Validation of a risk prediction calculator in Australian patients undergoing head and neck microsurgery reconstruction

BACKGROUND

The American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) surgical risk calculator (SRC) is an open access calculator predicting patients' risk of postoperative complications. This study aims to assess the validity of the SRC in patients undergoing microsurgical free flap reconstruction at an Australian tertiary referral centre.

METHODS

This is a retrospective cohort study of 200 consecutive patients treated up to November 2020. SRC-predicted rates of postoperative complications and hospital length of stay (LOS) were compared to those observed for the ablative and reconstructive components of the procedure. The performance of the SRC was assessed using Brier scores, area under the receiver operating characteristic (ROC) curve (AUC), and the Hosmer-Lemeshow test.

RESULTS

For both ablative and reconstructive components, the SRC discriminates well for pneumonia and urinary tract infection, and it is calibrated well for readmission and sepsis, but it does not discriminate and calibrate well for any single outcome. SRC-predicted hospital LOS and actual LOS did not correlate well for the reconstructive component, but they correlated strongly for the ablative component.

CONCLUSIONS

The SRC is a poor predictor of postoperative complication rates and hospital LOS in patients undergoing head and neck microsurgical reconstruction.

Health-related quality of life in maxillectomy patients undergoing dentoalveolar rehabilitation

OBJECTIVES

Surgical resection of the maxilla impairs aesthetics, speech, swallowing, and mastication. Maxillary reconstruction is increasingly performed with virtual surgical planning (VSP) to enhance functional dental rehabilitation with a conventional denture or osseointegrated implants. The aim of this study was to determine whether dental status and VSP is associated with health-related quality of life (HRQOL) and function in patients who have undergone maxillectomy.

MATERIALS AND METHODS

A cross-sectional study was conducted among patients who underwent free flap reconstruction or obturation of the maxilla between July 2009 and December 2020. The FACE-Q Head and Neck Cancer (FACE-Q) module, M.D. Anderson Dysphagia Inventory (MDADI), and Speech Handicap Index (SHI) were used to evaluate HRQOL.

RESULTS

Forty-three patients (response rate 59%) completed questionnaires and 48% underwent dental rehabilitation. In Okay Class II and III defects, adjusting for the effect of radiotherapy and time from surgery, there was a positive association between denture status and FACE-Q smiling (p = 0.020), eating (p = 0.012), smiling (p = 0.015), and MDADI global (p = 0.015), emotional (p = 0.027), functional (p = 0.028), and composite (p = 0.029) scores. VSP was associated with FACE-Q swallowing (p = 0.005), drooling (p = 0.030), eating (p = 0.008), smiling (p = 0.021), MDADI global (p = 0.017), emotional (p = 0.041), functional (p = 0.040), composite (p = 0.038), and SHI total scores (p = 0.042).

CONCLUSIONS

Dentoalveolar rehabilitation and VSP were associated with higher HRQOL scores relating to eating and drinking, smiling, and speaking.

Improvement in epistaxis management: the experience of a dedicated hereditary haemorrhagic telangiectasia clinic

BACKGROUND

Hereditary haemorrhagic telangiectasia (HHT) is a rare genetic vascular disorder which is characterised by the development of arteriovenous malformations and telangiectasias. A key clinical manifestation is recurrent epistaxis. This study examined the impact of a dedicated HHT clinic in a major Australian tertiary hospital on epistaxis symptoms and subjective quality of life.

METHODS

A multidisciplinary HHT clinic was established in 2015. All patients satisfied either genetic diagnosis or fulfilled Curacao criteria. A protocol based clinical assessment was performed and a standardised treatment regimen was implemented. Patients completed quality of life and epistaxis severity score (ESS) questionnaires at each review.

RESULTS

Participants of the dedicated clinic included 21 females (58.3%) and 15 males (41.7%), with a mean age of 49.0 ± 24.0 years. The ACVRL1 variant was the most common (n = 20, 55.6%). A statistically significant reduction in epistaxis severity was noted between the baseline and second review (P = 0.02) and was maintained to the third visit (P = 0.015). Patients older than 50 years demonstrate a consistently higher ESS than those less than 50 years old (P = 0.03). This trend is noted throughout the follow up period with the dedicated clinic.

