Chemoprevention in head and neck cancer: basic science and clinical application

Dormancy programs as emerging antimetastasis therapeutic alternatives

We recently published that the retinoid-responsive gene NR2F1 (nuclear receptor subfamily 2, group F, member 1) mediates postsurgical dormancy of local residual tumor cells and disseminated tumor cells. Importantly, the combination of azacytidine with retinoids induces dormancy of malignant tumor cells by reinstating the NR2F1-regulated gene program. These findings open the door to the development of strategies that may stop minimal residual disease from becoming life-threatening metastases.

Evidence for a field change effect based on angiogenesis in the oral mucosa? A brief report

The concept of field cancerisation was proposed to explain the development of second primary tumours in the upper aerodigestive tract. The formation of new blood vessels (angiogenesis) has been shown to accompany oral disease progression, however, little is known about its potential role as an indicator of field cancerisation. The aims of this study were to compare the angiogenic profile of normal oral mucosa from oral cancer patients with that sampled from cancer-free patients to seek evidence for differences that might be termed a field change. Oral mucosal tissue (NC) was obtained from 25 oral cancer patients from a site at least 1 cm distant from the primary tumour and was compared with normal oral mucosa (NN) from a further 20 non-cancer patients. The vascularity of the tissue was investigated immunohistochemically using four antibodies and three methods of quantitation. Vascularity was significantly higher in the NC group than the NN with all four markers (p<0.01). Significantly higher indices of vascularity were found for patients who were smoker/drinkers in the NC group (p<0.05). The increased vascularity may provide a rationale for anti-angiogenic drug therapy for tertiary prevention.

Chemoprevention of squamous cell carcinoma in recessive dystrophic epidermolysis bullosa: results of a phase 1 trial of systemic isotretinoin

BACKGROUND

Patients with recessive dystrophic epidermolysis bullosa (RDEB) are at high risk of developing squamous cell carcinoma on or after midadolescence, and most patients die of metastatic squamous cell carcinoma within 5 years of diagnosis of their first squamous cell carcinoma.

OBJECTIVE

We sought to determine whether isotretinoin can be safely administered to patients with RDEB as a possible chemopreventive agent.

METHODS

A total of 20 patients with RDEB aged 15 years or older were treated daily for 8 months with isotretinoin (with a targeted dosage of 0.5 mg/kg/d).

RESULTS

No unusual adverse reactions were noted in this patient population. Several patients experienced reduced blistering at lower doses and increased mechanical fragility at maintenance dosage.

CONCLUSIONS

Isotretinoin, at least up to a dosage of 0.5 mg/kg/d, may be safely used in patients with RDEB. Although increased fragility may occur, patients tolerated this drug well and were receptive to its long-term use for possible chemoprevention of cancer. Whether such an effect will occur is yet to be proven.