Natural history and prognosis of recurrent breast cancer.

Patterns of recurrent disease were analysed in 603 patients with breast cancer. The time of onset, frequency of recurrence, and survival after recurrence were not influenced by age or menopausal state. While survival after local recurrence was longer than survival after distant metastasis, the time to onset of local and distant disease followed an identical pattern, indicating that local recurrence should be regarded as a manifestation of systemic disease. Postoperative radiotherapy did not affect the time of onset of local recurrence. We suggest that patients with local recurrence should receive both systemic and local treatment and that controlled trials of chemotherapeutic agents in these patients might be valuable in finding the most effective drug combinations to be used as adjuvant treatment after mastectomy.     

Managing soft tissue sarcomas in a developing country: are prognostic factors similar to those of developed world?

ABSTRACT: BACKGROUND: Managing soft tissue sarcomas (STS) in a developing country with limited financial resources and a poor health referral system is a challenge. Presenting late, these extremity STS are prone to recurrence despite apparently complete resection. This study aimed to explore and compare the impact of clinico-pathological factors on recurrence and survival in Pakistan with the corresponding figures quoted from the developed world. METHODS: An institutional review was performed on all patients with primary STS of the extremities operated on between 1994 and 2008. The prognostic influence of clinical, pathologic, and treatment variables on local recurrence free survival (LRFS), metastasis free survival (MFS) and overall survival (OS) were analyzed by univariate and multivariate Cox regression analysis and Kaplan Meier survival curves. RESULTS: A total of 84 patients with a mean age of 41.8 +/- 21.9 years were included in the study. The local recurrence rate was 14.3% after a median of 6 (mean 7.4) months. Metastases occurred in 7 patients (8.3%) and 65 patients were alive without evidence of disease after a mean follow-up of 52.6 +/- 39.8 months. Tumor size > 5 cm, grade 3 tumors and margin < 10 mm significantly increased local recurrence rates. A margin >= 10 mm and age < 45 years significantly enhanced cumulative survival. Significant multivariate risk factors for metastases were margin < 10 mm and tumor grade G3. CONCLUSIONS: Despite a poor health referral system in our country, our results are no different from those reported from the developed world. Surgical margins and tumor grade prognostically influenced LRFS, MFS and OS.     

Prognostic Significance of Tumor Volume in Locally Recurrent Nasopharyngeal Carcinoma Treated with Salvage Intensity-Modulated Radiotherapy

Introduction

To evaluate the prognostic value of gross tumor volume (TV) in patients with locally recurrent, nonmetastatic nasopharyngeal carcinoma.

Methods

Between 2001 and 2012, 291 consecutive patients with locally recurrent, nonmetastatic nasopharyngeal carcinoma underwent salvage IMRT were retrospectively reviewed. The correlations between TV and recurrent T classification were analyzed. Survival analyses were performed. Receiver operating characteristic (ROC) curves were calculated to identify cut-off point of TV. The Akaike information criterion and Harrell’s concordance index (c-index) were utilized to test the prognostic value.

Results

The median TV significantly increased with advancing recurrent T classification (P<0.001). The 5-year overall survival rate was 33.2% for the entire cohort. On multivariate analysis, TV was an independent negative prognostic factor for distant metastasis-free survival (hazard ratio =1.013, P =0.003), overall survival (hazard ratio = 1.015, P<0.001) and toxicity-related death (hazard ratio = 1.014, P<0.001). The 5-year overall survival rates were 63.1% and 20.8% for patients with a TV < 22 cm³ and TV ≥22 cm³, respectively (P < 0.001). In patient with TV <22 cm³, locoregional failure is the leading cause of death. In patients with TV≥22 cm³, distant metastasis rate is higher and occurred within short term after local recurrence; meanwhile, radiation-induced injuries became more common and led to half of deaths in this group. The Akaike information criterion and c-index analyses indicated that the predictive ability of recurrent T classification improved when combined with TV.