CONCLUSION

The introduction of a multidisciplinary, dedicated HHT clinic to provide enhanced assessment, monitored treatment regimen and greater access to care, resulted in improvement in the management of epistaxis and quality of life in these patients.

Dentoalveolar outcomes in maxillary reconstruction: A retrospective review of 85 maxillectomy reconstructions

BACKGROUND

Although microvascular free flaps are often used to reconstruct maxillary defects, dentoalveolar rehabilitation is arguably less common despite its importance to midface function and aesthetics. The aim of this study is to review the contemporary management of maxillary defects in a single quaternary referral institution to identify factors that assist or impede dentoalveolar rehabilitation.

METHODS

A retrospective review of maxillary reconstructions performed between February 2017 and December 2020 was performed. Patient characteristics, defect classification, operative techniques, complications and dentoalveolar outcomes were recorded.

RESULTS

A total of 85 maxillary reconstructions were performed in 73 patients. Of the 64 patients where dental rehabilitation was required, 31 received a functional denture (48%) with 24 (38%) being implant-retained. Significant predictors of successful rehabilitation included the use of virtual surgical planning (VSP; 86% vs. 25%, p < 0.001), preoperative prosthodontic assessment (82% vs. 21%, p < 0.001), prefabrication (100% vs. 40%, p = 0.002) and use of the zygomatic implant perforator flap technique (100% vs. 39%, p = 0.001). Preoperative prosthodontic consultation was associated with 21-fold increase in the odds of rehabilitation (odds ratio 20.9, 95% confidence interval 6.54-66.66, p < 0.005).

CONCLUSION

Preoperative prosthodontic evaluation, VSP and reconstructive techniques developed to facilitate implant placement are associated with increased dental rehabilitation rates. Despite using an institutional algorithm, functional dentures are frequently prevented by factors including soft tissue constraints, disease recurrence and patient motivation.

The significance of regional metastasis location in head and neck cutaneous squamous cell carcinoma

BACKGROUND

Regional metastasis of head and neck cutaneous squamous cell carcinoma (HNcSCC) can be seen in either parotid and/or cervical lymph nodes. The aim of this study was to assess whether there was a difference in prognosis between parotid and cervical nodal metastases.

METHODS

Patients with regional metastasis from HNcSCC were identified from an institutional database. Disease-specific (DSS) and overall survival (OS) were calculated using the Kaplan-Meier method and Cox proportional hazards models.

RESULTS

Five hundred and thirty-five patients were identified with median follow-up of 26.4 months (3-255 months). Two hundred and thirty-five patients had parotid metastasis, 96 patients had neck metastasis, and 204 patients had both. On multivariable analysis, any regional metastasis to the neck when compared to parotid alone conferred worse DSS (HR 1.8, p = 0.007) and OS (HR 1.3, p = 0.024).

CONCLUSION

Regional metastasis of HNcSCC to the neck confers worse outcomes compared to metastasis to the parotid alone.

Metrics of pN-staging in oral squamous cell carcinoma: An analysis of 1,905 patients

BACKGROUND

We aimed to compare the predictive performance of pN-categories in oral squamous cell carcinoma (OSCC) encompassing the most recent 8th edition (TNM8), its predecessor (TNM7), and a newly proposed algorithm (pN-N⁺), which classifies patients according to the number of positive lymph nodes and extranodal extension.

METHODS

Consecutive, primary OSCC patients from seven previously published cohorts were included and classified according to the three pN-classifications: TNM7, TNM8 and pN-N⁺. Overall survival probabilities were summarised with the Kaplan-Meier method. We added each of the three metrics to a Cox regression adjusted for pT-category, lymph nodal yield, age, sex, radiotherapy and chemotherapy, and trained these models in one institution. We evaluated the predictive performance in the remaining six institutions and assessed the predicted 5-year risk of death using the area under the receiver operating characteristics curve (AUC) and Brier scores.

