Cisplatin combined with laser‑activated nanotherapy as an adjuvant therapy for head and neck cancer.

Head and neck cancers (HNCs), in general, have a poor prognosis with a worldwide 5‑year survival rate of <50%. Numerous HNC patients with locoregionally advanced, difficult‑to‑treat, inoperable, recurrent and drug‑resistant tumors may require additional treatment options when the standard of care surgery, chemotherapy and radiation are not viable. The poor outcomes justify exploring strategies to increase the efficacy of lower doses of drugs, such as cisplatin, by combining these drugs with other treatment modalities and manipulating the dosing schedule. Cisplatin is a standard and effective anticancer drug; however, some patients cannot tolerate the side‑effects or exhibit drug resistance. Adjuvant therapies may lower the effective dose, decrease side‑effects, address drug resistance and improve overall survival outcomes, particularly for patients with difficult‑to‑treat tumors. The present study focuses on combining cisplatin with laser‑activated nanotherapy (LANT), as an adjuvant HNC therapy, with the aim of enhancing the therapeutic efficacy of lower doses of cisplatin and decreasing treatment times. The results demonstrate the potential of cisplatin and LANT co‑therapy as a possible addition to the adjuvant therapy options for HNC using 3 cell lines: Detroit 562, FaDu and CAL 27 cells. Combining cisplatin with LANT demonstrated up to a 5.4‑fold greater therapeutic efficacy than with cisplatin monotreatment. The most effective combination in the present study was 1 µM Cis + 5 nM LANT, which demonstrated cell death comparable to 5.9, 4.2 and 5.3 µM of Cis monotreatment, in Detroit 562, FaDu and CAL 27 cells, respectively. This result suggests that a lower cisplatin dose may be combined with LANT to achieve the same therapeutic efficacy as that obtained with higher doses of cisplatin monotreatment. The combination of LANT and cisplatin suggests that LANT may enhance the therapeutic efficiency of low doses of cisplatin, decrease treatment times and improve patient outcomes.