Oral potentially malignant disorders (OPMD) may precede oral squamous cell carcinoma (OSCC). Reported rates of malignant transformation of OPMD range from 3 to 50%. While some clinical, histological, and molecular factors have been associated with a high-risk OPMD, they are, to date, insufficiently accurate for treatment decision-making. Moreover, this range highlights differences in the clinical definition of OPMD, variation in follow-up periods, and molecular and biological heterogeneity of OPMD. Finally, while treatment of OPMD may improve outcome, standard therapy has been shown to be ineffective to prevent OSCC development in patients with OPMD. In this perspective paper, several experts discuss the main challenges in oral cancer prevention, in particular the need to (i) to define an OPMD classification system by integrating new pathological and molecular characteristics, aiming (ii) to better identify OPMD at high risk of malignant transformation, and (iii) to develop treatment strategies to eradicate OPMD or prevent malignant transformation.

Raman spectroscopic technology for quick and accurate assessment of tumor resection margins.

The tumor microenvironment (TME) is a complex and constantly changing entity. The TME consists of stromal cells, fibroblasts, endothelial cells, and innate and adaptive immune cells. Cancer development and progression occurs through this interplay between the tumor and the adjacent stroma. Cancer cells are capable of modifying their microenvironment by secreting various message-carrying molecules, such as cytokines, chemokines, and other factors. This action causes a reprogramming of the neighboring cells, which are enabled to play a crucial role in tumor survival and progression. The study of TME has many clinical implications in terms of cancer therapeutics because many new drugs, such as antibodies, kinase inhibitors, and liposome formulations that can encapsulate anti-cancer drugs, can be developed. Although chemotherapy is considered the standard of treatment for advanced disease, recent research has brought to light immunotherapy as a possible systemic alternative. However, the complex structure and function of the thymus hinders its routine use in clinical practice. The aim of this review paper is to discuss the recent advances in the investigation of the unique characteristics of the TME of thymic epithelial tumors that could possibly lead to the development of novel promising therapies.

Background: Head and neck squamous cell carcinoma (HNSCC) displays a large heterogeneity in treatment response, and consequently in patient prognosis. Despite extensive efforts, no clinically validated model is available to predict tumor response. Here we describe a functional test for predicting tumor response to radiation and chemotherapy on the level of the individual patient. Methods: Resection material of 17 primary HNSCC patients was cultured ex vivo, irradiated or cisplatin-treated, after which the effect on tumor cell vitality was analyzed several days after treatment. Results: Ionizing radiation (IR) affected tumor cell growth and viability with a clear dose-response relationship, and marked heterogeneity between tumors was observed. After a single dose of 5Gy, proliferation in IR-sensitive tumors dropped below 30% of the untreated level, while IR-resistant tumors maintained at least 60% of proliferation. IR-sensitive tumors showed on average a twofold increase in apoptosis, as well as an increased number and size of DNA damage foci after treatment. No differences in the homologous recombination (HR) proficiency between IR-sensitive and –resistant tumors were detected. Cisplatin caused a decrease in proliferation, as well as induction of apoptosis, again with marked variation between the samples. Conclusions: Our functional ex vivo assay discriminated between IR-sensitive and IR-resistant HNSCC tumors, and may also be suitable for predicting response to cisplatin. Its predictive value is currently under investigation in a prospective clinical study.

Background: Laryngeal and hypopharyngeal cancer is complex and resection margins are therefore constrained. The aim of this study was to investigate the clinical relevance of resection margins in laryngeal and hypopharyngeal surgery. Methods: A retrospective cohort study was performed for patients treated with a total laryngectomy (TL) or laryngopharyngectomy (TLP) for laryngeal or hypopharyngeal squamous cell carcinoma (LSCC and HSCC, respectively). Within the groups primary LSCC, recurrent LSCC, primary HSCC, and recurrent HSCC the relationship between the status of the resection margin according to the Royal Collage of Pathology and the recurrence and survival rates were investigated. Results: Positive resection margins were found in 54% for primary LSCC, 29% for recurrent LSCC, 62% for primary HSCC, and 44% for recurrent HSCC. For primary and recurrent LSCC, there was a linear association between total recurrence and narrowing margins (p = 0.007 resp. p = 0.008). Multivariate survival analysis for primary and recurrent LSCC showed a significantly worse disease free and disease-specific survival in case of positive margins compared to clear margins. Conclusion: Similar survival rates were recorded for close and clear margins for primary and recurrent LSCC. This may suggest that a margin > 5 mm is not clinically relevant in terms of survival. Therefore, a margin of 1–5 mm should be accepted in certain subsites. Margins < 1 mm are related to significantly worse outcomes and should be avoided.

Background: Resection margins are an important prognostic factor for patients with head and neck cancer. In general, for head and neck surgery, a margin >5 mm is advised by the Royal College of Pathologists. However, this cannot always be achieved during laryngeal and hypopharyngeal surgery. The aim of this study is to identify the resection surfaces and measure the maximum feasible margins per subsite. The clinical relevance of these maximum feasible resection margins were analyzed in this descriptive anatomical study. Methods: head and neck surgeons and a pathologist from the Erasmus MC performed a total laryngectomy and laryngopharyngectomy on a head and neck specimen specifically available for research. Results: For a total laryngectomy, resection margins >5 mm were not feasible for the ventral and dorsal resection surface. For a total laryngopharyngectomy, resection margins >5 mm were not feasible for the ventral, dorsal and lateral resection surface. Conclusion: Clear resection margins, defined as a margin >5 mm, are not always feasible in laryngeal and hypopharyngeal surgery, due to the anatomy of the larynx and tumor location. However, striving for a maximum feasible margin is still the main goal. We propose a new guideline for maximum feasible but adequate resection margins in larynx and hypopharynx tumor surgery.