José A. U. Hardillo

Discrimination between oral cancer and healthy tissue based on water content determined by Raman spectroscopy.

Tumor-positive resection margins are a major problem in oral cancer surgery. High-wavenumber Raman spectroscopy is a reliable technique to determine the water content of tissues, which may contribute to differentiate between tumor and healthy tissue. The aim of this study was to examine the use of Raman spectroscopy to differentiate tumor from surrounding healthy tissue in oral squamous cell carcinoma. From 14 patients undergoing tongue resection for squamous cell carcinoma, the water content was determined at 170 locations on freshly excised tongue specimens using the Raman bands of the OH-stretching vibrations (3350-3550 cm(-1)) and of the CH-stretching vibrations (2910-2965 cm(-1)). The results were correlated with histopathological assessment of hematoxylin and eosin stained thin tissue sections obtained from the Raman measurement locations. The water content values from squamous cell carcinoma measurements were significantly higher than from surrounding healthy tissue (p-value < 0.0001). Tumor tissue could be detected with a sensitivity of 99% and a specificity of 92% using a cutoff water content value of 69%. Because the Raman measurements are fast and can be carried out on freshly excised tissue without any tissue preparation, this finding signifies an important step toward the development of an intraoperative tool for tumor resection guidance with the aim of enabling oncological radical surgery and improvement of patient outcome.

Resection margins in oral cancer surgery: Room for improvement

The purpose of this review was to identify publications on resection margins in oral cancer surgery and compare these with the results from 2 Dutch academic medical centers. Eight publications were considered relevant for this study, reporting 30% to 65% inadequate resection margins (ie, positive and close margins), compared to 85% in Dutch centers. However, clinical outcome in terms of overall survival and recurrence seemed comparable. The misleading difference is caused by lack of unanimous margin definition and differences in surgicopathological approaches. This prevents comparison between the centers. Data from Dutch centers showed that inadequate resection margins have a significantly negative effect on local recurrence, regional recurrence, distant metastasis, and overall survival. These results confirm the need for improvement in oral cancer surgery. We underline the need for consistent protocols and optimization of frozen section procedures. We comment on development of optical techniques for intraoperative assessment of resection margins.

Investigation of the potential of Raman spectroscopy for oral cancer detection in surgical margins

The poor prognosis of oral cavity squamous cell carcinoma (OCSCC) patients is associated with residual tumor after surgery. Raman spectroscopy has the potential to provide an objective intra-operative evaluation of the surgical margins. Our aim was to understand the discriminatory basis of Raman spectroscopy at a histological level. In total, 127 pseudo-color Raman images were generated from unstained thin tissue sections of 25 samples (11 OCSCC and 14 healthy) of 10 patients. These images were clearly linked to the histopathological evaluation of the same sections after hematoxylin and eosin-staining. In this way, Raman spectra were annotated as OCSCC or as a surrounding healthy tissue structure (i.e., squamous epithelium, connective tissue (CT), adipose tissue, muscle, gland, or nerve). These annotated spectra were used as input for linear discriminant analysis (LDA) models to discriminate between OCSCC spectra and healthy tissue spectra. A database was acquired with 88 spectra of OCSCC and 632 spectra of healthy tissue. The LDA models could distinguish OCSCC spectra from the spectra of adipose tissue, nerve, muscle, gland, CT, and squamous epithelium in 100%, 100%, 97%, 94%, 93%, and 75% of the cases, respectively. More specifically, the structures that were most often confused with OCSCC were dysplastic epithelium, basal layers of epithelium, inflammation- and capillary-rich CT, and connective and glandular tissue close to OCSCC. Our study shows how well Raman spectroscopy enables discrimination between OCSCC and surrounding healthy tissue structures. This knowledge supports the development of robust and reliable classification algorithms for future implementation of Raman spectroscopy in clinical practice.

Adenoid cystic carcinoma of parotid gland treated with surgery and radiotherapy: Long-term outcomes, QoL assessment and review of the literature

To assess outcomes, toxicity and quality-of-life (QoL) of patients with parotid gland adenoid cystic carcinoma (PGACC) treated by surgery and postoperative radiotherapy. Between 1995 and 2010, 46 patients with PGACC were treated with parotidectomy±neck dissection followed by radiotherapy. Endpoints were loco-regional control (LRC), distant metastasis-free (DMFS), disease-free (DFS), cause-specific (CSS), and overall survival (OS), late toxicity, and QoL. After a median follow-up of 58 months (range 4-171), the 5-year Kaplan-Meier estimates of LRC, DMFS, DFS, CSS, and OS were 88%, 78%, 75%, 80%, and 67%, respectively and the 8-year rates were 88%, 75%, 72%, 77%, and 64%, respectively. On multivariate analysis, T-stage, N-stage, tumor grade, and perineural invasion correlate significantly with DMFS and DFS. The overall 5-year cumulative incidence of grade ≥2 late toxicity was 9%. QoL-scores deteriorate during and shortly after treatment but returned in all scales to almost baseline levels within 6 months. Excellent LRC rates were achieved in patients with PGACC treated by surgery and postoperative radiotherapy with low rate of late side-effects and preservation of good QoL. Despite the effective local therapy, 9 of 46 patients (20%) failed distantly. Because effective treatment strategies for this problem are lacking, prospective trials are needed to determine the role of adjuvant systemic or targeted therapy in patients at high risk of DM.

