Clinical and oncological outcomes after surgical excision of parotid gland tumours in patients aged over 80 years

Abstract

The objective of this study was to evaluate the surgical and long-term outcomes of a series of patients aged over 80 years, operated on for parotid neoplasms. Among 614 parotidectomies for neoplasms performed between 1998 and 2008, 34 patients (5.5%) aged over 80 years were identified retrospectively. Pathological examination showed a malignant tumour in 24 and a benign tumour in 10 cases. Overall survival (OS) and disease-free survival (DFS) were determined by Kaplan–Meier analysis. A search for parameters that could influence the postoperative complication rate and long-term outcomes was carried out by univariate analysis. There was no postoperative death. Eight patients (24%) had postoperative complications. Malignant histopathology ( P = 0.05) and radical resection ( P = 0.033) were found to have a significant negative impact on the postoperative course. Focusing on malignant tumours, only histopathological type (metastasis vs primary tumour) was found to have a negative impact on OS. The 2- and 5-year OS rates were 86% and 86%, respectively, for primary tumours, and 67% and 29%, respectively, for metastasis ( P = 0.05). Malignant or benign histopathology had no impact on OS. Our results showed acceptable clinical and long-term oncological outcomes in very elderly patients operated on for parotid tumours, including malignant tumours.

Introduction

Diseases affecting salivary glands include traumatic lesions, congenital diseases, and acute and chronic infections, as well as neoplastic lesions. Tumours of salivary glands are rare; they account for 0.4–6.5 cases per 100,000 persons per year and represent from 2% to 6.5% of neoplasms of the head and neck. They can occur in major salivary glands (90% cases) or in minor salivary glands (10% cases). The parotid gland is by far the most frequently affected site, while the submandibular gland (9%) and sublingual glands (1%) are much less frequently involved. Malignant tumours of salivary glands represent 0.7% of all malignant tumours, approximately 3% of those affecting the head and neck, and 30% of all salivary neoplasms. Malignant tumours of the parotid gland represent 1–3% of all tumours of the head and neck and constitute 70–80% of salivary gland tumours.

The most recent proposals for classification have been submitted by the World Health Organization. Pleomorphic adenoma is the most frequent benign neoplasm of the salivary glands, representing between 45% and 80% of all salivary gland tumours, followed by Warthin’s tumour, which represents 10%. Among malignant tumours, mucoepidermoid carcinomas represent 30%, followed by adenoid cystic carcinomas (25%), carcinomas on pleomorphic adenoma (15%), and acinic cell carcinomas (5–10%). Tumours of the parotid gland are benign in 80% of cases, pleomorphic adenoma being the most common (80% of cases).

It is well known that in the head and neck area, as in other human organs, malignant tumours become more frequent in old age. Likewise, tumours occurring in the parotid space increase during the last decades of life. This rise in incidence is particularly due to secondary parotid space neoplastic involvement from metastasis or primary tumours.

The aim of this study was to evaluate surgical and long-term outcomes of a series of patients aged over 80 years, operated on for parotid neoplasms.

Materials and methods

Patients

Among 614 patients who underwent parotidectomy at our institution during the study period (1998–2008), 34 (5.5%) aged over 80 years were studied retrospectively. The mean age of these patients was 83.5 years (range 80–91 years). There were 23 males and 11 females (male to female sex ratio 2.1:1). Tumours were located in the left parotid in 18 cases and in the right parotid in 16 cases. Pathological examination showed a malignant tumour in 24 cases (71%): this was a primary tumour of the parotid gland in 11/24 cases and metastasis in 13/24 cases.

Primary tumours were mucoepidermoid carcinoma in four, carcinoma ex-pleomorphic adenoma in two, basal cell carcinoma in two, sarcoma in one, and poorly differentiated carcinoma in two cases. Metastatic histopathological findings were: squamous cell carcinoma in 10, melanoma in one, Merkel cell carcinoma in one, and Hodgkin lymphoma in one case. Moreover, among malignant tumours, six patients were operated on for recurrent disease. In 10 cases the tumour was benign: pleomorphic adenoma in one, monomorphic adenoma in one, Warthin’s tumour in four, lipoma in one, inflammatory lesion in one, and benign cyst in two cases.

The procedure consisted of a total parotidectomy with facial nerve dissection in 15 cases, radical parotidectomy in four, lateral parotidectomy in 10, and partial parotidectomy in five. Neck dissection was performed in 22 cases.