Conclusions

Our data suggests TV is a significant prognostic factor for predicting the distant metastasis, overall survival and toxicity-related death of patients with locally recurrent, nonmetastatic nasopharyngeal carcinoma after salvage IMRT. TV should be considered when designing personalized salvage treatments for these patients. For patients with bulky local recurrent tumor, radiation may need to be de-emphasized in favor of systemic treatment or best supportive care.     

Haematogenous abdominal wall metastasis of differentiated, alpha-fetoprotein-negative hepatocellular carcinoma after previous antiandrogen therapy within a site of lipoma manifestation since childhood

Background

The guidelines established by the National Comprehensive Cancer Network do not describe mucinous histology as a clinical factor that should influence the therapeutic algorithm. However, previous studies show conflicting results regarding the prognosis of colorectal mucinous adenocarcinoma. In this study, we described the clinicopathological features of mucinous adenocarcinoma in Japan, to identify optimal therapeutic strategies.

Methods

144 patients with mucinous and 2673 with non-mucinous adenocarcinomas who underwent primary resection in two major centers in Yokohama, Japan were retrospectively evaluated for clinicopathological features and treatment factors. A multivariate analysis for overall survival followed by the comparison of overall survival using Cox proportional hazard model were performed.

Results

Patients with mucinous adenocarcinoma had larger primary lesions, higher preoperative CEA levels, a deeper depth of invasion, higher rates of nodal and distant metastasis, and more metastatic sites. A multivariate analysis for overall survival revealed a mucinous histology to be an independent prognostic factor. In the subgroup analysis stratified by stage, Patients diagnosed as StageIII and IV disease had a worse survival in mucinous adenocarcinoma than non-mucinous, while survival did not differ significantly in patients diagnosed as Stage0-II disease. In StageIII, local recurrence in rectal cases and peritoneal dissemination were more frequently observed in patients with a mucinous histology.

Conclusions

Our study indentified that mucinous adenocarcinoma was associated with a worse survival compared with non-mucinous in patients with StageIII and IV disease. In rectal StageIII disease with mucinous histology, additional therapy to control local recurrence followed by surgical resection may be a strategical alternative. Further molecular investigations considering genetic features of mucinous histology will lead to drug development and better management of peritoneal metastasis     

Circular RNA circMTO1 suppresses bladder cancer metastasis by sponging miR-221 and inhibiting epithelial-to-mesenchymal transition

Bladder cancer remains a leading cause of cancer-related death because of its distant metastasis and high recurrence rates. Deregulation of circular RNAs (circRNAs) can act either as tumor suppressors or oncogenes to control cell proliferation, migration, and metastasis. The role of circMTO1 in bladder cancer remain unknown. In this study, we investigated whether circMTO1 could use as a biomarker and therapeutic target for bladder cancer treatment. We first demonstrated that circMTO1 was an important circRNA frequently downregulated in bladder cancer tissue, and lower circMTO1 levels were positively correlated with bladder cancer patients' metastasis and poorer survival. Ectopic expression of circMTO1 in bladder cancer cells inhibited cell's epithelial-to-mesenchymal transition (EMT) and metastasis. In addition, we also revealed that circMTO1 was able to sponge miR-221 and overexpression of circMTO1 negatively regulated the E-cadherin/N-cadherin pathway to inhibit bladder cancer cells' EMT by competing for miR-221. In conclusion, our findings provide comprehensive evidences that circMTO1 is a prognostic biomarker in bladder cancer and suggest that circMTO1 may function as a novel therapeutic target in human bladder cancer.     

