Photodynamic Therapy for Head and Neck Cancer Treatment

PICHON-RIVIERE, A.; AUGUSTOVSKI, F. A.; GARCIA MARTI, S.; GLUJOVSKY, D.; ALCARAZ, A.; LOPEZ, A.; BARDACH, A.; CIAPPONI, A; GONZALEZ, L

Documento de Evaluación de Tecnologías Sanitarias

IECS

Año: 2012 p. 1 - 30

1668-2793

It is estimated that in 2008, occurred approximately 250,000 new cases and 120,000 deaths worldwide due to head and neck cancer. Over 90% of the tumors are squamous cell carcinomas. Standard treatment options include: laser, cryotherapy, surgery, radiotherapy and chemotherapy, alone or in combination. Surgery is one of the treatments of choice for almost every disease location. The estimated survival rate is about 70% at one year and 40% at 5 years. Local recurrence occurs in about 60% of the cases. Surgery or radiotherapy may be repeated in only a few cases, with a higher risk in terms of morbidity and lower effectiveness. Photodynamic Therapy (PDT) is proposed as a therapeutic alternative for the initial treatment of early stage patients or as palliative treatment for those patients with recurrent/refractory lesions.TechnologyPDT involves the initial marking of pathological tissue using an intravenous photosensitizer agent and later a tissue destruction process, by exposing it to a light source with a specific wavelength. Worldwide, there are 12 molecules used as photosensitizers of which two, the porfimer sodium (PS) and the temoporfine (or THCP for its chemical structure abbreviation) are used in the context of head and neck cancer-PurposeTo assess the available evidence on the efficacy, safety and coverage policy related aspects on the use of Photodynamic Therapy for the treatment of head and neck cancer.MethodsA bibliographic search was carried out on the main databases: DARE, NHS EED, on Internet general search engines, in health technology evaluation agencies and health sponsors. Priority was given to the inclusion of systematic reviews; controlled, randomized clinical trials (RCTs); health technology and economic evaluations (HTEE); clinical practice guidelines and coverage policies of other health systems.ResultsFor this report a RCT, four non-randomized clinical trials, seven case series, three clinical practice guidelines, one HTEE and four coverage policies were included.When analyzing the results obtained on PDT in this limited pooled evidence, complete response (CR) rates exceeding 65% for early stages are observed, with a calculated survival rate at one and two years around 90% and 75%, respectively. At advance stages, the CR rate ranges between 15% and 60%, achieving survival rates exceeding 35% at one year.Several clinical practice guidelines of International Societies do not mention PDT as a therapeutic alternative.PDT?s total cost, including the photosensitizer and professional fees, is AR$ 110,000 (Argentine pesos, August 2012) equivalent to about US$ 24,000 (U.S. dollars, August 2012). Several U.S. health insurance companies do not cover PDT for head and neck treatment because they consider it at experimental stage for this indication.ConclusionsThe evidence found was of poor quality, comprising some RCTs with methodological defects and several uncontrolled case series.The main limitation to evaluate the usefulness of PDT for head and neck cancer is the lack of comparative studies against the standard treatment options.The patients included in the studies found are a heterogeneous group of cases; they included patients with oral, nasal, pharynx cavity, hypopharynx and larynx lesions at different stages; some of them are primary lesions and others are recurrent or refractory to different types of treatments. If compared directly, some of the results could be similar to those achieved with other therapeutic methods such as surgery or radiotherapy where the initial local control rates reported range between 50% and 95%. In other cases, the results reported seem to be better, when comparing those patients undergoing surgery or rescue radiotherapy, with overall survival rates achieved at 12 months around 50%. However, it is worth mentioning that direct comparison with standard options is not possible in view of the heterogeneity of the populations in the PDT studies.Although the method has a lower morbidity than the other alternatives, to date there is no evidence to recommend PDT use as a therapeutic alternative for the treatment of head and neck cancer.