Photodynamic therapy outcome for T1/T2 N0 oral squamous cell carcinoma

This new prospective clinical study assessed the oncological outcomes following surface illumination mTHPC-photodynamic therapy of T1/T2 N0 oral squamous cell carcinoma (OSCC) patients.

Thirty-eight patients participated in this study. Their mean age at the first diagnosis of OSCC was 58.0 years. Common clinical presentation was an ulcer mainly identified in the tongue, floor of mouth (FOM), or buccal mucosa. Current and ex-smokers represented 89.5% of the cohort; while current and ex-drinkers were 86.8%. Clinically nine patients had T1 disease while 29 had T2 disease.

Pathological analysis revealed that 12 patients had well differentiated SCC, 16 moderately differentiated and 10 had poorly-differentiated cancer. All patients were discussed in a multidisciplinary meeting and, subsequently, underwent mTHPC-PDT. PDT was repeated in 6- to 7-month period following the first round when residual tumor was identified in the treated site. At last clinic review post-PDT, 26/38 patients showed complete normal clinical appearance of their oral mucosa in the primary tumor site. Recent surgical biopsies from the study cohort showed that 17 had normal mucosa, five with hyperkeratinization, 10 with dysplastic changes and six showed recurrent SCC. The overall recurrence was 15.8% and the 5-year survival was 84.2%. Death from loco-regional and distant disease spread was identified in three patients. The recurrence group comprised six patients. Most common presentation was an ulcer involving the buccal mucosa or retromolar area, identified in current or ex-smokers and current drinkers. The surgical margins in this group were also evaluated following laser or surgical excision and reconstruction.

mTHPC-photodynamic therapy (up to three rounds) is a comparable modality to other traditional interventions in the management of low-risk tumors of the oral cavity. Although, sometimes, multiple rounds of the treatment is required, morbidity following PDT is far less when compared to the three conventional modalities: surgery, radiotherapy, and chemotherapy.