Pitfalls in the surgical management of cancer of the larynx and hypopharynx

In vitro evaluation of a biomaterial-based anticancer drug delivery system as an alternative to conventional post-surgery bone cancer treatment

Patients diagnosed with osteosarcoma are currently treated with intravenous injections of anticancer agents after tumor resection. However, due to remaining neoplastic cells at the site of tumor removal, cancer recurrence often occurs. Successful bone regeneration combined with the control of residual cancer cells presents a challenge for tissue engineering. Cyclodextrins loaded with chemotherapeutic drugs reversibly release the drugs over time. Hydroxyapatite bone biomaterials coated with doxorubicin-loaded cyclodextrin should release the drug with time after implantation directly at the original tumor site and may be a way to eliminate residual neoplastic cells. In the present study, we have carried out in vitro studies to evaluate such a drug-delivery system and have shown that doxorubicin released from cyclodextrin-coated hydroxyapatite retained biological activity and exhibited longer and higher cytotoxic effects on both cancer (osteosarcoma cells) and healthy cells (primary osteoblasts and endothelial cells) compared to biomaterials without cyclodextrin loaded with doxorubicin. Furthermore, doxorubicin released from biomaterials with cyclodextrin moderately induced the expression of tumor suppressor protein p53 whereas p21 expression was similar to control cells. In addition, hypoxic conditions, which occur after implantation until blood-flow to the area is regenerated, protected endothelial cells and primary osteoblasts from doxorubicin-induced cytotoxicity. This chemo-protective effect was far less prominent for the osteosarcoma cells. These findings indicate that a hydroxyapatite-cyclodextrin-doxorubicin chemotherapeutic strategy may enhance the drug-targeting effect on tumor cells while protecting the more sensitive healthy cells for a period of time after implantation. A successful integration of such a drug delivery system might allow healthy cells to initially survive during the doxorubicin exposure period, while eliminating residual neoplastic cells.

Open questions and novel concepts in oral cancer surgery

The persistence of cancerous cells after surgery in oral squamous cell carcinoma (OSCC) represents a major challenge, as it often leads to local recurrences and secondary primary tumors, which are eventually responsible for a large proportion of deaths. This persistence is currently evaluated by histological analyses. In this review we discuss some important pitfalls of the histopathological analysis, such as margin evaluation, specimen shrinkage and T staging. In addition, we critically analyze the appropriateness of current surgical techniques in relation to the concept of field cancerization. Finally, we describe some novel imaging and molecular approaches, which might be useful in tailoring surgical resections and encourage the use of OSCC animal models to explore and provide proof of concept of the feasibility and potential clinical utility of innovative surgical protocols.

MicroRNA-137 promoter methylation is associated with poorer overall survival in patients with squamous cell carcinoma of the head and neck

BACKGROUND

The overall 5-year survival rate of approximately 60% for head and neck cancer patients has remained essentially unchanged over the past 30 years. MicroRNA-137 (miR-137) plays an essential role in cell-cycle control at the G1/S-phase checkpoint. However, the aberrant miR-137 promoter methylation observed in squamous cell carcinoma of the head and neck (SCCHN) suggests a tumor-specific molecular defect that may contribute to disease progression.

METHODS

The goal of this study was to assess, in formalin-fixed, paraffin-embedded tumor tissue, the association between miR-137 promoter methylation and survival (both overall and disease free) and with prognostic factors including stage, tumor size, lymph node positivity, tumor grade, and surgical tumor margin positivity.

RESULTS

The promoter methylation status of miR-137 was ascertained by methylation-specific polymerase chain reaction and detected in 11 of 67 SCCHN patients (16.4%), with no significant differences according to site (oral cavity, pharynx, larynx). Methylation of the miR-137 promoter was significantly associated with overall survival (hazard ratio, 3.68; 95% confidence interval, 1.01-13.38) but not with disease-free survival or any of the prognostic factors evaluated.