Glypican-3, a novel prognostic marker of hepatocellular cancer, is related with postoperative metastasis and recurrence in hepatocellular cancer patients

Metastasis/recurrence has been the most fundamental characteristic of hepatocellular cancer (HCC) and the ultimate cause of most HCC-related deaths. However, there are still a limited number of reliable tumor markers that can be used to predict the possibility of metastasis/recurrence in an HCC patient after operation. Recently, much evidence has shown that glypican-3 (GPC3) can be a useful tool to identify the early development of HCC, but little research has been done to test its usefulness as a prognostic marker related to post-operative metastasis/recurrence in HCC patients. In this study, the expression of GPC3 and its relationship with clinicopathological factors were determined by immunohistochemical analysis in 61 primary HCC patients. The potential prognostic value of GPC3 was investigated by comparing the survival time between HCC patients with high and low GPC3 expression. The results demonstrated that GPC3 expression was closely related with metastasis/recurrence in an HCC patient who can receive the operation. The risk of metastasis/recurrence after surgery in an HCC patient with high GPC3 expression was increased to 3.214 as compared to that of an HCC patient with low GPC3 expression. Survival analysis showed that HCC patients with high GPC3 expression had a significantly shorter overall survival time than HCC patients with low GPC3 expression (P = 0.003). Further, multivariate analysis showed that GPC3 expression was a significant, independent prognostic parameter (P = 0.030) for HCC patients. Overall, the study indicates that GPC3 might be a valuable marker closely related with prognosis and post-operative metastasis/recurrence in HCC patients.     

Appropriate endpoints for stereotactic body radiotherapy for bone metastasis: Classification into five treatment groups

Treatment of bone metastasis using stereotactic body radiotherapy (SBRT) is being widely used in clinical practice. The reported clinical advantages of SBRT include high pain and local control rates, high response rates against bone metastasis from radio-resistant tumors, and safe re-irradiations. Although most reports in the literature use local control as the primary treatment endpoint, this endpoint is not appropriate because local control does not relate directly to patient benefit. Herein, we proposed five pathophysiology-based patient groups, as well as appropriate endpoints for each group.     

Time course and pattern of metastasis of cutaneous melanoma differ between men and women

Background

This study identified sex differences in progression of cutaneous melanoma.

Methodology/Principal Findings

Of 7,338 patients who were diagnosed as an invasive primary CM without clinically detectable metastases from 1976 to 2008 at the University of Tuebingen in Germany, 1,078 developed subsequent metastases during follow up. The metastatic pathways were defined in these patients and analyzed using the Kaplan-Meier method. Multivariate survival analysis was performed using Cox modeling. In 18.7% of men and 29.2% of women (P<0.001) the first metastasis following diagnosis of primary tumor was locoregional as satellite/in-transit metastasis. The majority of men (54.0%) and women (47.6%, P = 0.035) exhibited direct regional lymph node metastasis. Direct distant metastasis from the stage of the primary tumor was observed in 27.3% of men and 23.2% of women (P = 0.13). Site of first metastasis was the most important prognostic factor of survival after recurrence in multivariate analysis (HR:1.3; 95% CI: 1.0–1.6 for metastasis to the regional lymph nodes vs. satellite/in-transit recurrence, and HR:5.5; 95% CI: 4.2–7.1 for distant metastasis vs. satellite/in-transit recurrence, P<0.001). Median time to distant metastasis was 40.5 months (IQR, 58.75) in women and 33 months (IQR, 44.25) in men (P = 0.002). Five-year survival after distant recurrence probability was 5.2% (95% CI: 1.4–2.5) for men compared with 15.3% (95% CI: 11.1–19.5; P = 0.008) for women.

Conclusions/Significance

Both, the pattern of metastatic spread with more locoregional metastasis in women, and the time course with retracted metastasis in women contributed to the more favorable outcome of women. Furthermore, the total rate of metastasis is increased in men. Interestingly, there is also a much more favorable long term survival of women after development of distant metastasis. It remains a matter of debate and of future research, whether hormonal or immunologic factors may be responsible for these sex differences.     

