Increased incidence of tongue cancer after primary radiotherapy for nasopharyngeal carcinoma--the possibility of radiation carcinogenesis

Second primary cancer after intensity-modulated radiotherapy for nasopharyngeal carcinoma: A territory-wide study by HKNPCSG

OBJECTIVES

Long-term risk of second primary cancer (SPC) after definitive intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC) remains unclear. This study aims to evaluate the risk, predictive factors and survival impact of SPC in a large territory-wide cohort of NPC survivors in an endemic region.

MATERIALS AND METHODS

In this multicenter study, consecutive NPC patients (n = 3166) who underwent definitive IMRT in all six public oncology centers in Hong Kong between 2001 and 2010 were included. SPC risks were quantified by standardized incidence ratios (SIRs) and absolute excess risks (AERs) estimated from corresponding age-, sex-, and calendar year-specific population cancer incidence data from the Hong Kong Cancer Registry. Predictive factors and SPC-specific mortality were analyzed.

RESULTS

Over a median follow-up period of 10.8 years, 290 cases of SPC were observed with a crude incidence of 9.2%. Cancer risk in NPC survivors was 90% higher than that in general population [SIR, 1.9; 95% confidence interval (CI), 1.7-2.2], with an AER of 52.1 (95% CI, 36.8-67.3) per 10,000 person-years at risk. Significant excess cancer risks were observed for oral cavity, sarcoma, oropharynx, paranasal sinus, salivary gland, thyroid, skin and lung. Advanced age, smoking, hepatitis B status, and re-irradiation were independent predictive factors. SPC accounted for 9.4% of all deaths among NPC survivors during the study period, and 10-year SPC-specific mortality was 3.4%.

CONCLUSIONS

Second cancer risk after IMRT was substantial among NPC patients. SPC impairs long-term survival, and close surveillance is warranted as part of survivorship care.

Risk Assessment of Secondary Primary Malignancies in Nasopharyngeal Carcinoma: A Big-Data Intelligence Platform-Based Analysis of 6,377 Long-term Survivors from an Endemic Area Treated with Intensity-Modulated Radiation Therapy during 2003-2013

PURPOSE

The incidence, risk factors and survival impact of secondary primary malignancies (SPMs) among survivors of nasopharyngeal carcinoma (NPC) treated with definitive intensity-modulated radiation therapy (IMRT) with or without chemotherapy are poorly characterized.

METHODS AND MATERIALS

Consecutive patients (n=6,377) from the big-data intelligence platform at Sun Yat-sen University Cancer Center, China (in a high-incidence area) with newly diagnosed non-metastatic pathologically proven non-keratinizing undifferentiated NPC treated with IMRT±chemotherapy between January 2003 and June 2013 were retrospectively analyzed. Cumulative incidence of SPMs was calculated using the Kaplan-Meier method. Cox proportional hazards model was used to identify potential risk factors for SPMs and assess whether SPMs affect overall survival.

RESULTS

Of the 6,377 patients, 189 (3.0%) suffered SPMs (median follow-up, 62 months). One-, 2-, 3-, 4-, and 5-cumulative risks of SPMs were 0.4%, 0.9%, 1.6%, 2.2%, and 2.6%, respectively. Latency from start of IMRT to SPMs diagnosis was 37 months (range, 6 to 102 months). In patients with SPMs, 14.3% suffered SPMs within 1 year post-IMRT: 1-3 years, 38.1%; 3-5 years, 33.9%; and >5 years, 13.7%. Lung cancer was the most common SPM (50/6,377, 0.78%). Multivariate analysis demonstrated sex (male, 64% increase), age (≥50 years, 68% increase), and smoking history (41% increase) were significant risk factors for SPMs, and SPMs were associated with poorer overall survival.

CONCLUSION

This large cohort study confirms SPMs a dreadful complication for long-term survivors of NPC treated with IMRT. SPMs negatively impact overall survival in NPC. Close follow-up is recommended for older male survivors with a smoking history.

Secondary Squamous Cell Carcinoma of the Oral Cavity after Nasopharyngeal Carcinoma

Purpose

The main goal of this study was to analyze the prognosis of secondary oral squamous cell carcinoma (SCC) with a comparison with sporadic oral SCC by a matched-pair design.

Materials and Methods

Records of patients with surgically treated primary oral SCC were reviewed, and a total of 83 patients with previous history of radiotherapy for nasopharyngeal carcinoma (NPC) were retrospectively enrolled. A matched-pair study was performed, each NPC survivor was matched with two sporadic oral SCC patients by age, sex, primary tumor site, adverse pathologic characteristics, disease stage, neck node status, and tumor stage. The overall survival (OS) and disease-specific survival (DSS) rates were calculated by the Kaplan-Meier method; independent prognostic factors were evaluated by the Cox proportional hazards method.

Results

Compared with sporadic oral SCC patients, NPC survivors were less likely to be smokers (p=0.004), perineural invasion and lymphovascular invasion were more common in NPC survivors (both p < 0.001). The 5-year OS and DSS rates in NPC survivors were 47% and 54%, respectively; the 5-year OS and DSS rates in sporadic oral SCC patients were 62% and 67%, respectively; the difference was significant (both p < 0.05). In survival analysis, disease stage remained to be independent prognostic factor for both the OS and DSS.

Conclusion

NPC survivors had worse OS and DSS than sporadic oral SCC patients, NPC survivors were less likely to be smokers, but had higher opportunity of perineural invasion and lymphovascular invasion. Disease stage was the most important predictor for the survival in NPC survivors.

