Survival of dental implants and occurrence of mucosal overgrowth in patients with head and neck cancer treated with/without radiotherapy and mucosal graft-two-year follow-up

OBJECTIVES

The primary aim of the present study was to compare head and neck cancer treatment modality surgery and surgery with radiotherapy or chemoradiotherapy alone for dental implant (DI) survival. The second aim was to evaluate the prevalence of mucosal overgrowth around DI after treatment with or without mucosal grafts.

MATERIALS AND METHODS

An observational retrospective study consisted of 59 patients with malignant head and neck tumors that received DI between 2015 and 2019. Treatment modalities together with information on oral rehabilitation with DI, prevalence of mucosal overgrowth, and precursor lesions were gathered from the hospital records. Radiation doses were determined using a sum of three-dimensional dose distributions.

RESULTS

Overall DI survival rate was 88%, in irritated jaw 89%, and in nonirradiated jaw 88% in this observational period (p = 0.415, mean follow-up was 2 years 10 months, range 9-82 months). Mucosal overgrowth was found in 42 of 196 implants (21%), of which 36 cases (86%) were associated in grafted areas (p < 0.001). Oral lichen planus/lichenoid reaction was diagnosed in 14 of all 59 (24%) oral cancer patients.

CONCLUSION

Implant survival was not significantly influenced by radiation therapy in this observational period. In grafted bone, implant survival was significantly inferior than in native bone. Mucosal overgrowth around implants was more common in mucosal grafted areas versus nongrafted.

CLINICAL RELEVANCE

This study demonstrates the impact of grafted bone to dental implant survival rate and mucosal overgrowth.

The effect of matrices on the gene expression profile of patient-derived head and neck carcinoma cells for in vitro therapy testing

OBJECTIVE

Head and neck squamous cell carcinoma (HNSCC) is a highly aggressive tumor with a 5-year mortality rate of ~ 50%. New in vitro methods are needed for testing patients' cancer cell response to anti-cancer treatments. We aimed to investigate how the gene expression of fresh carcinoma tissue samples and freshly digested single cancer cells change after short-term cell culturing on plastic, Matrigel or Myogel. Additionally, we studied the effect of these changes on the cancer cells' response to anti-cancer treatments.

MATERIALS/METHODS

Fresh tissue samples from HNSCC patients were obtained perioperatively and single cells were enzymatically isolated and cultured on either plastic, Matrigel or Myogel. We treated the cultured cells with cisplatin, cetuximab, and irradiation; and performed cell viability measurement. RNA was isolated from fresh tissue samples, freshly isolated single cells and cultured cells, and RNA sequencing transcriptome profiling and gene set enrichment analysis were performed.

RESULTS

Cancer cells obtained from fresh tissue samples changed their gene expression regardless of the culturing conditions, which may be due to the enzymatic digestion of the tissue. Myogel was more effective than Matrigel at supporting the upregulation of pathways related to cancer cell proliferation and invasion. The impacts of anti-cancer treatments varied between culturing conditions.

CONCLUSIONS

Our study showed the challenge of in vitro cancer drug testing using enzymatic cell digestion. The upregulation of many targeted pathways in the cultured cells may partially explain the common clinical failure of the targeted cancer drugs that pass the in vitro testing.

Evaluation of in vitro and in vivo personalized cancer treatment assays for oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) is a common cancer with a high heterogeneity and few approved treatments. OSCC is one of the least explored areas for precision oncology. In this study, we aimed to test the reliability of our three established rapid cancer systemic treatment-testing assays: human tumour-derived matrix (Myogel)-coated well-plates, zebrafish xenografts, and 3D microfluidic chips.

METHODS

Chemo-, radio- and targeted-therapy testing in Myogel-coated wells and zebrafish xenografts was conducted nine times using five samples; two primary and three metastatic lymph node samples from three OSCC patients. Peripheral blood mononuclear cells (PBMNCs) were isolated from the patients' blood. The response of the tumour cells to radio-, chemo-, and targeted therapy was tested using Myogel-coated wells and zebrafish larvae xenografts. The tumour cells' response to immunotherapy was tested using 3D microfluidic chips. The cells' sensitivity to the treatments was compared with the patients' clinical response. Primary and metastatic lymph node tissue-derived DNA samples from two patients underwent whole exome sequencing to compare the mutational profiles of the samples.

