Cancers des voies aérodigestives supérieures : le retour de la chimiothérapie néoadjuvante ?

Induction chemotherapy in patients with resectable laryngeal cancer: A meta-analysis

Head and neck squamous cell carcinoma (SCC) ranks 6th among the most frequently diagnosed carcinomas globally. Laryngeal carcinoma is quite common, and 95% of the cases are SCCs. Since the introduction of larynx-preserving surgery, induction chemotherapy (IC) has played a substantial role. The aim of IC is to shrink or downstage primary laryngeal carcinomas, increasing the chances of complete surgical removal, particularly in cases with advanced but potentially resectable lesions. The aim of the present study was to investigate the value of IC in patients with resectable laryngeal cancer. A meta-analysis was performed of randomized controlled trials (1985-2017) investigating the effect of IC on survival, disease control, larynx-preserving surgery and disease-free survival. Engauge-Digitizer software was used to construct Kaplan-Meier curves and RevMan software was used for the analysis of the data. A total of 12 trials (4,320 patients) were included. There was no significant difference in local recurrence or locoregional control between patients receiving and those not receiving IC (P>0.05). However, the experimental group (IC) exhibited a lower propensity for distant metastasis by 11.7% (95% confidence interval: 10.3-13.3%, P=0.02) compared with the control group (no IC). Among patients with laryngeal cancer, larynx preservation was possible in those who responded well to IC, without a significant decrease in survival compared with radical surgery (P<0.05). Taking into consideration these findings, IC confers an advantage in terms of lowering the risk of distant metastasis in patients with resectable laryngeal carcinoma, and enables laryngeal preservation in responders. Moreover, IC increases the overall survival rate in patients with locally advanced but resectable LC.

[Radioresistance parameters in head and neck cancers and methods to radiosensitize]

Head and neck cancers have been widely studied concerning their sensitivity to radiation therapy. Several parameters affect tumour response to radiation therapy. Some parameters are linked to the tumour. Large or invasive tumours, localization, such as oral cavity or adenopathy, are factors of radioresistance. Others parameters are linked to the patients themselves. Tobacco intoxication during radiotherapy and a low hemoglobin level contribute to radioresistance. More recently, a positive human papilloma virus (HPV) status has been reported to positively affect radiosensitivity. Finally, other parameters are related to tumour biology. Hypoxia, intrinsic radiosensitivity of tumour cells, tumour differentiation and repopulation (provided by Ki-67 index or EGFR level) are components of radiosensitivity. Currently, concurrent chemoradiotherapy is one of the gold standard treatments to overcome clinical outcome of locally advanced head and neck cancer. This combination increases locoregional control and survival. Taxane-based induction chemotherapy can also be an alternative. Another validated approach is the association of radiotherapy with cetuximab (EGFR targeting) but only one randomized study has been published. Fractionation modifications, especially hyperfractionation, have given positive results on both tumour control and survival. Strategies targeting hypoxia improve locoregional control but have less clinical impact.