Frequency of skeletal metastases in nasopharyngeal carcinoma after initiation of therapy: should bone scans be used for follow-up?

Predicting Bone Metastasis Risk Based on Skull Base Invasion in Locally Advanced Nasopharyngeal Carcinoma

Objective

To develop and validate a bone metastasis prediction model based on skull base invasion (SBI) in patients with locally advanced nasopharyngeal carcinoma (LA-NPC).

Methods

This retrospective cohort study enrolled 290 patients with LA-NPC who received intensity-modulated radiation therapy in two hospitals from 2010 to 2020. Patient characteristics were grouped by SBI and hospital. Both unadjusted and multivariate-adjusted models were used to determine bone metastasis risk based on SBI status. Subgroup analysis was performed to investigate heterogeneity using a forest graph. Cox proportional hazard regression analysis was used to screen for risk factors of bone metastasis-free survival (BMFS). A nomogram of BMFS based on SBI was developed and validated using C-index, receiver operating characteristic curve, calibration curves, and decision curve analysis after Cox proportional hazard regression analysis.

Results

The incidence of bone metastasis was 14.83% (43/290), 20.69% (24/116), and 10.92% (19/174) in the overall population, SBI-positive group, and SBI-negative group, respectively. In the unadjusted model, SBI was associated with reduced BMFS [HR 2.43 (1.32–4.47), P = 0.004], and the results remained stable after three continuous adjustments (P <0.05). No significant interaction was found in the subgroup analyses (P for interaction >0.05). According to Cox proportional hazard regression analysis and clinical value results, potential risk factors included SBI, Karnofsky performance status, TNM stage, induction chemotherapy, concurrent chemoradiotherapy, and adjuvant chemotherapy. Using a training C-index of 0.80 and a validation C-index of 0.79, the nomogram predicted BMFS and demonstrated satisfactory prognostic capability in 2, 3, and 5 years (area under curve: 83.7% vs. 79.6%, 81.7% vs. 88.2%, and 79.0% vs. 93.8%, respectively).

Conclusion

Skull base invasion is a risk factor for bone metastasis in patients with LA-NPC. The SBI-based nomogram model can be used to predict bone metastasis and may assist in identifying LA-NPC patients at the highest risk of bone metastasis.

Multiple Regression Analysis of Predictors of Bone Scintigraphy Positivity in Patients with Head and Neck Cancers

Purpose

The value of bone scintigraphy (BS) in patients with head and neck cancers (HNCs) has been questioned, with conflicting findings regarding positivity yield with some reports recommending BS be omitted from work-up of HNC patients since it rarely yields positive results. This study aims to determine the positivity yield of BS in HNCs and to determine predictors for BS positivity to help tailor appropriate BS utilization.

Methods

BS studies of HNC patients were reviewed, the positivity yield was determined. Clinical predictors for BS positivity including age, sex, site of cancer, staging, histological grading were analyzed using univariable and multivariable logistic regression.

Results

Among the 259 BS studies included, 35 (13.5%), 194 (74.9%), and 30 (11.6%) were positive, negative, and equivocal for bone metastasis, respectively. After exclusion of equivocal cases, 229 were analyzed in the regression models. Independent predictors of BS positivity include site of tumor at the nasopharynx (OR 4.37, 95% C.I. 1.04-18.41, p = 0.044), age less than 45 years (OR 3.01, 95% C.I. 1.24-7.33, p = 0.015), and presence of distant metastasis to other organs (OR 3.84, 95% C.I. 1.19-12.43, p = 0.025).

Conclusions

In contrast to several studies, bone metastasis as detected by BS was found in a relatively high proportion of patients with HNCs. Independent predictors of BS positivity include the age of less than 45 years, tumor site at the nasopharynx, and the presence of extraskeletal distant metastasis. BS could be useful in patients with these characteristics which enhance the pretest probability of bone metastasis.

Post-treatment serum lactic dehydrogenase as a predictive indicator for distant metastasis and survival of patients with nasopharyngeal carcinoma

Purpose

To examine the function of serum lactic dehydrogenase (SLDH) level after intensity-modulated radiotherapy (IMRT) as a predictive factor for and loco-regional relapse free survival (LRFS), distant metastasis-free survival (DMFS), disease free survival (DFS), and overall survival(OS) among patients with in-situ nasopharyngeal carcinoma (NPC).

Results

Compared with the normal pt-SLDH group, elevated pt-SLDH demonstrated significant lower DMFS (46 versus 66 months, hazard ratio (HR) 4.07, 95% CI 2.43–6.80, p < 0.001), DFS (46 versus 63 months, HR 2.78, 95% CI 1.70–4.53, p < 0.001), and OS (54 versus 66 months, HR 2.93, 95% CI 1.65–5.23, p < 0.001). Distant metastasis were observed in 32.8% (20/61) patients with elevated pt-SLDH, and 8% (54/678) in normal SLDH (odds ratio (OR) 6.13, 95% CI 3.35–11.18, p < 0.001). COX regression showed that pt-SLDH was an independent prognostic factors for OS (HR 2.91, 95% CI 1.57–5.41, p < 0.001), DMFS (HR 4.21, 95% CI 2.51–7.07, p < 0.001), LRFS (HR 2.53, 95% CI 1.22–5.24, p < 0.001), and DFS (HR 2.81, 95% CI 1.72–4.59, p < 0.001).