紫杉醇脂质体联合顺铂同步放疗对老年宫颈癌有较好疗效

本研究将178例具有危险因素的老年宫颈癌术后患者随机分为研究组和对照组各89例,对照组给予紫杉醇联合顺铂同步放化疗方案,研究组给予紫杉醇脂质体联合顺铂同步放化疗方案,观察2组患者治疗期间的毒副反应及1年、2年、3年生存率、局部复发率和远处转移率,以期探讨老年宫颈癌患者术后不同化疗方案联合同步放疗的有效性和安全性。研究结果表明:研究组骨髓抑制、消化道反应、肝肾功能异常、脱发发生率低于对照组(p<0.05);研究组1年、2年、3年生存率与对照组相比较均无统计学差异(p>0.05);研究组与对照组1年、2年、3年局部复发率和远处转移率相比较差异均无统计学意义(p>0.05)。本研究初步结论认为,老年宫颈癌患者术后采用紫杉醇脂质体联合顺铂同步放化疗方案更为安全有效,采用紫杉醇脂质体代替紫杉醇注射液值得在临床推广应用。     

Ubiquitin-Specific Peptidase 22, a Histone Deubiquitinating Enzyme,Is a Novel Poor Prognostic Factor for Salivary Adenoid Cystic Carcinoma

Salivary Adenoid Cystic Carcinoma (SACC) is characterized by a high rate of local recurrence and infiltration, strong invasion to peripheral nerves or late distant metastasis. Our aim was to investigate the expression of Ubiquitin-specific protease 22 (USP22) in SACC patients and its possible relationship to the outcome of the disease. A total of 135 SACC tissues and adjacent non-cancerous tissues which were diagnosed between 2002 and 2007 were enrolled in this study. Immunohistochemistry was used to compare the expression pattern of USP22 in SACC and adjacent non-cancerous groups, and the prognostic significance was assessed by Kaplan-Meier analysis and Cox proportional hazards regression in SACC patients. The rate of high expression of USP22 was significantly higher in SACC group than that in adjacent non-cancerous group. High expression of USP22 was significantly correlated with histological subtype, lymph node metastasis, grade, Ki-67 and SOX2 expression. Furthermore, USP22 acts as an oncogene by regulation the BMI-1 pathway and c-Myc pathway. SACC patients with high USP22 expression showed the poorer overall survival (OS) and disease-free survival (DFS) than those patients with low USP22 expression. In multivariate analysis, only lymph node metastasis and USP22 expression were the independent prognostic factors for OS and DFS in SACC. Our study provides evidence that USP22 expression is an independent prognostic factor for SACC patients.     

Circadian rhythms in Neurospora: a new measurement, the reset zone

The authors define a new feature of a circadian rhythm, the reset zone, and point out its usefulness for predictions concerning oscillator behavior. The reset zone measures the responses of a circadian system to resetting pulses. It can be easily determined from a phase transition curve (PTC), which is simply a phase response curve (PRC) replotted as new phase versus old phase (Winfree's format). The reset zone is the range of new phases seen in such a plot and has two potentially useful characteristics: its size and its midpoint. A series of experiments with Neurospora involving temperature pulses indicated that the size of the reset zone changed in a nonlinear way in response to both the duration of 40 degrees C pulses and to the magnitude of temperature change for 3-h pulses. Other existing data are replotted to show how the reset zone size varies with growth temperature and with the period of different clock mutants. Employing exclusively reset zone data within the framework of a limit cycle displacement model, an equation is formulated that predicts the relative changes in the values of state variables of the oscillator for changes in any given environmental condition, such as temperature. Examples are also drawn from other organisms, such as hamsters, Gonyalaux, Kalanchoe, and Drosophila, illustrating the usefulness of the reset zone measurement. It can be used as a numerical scale for assessing the strength of a pulse, for comparing the relative effects of a given pulse applied to different organisms or mutants, for determining the directionality of the changes in state variables produced by various types of pulses, and possibly for measuring clock amplitude.     

