Nomograms predictive for oncological outcomes in malignant parotid tumours: recurrence and mortality rates of 228 patients from a single institution

Survival in Patients with Primary Parotid Gland Carcinoma after Surgery—Results of a Single-Centre Study

This study aims to analyse a single-centre cohort series of patients who underwent parotidectomy for primary malignant parotid tumours. A retrospective chart review of 64 consecutive patients treated from November 2010 to March 2022 was performed. Outcomes were analysed by Kaplan-Meier curves. Sixty-four patients with a primary parotid malignancy were included in the study, with one bilateral case in this cohort. Patients were classified as stage I–II in 39 cases and stage III–IV in 26 cases. The five-year overall survival (OS), disease-specific survival (DSS), local relapse-free survival (LRFS), and distant metastasis-free survival (DMFS) rates were 78.4%, 89%, 92.5%, and 87.1%, respectively. Univariate analysis showed that high-risk histology, stage IV disease, lymphovascular invasion, perineural invasion, node metastasis, skin involvement, facial nerve involvement, and positive or close margins were risk factors associated with poorer outcomes. At present, the best evidence suggests that radical surgery should be the standard approach, and adjuvant therapy, in terms of radiotherapy/chemoradiotherapy, is recommended in patients with risk factors.

A nomogram involving immune-inflammation index for predicting distant metastasis-free survival of major salivary gland carcinoma following postoperative radiotherapy

BACKGROUND

Postoperative radiotherapy (PORT) is beneficial in the improvement of local-regional control and overall survival (OS) for major salivary gland carcinomas (SGCs), and distant metastasis remained the main failure pattern. This study was designed to develop a nomogram model involving immune-inflammation index to predict distant metastasis-free survival (DMFS) of major SGCs.

PATIENTS AND METHODS

A total of 418 patients with major SGCs following PORT were randomly divided into a training (n = 334) and validation set (n = 84). The pre-radiotherapy neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) were calculated and transformed as continuous variables for every patient. Associations between DMFS and variables were performed by univariate and multivariable analysis using Log-rank and Cox regression methods. A nomogram was constructed based on the prognostic factors identified by the Cox hazards model. The decision curve analysis (DCA) was conducted with the training and validation set.

RESULTS

The estimated 3-, 5-, and 10-year DMFS were 79.4%, 71.8%, and 59.1%, respectively. The multivariate analysis revealed that age (p = 0.033), advanced T stage (p = 0.003), positive N stage (p < 0.001), high-risk pathology (p = 0.011), and high PLR (p = 0.001) were significantly associated with worse DMFS. The nomogram showed good calibration and discrimination in the training (AUC = 80.9) and validation set (AUC = 87.9). Furthermore, the DCA demonstrated favorable applicability, and a significant difference (p < 0.001) was observed for the DMFS between the subgroups based on the nomogram points.

CONCLUSION

The nomogram incorporating clinicopathological features and PLR presented accurate individual prediction for DMFS of the patients with major SGCs following PORT. Further external validation of the model is warranted for clinical utility.

The role of perineural invasion in parotid malignancy outcomes: A systematic review and meta-analysis

PURPOSE

At present, perineural invasion is used as a histologic indicator of aggressive salivary gland disease. In other head and neck malignancies, perineural invasion impacts staging of cancer lesions and therefore affects treatment options.

OBJECTIVE

To compare survival outcomes in primary parotid malignancies with and without perineural invasion.A systematic review pooled data from the scientific literature in patients with any primary parotid malignancy to investigate the prognosis of those with perineural invasion.

DATA SOURCES

PubMed (Medline), Scopus and Cochrane databases were queried from inception to July 2020 without any initial search constraints. Additional publications were included from review of pertinent articles.

STUDY SELECTION

Our inclusion criteria included primary parotid cancers with reported perineural invasion on survival outcomes. Exclusion criteria were non-English language text, non-human studies, reviews, textbooks, abstracts, case reports and case series. Two authors independently reviewed articles for inclusion. Of the initial 465 records, 83 articles were reviewed in full to yield a final collection of 14 studies.