Materials and Methods

The records of 739 in-situ NPC patients admitted to Zhejiang Cancer Hospital between January 2007 and May 2012 were retrospectively reviewed. The relationships between post-treatment SLDH (pt-SLDH) and LRFS, DMFS, DFS, and OS were analyzed.

Conclusions

Our finding indicated that elevated pt-SLDH could be a simple available prognostic indicator for distant metastasis and survival for in-situ NPC patients.

18F-Fluorodeoxyglucose-positron Emission Tomography/Computed Tomography Imaging of Metastatic Nasopharyngeal Cancer with Emphasis on the Distribution of Bone Metastases

Distant metastases change the prognosis of patients with nasopharyngeal carcinoma (NPC) which most commonly metastasizes to the bone. ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) is reported as useful in imaging NPC metastases. Our study assesses the incidence and distribution of bone metastases detected by ¹⁸F-FDG PET/CT in NPC. 717 ¹⁸F-FDG PET/CT scan reports of histologically proven NPC patients imaged in Singapore General Hospital, Singapore, between 2003 and 2009 were reviewed for the total number of metastases (scanned from vertex to mid-thigh) and analyzed for distribution. Of the 709 FDG avid metastases in these reports, 357/709 (50.35%) were locoregional nodal metastasis and 352/709 (49.65%) were distant metastases of which 192/709 (27.08%) of total metastases and 54.54% of distant metastases (192/352) were in the bones. The majority of the bone lesions 125/192 (65.1%) were in the axial skeleton with 109/192 (56.77%) in the lower skeleton (thoracolumbar spine, sacrum, and pelvis). The incidence of bone metastases in our study (27.08%) was higher than that reported in other studies, for example, 15% by Liu et al. and 11% (230 patients) by Caglar et al. Bone metastases have been reported in the femurs and the feet and as such some metastases may have been outside the field of view of the scans. In our study, 27% of FDG avid NPC metastases are in the bones.

Fate of patients with nasopharyngeal cancer who developed distant metastasis as first failure after definitive radiation therapy

BACKGROUND

No consensus has been reached on the optimal treatment for patients with nasopharyngeal cancer (NPC) who develop distant metastasis after initial radiation therapy (RT).

METHODS

Two hundred eighty-two patients with NPC received curative RT (+/- chemotherapy). Forty-six patients (16.3%) who developed distant metastasis as first failure formed the study group for the current analysis.

RESULTS

The median interval from initial RT until distant metastasis was 11.6 months. With a median follow-up of 30 months among survivors, overall survival (OS) rates at 2 and 5 years were 53.7% and 30.5%, respectively. On multivariate analyses, 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/CT for initial staging, RT plus chemotherapy as initial treatment, metastatic lesion number <6, disease-free interval >9 months, distant metastasis only to lungs, and treatment with curative intent after distant metastasis were predictive of significantly better OS.

CONCLUSION

Combined with FDG-PET/CT, an aggressive treatment approach using locoregional modalities might be beneficial to patients with NPC with favorable prognostic factors, even after distant metastasis. © 2015 Wiley Periodicals, Inc. Head Neck 38: E293-E299, 2016.

Accuracy of whole-body FDG-PET and FDG-PET/CT in M staging of nasopharyngeal carcinoma: a systematic review and meta-analysis

BACKGROUND

A meta-analysis was conducted to evaluate the accuracy of whole-body positron emission tomography (PET) or PET/CT in M staging of nasopharyngeal carcinoma (NPC).

METHODS

Through a search of relevant English language studies from October 1996 to September 2011, pooled estimated sensitivity, specificity, positive likelihood ratios, negative likelihood ratios, and summary receiver operating characteristic (SROC) curves of whole-body PET or PET/CT in M staging of NPC were calculated.

RESULTS

Three PET and 5 PET/CT studies were identified. The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of FDG-PET or PET/CT were 0.83 (95% confidence interval [CI], 0.77-0.88), 0.97 (95% CI, 0.95-0.98), 23.38 (95% CI, 16.22-33.69), and 0.19 (95% CI, 0.13-0.25), respectively. The area under curve was 0.9764 and Q* index estimate was 0.9307 for FDG-PET or PET/CT.

CONCLUSION

Current evidence confirms the good diagnostic performance of the whole-body FDG-PET or PET/CT in M staging of NPC.

[Scintigraphy in staging upper aerodigestive tract epidermoid carcinomas]

OBJECTIVES

To determine the value of technetium-99m bone scintigraphy in the screening of bone metastases in the systematic initial extension assessment of upper aerodigestive tract suamous cell carcinomas; to identify risk factors of these bone metastases for better screening.