RESULTS

Test results were in line with patients' responses in 7/9 (77%) zebrafish xenograft assays and 5/9 (55%) Myogel-coated wells assays. Immunotherapy testing was done using one metastatic patient sample which matched the patients' response. Differences in responses to treatments between primary and metastatic samples of the same patient were detected in 50% of the zebrafish larvae assays.

CONCLUSIONS

Our results show the potential of using personalized cancer treatment testing assays - specifically zebrafish xenografts that revealed promising results - in OSCC patient samples.

Patient and health care delays in large (class T3-T4) oral, oropharyngeal, and laryngeal carcinomas

BACKGROUND

Head and neck cancers (HNCs) are often diagnosed at an advanced stage. We investigated the lengths and factors associated with patient, primary health care (PHC), and specialist care (SC) delays in T3-T4 oral, oropharyngeal, and laryngeal cancer.

METHODS

A nationwide prospective questionnaire-based study (n = 203) with the 3-year long data collection period.

RESULTS

The median patient, PHC and SC delays were 58, 13, and 43 days, respectively. Lower level of education, heavy alcohol use, hoarseness, difficulties breathing, and eventual palliative treatment associated with a longer patient delay. A lump on the neck or facial swelling associated with a shorter PHC delay. Conversely, if symptoms were treated as an infection, PHC delay was longer. The treatment modality and tumor site affected SC delay.

CONCLUSIONS

Patient delay stands as the most notable factor contributing to delays before treatment. HNC symptom awareness thus remains especially important among HNC risk groups.

Risk factors for evaluating early mortality after microvascular reconstruction of head and neck cancers

BACKGROUND

Free tissue transfer reconstruction carries significant complication rates in surgical head and neck oncology. A registry-based approach offers a possibility to investigate the factors affecting increased morbidity and early mortality, that is, death within 6 months of treatment.

METHODS

A retrospective registry review was conducted on a series of 317 consecutive microvascular free tissue transfers in head and neck cancer patients performed during 2013-2017 at the Helsinki University Hospital (Helsinki, Finland). All surviving patients had a minimum follow-up of 2 years (range 24-84 months).

RESULTS

Overall, 36 (11.4%) early deaths occurred in this series. In multivariable logistic regression analysis, patients aged 75 years and older (p = 0.019), Adult Comorbidity Evaluation-27 (ACE-27) score of 3 (p = 0.048), tumor class T3 (p = 0.005), lymph node class N2 (p = 0.014), or thrombocyte count of 360 (× 10⁹ L) or more (p = 0.001) were more likely to die within 6 months of surgery. Of these 36 patients, 27 (75%) had a complication warranting hospital care and most (n = 22, 61%) had several complications.

CONCLUSIONS

Early postoperative mortality most frequently affects patients aged 75 years and above, with a high ACE-27 score, advanced tumor stage, or high thrombocyte count. Therefore, preoperative assessment and patient selection should have a crucial role in this patient population.

Carotid interposition in patients with head and neck tumors: clinical experience of 13 cases reconstructed with a great saphenous vein autograft

BACKGROUND

Carotid interposition graft (CIG) surgery in the setting of head & neck cancer (HNC) is a rare procedure with a limited number of cases described in the literature.

AIMS/OBJECTIVES

To assess the outcomes of the surgery at Helsinki University Hospital.

MATERIALS AND METHODS

Patients who underwent CIG in a head and neck tumor surgery were retrospectively analyzed over 15 years. Overall-survival (OS) was calculated until 1 May 2020. The primary-outcome was to measure the 30-day OS, postoperative stroke rate, and other complications. The secondary-outcome was to measure 1-, 2-, and 5-year OS.

RESULTS

Thirteen patients were identified, 11 with HNC and two with Shamblin III Carotid Body Tumors. The great saphenous vein was used for all vascular reconstructions, and shunting was routinely performed. The 30-day stroke incidence was nil. Two graft-blowouts were encountered, one of which lead to death and the other was successfully managed. For HNC patients, the locoregional recurrence-rate was 36%. The 5-year OS was 46.2%.

