Pulsed potassium-titanyl-phosphate laser photoangiolytic treatment of mucosal squamous cell carcinoma in the hamster cheek pouch

The Hamster Model of Sequential Oral Carcinogenesis: An Update

Animal models are valuable tools for studying human cancer as well as for preclinical trials. The hamster model of chemically induced sequential oral carcinogenesis was developed by our group a decade ago in order to study the multistep process of alterations in gene expression during carcinogenesis. The purpose of this review was to discuss the utility of the hamster model of sequential oral carcinogenesis regarding the deciphering of the main pathways altered. An extended search for articles that cited that specific animal models was performed. Many studies have used the hamster model of sequential oral carcinogenesis either for evaluation of the expression of biomarkers alone, or for applying chemopreventive compounds and other therapeutic methods, or combining the use of biomarkers with the anticancer effect of some compounds. It seems that this animal model is indeed a useful tool that enables the study of cell biology, pathology and therapeutics of oral cancer.

Randomized controlled single-blinded clinical trial of functional voice outcome after vascular targeting KTP laser microsurgery of early laryngeal cancer

Background

Local control rate (LCR) of early glottic cancer is high after radiation therapy or transoral laser microsurgery (TLM). The aim of this study was to investigate functional voice outcome after TLM using a microvessel‐ablative potassium‐titanyl‐phosphate (KTP) laser in comparison with a gold standard cutting CO₂ laser.

Methods

The primary end point of this prospective, randomized, single‐blinded, clinical phase II study with control group was voice outcome during a follow‐up of 6 months assayed by Voice Handicap Index (VHI‐30)‐questionnaires in patients with unilateral high‐grade dysplasia, carcinoma in situ or early glottic cancer undergoing TLM‐KTP (n = 8) or TLM‐CO₂ (n = 12). The secondary end point was LCR.

Results

Starting from the 9‐week‐follow‐up visit, TLM‐KTP yielded significantly reduced VHI scores compared to TLM‐CO₂. No relapse occurred after TLM‐KTP in contrast to one recurrence after TLM‐CO₂ within 6 months.

Conclusion

Multicenter phase II or III studies on voice outcome or local control rate after TLM‐KTP in early glottic cancer are warranted enrolling larger patient cohorts.

Wound healing after transoral angiolytic laser surgery for early glottic carcinoma

OBJECTIVES/HYPOTHESIS

Wound healing after transoral angiolytic laser surgery for early glottic carcinoma was analyzed to identify factors influencing healing and clinical significance of persistent granulation tissue.

STUDY DESIGN

Retrospective review.

METHODS

A retrospective review of 100 consecutive patients undergoing endoscopic angiolytic laser surgery for T1 and T2 glottic carcinoma was performed. Patients with prior radiation or incomplete data were excluded. Postoperative endoscopic images were analyzed for time to healing, size and location of wound, and presence of granulation tissue. Three blinded, independent raters graded wound appearance and presence of granulation tissue.

RESULTS

Seventy-nine patients healed without need for intervention at a median of 3.5 months. Two patients had office-based ablation of granulation without biopsy and healed. The remaining 19 patients had biopsy for granulation tissue. Wounds that underwent biopsy at >3 months were more likely to contain carcinoma (5/6 patients, 83%) than wounds that were biopsied <3 months (2/13 patients, 15%) (P = .004). Presence of granulation significantly correlated with resection involving anterior commissure (P = .01), > 75%vocal fold length (P = .006), and depth into muscle (P = .001). Delayed healing (>3 months) correlated with T2b tumors (P = .02), depth into ligament (P = .002) and anterior commissure involvement (P = .04). T1a carcinomas more commonly healed in <3 months (P = .005).

CONCLUSIONS

Many vocal fold wounds heal completely within 3.5 months after angiolytic laser surgery for early glottic carcinoma. Larger and deeper wounds are more likely to heal with granulation tissue. Granulation can resolve without surgical intervention; however, granulation present > 3 months warrants biopsy due to increased risk of malignancy.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:435-440, 2019.