Head and neck squamous cell carcinoma in young patients: a 26-year clinicopathologic retrospective study in a Brazilian specialized center.

BACKGROUND: To describe the clinicopathologic profile of young patients with head and neck squamous cell carcinoma (HNSCC) and compare to middle-aged and elderly adults. MATERIAL AND METHODS: Patients' individual records were reviewed for clinicopathologic data. Eighty-nine patients with age 18-45 years old met the inclusion criteria of the study. Two additional groups of middle-aged (n=89) and old (n=89) adults were set to comparative analysis. RESULTS: Young patients represented 11.9% of all patients diagnosed with HNSCC. Women were more affected by HNSCC in the young and elder groups (p= 0.04), and young patients were more prone to be non-smokers (p= 0.01) and have lymph node metastasis at the time of diagnosis (p=0.04). In the young group, patients diagnosed with the disease in advanced stages were more prone to have a positive familial history of cancer (p= 0.04), a positive status of alcohol consumption (p= 0.03), and to be heavy drinkers (p= 0.01). Survival was not different for the young group in comparison to the other groups. CONCLUSIONS: HNSCC in young patients had a different profile when compared to older patients, especially regarding sex and exposure to the classic risk factors for this disease. The survival of the young group is similar to the older groups and advanced clinical stage is predictor of worse survival.

Potential antitumor activity of novel DODAC/PHO-S liposomes

In recent studies, we showed that synthetic phosphoethanolamine (PHO-S) has a great potential for inducing cell death in several tumor cell lines without damage to normal cells. However, its cytotoxic effect and selectivity against tumor cells could increase with encapsulation in cationic liposomes, such as dioctadecyldimethylammonium chloride (DODAC), due to electrostatic interactions between these liposomes and tumor cell membranes. Our aim was to use cationic liposomes to deliver PHO-S and to furthermore maximize the therapeutic effect of this compound. DODAC liposomes containing PHO-S (DODAC/PHO-S), at concentrations of 0.3-2.0 mM, prepared by ultrasonication, were analyzed by scanning electron microscopy (SEM) and dynamic light scattering. The cytotoxic effect of DODAC/PHO-S on B16F10 cells, Hepa1c1c7 cells, and human umbilical vein endothelial cells (HUVECs) was assessed by MTT assay. Cell cycle phases of B16F10 cells were analyzed by flow cytometry and the morphological changes by SEM, after treatment. The liposomes were spherical and polydisperse in solution. The liposomes were stable, presenting an average of similar to 50% of PHO-S encapsulation, with a small reduction after 40 days. DODAC demonstrated efficient PHO-S delivery, with the lowest values of IC50% (concentration that inhibits 50% of the growth of cells) for tumor cells, compared with PHO-S alone, with an IC50% value of 0.8 mM for B16F10 cells and 0.2 mM for Hepa1c1c7 cells, and without significant effects on endothelial cells. The Hepa1c1c7 cells showed greater sensitivity to the DODAC/PHO-S formulation when compared to B16F10 cells and HUVECs. The use of DODAC/PHO-S on B16F10 cells induced G2/M-phase cell cycle arrest, with the proportion significantly greater than that treated with PHO-S alone. The morphological analysis of B16F10 cells by SEM showed changes such as bleb formation, cell detachment, cytoplasmic retraction, and apoptotic bodies after DODAC/PHO-S treatment. Cationic liposomal formulation for PHO-S delivery promoted cytotoxicity more selectively and effectively against B16F10 and Hepa1c1c7 cells. Thus, the DODAC/PHO-S liposomal formulation presents great potential for preclinical studies