RESULTS

All 1,905 included patients were classified according to TNM7 and pN-N⁺. A subset of 1,575 patients was additionally classified according to TNM8, leading to upstaging in 27.0%. The pN-N⁺ ranked overall best determined by the obtained AUC and Brier scores. In contrast to pN-N⁺, TNM7 and TNM8 both suffered from disproportionate patient distribution across pN-categories and poor pN-categorial discrimination on overall survival.

CONCLUSIONS

The TNM8 pN-classification designates a larger subset to more advanced disease stages but failed to show improvement of its predictive performance compared to TNM7. The pN-categories of TNM7/8 are disproportionate and inconsistently discriminated. The pN-N⁺ conveyed the best measures of prognosis and should be considered in future TNM iterations.

Microvascular reconstruction of head and neck defects in the elderly

BACKGROUND

Microvascular free-flap reconstruction of the head and neck is a common technique utilized across many ages. The purpose of this study was to identify if advanced age or comorbidity was associated with worse post-operative outcomes in patients undergoing free-flap reconstruction.

METHODS

A retrospective analysis was performed on 344 consecutive patients undergoing free-flap surgery of the head and neck. Demographic, clinical and pathological factors were considered along with Charlson Comorbidity Index (CCI) scores and American Society of Anesthesiologists (ASA) status. Logistic regression analysis was used to investigate the association of age, CCI or ASA with post-operative complications.

RESULTS

Elderly patients (≥75 years) had a higher overall complication rate (odds ratio (OR) 1.7, P = 0.04) that was restricted to medical complications (OR 2.1, P = 0.05) and not surgical complications (OR 1.4, P = 0.14). Reconstructions of defects from cutaneous malignancy predominated in the elderly cohort (48% versus 29%, P < 0.01), but there was no difference in complication rate when cutaneous or mucosal subgroups were separated by age. ASA IV status was weakly associated with surgical complications (OR 3.89, P = 0.053), but CCI and elderly age were not associated with any outcome. Median length of stay was similar between age groups.

CONCLUSION

Free-flap reconstruction in older patients was associated with increased medical complications, and surgical complications were weakly associated with ASA status. Advanced age or comorbidity should not preclude microvascular reconstruction, but comorbid status should be optimized pre-operatively and factors predisposing to medical complications minimized where possible.

Geographical heterogeneity in the American Joint committee on Cancer oral cancer staging and prognostic implications

OBJECTIVES

The AJCC 8th edition (AJCC 8) has introduced depth of invasion (DOI) and extranodal extension (ENE) into staging for oral squamous cell carcinoma (OSCC). Although validations have been performed on institutional datasets have shown a good performance, particularly in early OSCC, there have been no studies on diverse patient populations that determine the impact on prognostic heterogeneity.

MATERIALS AND METHODS

Retrospective analysis of 4710 patients with oral squamous cell carcinoma (OSCC) treated with surgery +/- adjuvant therapy in 8 institutions in Australia, North America and Asia. With overall survival (OS) as endpoint, the prognostic performance of AJCC 7th and 8th editions were compared using Akaike Information Criterion (AIC), Bayesian Information Criteria (BIC), Harrell's concordance index (C-index).

RESULTS

When comparing AJCC 8 to AJCC 7, the heterogeneity in prediction of OS increased for T-category and N-category while remaining unchanged for TNM staging, suggesting AJCC 8 increased complexity with no improvement in predictive value. There were significant differences in median DOI and incidence of ENE between geographical regions, resulting in dissimilar rates of stage-migration when adopting AJCC 8.

CONCLUSION

In an attempt to improve prognostic performance, AJCC 8 introduced more variables; however heterogeneity in these results in significant geographical differences in model discrimination and performance. Caution should be applied as this may result in inaccurate and unreliable prognostic predictions that may impact treatment recommendations.

Implantable Doppler Ultrasound Monitoring in Head and Neck Free Flaps: Balancing the Pros and Cons

OBJECTIVES/HYPOTHESIS

Free flap transfer offers a versatile option for reconstruction in head and neck surgery, with success rates over 95%. There remains a substantial re-exploration rate of roughly 5% to 15%, with early recognition of compromise essential to flap survival. Monitoring techniques are highly desirable, with the gold standard being clinical monitoring. The Cook-Swartz Doppler (CSD) probe utilizes Doppler technology to inform clinicians about real-time flow. We aim to describe our adoption of this technology in 100 consecutive free flaps.

