Nodal failure patterns and utility of elective nodal irradiation in submandibular gland carcinoma treated with postoperative radiotherapy - a multicenter experience

Evaluation of the efficacy of adjuvant radiotherapy versus chemoradiotherapy in patients with salivary gland tumors

AIMS

The aim of this study was to compare the efficacy of adjuvant radiotherapy (RT) versus adjuvant chemoradiotherapy (CRT) in patients with salivary gland tumors (SGTs).

MATERIALS AND METHODS

Data from patients who underwent adjuvant RT for a diagnosis of SG cancer at Ankara Atatürk Education and Research Hospital, Ankara Numune Education and Research Hospital and Ankara Bilkent City Hospital between September 01, 2009 and September 01, 2022 were analysed retrospectively. We evaluated the efficacy of RT alone versus CRT in these patients in terms of acute response, treatment tolerance, overall survival (OS), and disease-free survival (DFS).

RESULTS

Fifty-five patients who underwent RT between September 14, 2009 and August 04, 2022 at Ankara Atatürk Education and Research Hospital, Ankara Numune Education and Research Hospital and Ankara Bilkent City Hospital were included in this study. Eight patients who did not meet the study criteria were excluded; thus, the analysis was performed for 47 patients. The median follow-up period was 60 months (range: 6-160 months). The median patient age was 53 years (range: 18-86 years). Thirty-nine patients (83%) had parotid tumors and eight patients (17%) had submandibular cancer. The time from surgery to RT was 48 days (range: 20-126 days). Intensity-modulated radiotherapy was administered to all patients and the median RT dose was 66 Gy (range: 52-70 Gy). Concomitant chemotherapy (CCT) (40 mg/m 2 of cisplatin weekly) was administered to 13 patients (27.7%). Acute adverse events were observed in 17 patients (36.2%). Interruption of RT was noted for only six patients (12.8%), and this proportion did not differ significantly between the CRT and RT-only arms ( P = 0.538). Acute side effects were observed in 17 patients (36.2%), and there were no significant relationships between acute side effects and the administration of CCT ( P = 0.112). Recurrence was observed in 10 patients (21.3%). All recurrences were locoregional and no distant metastases were observed during the follow-up period. The median DFS of the patients was 48 months (range: 4-160 months), 1-year DFS was 86%, 2-year DFS was 83.5%, and 5-year DFS was 77.9%. There was no statistically significant difference in DFS between the adjuvant CRT and RT-alone arms ( P = 0.114). At the date of last follow-up, 14 patients (29.8%) had died. The median OS of the patients was 58.5 months (range: 6-160 months), 1-year OS was 91.4%, 2-year OS was 86.8%, and 5-year OS was 78%. There was no statistically significant difference in OS between the adjuvant CRT and RT-only arms ( P = 0.453).

CONCLUSION

Stage was identified as the most important prognostic factor for DFS and OS. No significant differences in OS, DFS, or acute side effects were observed between the CRT and RT-only arms. Additional studies are needed to identify the subgroup of SGT patients for which CRT is most warranted.

A multicenter retrospective analysis of patients with salivary gland carcinoma treated with postoperative radiotherapy alone or chemoradiotherapy

BACKGROUND

The aim of this study was to interrogate if the use of postoperative chemoradiotherapy (POCRT) correlated with superior oncological outcomes for certain subgroups of patients with high-risk salivary gland carcinoma (SGC), compared with postoperative radiotherapy (PORT) alone.

METHODS

This multicenter retrospective study included 411 patients with surgically resected SGC who underwent PORT (n = 263) or POCRT (n = 148) between 2000 and 2015. Possible correlations of clinical parameters with outcomes were examined using the Kaplan-Meier analysis and Cox proportional-hazards regression model.