Laryngotracheal reconstruction with porous titanium in rabbits: are vascular carriers and mucosal grafts really necessary?

Laryngotracheal reconstruction requires a supportive structure with a mucosal lining, which needs a vascular supply in order to regenerate properly. We investigated the necessity of a vascular carrier and mucosal graft when using porous titanium for laryngotracheal reconstruction. Surgical defects of the laryngotracheal complex in 22 rabbits were reconstructed with: (a) porous titanium implanted on a vascularized fascia combined with a buccal mucosal graft (first stage) before transposing to the neck area (second stage); (b) porous titanium implanted on a vascularized fascia (first stage) combined with a mucosal graft (second stage); (c) porous titanium on a pedicled fascia flap; and (d) porous titanium alone. The grafts were tolerated well. Re‐epithelialization occurred in all groups. Normal mucosa with a submucosal layer containing vital cells was noted using the titanium implants. Blood vessels were grown in the pores of the titanium scaffold to supply the overlying mucosa. The scaffold was well integrated in the adjacent tracheal cartilage and surrounding tissues, except in the two cases that showed titanium displacement. Inflammation and granulation formation were seen in most rabbits in groups III and IV, initiated probably by the use of buccal mucosal grafts. Reconstruction of a rabbits trachea using composites of porous titanium, mucosal grafts and a fascia flap is feasible. Titanium seems to meet the requirements needed for closing a small defect of the tracheal wall and allows for re‐epithelialization. For larger defects, a vascular carrier with a mucosal graft is probably indispensable to ensure the process of re‐epithelialization. Copyright

Short-duration enzymatic treatment promotes integration of a cartilage graft in a defect.

Objectives: Surgical manipulation of cartilage tissue is associated with chondrocyte death in the wound edges that hinders integration. The objective of this study was to evaluate the effect of a short course of treatment of a cartilage graft with a combination of hyaluronidase and collagenase on chondrocyte density and integrative capacity. Methods: Cartilage explants were treated with enzymes for various time periods and at various concentrations. A central core was punched out of a larger explant, treated with enzymes, reimplanted, and placed subcutaneously in athymic mice. The number of chondrocytes in the wound edges was counted, and the integrative capacity of the grafts was evaluated by histology. Results: Treatment with collagenase for 48 hours led to a significant increase in the number of vital chondrocytes and restored it to normal after 14 days of culture. Treatment with hyaluronidase and collagenase for 48 hours further increased chondrocyte densities to supranormal values. Shortening the treatment to 1 hour restored the chondrocyte density to normal after 14 days of culture. In vivo integration experiments showed increased chondrocyte densities in treated wound edges and extracellular matrix fibers crossing over from enzyme-treated parts to untreated parts. Conclusions: Short-duration treatment of a cartilage graft with a combination of hyaluronidase and collagenase increases cell density at wound edges and promotes integrative repair.

Water Concentration Analysis by Raman Spectroscopy to Determine the Location of the Tumor Border in Oral Cancer Surgery

Adequate resection of oral cavity squamous cell carcinoma (OCSCC) means complete tumor removal with a clear margin of more than 5 mm. For OCSCC, 85% of the surgical resections appear inadequate. Raman spectroscopy is an objective and fast tool that can provide real-time information about the molecular composition of tissue and has the potential to provide an objective and fast intraoperative assessment of the entire resection surface. A previous study demonstrated that OCSCC can be discriminated from healthy surrounding tissue based on the higher water concentration in tumor. In this study, we investigated how the water concentration changes across the tumor border toward the healthy surrounding tissue on freshly excised specimens from the oral cavity. Experiments were performed on tissue sections from 20 patients undergoing surgery for OCSCC. A transition from a high to a lower water concentration, from tumor (76% ± 8% of water) toward healthy surrounding tissue (54% ± 24% of water), takes place over a distance of about 4 to 6 mm across the tumor border. This was accompanied by an increase of the heterogeneity of the water concentration in the surrounding healthy tissue. The water concentration distributions between the regions were significantly different (P < 0.0001). This new finding highlights the potential of Raman spectroscopy for objective intraoperative assessment of the resection margins. Cancer Res; 76(20); 5945-53. ©2016 AACR.