STUDY DESIGN

Prospective case series.

METHODS

Prospective data were collected from July 2014 to June 2015 on 100 consecutive free flaps performed at a head and neck unit in London, Ontario. All patients had a CSD inserted for arterial and venous monitoring.

RESULTS

A total of 100 free flaps were performed on 99 patients. Sensitivity was 87.1% and specificity was 85.7%. Positive predictive value was 98.8% and negative predictive value was 33.3%. False-negative and false-positive rate were 1.0% and 12.0%, respectively. The exploration rate was 12%, with no flap loss and two partial debridements. The CSD was helpful in management in 9% of cases and was clinically unhelpful in 11% of cases, with 10 of 11 abnormal signals ignored. There were three unique CSD complications; one retained wire, one pedicle laceration during extraction, and one clot around the probe interrupting signal.

CONCLUSIONS

The CSD is a helpful adjunct to clinical monitoring but has unique complications, which were not previously described. Pros and cons must be considered for new centers adopting this technology.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E1854-E1859, 2021.

A prospective study of intraoperative assessment of mucosal squamous cell carcinoma margins in the head and neck

BACKGROUND

In head and neck cancers, tumor margin assessment has important prognostic and therapeutic implications. Frozen section control of margins is commonly employed intraoperatively. However, this is not without limitations. The aim of this study is to determine whether intraoperative slicing of the whole specimen is feasible and what impact this may have on tumor margin assessment and the requirement for postoperative radiotherapy.

METHODS

From September 2016 to August 2018, we recruited 22 patients as a pilot study looking at both the practicalities and the clinical relevance of whole margin tumor analysis intraoperatively. Our project is a prospective single arm study with historical controls.

RESULTS

Forty-one percent of our patients required further intraoperative resection for close or involved margins. Seven of these patients who otherwise would have required adjuvant radiotherapy due to their margin status did not, after our intervention.

CONCLUSIONS

We found that although requiring resources, this process was feasible without unduly increasing operative times and with potential patient benefit including reduced incidence of adjuvant radiotherapy.

Survival outcomes following modern multidisciplinary management of oral squamous cell carcinoma in Australia

OBJECTIVE

Oral squamous cell carcinoma (SCC) has been traditionally described as a highly lethal disease. This study aims to provide updated multi-institutional data on the survival of patients with oral SCC in Australia.

STUDY DESIGN

Retrospective survival analysis was performed between 2008 and 2016. All new patients with oral SCC treated with curative intent were recruited from 2 high-volume Australian head and neck oncology centers. Outcomes were measured in overall survival (OS), disease-specific survival (DSS), disease-free survival, and salvage rates for recurrences.

RESULTS

Survival analysis included 771 patients with oral SCC. Five-year OS and DSS were 66.1% and 79.7%, respectively. Stage I and II oral SCC had significantly better survival than higher stages. Five-year OS and DSS for patients with stage I SCC were 79.7% and 93.4%, respectively, and for patients with stage IVB they were 37.9% and 54.3%, respectively. Two hundred forty-nine patients had disease recurrence (32.3%), with 66 patients (26.5% remaining disease free post salvage treatment.

CONCLUSION

Survival outcomes for oral SCC among Australian patients have improved, possibly due to advances in multidisciplinary care. Early detection of oral SCC leads to highly favorable prognosis; there is therefore an opportunity for routine oral cancer screening to be performed by community health practitioners with the aim of improving survival from oral SCC.

Soft Tissue Metastases in Head and Neck Cutaneous Squamous Cell Carcinoma

OBJECTIVE

Soft tissue metastases (STM) in head and neck cutaneous squamous cell carcinoma (HNcSCC) are non-nodal based metastases to the parotid and cervical soft tissues of the head and neck. This is a unique subgroup of regional metastases amongst patients with cSCC and have been shown to be associated with poor prognosis. Detailed studies of this subgroup are lacking in the literature. A retrospective cohort analysis was performed to characterize the prognostic significance of STM in HNcSCC based on individual clinicopathological features.