CONCLUSION AND SIGNIFICANCE

CIG in HNC setting can achieve oncologic-control with an acceptable rate of complications. Routine shunting, heparinization, and elevating blood-pressure during closure seem to be safe protocols to maintain cerebral-circulation perioperatively. A moderate graft-blowout risk should be considered.

Handgrip Strength Predicts Poorly the Surgical Outcome or Length of Hospitalization in Patients With Surgically Operated Oral Cancer

BACKGROUND/AIM

Handgrip strength has been used to evaluate the potential of elderly patients to survive different medical conditions or procedures, or to predict the nutritional status and length of hospitalization. The aim of this study was to evaluate the use of handgrip strength as a predictor of the length of hospitalization and need for prolonged intensive care in patients with oral malignancies requiring surgical resection and simultaneous primary reconstruction with microvascular free flap.

PATIENTS AND METHODS

This is a retrospective study of 37 head and neck carcinoma patients operated between 2012 and 2014 who had undergone a handgrip force test. The microvascular free flaps used were: radial forearm flap (n=23), anterolateral thigh flap (n=10), and iliac crest free flap (n=4).

RESULTS

Average stay at the hospital was 13.3 days after the operation and there was a 2.9-days need for intensive care. Handgrip strength did not predict susceptibility to complications, duration of hospitalization, or 12-month survival in the study population.

CONCLUSION

Other anamnestic and medical factors and not handgrip strength should be considered when evaluating operability of the patient or their individual risks for microvascular reconstruction.

Reliability of the pre-operative imaging to assess neck nodal involvement in oral cancer patients, a single-center study

Background

Primary sites for the metastasis of oral cancer are the cervical lymph nodes. Although there has been considerable technical advancement in the radiological imaging, capability to recognize all metastatic lymph nodes pre-operatively has remained as a challenge. Thus elective neck dissection (END) has remained as reliable practice to treat cervical lymph nodes. This study evaluated the accuracy of pre-operative imaging in pre-operative diagnostics of cervical lymph node status using computed tomography or magnetic resonance imaging in patients with oral squamous cell carcinoma (OSCC). We have also considered the reasons for the difficulties to recognise metastatic nodes in cervical area.

Material and Methods

Patient charts of patients who had had elective neck dissection as a treatment for primary OSCC in the Department of Oral and Maxillofacial Surgery, Helsinki University Hospital between 2016 and 2017 were assessed retrospectively. The outcome variable was post-operatively histologically confirmed lymph node metastasis in the neck area. The primary predictor variable was radiologically confirmed metastasis in the neck area. The explanatory variables were age, sex, pT-class, imaging modality, delay and location of the tumour. Descriptive statistics, sensitivity, specificity and Youden-J index were computed.

Results

Eighty-three patients were included in the study. The sensitivity to detect pathological lymph nodes was 44.8%, and the specificity for the examination was 87.0%. 19.3% of cN0 patients had metastasis in the cervical nodes, whereas of the cN+ patients 8.4% were actually pN0. Patients having cN0, the largest neck metastasis was over 10 mm in 12.5%, whereas cN1-3 patients the corresponding rate was 45.5%. The computational threshold to diagnose a metastatic node was 7 mm.

Conclusions

Especially small metastases are difficult to diagnose. Limitations of radiological diagnostics must be considered when treating OSCC.

Key words:Oral cancer, Metastasis, CT, MRI, Neck dissection.

Patient-Specific Bioimplants and Reconstruction Plates for Mandibular Defects: Production Workflow and In Vivo Large Animal Model Study