Three patients initially treated at another institution had received preoperative radiotherapy and were treated surgically for a recurrence as salvage surgery. Thirteen patients received postoperative radiotherapy. Postoperative radiotherapy was discussed in all cases depending on the patient’s local and general conditions. Indications for postoperative radiotherapy were high-grade cancers, parotid metastases, and positive lymph nodes.

The main characteristics of the patients are summarized in Table 1 .

Table 1
Characteristics of the study population.
Number of patients 34
Sex ratio 23/11, M/F
Mean age (range) 83.5 years (80–91)
Cardiovascular problems
Yes 18 (53%)
No 16 (47%)
ASA score
ASA 2 22 (65%)
ASA 3 12 (35%)
Histology
Malignant 24 (71%)
Benign 10 (29%)
Surgical technique
Conservative surgery 30 (88%)
Radical surgery 4 (12%)
Neck dissection
Yes 22 (65%)
No 12 (35%)
Postoperative complications
Yes 8 (24%)
No 26 (76%)

All patients had received preoperative loco-regional and general work-ups to assess the feasibility of salvage surgery and to search for distant metastases. Moreover, all patients underwent a general health work-up including blood tests, vascular sonography, and cardiac check-up to assess the feasibility of general anaesthesia. All diagnostic and therapeutic decisions concerning patients in this study were taken at multidisciplinary meetings attended by teams representing head and neck surgery, medical oncology, radiation therapy, pathology, and radiology.

This study had institutional review board approval.

Main outcome measures

Overall survival (OS) and disease-free survival (DFS) were determined by Kaplan–Meier analysis.

The impact on the postoperative complication rate of the following factors was analysed by univariate analysis: histopathology, radical surgery, lymph node surgery, radiotherapy, American Society of Anesthesiology (ASA) score, duration of general anaesthesia, and duration of hospital stay.

The impact on patient outcomes (OS and DFS) of the following factors was investigated by univariate analysis: gender, co-morbidity using the ASA score, history of cardiovascular problems, duration of general anaesthesia, duration of hospital stay, postoperative complications, and histopathology.

With regard to malignant tumours, the following factors were also analysed: metastases vs primary tumours, radical surgery vs limited surgery, lymph node surgery, preoperative or postoperative facial palsy, facial nerve resection, postoperative radiotherapy, and salvage surgery.

Statistical analysis

Categorical variables were described using numbers and proportions, and quantitative variables by the mean and standard deviation. Categorical variables were compared by Fisher’s exact probabilities test. OS and DFS were estimated by Kaplan–Meier analysis.

Survival curves were compared using the log-rank test. The Cox model was used to study the effect of quantitative variables on the events considered.

All statistical tests were performed with the R.2.13 software program for Windows, with a 5% threshold of significance.

Materials and methods

Patients

Among 614 patients who underwent parotidectomy at our institution during the study period (1998–2008), 34 (5.5%) aged over 80 years were studied retrospectively. The mean age of these patients was 83.5 years (range 80–91 years). There were 23 males and 11 females (male to female sex ratio 2.1:1). Tumours were located in the left parotid in 18 cases and in the right parotid in 16 cases. Pathological examination showed a malignant tumour in 24 cases (71%): this was a primary tumour of the parotid gland in 11/24 cases and metastasis in 13/24 cases.

Primary tumours were mucoepidermoid carcinoma in four, carcinoma ex-pleomorphic adenoma in two, basal cell carcinoma in two, sarcoma in one, and poorly differentiated carcinoma in two cases. Metastatic histopathological findings were: squamous cell carcinoma in 10, melanoma in one, Merkel cell carcinoma in one, and Hodgkin lymphoma in one case. Moreover, among malignant tumours, six patients were operated on for recurrent disease. In 10 cases the tumour was benign: pleomorphic adenoma in one, monomorphic adenoma in one, Warthin’s tumour in four, lipoma in one, inflammatory lesion in one, and benign cyst in two cases.

The procedure consisted of a total parotidectomy with facial nerve dissection in 15 cases, radical parotidectomy in four, lateral parotidectomy in 10, and partial parotidectomy in five. Neck dissection was performed in 22 cases.

Three patients initially treated at another institution had received preoperative radiotherapy and were treated surgically for a recurrence as salvage surgery. Thirteen patients received postoperative radiotherapy. Postoperative radiotherapy was discussed in all cases depending on the patient’s local and general conditions. Indications for postoperative radiotherapy were high-grade cancers, parotid metastases, and positive lymph nodes.

The main characteristics of the patients are summarized in Table 1 .

Jan 20, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Clinical and oncological outcomes after surgical excision of parotid gland tumours in patients aged over 80 years
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