Using SCC Antigen and CRP Levels as Prognostic Biomarkers in Recurrent Oral Cavity Squamous Cell Carcinoma

Squamous cell carcinoma antigen (SCC-Ag) and C-reactive protein (CRP) levels have been successfully used to stratify risk groups in primary oral squamous cell carcinoma (OSCC) patients; however, related biomarkers have rarely been investigated in recurrent OSCC. The purpose of the present study was to analyze the relationships of SCC-Ag and CRP levels at the time of recurrence with clinical factors and prognosis. We retrospectively recruited patients with recurrence in a cohort of 534 OSCC patients between March 2001 and July 2013. One hundred patients had recurrence. The serum SCC-Ag and CRP levels were measured at the time of cancer diagnosis, 3 to 6 months after treatment with clinical disease-free, and at the time of recurrence. The SCC-Ag levels were significantly lowered after treatment (paired t-test: p = 0.001) and re-elevated at the time of recurrence (paired t-test: p = 0.027). An SCC-Ag level ≥2.0 ng/ml and a CRP level ≥5.0 mg/L at the time of recurrence were significantly associated with recurrent tumor status (P<0.001), recurrent nodal metastasis (χ² trend test: P = 0.020), distant metastasis (P<0.001), and overall survival (P<0.001). Moreover, the influence of both elevated SCC-Ag and CRP levels on overall survival (P<0.001, H.R. [95% CI]: 5.406 [2.210–13.222]) still existed after adjusting for the recurrent tumor stage and patient age. The present study demonstrates that concurrent high levels of both SCC-Ag and CRP at the diagnosis of recurrence acts as a predictor of recurrent tumor status, recurrent advanced tumor stage, distant metastasis, and survival after the diagnosis of recurrence. This study expands the applicability of these two markers in the risk stratification in recurrent OSCC.     

Proteomic analyses reveal high expression of decorin and endoplasmin (HSP90B1) are associated with breast cancer metastasis and decreased survival

Background

Breast cancer is the most common malignancy among women worldwide in terms of incidence and mortality. About 10% of North American women will be diagnosed with breast cancer during their lifetime and 20% of those will die of the disease. Breast cancer is a heterogeneous disease and biomarkers able to correctly classify patients into prognostic groups are needed to better tailor treatment options and improve outcomes. One powerful method used for biomarker discovery is sample screening with mass spectrometry, as it allows direct comparison of protein expression between normal and pathological states. The purpose of this study was to use a systematic and objective method to identify biomarkers with possible prognostic value in breast cancer patients, particularly in identifying cases most likely to have lymph node metastasis and to validate their prognostic ability using breast cancer tissue microarrays.

Methods and Findings

Differential proteomic analyses were employed to identify candidate biomarkers in primary breast cancer patients. These analyses identified decorin (DCN) and endoplasmin (HSP90B1) which play important roles regulating the tumour microenvironment and in pathways related to tumorigenesis. This study indicates that high expression of Decorin is associated with lymph node metastasis (p<0.001), higher number of positive lymph nodes (p<0.0001) and worse overall survival (p = 0.01). High expression of HSP90B1 is associated with distant metastasis (p<0.0001) and decreased overall survival (p<0.0001) these patients also appear to benefit significantly from hormonal treatment.

Conclusions

Using quantitative proteomic profiling of primary breast cancers, two new promising prognostic and predictive markers were found to identify patients with worse survival. In addition HSP90B1 appears to identify a group of patients with distant metastasis with otherwise good prognostic features.     

Late recurrence of localized cutaneous melanoma: its influence on follow-up policy

This paper reports 11 cases of recurrence 10 years or more after primary treatment of clinically local cutaneous melanoma at the Peter MacCallum Cancer Institute. Using the product-limit method for estimating recurrence-free survival, two late recurrence rates have been calculated. The estimated late recurrence rate among all treated patients is 5 percent (95 percent confidence interval: 2 to 8 percent), and the estimated late recurrence rate for the group who survived the first 10 years without recurrence is 7 percent (95 confidence interval: 3 to 11 percent). No prognostic factors were found that could identify a patient subgroup significantly at risk of late recurrence. Recurrence-free survival curves show that most recurrences have presented by the end of 6 years, but later recurrences are seen, the latest in this series being 18.2 years following treatment. While patients probably do not require long-term follow-up in specialist clinics provided they are adequately educated in the nature of their disease, this paper shows the value of long-term statistical surveillance.     