A major challenge with extensive craniomaxillofacial bone reconstruction is the limited donor-site availability to reconstruct defects predictably and accurately according to the anatomical shape of the patient. Here, patient-specific composite bioimplants, consisting of cross-linked poly(trimethylene carbonate) (PTMC) networks and β-tricalcium phosphate (β-TCP), were tested in vivo in twelve Göttingen minipigs in a large mandibular continuity defect model. The 25 mm defects were supported by patient-specific titanium reconstruction plates and received either osteoconductive composite bioimplants (PTMC+TCP), neat polymer network bioimplants (PTMC), autologous bone segments (positive control) or were left empty (negative control). Post-operatively, defects treated with bioimplants showed evident ossification at 24 weeks. Histopathologic evaluation revealed that neat PTMC bioimplant surfaces were largely covered with fibrous tissue, while in the PTMC+TCP bioimplants, bone attached directly to the implant surface showing good osteoconduction and histological signs of osteoinductivity. However, PTMC+TCP bioimplants were associated with high incidence of necrosis and infection, possibly due to rapid resorption and/or particle size of the used β-TCP. The study highlights the importance of testing bone regeneration implants in a clinically relevant large animal model and at the in situ reconstruction site, since results on small animal models and studies in non-loadbearing areas do not translate directly. This article is protected by copyright. All rights reserved.

The combined anterolateral thigh-Partial iliac crest minihybrid free flap for mandibular reconstruction

BACKGROUND AND AIMS

Tumors of the oral cavity often require extensive resections leading to significant hard and soft tissue defects. Microvascular free flaps, consisting of both hard and soft tissue, are often required in reconstructions. Hybrid flaps, composed of two different joint free flaps, offer potential alternatives for head and neck reconstruction. This report presents our results with a modified hybrid ALT/DCIA, that is, minihybrid free flap (MH-flap) composed of the anterolateral thigh (ALT) and a partial inner lamina iliac crest only (partial DCIA) for reconstruction of the mandibular region.

PATIENTS AND METHODS

Eight patients underwent oral cancer reconstruction of the mandible with the MH-flap. The MH-flap was harvested sparing the outer crest and lamina of crista, and its pedicle was combined to the distal pedicle of ALT. Clinical data and postoperative complications were analyzed.

RESULTS

The mean length of the osseous graft was 64 mm (range 54-78 mm). None of the patients had complications requiring surgical intervention. No donor site complications were observed. The overall survival rate was 100%. The mean length of follow-up was 16 months (range 7-30 months).

CONCLUSIONS

According to our results, the ALT-partial DCIA MH-flap has postoperative outcomes comparable to those of the fibular flap. The flap is a good option with excellent bone properties for reconstruction of limited mandibular defects not suitable for fibular or scapular reconstruction.

Periosteal Flaps Enhance Prefabricated Engineered Bone Reparative Potential

The clinical translation of bone tissue engineering for reconstructing large bone defects has not advanced without hurdles. The in vivo bioreactor (IVB) concept may therefore bridge between bone tissue engineering and reconstructive surgery by employing the patient body for prefabricating new prevascularized tissues. Ideally, IVB should minimize the need for exogenous growth factors/cells. Periosteal tissues are promising for IVB approaches to prefabricate tissue-engineered bone (TEB) flaps. However, the significance of preserving the periosteal vascular supply has not been adequately investigated. This study assessed muscle IVB with and without periosteal/pericranial grafts and flaps for prefabricating TEB flaps to reconstruct mandibular defects in sheep. The sheep (n = 14) were allocated into 4 groups: muscle IVB (M group; n_M = 3), muscle + periosteal graft (MP group; n_MP = 4), muscle + periosteal flap (MVP group; n_MVP = 4), and control group (n_Control = 3). In the first surgery, alloplastic bone blocks were implanted in the brachiocephalic muscle (M) with a periosteal graft (MP) or with a vascularized periosteal flap (MVP). After 9 wk, the prefabricated TEB flaps were transplanted to reconstruct a mandibular angle defect. In the control group, the defects were reconstructed by non-prevascularized bone blocks. Computed tomography (CT) scans were performed after 13 wk and after 23 wk at termination, followed by micro-CT (µCT) and histological analyses. Both CT and µCT analysis revealed enhanced new bone formation and decreased residual biomaterial volume in the MVP group compared with control and MP groups, while the M group showed less new bone formation and more residual biomaterial. The histological analysis showed that most of the newly formed bone emerged from defect edges, but larger areas of new bone islands were found in MP and MVP groups. The MVP group showed enhanced vascularization and higher biomaterial remodeling rates. The periosteal flaps boosted the reconstructive potential of the prefabricated TEB flaps. The regenerative potential of the periosteum was manifested after the transplantation into the mechanically stimulated bony defect microenvironment.

