Interventional laser surgery for oral potentially malignant disorders – a longitudinal patient cohort study

Oral squamous cell carcinoma (OSCC) is a lethal disease, with rising incidence. In 2011, 6,767 new cases and 2,056 deaths occurred in the UK. Cancers are preceded by oral potentially malignant disorders (PMD), recognizable mucosal diseases harbouring increased, SCC risk offering clinicians a ‘therapeutic window’ to intervene. Contemporary practice remains unable to predict lesion behaviour or quantify malignant transformation (MT) risk. No clear management guidelines exist and the literature cannot determine whether early diagnosis and intervention prevents cancer. 773 laser treatments were performed between 1996 and 2014 in Newcastle Maxillofacial Surgery and efficacy of intervention examined by reviewing clinico-pathological details and clinical outcome for 590 PMD patients followed for a mean of 7.3yrs. Histopathology required ‘up-grading’ in 36% on examining excision specimens. 74.2% of patients were disease free (DF), younger patients with ‘low-grade’ dysplasia, whilst 9% exhibited persistent disease and were older with proliferative verrucous leukoplakia (PVL). DF status was less likely for erythroleukoplakia (p=0.022), ‘high-grade’ dysplasia (p<0.0001) and with lichenoid inflammation (P=0.028). In 12%, unexpected OSCC was identified, whilst 4.8% transformed to malignancy. Interventional laser surgery facilitates definitive diagnosis and treatment, allows early diagnosis of OSCC, identifies progressive disease and defines outcome categories. Evidence is lacking that intervention halts carcinogenesis. Multi-centre, prospective, RCTs are needed to confirm the efficacy of surgery.