Comparison of five different scoring methods in the evaluation of inflammatory infiltration (tumor‐infiltrating lymphocytes) in superficial spreading and nodular melanoma

The objective of our study was to compare the five different scoring methods of tumor‐infiltrating lymphocytes (TILs) assessment in a group of 213 cases of superficial spreading and nodular melanoma. The scoring methods include (a) Clark scoring; (b) Melanoma Institute Australia system; (c) scoring system used in the study of Saldanha et al.; (d) scoring system used in the TCGA study and modified by Park et al.; and (e) the system recently proposed by the “International Immuno‐Oncology Biomarker Working Group” for TILs scoring in all solid tumors. Prediction of survival with three main outcomes—disease‐specific‐free survival, local recurrence‐free survival, and distant metastasis‐free survival—was evaluated. The prognostic value of TILs showed statistical significance in univariate analysis regarding all three of the outcomes only for three of the five evaluated methods; the Clark scoring, the Melanoma Institute Australia system, and the system proposed by the “International Immuno‐Oncology Biomarker Working Group”. However, in multivariate analysis with covariants including Breslow thickness, type of melanoma, location, sex, and age, we did not find TILs to be an independent prognostic factor.     

Eph/ephrin profiling in human breast cancer reveals significant associations between expression level and clinical outcome

Pre-clinical studies provide compelling evidence that Eph family receptor tyrosine kinases (RTKs) and ligands promote cancer growth, neovascularization, invasion, and metastasis. Tumor suppressive roles have also been reported for the receptors, however, creating a potential barrier for clinical application. Determining how these observations relate to clinical outcome is a crucial step for translating the biological and mechanistic data into new molecularly targeted therapies. We investigated eph and ephrin expression in human breast cancer relative to endpoints of overall and/or recurrence-free survival in large microarray datasets. We also investigated protein expression in commercial human breast tissue microarrays (TMA) and Stage I prognostic TMAs linked to recurrence outcome data. We found significant correlations between ephA2, ephA4, ephA7, ephB4, and ephB6 and overall and/or recurrence-free survival in large microarray datasets. Protein expression in TMAs supported these trends. While observed no correlation between ephrin ligand expression and clinical outcome in microarray datasets, ephrin-A1 and EphA2 protein co-expression was significantly associated with recurrence in Stage I prognostic breast cancer TMAs. Our data suggest that several Eph family members are clinically relevant and tractable targets for intervention in human breast cancer. Moreover, profiling Eph receptor expression patterns in the context of relevant ligands and in the context of stage may be valuable in terms of diagnostics and treatment.     

Hazard-Rate Analysis and Patterns of Recurrence in Early Stage Melanoma: Moving towards a Rationally Designed Surveillance Strategy

Background

While curable at early stages, few treatment options exist for advanced melanoma. Currently, no consensus exists regarding the optimal surveillance strategy for patients after resection. The objectives of this study were to identify patterns of metastatic recurrence, to determine the influence of metastatic site on survival, and to identify high-risk periods for recurrence.

Methods

A retrospective review of the Duke Melanoma Database from 1970 to 2004 was conducted that focused on patients who were initially diagnosed without metastatic disease. The time to first recurrence was computed from the date of diagnosis, and the associated hazard function was examined to determine the peak risk period of recurrence. Metastatic sites were coded by the American Joint Committee on Cancer (AJCC) system including local skin, distant skin and nodes (M1a), lung (M1b), and other distant (M1c).

Results

Of 11,615 patients initially diagnosed without metastatic disease, 4616 (40%) had at least one recurrence. Overall the risk of initial recurrence peaked at 12 months. The risk of initial recurrence at the local skin, distant skin, and nodes peaked at 8 months, and the risk at lung and other distant sites peaked at 24 months. Patients with a cutaneous or nodal recurrence had improved survival compared to other recurrence types.