Mass spectrometry-based lipidomics of oral squamous cell carcinoma tissue reveals aberrant cholesterol and glycerophospholipid metabolism - A Pilot study

Lipid metabolic reprogramming is one hallmark of cancer. Lipid metabolism is regulated by numerous enzymes, many of which are targeted by several drugs on the market. We aimed to characterize the lipid alterations in oral squamous cell carcinoma (OSCC) as a basis for understanding its lipid metabolism, thus identifying potential therapeutic targets. We compared lipid species, classes, and glycerophospholipid (GPL) fatty acid species between paired tumor tissue and healthy oral tongue mucosa samples from 10 OSCC patients using a QExactive mass spectrometer. After filtering the 1370 lipid species identified, we analyzed 349 species: 71 were significantly increased in OSCC. The GPL metabolism pathway was most represented by the lipids differing in OSCC (P = .005). Cholesterol and the GPLs phosphatidylcholines, phosphatidylethanolamines, and phosphatidylinositols were most significantly increased in OSCC tissue (FC 1.8, 2.0, 2.1, and 2.3 and, P = .003, P = .005, P = .002, P = .007). In conclusion, we have demonstrated a shift in the lipid metabolism in these OSCC samples by characterizing the detailed landscape. Predominantly, cholesterol and GPL metabolism were altered, suggesting that interactions with sterol regulatory binding proteins may be involved. The FA composition changes of the GPLs suggest increased de novo lipogenesis.

Sentinel lymph node biopsies in early stage oral and oropharyngeal carcinoma: a retrospective single-centre experience

The aim of this retrospective study was to analyse a consecutive series of patients with oral and oropharyngeal carcinoma who had had sentinel lymph node biopsy (SLNB) at our hospital during 2008-2017. A total of 70 patients with clinically and radiologically confirmed primary oral (n=67) or oropharyngeal (n=3) carcinoma, with no signs of metastatic lymph nodes preoperatively (clinically N0) were included. Patients' clinical and personal data, characteristics of the tumours, sentinel lymph node (SLN) status and outcomes were recorded. Eight patients had invaded SLN. Two patients with clear sentinel lymph node biopsies had recurrences in the cervical lymph nodes with no new primary tumour as origin. The negative predictive value (NPV) and sensitivity for SLNB were 97% and 80%, respectively. The depth of invasion was an individual predictor for cervical lymph node metastasis (p=0.043). Single photo emission computed tomography (SPECT) detected fewer SLN in patients with invaded lymph nodes than in patients with clear lymph nodes (p=0.018). Our data support the use of SLNB as a minimally invasive method for staging the cervical lymph nodes among patients with cN0 oral and oropharyngeal carcinoma. Our results further confirm that greater depth of invasion is associated with cervical lymph node metastases.

Long-term quality of life after surgery of head and neck cancer with microvascular reconstruction: a prospective study with 4.9-years follow-up

Purpose

The aim of this study was to evaluate the long-term health-related quality of life (HRQoL) of head and neck cancer patients with microvascular surgery. Surgical treatment causes great changes in patient HRQoL. Studies focusing on long-term HRQoL after microvascular reconstruction for head and neck cancer patients are scarce.

Methods

We conducted a prospective study of 93 patients with head and neck cancer and microvascular reconstruction in Helsinki University Hospital Finland. HRQoL was measured using the 15D instrument at baseline and after a mean 4.9-years follow up. Results were compared with those of an age-standardized general population.

Results

Of the 93 patients, 61 (66%) were alive after follow-up; of these, 42 (69%) answered the follow-up questionnaire. The median time between surgery and HRQoL assessment was 4.9 years (range 3.7–7.8 years). The mean 15D score of all patients (n = 42) at the 4.9-years follow up was statistically significantly (p = 0.010) and clinically importantly lower than at baseline. The dimensions of “speech” and “usual activities” were significantly impaired at the end of follow up. There was a significant difference at the 4.9-years follow-up in the mean 15D score between patients and the general population (p = 0.014). After follow up, patients were significantly (p < 0.05) worse off on the dimensions of “speech,” “eating,” and “usual activities.”

