A matched cohort comparison of mTHPC-mediated photodynamic therapy and trans-oral surgery of early stage oral cavity squamous cell cancer

Abstract

Photodynamic therapy (PDT) of early stage oral cavity tumors have been thoroughly reported. However, statistical comparison of PDT to the surgical treatment is not available in published literature. We have identified and matched cohorts of patients with early stage oral cavity cancers undergoing surgery (n = 43) and PDT (n = 55) from a single institute experience. The groups are matched demographically and had the same pre-treatment screening and follow-up schedule. Both groups consisted only of tumors thinner than 5 mm to ensure comparability. The endpoints were local disease free survival, disease free survival, overall survival and response to initial treatment. Local disease free survival at 5 years were 67 and 74 % for PDT and surgery groups, respectively [univariate HR = 1.9 (p = 0.26), multivariable HR = 2.7 (p = 0.13)]. Disease free survival at 5 years are 47 and 53 % for PDT and surgery groups, respectively [univariate HR = 0.8 (p = 0.52), multivariable HR = 0.75 (p = 0.45)]. Overall survival was 83 and 75 % for PDT and surgery groups, respectively [(univariate HR = 0.5 (p = 0.19), multivariable HR = 0.5 (p = 0.17)]. In the PDT group, six patients (11 %) and in the surgery group 11 patients (26 %) had to receive additional treatments after the initial. All of the tested parameters did not have statistical significant difference. Although there is probably a selection bias due to the non-randomized design, this study shows that PDT of early stage oral cavity cancer is comparable in terms of disease control and survival to trans-oral resection and can be offered as an alternative to surgical treatment.