Conclusions

The risk of developing recurrent melanoma peaked at one year, and the site of first recurrence had a significant impact on survival. Defining the timing and expected patterns of recurrence will be important in creating an optimized surveillance strategy for this patient population.     

A network model for activity-dependent sleep regulation

We develop and characterize a dynamical network model for activity-dependent sleep regulation. Specifically, in accordance with the activity-dependent theory for sleep, we view organism sleep as emerging from the local sleep states of functional units known as cortical columns; these local sleep states evolve through integration of local activity inputs, loose couplings with neighboring cortical columns, and global regulation (e.g. by the circadian clock). We model these cortical columns as coupled or networked activity-integrators that transition between sleep and waking states based on thresholds on the total activity. The model dynamics for three canonical experiments (which we have studied both through simulation and system-theoretic analysis) match with experimentally observed characteristics of the cortical-column network. Most notably, assuming connectedness of the network graph, our model predicts the recovery of the columns to a synchronized state upon temporary overstimulation of a single column and/or randomization of the initial sleep and activity-integration states. In analogy with other models for networked oscillators, our model also predicts the possibility for such phenomena as mode-locking.     

Cutaneous leiomyosarcoma

Cutaneous leiomyosarcoma is a rare soft-tissue sarcoma with negligible metastatic potential, but local recurrence rates after surgical excision have ranged from 14 percent to 42 percent. Unlike other sarcomas, guidelines for the optimal surgical excision margin of cutaneous leiomyosarcoma are not clearly defined in the existing literature. A review of local experience with this condition revealed eight patients over 12 years, none of whom developed local recurrence or distant metastases. This is despite poor prognostic factors in seven patients and excision margins ranging from 1 to 27 mm. These findings are compared with previously published data, and conclusions are drawn based on analysis of the collective results. Complete surgical excision with a narrow margin is recommended, and patients should be observed for a minimum of 5 years after surgery.     

Prognostic Value and Staging Classification of Retropharyngeal Lymph Node Metastasis in Nasopharyngeal Carcinoma Patients Treated with Intensity-modulated Radiotherapy

Background

The development of intensity-modulated radiotherapy (IMRT) has revolutionized the management of nasopharyngeal carcinoma (NPC). The purpose of this study was to evaluate the prognostic value and classification of TNM stage system for retropharyngeal lymph node (RLN) metastasis in NPC in the IMRT era.

Material and Methods

We retrospectively reviewed data from 749 patients with biopsy-proven, non-metastatic NPC. All patients received IMRT as the primary treatment. Chemotherapy was administered to 86.2% (424/492) of the patients with stage III or IV disease.

Results

The incidence of RLN metastasis was 64.2% (481/749). Significant differences were observed in the 5-year disease-free survival (DFS; 70.6% vs. 85.4%, P<0.001) and distant metastasis-free survival (DMFS; 79.2% vs. 90.1%, P<0.001) rates of patients with and without RLN metastasis. In multivariate analysis, RLN metastasis was an independent prognostic factor for disease failure and distant failure (P = 0.005 and P = 0.026, respectively), but not for locoregional recurrence. Necrotic RLN metastases have a negative effect on disease failure, distant failure and locoregional recurrence in NPC with RLN metastasis (P = 0.003, P = 0.018 and P = 0.005, respectively). Survival curves demonstrated a significant difference in DFS between patients with N0 disease and N1 disease with only RLN metastasis (P = 0.020), and marginally statistically significant differences in DMFS and DFS between N1 disease with only RLN metastasis and other N1 disease (P = 0.058 and P = 0.091, respectively). In N1 disease, no significant differences in DFS were observed between unilateral and bilateral RLN metastasis (P = 0.994).

Conclusions

In the IMRT era, RLN metastasis remains an independent prognostic factor for DFS and DMFS in NPC. It is still reasonable for RLN metastasis to be classified in the N1 disease, regardless of laterality. However, there is a need to investigate the feasibility of classifying RLN metastasis as N1a disease in future by a larger cohort study.