Conclusions

Long-term HRQoL was significantly reduced in the whole patient cohort. Speech and usual activities were the most affected dimensions in head and neck cancer patients with microvascular reconstruction at the end of the 4.9-years follow up.

In vitro humanized 3D microfluidic chip for testing personalized immunotherapeutics for head and neck cancer patients

OBJECTIVES

Immunotherapy and personalized medicine therapeutics are emerging as promising approaches in the management of head and neck squamous cell carcinoma (HNSCC). In spite of that, there is yet no assay that could predict individual response to immunotherapy.

METHODS

We manufactured an in vitro 3D microfluidic chip to test the efficacy of immunotherapy. The assay was first tested using a tongue cancer cell line (HSC-3) embedded in a human tumour-derived matrix "Myogel/fibrin" and immune cells from three healthy donors. Next, the chips were used with freshly isolated cancer cells, patients' serum and immune cells. Chips were loaded with different immune checkpoint inhibitors, PD-L1 antibody and IDO 1 inhibitor. Migration of immune cells towards cancer cells and the cancer cell proliferation rate were evaluated.

RESULTS

Immune cell migration towards HSC-3 cells was cancer cell density dependent. IDO 1 inhibitor induced immune cells to migrate towards cancer cells both in HSC-3 and in two HNSCC patient samples. Efficacy of PD-L1 antibody and IDO 1 inhibitor was patient dependent.

CONCLUSION

We introduced the first humanized in vitro microfluidic chip assay to test immunotherapeutic drugs against HNSCC patient samples. This assay could be used to predict the efficacy of immunotherapeutic drugs for individual patients.

Clinical Comparison of Scapular, Fibular, and Iliac Crest Osseal Free Flaps in Maxillofacial Reconstructions

Background and Aims:

This study compared the three most used composite flaps in maxillofacial reconstructions in our institute.

Patients and Methods:

Between 2000 and 2012, a total of 163 patients with mandibular, maxillary, and orbital defects received either scapular, fibular, or iliac crest osseal reconstructions in Helsinki University Hospital, Departments of Plastic Surgery and Maxillofacial Surgery. Data regarding the patient demographics, complications, and outcomes were analyzed.

Results:

There were 92 deep circumflex iliac artery flaps (56%), followed by 42 scapular (26%) and 29 fibular flaps (18%). The rate of flap loss was the highest in the deep circumflex iliac artery group (p = 0.001). Reconstructions using fibula were fastest (p = 0.001) and had lowest perioperative blood loss (p = 0.013). There were no significant differences in the number of early or late complications between the flaps, but donor site complications were more severe in deep circumflex iliac artery. Osteotomies as well as dental implants were safely performed in all flaps with equal results.

Conclusion:

All three flaps of this study can be performed with awareness of the deep circumflex iliac artery flap being the least reliable alternative. The knowledge of the advantages and disadvantages of several osseal-free flap alternatives is beneficial in selecting the best suitable method for each individual patient requiring maxillofacial osseal reconstruction.

The pedicled latissimus dorsi flap in head and neck reconstruction: an old method revisited

In head and neck cancer patients with significant comorbidities, the reconstructive options are limited, and there is a need for a safe alternative for microvascular flaps without compromising flap size. During the study period, 331 head and neck cancer patients were reconstructed with microvascular tissue flaps. Ten patients requiring large resections were considered to have high risks for long surgery and to be poor candidates for free tissue transfer and thus were reconstructed with a subpectorally tunneled pedicled latissimus dorsi (SP-LD) flap. The flap was raised simultaneously with the tumor resection and tunneled to the head and neck region. The flap was used for reconstruction of oral, mandibular, pharyngeal, or neck defects. Median follow-up was 3.6 years. Median duration of surgery was 7 hours and 17 minutes, and total hospital stay was 20 days. During the follow-up, four patients died of their disease and one from another cause (median of 329 days). We were able to perform large tumor resections with a curative intent and reconstruct major defects in high-risk head and neck cancer patients with a SP-LD flap. It possesses many of the characteristics of a free flap with the benefits of a shorter operation time and less perioperative risk.