METHODS

Patients with HNcSCC with STM were identified from the Sydney Head and Neck Cancer Institute database. Clinicopathological characteristics were extracted from the histopathological reports. Recurrence and follow-up data were analyzed to determine disease-free and overall survival using the Kaplan-Meier method and Cox proportional hazards models.

RESULTS

After excluding all patients with lymph node metastasis with no STM, there were 200 patients identified (161 parotid, 32 cervical, and seven with concurrent parotid and cervical STM) with a 5-year overall survival of 36%. In univariable analysis, age of patients, size of the deposits, location of the deposits, and patients that were not offered adjuvant radiotherapy have worse overall survival. However, on multivariable analysis, age and the number of STM deposits were independent factors that predict for worse survival.

CONCLUSION

The presence of STM in patients with HNcSCC is associated with poor prognosis. Increasing number of STM deposits, as well as involved margin of the regional excision, negatively impacted on the overall prognosis.

LEVEL OF EVIDENCE

Level III - retrospective cohort study. Laryngoscope, 131:E1209-E1213, 2021.

Number of nodal metastases and the American Joint Committee on cancer staging of head and neck cutaneous squamous cell carcinoma: A multicenter study

OBJECTIVES

We aimed to determine if the number of nodal metastases is an independent predictor of survival in HNcSCC, whether it provides additional prognostic information to the AJCC N and TNM stage and identify optimal cut-points for risk stratification.

MATERIALS AND METHODS

Retrospective multi-institutional cohort study of patients with parotid and/or cervical nodal metastases from HNcSCC treated with curative intent by surgery ± adjuvant therapy. The impact of number of nodal metastases on disease-specific and overall survival was assessed using multivariate Cox regression. Optimal cut-points for prognostic discrimination modelled using the AIC, BIC, C-index and PVE.

RESULTS

The study cohort included 1128 patients, with 962 (85.3%) males, median age of 72.9 years (range: 18-100 years) and median follow-up 3.4 years. Adjuvant radiotherapy was administered to 946 (83.9%) patients. Based on objective measures of model performance, number of nodal metastases was classified as 1-2 (N = 816), 3-4 (N = 162) and ≥5 (N = 150) nodes. In multivariate analyses, the risk of disease-specific mortality progressively increased with 3-4 nodes (HR, 1.58; 95% CI: 1.03-2.42; p = 0.036) and ≥5 nodes (HR, 2.91; 95% CI: 1.99-4.25; p < 0.001) with similar results for all-cause mortality. This simple categorical variable provided superior prognostic information to the TNM stage.

CONCLUSION

Increasing number of nodal metastases is an independent predictor of mortality in HNcSCC, with categorization as 1-2, 3-4 and ≥5 nodes optimizing risk stratification and providing superior prognostic information to TNM stage. These findings may aid in the development of future staging systems as well as identification of high-risk patients in clinical trials.

Trends in parotidectomy over 30 years in an Australian tertiary care center

BACKGROUND

Nomenclature, classification, and management of parotid tumors are constantly evolving; this study was performed to identify temporal trends in histology and facial nerve sacrifice in parotidectomy during a 30-year period (1987-2018).

METHODS

Retrospective analysis of patients treated in a single tertiary-care institution during this time period was performed with analysis of temporal trends.

RESULTS

Two thousand eight hundred and fifty-seven parotidectomies were performed; pleomorphic adenoma was the most common histology (34.3%), followed by skin cancer metastases (32.3%). Significant trends noted were increasing age (P < .001), fewer parotidectomies for inflammatory lesions (P < .001), reduced incidence of mucoepidermoid carcinoma (P = .048), increasing incidence of parotidectomy for cutaneous malignancies (P < .001), and reduced facial nerve sacrifice (P = .034).

CONCLUSION

In this contemporary series of parotid pathology, metastatic cutaneous malignancies accounted for a third of cases. Despite reducing facial nerve sacrifice in parotid disease, it is still required in approximately 15% of malignancy and needs to be discussed with all patients preoperatively.

Recreation of eyelid mechanics using the sling concept✰

BACKGROUND

Paralytic lagophthalmos causes major functional, aesthetic and psychological problems in patients with facial paralysis. The Bionic Lid Implant for Natural Closure (BLINC) project aims to restore eyelid function using an implanted electromagnetic actuator combined with an eyelid sling. The authors performed a preliminary study using cadaveric heads to investigate the optimal application of an eyelid sling in various configurations around the orbit.