DATA EXTRACTION AND SYNTHESIS

PRISMA-p guidelines were used in the reporting of our studies. A MOOSE Checklist was also used. MINORS criteria were applied to assess risk of bias. Random-effects models were used to estimate pooled effect sizes. No institutional review board review was needed for our study.

MAIN OUTCOMES AND MEASURES

Primary study outcomes were set prior to data collection and included overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS) and distant-metastasis-free survival (DMFS) in patients with and without perineural invasion.

RESULTS

Fourteen studies contributed to this meta-analysis. Compared to patients without perineural invasion, the pooled rate of mortality (HR = 3.64), time to recurrence (HR = 3.56), disease-specific mortality (HR = 2.77) and distant metastasis (HR = 3.84) was significantly higher for patients with PNI (all p <.001). Controlling for perineural invasion status, no moderator was associated with these survival outcomes (all p >.05). Given the clinical severity of perineural invasion, few studies were null as shown in a panel of publication bias plots.

CONCLUSION

Perineural invasion portends a poor survival outcome in patients with parotid malignancies.

LEVEL OF EVIDENCE: 1

Development and validation of nomograms for predicting survival and recurrence in patients with parotid gland cancer

Background

To develop nomograms for predicting recurrence risk and long-term survival in patients with parotid gland cancer (PGC).

Methods

A total of 301 consecutive patients with PGC who underwent surgery were enrolled and randomly divided into a training cohort (n=210) and a validation cohort (n=91). Predictive nomograms were constructed based on the independent indicators of overall survival (OS) and disease-free survival (DFS) as determined by multivariate Cox regression analysis. The discrimination and calibration of nomograms were evaluated using C-indices and calibration curves.

Results

Six independent predictors of OS were identified. Incorporating these factors, the nomogram showed good concordance statistics of 0.84 and 0.78 in predicting the 5-year OS in the training and validation cohorts. Five independent predictors of DFS were identified and integrated into the nomogram. The concordance statistics were 0.84 and 0.74 in predicting the 5-year DFS in the training and validation cohorts. The predictive performance of the nomograms outperformed the TNM model. Additionally, the patients were divided into two groups according to the nomogram score, and significant differences in OS and DFS were observed between the high risk and low risk groups. Finally, the role of postoperative treatments was evaluated based on the risk stratification; patients at high risk of disease recurrence showed an improvement in DFS after receiving postoperative treatments.

Conclusions

The nomogram showed good performance in predicting both OS and DFS in patients with PGC. It might be useful for selecting patients for postoperative treatments.

Validated Prognostic Nomograms for Patients With Parotid Carcinoma Predicting 2- and 5-Year Tumor Recurrence-Free Interval Probability

Introduction: Salivary gland malignancies are rare tumors with a heterogenous histological and clinical appearance. Previously, we identified multiple prognostic factors in patients with parotid cancer and developed prognostic indices which have repeatedly been validated internationally, demonstrating their general applicability and lasting relevance. Recently, nomograms gained popularity as a prognostic tool. Thus, in this research we aimed to construct nomograms based on our previous validated prognostic models.

Material and Methods: Nomograms were constructed using the previously reported dataset of 168 patients with parotid cancer which was used to develop pre- and postoperative prognostic scores, PS1 and PS2, respectively. Concordance indices for PS1 and PS2 were previously estimated at 0.74 and 0.71, respectively, and are in line with other, widely accepted oncological nomograms.

Results: Pre- and postoperative nomograms predicting 2- and 5-year tumor recurrence-free survival probability are presented. All previously multivariately identified and validated prognostic factors, are incorporated (T size, N classification, pain, age at diagnosis, skin invasion, facial nerve dysfunction, perineural growth, and positive surgical margins). Examples of clinical application and interpretation are given.

Conclusions: The presented prognostic nomograms for predicting 2- and 5-year tumor recurrence-free probability in patients with parotid cancer are powerful, user-friendly, visual tools and are based on internationally validated prognostic indices. They allow for a reliable prognostic assessment and result in a more individualized estimate of the risk for recurrence than the prognostic grouping based on PS1 and PS2. This facilitates assigning trial-patients to risk groups, and may assist in therapeutic decision making and determining appropriate follow-up intervals in clinical practice.