 was 67% for women and 61% for men.

Early diagnostics is relevant, since oral squamous cell carcinoma tumors have a tendency to grow rapidly and metastasize early to regional lymphnodes and later on to lungs, liver and bones. Typical locations of the tumor are tongue, gums and sole of mouth.

The primary treatment option for oral squamous cell carcinoma is surgical removal of the tumor with 0,5 - 1cm healthy tissue margin. The aim of the operation is to remove the tumor entirely so that the healthy tissue margins are as sparing as possible and that the functional and cosmetic outcomes are as satisfactory as possible. Sufficient healthy tissue margin is one of the most important prognostic factors. Nevertheless, there is only little evidence based knowledge of sufficient healthy tissue margins.

Differential mobility spectrometry (DMS) based application called automatic tissue analysis (ATAS) can be utilized to identify tumor cells from healthy tissue. Tissue identification is done by analyzing tissue smoke that is generated by the use of an electrosurgical instrument called diathermy.

The objective of the trial is to test whether it is possible to identify oral squamous cell carcinoma tissue from normal oral mucosa by using ATAS. A 4mm punch biopsy of an oral squamous cell carcinoma tumor and a control biopsy of healthy oral mucosa will be collected from 30 - 40 patients undergoing oral tumor excision. The biopsies will be examined in the research laboratory with ATAS to test tissue recognition.

Inclusion Criteria:

• Biopsy diagnosed oral squamous cell carcinoma.
• Tumor diameter of 2 cm or larger.
• Operable patient that is willing to participate in the trial.

Exclusion Criteria:

• Tumor diameter less than 2 cm.
• Patient that is unwilling to take part in the trial.
• Patient that is not able to understand given information concerning the trial or to give concent to take part in the trial.

Patients diagnosed with oral squamous cell carcinoma and treated in the outpatient clinic of otorhinolaryngology in Tampere University Hospital, Finland.

The research data will be published statistically and anonymously. A single participant can not be identified of the research data. Only the members of the research group will handle the individual participant data (IPD).