MATERIAL AND METHODS

In this prospective study, the initial assessment of tumoral extension was systematically associated with bone scintigraphy. Only patients with no malignant tumors were included in the study. Any skeletal fixation identified was then analyzed with standard radiography and/or tomodensitometry and with the patient's clinical progression to confirm whether or not the fixation was metastatic. The sensitivity and specificity of bone scintigraphy was then calculated. A correlation between bone pain or hypercalcemia and confirmed bone metastases was also systematically sought to determine whether these factors were predictive of bone metastases so as to better target the screening.

RESULTS

Among the 55 patients included in the study, three had confirmed bone metastases. All were detected by the bone scintigraphy, with a sensitivity of 100%. However, the 20 false-positive results gave a low specificity of 62%. Bone pain was described by two patients, but they were among the three metastatic patients. Specificity was 100%, but the sensitivity was only 67%. Three patients had hypercalcemia: the three metastatic patients. The sensitivity and specificity were 100%. In the tumoral status of the three patients with bone metastasis, tumors were small, classified as T1 or T2, but with substantial node involvement, classified N3, and with invasion of the internal jugular vein in two cases.

CONCLUSION

The incidence of bone metastases in the initial extension assessment was low; consequently, they are not sought systematically. However, their presence radically changes the prognosis and the therapeutic management, raising the question of screening. The technetium-99m bone scintigraphy has limits, with many false-positive resulting the need for additional investigations. Defining the risk factors for bone metastases would improve screening. Two questions remain: what factors are involved? The bone pain and the hypercalcemia must be analyzed with a larger number of cases, but they seem to be nonspecific. The node involvement stage could be a more reliable parameter, in particular in cases of jugular vein invasion; what method should be used? In the future, the PET scan could be the key procedure not only in the locoregional extension assessment, but also for general extensions, in a single procedure investigating the whole body.

[18F]fluorodeoxyglucose positron emission tomography is more sensitive than skeletal scintigraphy for detecting bone metastasis in endemic nasopharyngeal carcinoma at initial staging

PURPOSE

Bone metastasis occurs frequently in patients with endemic nasopharyngeal carcinoma (NPC). The main objective of this study is to evaluate positron emission tomography (PET) using fluorine-18-labeled fluorodeoxyglucose ([18F]FDG) and conventional skeletal scintigraphy (SS) for detecting bone metastasis at initial staging. Auxiliary objectives are to identify risk factors for bone metastasis and features associated with poor survival in patients with bone metastasis.

PATIENTS AND METHODS

Patients with endemic NPC before initiation of treatment were enrolled. PET and SS were performed at initial staging and compared using McNemar's paired-sample test. Bone metastasis was considered to be present if there was any reliable evidence identified within 1 year after primary diagnosis. Multiple logistic regression and Cox's proportional hazards models were used for auxiliary objectives.

RESULTS

Thirty (15%) of 202 eligible patients were found to have bone metastasis. [18F]FDG PET was found to be more sensitive than SS in the patient-based analysis (P = .006) and in the region-based analysis at the spine (P = .001). Advanced N stage was the only significant risk factor (P < .0001), and the coexistence of hepatic metastasis was a prognosticator of poor survival (P = .017). The survival was not significantly better for patients with bone metastasis undetected at primary staging than for those with initially detectable bone metastasis (P = .620).

CONCLUSION

[18F]FDG PET is more sensitive than SS for detecting bone metastasis in endemic NPC at initial staging, whereas SS can be considered as supplementary in this setting.

Optimal management of nasopharyngeal carcinoma

PURPOSE OF REVIEW

Given the high rate of mortality still associated with advanced stages of nasopharyngeal carcinoma, this review focuses on some specific aspects of this potentially curable disease that could translate into improved therapeutic approaches.

RECENT FINDINGS

Epstein-Barr viral-induced carcinogenesis is almost constantly reported in the undifferentiated type of nasopharyngeal carcinoma. Nasopharyngeal carcinoma retains clonal characteristics and p53 functionality up to late stages that may account for its high level of chemo- and radiotherapy sensitivity, with several cases of long-term survivors reported among patients with bone metastasis. Recent imaging and biologic techniques will help to identify patients at risk of distant failures (detection of plasma Epstein-Barr virus DNA) or those harboring posttherapeutic residual diseases (positron emission tomographic scan). Cisplatin-based induction chemotherapy has shown disease-free survival benefit, whereas concomitant chemoradiotherapy is associated with an improved local-regional control. Late radiation-induced toxicities (especially xerostomia) will hopefully be reduced using intensity-modulated radiation therapy. New therapeutic agents such as taxanes, or targeted therapies (epidermal growth factor receptor inhibitors) are of major interest in the challenge of circumventing resistance to alkylating agents.

SUMMARY

Better knowledge of nasopharyngeal carcinoma pathogenesis and biology, management of patients in highly specialized oncologic units, and careful selection of cytotoxic agents along with multimodality integrated therapeutic programs will likely yield to improved survival, particularly for patients with locally advanced nasopharyngeal carcinoma.