Highly-conformal intensity-modulated radiotherapy reduced toxicity without jeopardizing outcome in patients with paranasal sinus cancer treated by surgery and radiotherapy or (chemo)radiation

OBJECTIVES To report oncologic outcomes of patients with paranasal sinus cancer (PNSC) treated by surgery and radiotherapy or (chemo)radiation and to investigate the impact of improving the radiation technique on outcomes and toxicity. MATERIALS AND METHODS Between 1999 and 2010, 82 consecutive patients with PNSC were treated by surgery and radiotherapy or by definitive (chemo)radiation. Three-dimensional conformal (3DCRT) or highly-conformal intensity-modulated RT (IMRT) was used. Endpoints were local control (LC), regional control (RC), disease-free (DFS), cause-specific (CSS), and overall survival (OS), late toxicity, and quality-of-life (QoL). RESULTS After median follow-up of 51 months, the 5-year actuarial rates of LC, RC, DFS, CSS, and OS were 74%, 94%, 56%, 64%, and 54%, respectively. Grade ≥ 2 late toxicity at 5-years was 28%. High T-stage and perineural invasion were significantly associated with poor LC and RT-technique with late toxicity. Late toxicity was significantly lowered using IMRT, compared to 3DCRT (17% vs. 52%, p<0.0001). Visual preservation were significantly improved using IMRT (88% and 65%, respectively, p=0.01). LC-rate was also improved by IMRT (80% vs. 64%, respectively, p=0.2). QoL-scores deteriorated during and shortly after treatment but returned in almost all scales to baseline levels within 3-12 months. CONCLUSIONS Surgery and radiotherapy or definitive (chemo)radiation resulted in good LC rates but with high rate of late side-effects. However, late toxicity and permanent visual impairment were significantly decreased by using highly-conformal IMRT without jeopardizing outcome. The improvements in the therapeutic ratio achieved by using IMRT would allow dose escalation of RT to further improve outcomes.

Tracheal Reconstruction: Mucosal Survival on Porous Titanium

OBJECTIVE To investigate whether porous titanium can provide a better support for revascularization of a mucosal graft ideal for tracheal reconstruction. In patients with laryngotracheal stenosis or tumor, the mucosa with supporting structures can be damaged, resulting in a defect that has to be reconstructed. Autologous tissues like cartilage and mucosa have been used for reconstruction. The main problem has been incomplete mucosal reepithelialization. DESIGN In the first experiment, porous titanium or ear cartilage was combined with mucosa and implanted subcutaneously in athymic mice for different periods of time. In the second experiment, using rabbits, surgically created defects were reconstructed with porous titanium and mucosa on a pedicled fascia flap using a 2-stage procedure. The implants were analyzed with emphasis on angiogenesis and mucosal survival. SUBJECTS Male New Zealand white rabbits and nude athymic mice (BALB-c nu/nu). RESULTS Normal mucosa having a submucosal layer with vital cells was noted on top of the titanium. Multiple blood vessels were observed extending from the muscle layer through the titanium. Cytokeratin expression was detected in the suprabasal and basal layers of the mucosal epithelium. In contrast, the mucosa on cartilage showed no vital cells and no cytokeratin expression. In the rabbit experiment, all animals survived the reconstruction. The titanium was well integrated to the adjacent tracheal cartilage and surrounding tissues, supporting a fully vital mucosa. CONCLUSIONS Porous titanium is an inert biomaterial that provides support and allows easy revascularization of a mucosal graft. Titanium, in combination with viable autologous tissues, is a good alternative for tracheal reconstruction.

Heat-induced BRCA2 degradation in human tumours provides rationale for hyperthermia-PARP-inhibitor combination therapies

Abstract Purpose: Hyperthermia (40–44 °C) effectively sensitises tumours to radiotherapy by locally altering tumour biology. One of the effects of heat at the cellular level is inhibition of DNA repair by homologous recombination via degradation of the BRCA2-protein. This suggests that hyperthermia can expand the group of patients that benefit from PARP-inhibitors, a drug exploiting homologous recombination deficiency. Here, we explore whether the molecular mechanisms that cause heat-mediated degradation of BRCA2 are conserved in cell lines from various origins and, most importantly, whether, BRCA2 protein levels can be attenuated by heat in freshly biopted human tumours. Experimental design: Cells from four established cell lines and from freshly biopsied material of cervical (15), head- and neck (9) or bladder tumours (27) were heated to 42 °C for 60 min ex vivo. In vivo hyperthermia was studied by taking two biopsies of the same breast or cervical tumour: one before and one after treatment. BRCA2 protein levels were measured by immunoblotting. Results: We found decreased BRCA2-levels after hyperthermia in all established cell lines and in 91% of all tumours treated ex vivo. For tumours treated with hyperthermia in vivo, technical issues and intra-tumour heterogeneity prevented obtaining interpretable results. Conclusions: This study demonstrates that heat-mediated degradation of BRCA2 occurs in tumour material directly derived from patients. Although BRCA2-degradation may not be a practical biomarker for heat deposition in situ, it does suggest that application of hyperthermia could be an effective method to expand the patient group that could benefit from PARP-inhibitors.