Evidence-based surveillance protocol for vestibular schwannomas: a long-term analysis of tumor growth using conditional probability.

OBJECTIVE: The growth characteristics of vestibular schwannomas (VSs) under surveillance can be studied using a Bayesian method of growth risk stratification by time after surveillance onset, allowing dynamic evaluations of growth risks. There is no consensus on the optimum surveillance strategy in terms of frequency and duration, particularly for long-term growth risks. In this study, the long-term conditional probability of new VS growth was reported for patients after 5 years of demonstrated nongrowth. This allowed modeling of long-term VS growth risks, the creation of an evidence-based surveillance protocol, and the proposal of a cost-benefit analysis decision aid. METHODS: The authors performed an international multicenter retrospective analysis of prospectively collected databases from five tertiary care referral skull base units. Patients diagnosed with sporadic unilateral VS between 1990 and 2010 who had a minimum of 10 years of surveillance MRI showing VS nongrowth in the first 5 years of follow-up were included in the analysis. Conditional probabilities of growth were calculated according to Bayes' theorem, and nonlinear regression analyses allowed modeling of growth. A cost-benefit analysis was also performed. RESULTS: A total of 354 patients were included in the study. Across the surveillance period from 6 to 10 years postdiagnosis, a total of 12 tumors were seen to grow (3.4%). There was no significant difference in long-term growth risk for intracanalicular versus extracanalicular VSs (p = 0.41). At 6 years, the residual conditional probability of growth from this point onward was seen to be 2.28% (95% CI 0.70%-5.44%); at 7 years, 1.35% (95% CI 0.25%-4.10%); at 8 years, 0.80% (95% CI 0.07%-3.25%); at 9 years, 0.47% (95% CI 0.01%-2.71%); and at 10 years, 0.28% (95% CI 0.00%-2.37%). Modeling determined that the remaining lifetime risk of growth would be less than 1% at 7 years 7 months, less than 0.5% at 8 years 11 months, and less than 0.25% at 10 years 4 months. CONCLUSIONS: This multicenter study evaluates the conditional probability of VS growth in patients with long-term VS surveillance (6-10 years). On the basis of these growth risks, the authors posited a surveillance protocol with imaging at 6 months (t = 0.5), annually for 3 years (t = 1.5, 2.5, 3.5), twice at 2-year intervals (t = 5.5, 7.5), and a final scan after 3 years (t = 10.5). This can be used to better inform patients of their risk of growth at particular points along their surveillance timeline, balancing the risk of missing late growth with the costs of repeated imaging. A cost-benefit analysis decision aid was also proposed to allow units to make their own decisions regarding the cessation of surveillance.

The risk of recurrence in surgically treated head and neck squamous cell carcinomas: a conditional probability approach.

BACKGROUND: Over 50% of patients with head-and-neck squamous cell carcinoma (HNSCC) experience locoregional recurrence, which is associated with poor outcome. In the course of follow-up for patients surviving primary surgery for HNSCC, one might ask: What is the probability of recurrence in one year considering that the cancer has not yet recurred to date? MATERIALS AND METHODS: To answer this question, 979 patients surgically treated for HNSCC (i.e. cancer of the oral cavity, oropharynx, hypopharynx or larynx) between March 2004 and June 2018 were enrolled in a multicenter retrospective cohort study, followed up for death and recurrence over a 5 year period. The conditional probability of recurrence in 12 months - i.e. the probability of recurrence in the next 12 months given that, to date, the patient has not recurred - was derived from the cumulative incidence function (Aalen-Johansen method). RESULTS: Overall, the probability of recurrence was the highest during the first (17.3%) and the second years (9.6%) after surgery, declining thereafter to less than 5.0% a year thereafter. The probability of recurrence was significantly higher for stage III-IV HNSCCs than for stage I-II HNSCCs in the first year after surgery (20.4% versus 10.0%; p < 0.01), but not thereafter. This difference was most pronounced for oral cavity cancers. No significant differences were observed across different tumor sites. CONCLUSION: This dynamic evaluation of recurrence risk in patients surgically treated for HNSCC provides helpful and clinically meaningful information, which can be useful to patients in planning their future life, and to clinicians in tailoring post-treatment surveillance according to a more personalized risk stratification.

Advanced lung cancer inflammation index and its prognostic value in HPV-negative head and neck squamous cell carcinoma: a multicentre study.

PURPOSE: The aim of this study is to evaluate the prognostic value of pre-treatment advanced lung cancer inflammation index (ALI) in patients with HPV-negative HNSCC undergoing up-front surgical treatment. METHODS: The present multi-centre, retrospective study was performed in a consecutive cohort of patients who underwent upfront surgery with or without adjuvant (chemo)-radiotherapy for head and neck squamous cell carcinoma (HNSCC). Patients were stratified by ALI, and survival outcomes were compared between groups. In addition, the prognostic value of ALI was compared with two other indices, the prognostic nutritional index (PNI) and systemic inflammatory index (SIM). RESULTS: Two hundred twenty-three patients met the inclusion criteria (151 male and 72 female). Overall and progression-free survival were significantly predicted by ALI < 20.4 (HR 3.23, CI 1.51-6.90 for PFS and HR 3.41, CI 1.47-7.91 for OS). Similarly, PNI < 40.5 (HR = 2.43, 95% CI: 1.31-4.51 for PFS and HR = 2.40, 95% CI: 1.19-4.82 for OS) and SIM > 2.5 (HR = 2.51, 95% CI: 1.23-5.10 for PFS and HR = 2.60, 95% CI: 1.19-5.67 for OS) were found to be significant predictors. Among the three indices, ALI < 20.4 identified the patients with the worst 5-year outcomes. Moreover, patients with a combination of low PNI and low ALI resulted to be a better predictor of progression (HR = 5.26, 95% CI: 2.01-13.73) and death (HR = 5.68, 95% CI: 1.92-16.79) than low ALI and low PNI considered alone. CONCLUSIONS: Our results support the use of pre-treatment ALI, an easily measurable inflammatory/nutritional index, in daily clinical practice to improve prognostic stratification in surgically treated HPV-negative HNSCC.