RESULTS

The median follow-up of survivors is 10.9 years. For the entire cohort, adding concurrent chemotherapy to PORT was not associated with OS, PFS, or LRC improvement. However, patients with nodal metastasis who underwent POCRT had significantly higher 10-year OS (46.2% vs. 18.2%, P = 0.009) and PFS (38.7% vs. 10.0%, P = 0.009) rates than those treated with PORT alone. The presence of postoperative macroscopic residual tumor (R2 resection) was identified as an independent prognosticator for inferior OS (P = 0.032), PFS (P = 0.001), and LRC (P = 0.007). Importantly, POCRT significantly correlated with higher 10-year LRC rates in patients with R2 resection (74.2% vs. 40.7%, P = 0.034) or adenoid cystic carcinoma (AdCC, 97.6% vs. 83.6%, P = 0.039). On multivariate analyses, the use of POCRT significantly predicted superior OS (P = 0.037) and PFS (P = 0.013) for node-positive patients and LRC for patients with R2 resection (P = 0.041) or AdCC (P = 0.005).

CONCLUSIONS

For surgically resected SGC, POCRT was associated with improved long-term OS and PFS for patients with nodal metastasis and superior LRC for patients with R2 resection or AdCC.

Epidemiology, outcomes, and prognostic factors in submandibular gland carcinomas: a national DAHANCA study

PURPOSE

The aim of this study is to present incidence, histological subtypes, survival rates, and prognostic factors based on a national cohort of patients with salivary gland carcinoma.

METHODS

All Danish patients with submandibular gland carcinoma diagnosed from 1990 to 2015 (n = 206) were included and analyzed following histological re-evaluation. Data were collected by the Danish Head and Neck Cancer Group (DAHANCA). Overall, disease-specific and recurrence-free survival were evaluated. Prognostic factors were analyzed with multivariate Cox Hazard Regression.

RESULTS

The study population consisted of 109 (53%) men and 97 (47%) women, median age 62 years (range 11-102). Adenoid cystic carcinoma was the most frequent subtype (50%). Tumour classification T1/T2 (75%) and N0 (78%) was most frequent. The mean crude incidence was 0.17/100,000/year. Most patients (n = 194, 94%) were treated with primary surgery, and 130 (67%) received postoperative radiotherapy. The 5- and 10-year survival rates were for overall survival 64% and 41%, disease-specific survival 74% and 61%, and recurrence-free survival 70% and 56%, respectively. Survival rates were higher for adenoid cystic carcinoma compared to other subtypes, but the difference was not significant in multivariate analysis. Recurrence occurred in 69 patients, and 37 (53.6%) of them had recurrence in a distant site. Advanced T-classification and regional lymph-node metastases had significant negative impact on survival rates.

CONCLUSION

The incidence of submandibular gland carcinoma in Denmark was 0.17/100,000/year and stable during the time period. The most frequent subtype was adenoid cystic carcinoma. Half of the recurrences presented in a distant site, and multivariate analysis confirmed that advanced stage was independent negative prognostic factor for recurrence and survival.

Intensity-modulated proton and carbon-ion radiation therapy in the management of major salivary gland carcinomas

Background

Primary major salivary gland carcinomas (SGCs) present with diverse histological types that are known to be largely radioresistant with a high tendency to develop distant metastasis (DM). Photon-based radiotherapy (RT) is limited in terms of its therapeutic effect and toxicities. In view of the physical and biological advantages of intensity-modulated proton and/or carbon-ion radiation therapy, we aimed to evaluate the short-term therapeutic effect and toxicities in patients with major SGCs treated with this form of radiation therapy.

Methods

Between August 2015 and November 2019, a total of 55 consecutive and non-selected major SGC patients who received particle RT at the Shanghai Proton and Heavy Ion Center (SPHIC) were retrospectively analyzed. The 2-year overall survival (OS), progression-free survival (PFS), local-regional recurrence-free survival (LRRFS), and distant metastasis-free survival (DMFS) rates, as well as prognostic factors were analyzed. Additionally, acute and late toxicities were also analyzed.

Results

With a median follow-up time of 24 (range, 6-57) months, the 2-year OS, PFS, LRRFS, and DMFS rates were 91.6%, 78.6%, 94.2%, and 83.9%, respectively. At the time of this analysis, four patients had developed local or regional recurrence, and seven additional patients had developed DM. Three patients had died due to disease progression, and another patient with recurrence experienced a late Grade 5 event (hemorrhage) at 9 months after re-irradiation with carbon ion and subsequently died. Otherwise, none of the patients had grade 3 or higher treatment-induced acute or late adverse effects except one who developed grade 3 acute mucositis.