METHODS

The sling was tested in a cadaveric sheep head using 2 medial anchor points and 4 lateral ostectomy points. An impulse was generated using gravitational force to test each combination of medial and lateral sling insertion sites using weights between 10 and 50 g. Each generated blink was recorded and analysed. The final result was validated in a human cadaveric model.

RESULTS

The maximum amount of eye closure and closure speed displayed in sheep were 83.7 ± 9.4% of total closure and 70.6 ± 6.9 mm/s at a maximum force of 490 mN, respectively. The 2 inferior lateral attachments performed better at displacing the eyelid than the superior attachments. The position with the highest degree of eye-closure (improvement of 21.6%, p < 0.001) and speed (improvement of 30.4 mm/s, p < 0.001) was the combination of a posterior medial attachment and an inferior-posterior lateral attachment, which resulted in a near physiological closure in human cadaver.

CONCLUSION

Closure improved with an inferior lateral position due to increased force acting in the direction of closure. Posterior positioning increases force acting radially, towards the centre of eyelid movement. The latter directs the closure force to effectively move the eyelid around the curved globe.

Assessment of shoulder function following scapular free flap

BACKGROUND

The scapular system free flap has been increasing in popularity to reconstruct short segment mandibular bony defects. It is important to assess donor site morbidities systematically.

METHODS

Prospective cohort study using objective measures of range of motion (ROM) and shoulder strength were measured. Subjective disability was evaluated with validated questionnaires-Neck Disability Impairment Index and Shoulder Pain and Disability Index.

RESULTS

Twenty-six patients were recruited-19 with scapular tip and 7 with lateral border scapular free flap. Decreased ROM on the operated side was noted for shoulder abduction, shoulder flexion, and external rotation. No significant difference was noted for shoulder extension. Strength was reduced for shoulder flexion, shoulder abduction, and external rotation. Subjective measurements did not indicate significant shoulder function disruption.

CONCLUSION

Patients with scapular free flap reconstruction did not experience significant shoulder morbidity. Measures of shoulder ROM and power were objectively affected; however, subjective measures of shoulder disability were not significantly affected.

Tumour mismatch repair protein loss is associated with advanced stage in oral cavity squamous cell carcinoma

An unexplained increase in the incidence of oral cavity squamous cell carcinoma (oSCC) has been observed despite decreasing smoking rates, particularly in younger patients. Links to defects in the DNA mismatch repair (MMR) system are well established in early onset colorectal, urothelial and gynaecological malignancies. MMR deficient patients treated with immune checkpoint inhibitors have demonstrated improved response rates. Studies exploring MMR status in head and neck squamous cell carcinoma (HNSCC) demonstrate conflicting results. This study explores the incidence of MMR protein loss and its association with clinicopathological features and outcome in oSCC. Immunohistochemical staining using tissue microarrays to assess the expression of MMR proteins (hMLH1, hMSH2, hMSH6, and hPMS2) was performed on 285 consecutive oSCC cases between 2000 and 2016. Data on smoking, alcohol and metachronous malignancies were retrospectively collected. Proportional hazards regression models were used to compare survival in MMR intact and deficient patients. MMR deficiency was seen in 21 patients (7.4%). MMR deficient tumours were associated with bone invasion (52% vs 32%, p=0.05), higher pT stage (pT4 in 57% vs 35%, p<0.001) and a higher number of metachronous malignancies (p=0.05). MMR deficiency was not associated with younger age at presentation or absence of smoking or alcohol. There was no significant association between MMR status and survival (overall survival hazard ratio 1.36; p=0.32). The incidence of MMR loss in oSCC is low and is not associated with young age at presentation. MMR deficiency in oSCC is associated with an increase in the number of metachronous malignancies and more advanced primary tumours.

Multifocal perineural invasion is a better prognosticator than depth of invasion in oral squamous cell carcinoma

OBJECTIVES

Prognostic significance of perineural invasion (PNI) in oral squamous cell carcinoma (OSCC) characterized as unifocal and multifocal was compared to depth of invasion (DOI) and extranodal extension (ENE).