CONCLUSIONS

The results of this study indicate that miR-137 is methylated in tumor tissue from pharyngeal and laryngeal squamous cancers, in addition to oral squamous cell carcinoma, and that miR-137 promoter methylation has potential utility as a prognostic marker for SCCHN.

Resection margins and other prognostic factors regarding surgically treated glottic carcinomas

BACKGROUND AND OBJECTIVES

This study aims to assess the prognostic significance of free histopathologic margins in the surgical treatment of glottic cancer. Furthermore, it evaluates other prognostic factors regarding cases that receive surgical management for glottic lesions.

METHODS

A retrospective case-series study was conducted at an academic tertiary referral center. The files of 1,314 cases that underwent primary surgical treatment for glottic cancer were studied. Various prognostic factors, including age, surgical procedure, T classification, N classification, histological grade, and status of margins were assessed in univariate and multivariate analyses. All variables were investigated for their association with local and regional disease control as well as disease specific and overall survival.

RESULTS

Status of margins significantly affected disease specific survival and local control regardless of tumor stage in this series. All other variables assessed in the univariate analysis for their association with survival were also found to be significant. However, status of surgical margins and N classification were the only significant variables in multivariate analysis.

CONCLUSION

The prognostic value of negative surgical margins for the treatment of glottic cancer cannot be overestimated. Responsibility of the surgeon during primary surgical treatment of glottic carcinomas is emphasized.

Prognostic significance of surgical margins in transoral CO2 laser microsurgery for T1–T4 pharyngo-laryngeal cancers

Histological affected or close margin is an adverse factor in conventional surgery of larynx-hypopharynx cancer. Our objective was to analyze the relevance of the margins in transoral laser microsurgery (TLM). A retrospective study of 357 consecutive patients with cancer of the larynx and hypopharynx (T1-T4) treated with TLM. Three possible margins were considered: tumor free, affected, and uncertain. An affected margin showed marked tumor infiltration. An uncertain margin was defined when the sample was insufficient, when it showed carbonization impeding accurate evaluation, or when tumor cells were less than 2 mm. Margins were free in 254 (71.1%) patients, affected in 64 (17.9%) and uncertain in 39 (10.9%). One hundred and three patients (28.9%) presented tumor relapse. The margins were associated with tumor relapse (P < 0.001), but were not significantly related to the tumor site (P = 0.307), the pT classification (P = 0.183), or the difficulty of surgical exposure (P = 0.427). Distant metastases were found in 4.7% of the patients with free margins, in 7.7% of those with uncertain margins, and in 14.1% with affected margins. These differences were statistically significant (P = 0.028). Tumor involvement of the surgical margin was associated with higher rates of local relapse, distant metastasis and the necessity of salvage surgery, together with a lower specific actuarial survival rate.

Prognostic Value of Resection Margins in Supracricoid Laryngectomy

OBJECTIVES

The objective was to assess the prognostic value of surgical margin involvement in patients treated for squamous cell carcinoma of the larynx.

STUDY DESIGN

Retrospective study.

METHODS

A review was made of 253 patients treated with supracricoid laryngectomy between 1984 and 2001. A histopathological study on the surgical resection margins was performed in all cases. The incidence of local recurrence was correlated with the histological features of resection margins.

RESULTS

Forty patients (15.8%) were identified as having positive margins: 29 had invasive carcinoma and 11 had dysplastic lesions. The remaining 213 patients (84.2%) had negative margins. Subsequent follow-up showed that 19 of 253 patients developed local recurrence and 3 patients developed regional recurrence. Nine of these patients had positive resection margins (six with invasive carcinoma and three with dysplastic lesions), and 10 had negative resection margins. Overall survival at 3 years was significantly higher for patients without recurrence than for patients with local or regional failure (89.9% vs. 45.5% [P <.05]).

CONCLUSION

According to results of the study, patients with positive resection margins developed local recurrence more frequently than those with clear resection margins (P <.05).