Determinants of Vestibular Schwannoma Growth.

OBJECTIVE: Management of vestibular schwannomas (VS) involves surgery, radiotherapy, or surveillance, based on patient and tumor factors. We recently described conditional probability as a more accurate method for stratifying VS growth risk. Building on this, we now describe determinants of VS growth, allowing clinicians to move toward a more personalized approach to growth-risk profiling. METHODS: Retrospective analysis of a prospectively collected database in a tertiary referral skull base unit between 2005 and 2014. Inclusion of patients with unilateral VS managed on surveillance protocol for a minimum of 5 years. Analysis of patient age, sex, tumor location, tumor size, and symptomology using conditional probability. RESULTS: A total of 340 patients met inclusion criteria. The conditional probability of growth of extracanalicular VS was significantly higher versus intracanalicular (IC) VS (30% versus 13%, p < 0.001) as was small-sized VS versus IC VS (28 versus 13%, p = 0.002), but only in the first year after diagnosis. Sex, age, and presenting symptoms did not significantly affect VS growth. CONCLUSION: In our series, extracanalicular VS were more likely to grow than IC VS and small-sized VS more likely to grow than IC VS, but only in the first year after diagnosis. Conversely, sex, age, and presenting symptoms did not affect the conditional probability of VS growth.

Pain After Cochlear Implantation Without Signs of Inflammation: A Systematic Review.

OBJECTIVES: This review summarizes current evidence on causes and management strategies for delayed pain post-cochlear implantation (CI) surgery, without clinical evidence of inflammation or infection. METHODS: The systematic review was undertaken in line with Preferred Reporting Items for Systematic review and Meta-Analysis Protocols 2015 guidelines. A literature search was undertaken, with inclusion of patients who underwent CI and presented with delayed pain (>3 months post-operatively) around their device site without an identifiable cause. Analysis was undertaken using MATLAB (MathWorks, Natick, MA) and the R-software package (www.r-project.org). RESULTS: 4 articles (48 patients), all retrospective case series, met inclusion criteria. The mean onset of pain post-CI was 60 months and mean follow-up was 15.8 months, there was no difference in the prevalence of pain between device brands (p=0.13). The majority (90%) did not have any hearing deterioration, and investigations did not reveal a cause for the pain in any of the patients. In terms of management, medical therapies, including oral therapy (analgesia, non-steroidal anti-inflammatories, antibiotics) and local treatments (topical, injections) resolved pain in 41% and 63%, respectively. Surgical intervention (explantation, magnet replacement, tympanic neurectomy), where undertaken, resolved pain in 100%. A minority had an identifiable infective microorganism cultured from intra-operative soft tissue or biofilm samples. CONCLUSIONS: Evidence for the causes and management of delayed pain post-CI without clinical evidence of inflammation is scarce. A stepwise approach is deemed best, with decisions being made on an individual basis, evaluating each patient's specific circumstances and priorities. Further evaluation of explanted devices would allow for better understanding of the causes and treatment of this group of patients.

The Conditional Probability of Vestibular Schwannoma Growth at Different Time Points After Initial Stability on an Observational Protocol.

OBJECTIVE: The natural history of vestibular schwannomas (VS) is well documented in the literature, with tumour growth being paramount to decision making for both surveillance and treatment of these patients. Most previous studies refer to the risk of VS growth over a given period of time; however, this is not useful for counselling patients at different stages of their follow-up, as the risk of tumour growth is likely to be less following each subsequent year that a tumour does not grow. Accordingly, we investigated the conditional probability of VS growth at particular time-points, given a patient has not grown thus far. This Bayesian method of risk stratification allows for more tailored and accurate approximations of the risk of growth versus nongrowth of VS. METHODS: Retrospective analysis of a prospectively collected database in a tertiary referral skull base unit, containing all patients diagnosed between 2005 and 2014 with sporadic unilateral VS and a minimum of 5-year surveillance. RESULTS: A total of 341 patients met the inclusion criteria. The mean age at diagnosis was 67 years, the sizes of the VS at diagnosis were intracanalicular in 49%, small in 39%, medium in 11%, and large in 1%. Over the entire 5-year surveillance period, a total of 139 tumours were seen to grow (41%) and 202 did not grow (59%). At 1 year, the probability of growth given that the tumour had not grown to date was seen to be 21%, at 2 years 12%, at 3 years 9%, at 4 years 3%, and at 5 years 2%. The conditional probability of growth of extracanalicular VS was significantly higher in the first year when compared with intracanalicular VS (29% versus 13%, p = 0.01), but there was no such difference in years 2, 3, 4 or 5 (p = 0.60, 0.69, 0.36, 0.39, respectively). CONCLUSION: This is the first study in the literature concerned specifically with the conditional probability of VS growth. The data presented here can be used to better inform VS patients of their risk of growth at particular time points in their disease-the longer VS have been observed to be stable, the lower the risk of subsequent growth in a given year. Further, an extracanalicular vestibular schwannoma is more likely to grow in the first year compared with an intracanalicular vestibular schwannoma. Our data also adds support to surveillance protocols with increasingly infrequent MRI scans, as after 4 years of not growing, the risk of growth in year 5 falls to <2%.