MATERIALS AND METHODS

Univariable and multivariable analyses of 861 consecutive patients with OSCC undergoing treatment between 1995 and 2018 were performed, with local failure (LF) and disease-specific mortality (DSS) as the primary endpoints.

RESULTS

After adjusting for other adverse histopathological factors and adjuvant therapy, multifocal PNI was associated with a greater risk of LF (P = .01) and DSS (P = 0.02) compared to DOI. The effect of multifocal PNI was comparable to the effect of nodal metastases without ENE (P = 0.02). LF and DSS were not improved by the administration of adjuvant radiotherapy within unifocal or multifocal PNI groups.

CONCLUSION

Multifocal PNI is associated with a greater risk of death in OSCC than DOI. Its effect is comparable to that of nodal metastases (without ENE).

Is high-risk cutaneous squamous cell carcinoma of the head and neck a suitable candidate for current targeted therapies?

OBJECTIVE

Cutaneous squamous cell carcinoma (cSCC) is the second most common malignancy, most frequently affecting the head and neck. Treatment often requires surgery and can have significant functional morbidity. Research into disease pathogenesis and second line medical management of cSCC is limited. We assess genetic mutations in high-risk, primary head and neck cutaneous squamous cell carcinomas (HNcSCC) that may hinder or be beneficial for use of targeted therapy in disease management.

METHODS

Genetic alterations and variant allele frequencies (VAFs) were analysed using a clinically relevant 48 gene panel in 10 primary high-risk non-metastatic treatment-naïve HNcSCC to evaluate applicability of targeted therapeutics. Variants present at all VAFs were evaluated for pathogenicity. Somatic mutation patterns of individual tumours were analysed.

RESULTS

High-risk HNcSCC showed a high proportion (82%) of C to T transitions in keeping with ultraviolet-mediated damage. There was significant intratumour genetic heterogeneity in this cohort (MATH scores 20-89) with the two patients <45 years of age showing highest intratumour heterogeneity. TP53 was altered at VAF >22% in all cases, and mutations with highest VAF were observed in tumour suppressor genes in 80%. 70% of cases demonstrated at least one mutation associated with treatment resistance (KIT S821F, KIT T670I, RAS mutations at codons 12 and 13).

CONCLUSION

We demonstrate high proportion tumour suppressor loss of function mutations, high intratumour genetic heterogeneity, and presence of well recognised resistance mutations in treatment naïve primary HNcSCC. These factors pose challenges for successful utilisation of targeted therapies.

Validation of the eighth edition AJCC staging system in early T1 to T2 oral squamous cell carcinoma

BACKGROUND

To validate the newly proposed American Joint Committee on Cancer (AJCC) eighth edition staging in early T1 and T2 oral cavity cancers and its effect in predicting tumour control.

METHODS

Retrospective analysis of treatment outcomes of 441 T1 to T2 oral squamous cell carcinoma (OSCC). Overall survival (OS), disease-specific survival (DSS), and tumour control were calculated and compared between the AJCC 7 and 8 staging systems.

RESULTS

The 5-year OS was 78% and 61% for T1 and T2 tumours, respetively (P < 0.001) (AJCC 7) vs 87% and 67% (P < 0.001) (AJCC 8). The 5-year DSS was 78% and 61% for T1 and T2, respectively (P < 0.001) (AJCC 7) vs 89% and 71% (P < 0.001) (AJCC 8). For stages I and II tumours the 5-year OS was 81% and 76%, respectively (P < 0.302) (AJCC 7) vs 87% and 73% (P < 0.017) (AJCC 8). The 5-year DSS was 83% and 82% (P < 0.222) vs 89% and 77% (P < 0.016). With the AJCC eighth edition the 5-year local, regional, and distant control rates for T1 vs T2 tumours were 85% vs 74% (P = 0.003), 95% vs 77% (P = 0.001), and 95% vs 80% (P = 0.014), respectively.

CONCLUSION

The AJCC 8th staging system provided for more accurate prediction of OS, DSS, and disease control in early oral cavity cancers.