Conclusions

Overall, intensity-modulated proton and/or carbon-ion radiation therapy provided satisfactory therapeutic effectiveness in our major SGCs patients with a low incidence of acute and late toxicities.

The rate of occult nodal metastasis in submandibular gland malignancies: A case series and meta-analysis

OBJECTIVE

Submandibular gland (SMG) malignancies are exceedingly rare. Lymph node metastasis is one of the most important determinants of outcome in SMG malignancies. The aim of this study was to investigate the overall rate of occult neck nodal metastasis in SMG malignancies.

STUDY DESIGN

The study design is a meta-analysis of all studies on patients with a primary SMG malignancy, without evidence of neck nodal metastasis, who underwent an elective neck dissection (END). The search strategy identified 158 papers that appeared in print from January 1980 to July 2020. All eligible patients from the Tel-Aviv Medical Center were analyzed and consolidated into a case series. A total of 12 retrospective studies that included 306 suitable patients met inclusion criteria.

RESULTS

The risk for occult metastasis in primary SMG malignancies was 0.0% to 50.0%, with a fixed effect model of 19.52% (95% CI, 14.9%-24.5%). The analyzed studies included a wide range of pathologies. The most common malignancies were adenoid cystic carcinoma and mucoepidermoid carcinoma.

CONCLUSIONS

The overall rate of occult neck metastasis in SMG malignancies is relatively high, and an END should be the default intervention in these cases. An END is unwarranted in tumors judged clinically to be low stage and low grade.

Radiotherapy of salivary gland tumours

Primary tumours of the salivary glands account for about 5 to 10% of tumours of the head and neck. These tumours represent a multitude of situations and histologies, where surgery is the mainstay of treatment and radiotherapy is frequently needed for malignant tumours (in case of stage T3-T4, nodal involvement, extraparotid invasion, positive or close resection margins, histological high-grade tumour, lymphovascular or perineural invasion, bone involvement postoperatively, or unresectable tumours). The diagnosis relies on anatomic and functional MRI and ultrasound-guided fine-needle aspiration for the diagnostic of benign or malignant tumors. In addition to patient characteristics, the determination of primary and nodal target volumes depends on tumor extensions and stage, histology and grade. Therefore, radiotherapy of salivary gland tumors requires a certain degree of personalization, which has been codified in the recommendations of the French multidisciplinary network of expertise for rare ENT cancers (Refcor) and may justify a specialised multidisciplinary discussion. Although radiotherapy is usually recommended for malignant tumours only, recurrent pleomorphic adenomas may sometimes require radiotherapy based on multidisciplinary discussion. An update of indications and recommendations for radiotherapy for salivary gland tumours in terms of techniques, doses, target volumes and dose constraints to organs at risk of the French society for radiotherapy and oncology (SFRO) was reported in this article.

Management of Salivary Gland Malignancy: ASCO Guideline

PURPOSE

To provide evidence-based recommendations for practicing physicians and other healthcare providers on the management of salivary gland malignancy.

METHODS

ASCO convened an Expert Panel of medical oncology, surgical oncology, radiation oncology, neuroradiology, pathology, and patient advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 2000 through 2020. Outcomes of interest included survival, diagnostic accuracy, disease recurrence, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 293 relevant studies to inform the evidence base for this guideline. Six main clinical questions were addressed, which included subquestions on preoperative evaluations, surgical diagnostic and therapeutic procedures, appropriate radiotherapy techniques, the role of systemic therapy, and follow-up evaluations.

RECOMMENDATIONS

When possible, evidence-based recommendations were developed to address the diagnosis and appropriate preoperative evaluations for patients with a salivary gland malignancy, therapeutic procedures, and appropriate treatment options in various salivary gland histologies.Additional information is available at www.asco.org/head-neck-cancer-guidelines.

The Role of Prognostic Factors in Salivary Gland Tumors Treated by Surgery and Adjuvant Radio- or Chemoradiotherapy - A Single Institution Experience

Purpose

Salivary gland neoplasms are rare cancers of the head and neck region. Radical treatment in tumors of large salivary glands is surgery. Adjuvant treatment depends on the presence of risk factors that worsen the prognosis, but the role of these factors in patients treated by surgery with radio- or radiochemotherapy still remains unclear. The aim of the study is assessment of treatment results and identification of the risk factors affecting the prognosis in patients with tumors of large salivary glands subjected to adjuvant radio- or radiochemotherapy.

Patients and Methods

The study included 126 patients with local stage large salivary gland cancer who were treated surgically with adjuvant radio- or radiochemotherapy. The study excluded inoperable patients, patients with distant metastases, patients in a poor general condition and patients with contraindications to adjuvant treatment. They were treated between 2006 and 2016 and evaluated in terms of OS (overall survival), CSS (cancer-specific survival), RFS (relapse-free survival) and LRFS (local relapse-free survival).

Results

During a 44-month follow-up, 5-OS, CSS, RFS and LRFS were 55%, 68%, 60% and 73%, respectively. Multivariate analysis showed that OS was influenced by the following parameters: WHO performance status, TNM stage (T and N parameters), radicality of surgery, histopathological type, applied method of radiotherapy planning and tumor volume. WHO performance status, T and N parameters of the TNM stage and large volume of elective area influenced CSS, and the T parameter of the TNM stage, the dose below 60Gy and tumor volume influenced RFS and LRFS. Chemoradiotherapy can be used in N-positive patients.

Conclusion

The analysis indicates that the TNM grade, histopathological type, patient’s condition, radicality of the procedure, technique and dose of radiotherapy are the most important prognostic factors in these patients.

[Proposal for the selection and delineation of clinical target volumes for the radiotherapy of submandibular gland tumours]

This article provides a proposal for the selection and delineation of clinical target volumes for the treatment with radiation of submandibular glands tumours. This article does not deal with external radiotherapy indications but specifies the volumes to be treated if radiotherapy is chosen. High-risk and low-risk peritumoral clinical target volumes are described based on the probability of local tumoral spread. High-risk and low-risk clinical target volumes are illustrated on CT-scan slices. A proposal for the selection of nodal clinical target volumeis also proposed.

Lymph node ratio predictive of recurrence, distant metastasis, and survival in submandibular gland carcinoma patients

PURPOSE

Submandibular gland (SMG) carcinoma has an unfavorable clinical course and a low survival rate. Specific tumor and nodal findings might help predict posttreatment recurrence and survival in SMG carcinoma patients. This study evaluated factors predictive of posttreatment recurrence and survival in SMG carcinoma patients.

METHODS

This study enrolled 99 consecutive patients with previously untreated SMG carcinoma. All patients underwent tumor and metastatic lymph node resection along with or without radiation/chemo-radiation. The predictive clinical and pathological factors for disease-free survival (DFS), distant metastasis-free survival (DMFS), disease-specific survival (DSS), and overall survival (OS) were determined using univariate and multivariate Cox proportional hazards regression analyses.

RESULTS

The median tumor size was 2.7 cm and 53 patients (53.5%) had high-grade tumors. The rates of initial nodal and distant metastasis at initial presentation or follow-up were 45.5% and 42.4%, respectively. The actuarial 5-year DFS, DMFS, DSS, and OS rates were 46.4%, 55.9%, 61.5%, and 59.7%, respectively. The independent factors associated with poor DFS, DMFS, DSS, and OS outcomes (all p < 0.05) were T3-T4 classification and lymph node ratio. A histological high-grade tumor was an independent prognostic factor predictive of poor DMFS, DSS, and OS outcomes (all p < 0.05).

CONCLUSIONS

A high rate of distant site failure is associated with SMG carcinoma, resulting in a poor survival rate. Lymph node ratio might help predict recurrence, distant metastasis, and death due to SMG carcinoma.