Risk, pattern and survival impact of second primary tumors in patients with nasopharyngeal carcinoma following definitive intensity-modulated radiotherapy

AIM

Second primary tumor (SPT) is a serious late complication after definitive radiotherapy for nasopharyngeal carcinoma (NPC). We evaluated the incidence, pattern, risk factors and survival impact of SPT in NPC patients following definitive intensity-modulated radiotherapy (IMRT).

METHODS

A retrospective review of 780 consecutive IMRT-treated NPC patients between February 2003 and September 2011 was conducted. Cumulative SPT incidence and overall survival after SPT diagnosis were estimated. Associations between clinical characteristics and SPT risk were analyzed. Standardized incidence ratios (SIR) were calculated using age, gender and calendar-year-specific cancer incidences from the Hong Kong Cancer Registry.

RESULTS

At a median follow-up of 7.5 years, 51 SPTs (6.7%) were identified, 22 (43.1%) of which occurred within previous radiotherapy fields. Tongue cancers (31.8%) and sarcomas of the head and neck (31.8%) were the most common in-field SPTs. Age [hazard ratio (HR), 1.051; 95% confidence interval (CI), 1.025-1.078] and smoking status (HR, 1.755; 95% CI, 1.002-3.075) were independent risk factors associated with SPT development. Median overall survival after SPT diagnosis was 2.9 years. There was an 84% increase in cancer risk (SIR, 1.84; 95% CI, 1.37-2.42) compared with the general population. Significant excess risks were observed for sarcoma, tongue, oropharyngeal, prostate and liver cancer. Excess risks were higher beyond 5 years of follow-up.

CONCLUSION

Substantial risk of SPT, especially for in-field sarcoma and tongue cancers, exists after definitive IMRT for NPC. SPT severely negates longevity of NPC survivors. High awareness and careful surveillance is warranted for this late lethal complication.

The poor outcome of second primary oral squamous cell carcinoma is attributed to Bmi1 upregulation

Radiotherapy for nasopharyngeal carcinoma has been reported to cause second primary oral squamous cell carcinoma (s-OSCC). The prognosis and pathologic characteristic of s-OSCC are largely unknown. Bmi1 was associated with the repair of radiation-induced DNA damage, suggesting its possible involvement in the pathologic process of s-OSCC. Herein, we compared the prognosis between s-OSCC and primary OSCC (p-OSCC) and explored the involvement of Bmi1 in s-OSCC development. In this retrospective study, s-OSCC and p-OSCC patients were matched by propensity scores. Their outcomes were compared by univariate and multivariate analyses. The expression of Bmi1 in s-OSCC and p-OSCC was detected by immunohistochemistry (IHC). Radiation-induced Bmi1 alteration in early-stage was explored in a rat model and HaCaT cells. After matching, 116 pairs of patients with highly balanced characteristics were included. In univariate analysis, the overall survival (OS), disease-specific survival (DSS), and local recurrence-free survival (LRFS) were poorer in s-OSCC than in p-OSCC (P < 0.05), while their regional metastasis-free survival (RMFS) was parallel (P = 0.112). Multivariate analysis further revealed that radiotherapy history was an independent risk factor for OS, DSS, and LRFS (P < 0.05). IHC results showed that the positive rate of Bmi1 was higher in s-OSCC (P = 0.0027). In a rat model of radiotherapy-induced mucositis, Bmi1 upregulation was observed 8 days after irradiation. Consistently, Bmi1 was upregulated in HaCaT cells 1 h after irradiation, and its upregulation was in accord with X-ray exposure duration. In conclusion, the prognosis of s-OSCC is poorer as compared to p-OSCC, which may be attributed to Bmi1 upregulation.

Investigation of long-term survival outcomes and failure patterns of patients with nasopharyngeal carcinoma receiving intensity-modulated radiotherapy: a retrospective analysis

Intensity-modulated radiotherapy (IMRT) has replaced the conventional radiotherapy (2D-RT) and improved clinical efficacy in Nasopharyngeal Carcinoma (NPC) patients. In the present study, we retrospectively analyzed the clinical characteristics of patients with NPC treated with IMRT to assess the long-term survival outcomes and failure patterns. Of the 527 patients, One hundred and twenty-one patients experienced treatment failure, 86 patients developed distant metastases, and 12 patients developed a second primary tumor. The local and regional recurrence rates were 31.4% and 14.0%, respectively. The 5-year overall survival (OS), progression-free survival (PFS), local recurrence-free survival (LRFS), regional relapse-free survival (RRFS), and distant metastatic relapse-free survival (DMFS) rates were 80.9%, 75.6%, 91.7%, 96.2%, and 83.0%, respectively. The 5-year LRFS rates of Stage T1-4 patients were 100.0%, 93.1%, 92.0%, and 85.8%, respectively. The 5-year DMFS rates of Stage N0-3 patients were 95.0%, 86.1%, 79.5%, and 67.2%, respectively. Multivariate analysis showed age and T-stage were independent predictors of OS, T-stage was an independent predictor of LRFS, and age and N-stage were independent predictors of PFS and DMFS.

In summary, the improved treatment results with IMRT are primarily due to the achievement of a higher local tumor control rate and OS in NPC patients. However, distant metastasis was the most commonly observed failure pattern after treatment. These results provide deep insights about the value of IMRT in the treatment and prognosis of NPC patients.

The clinical characteristics of secondary primary tumors in patients with nasopharyngeal carcinoma after intensity-modulated radiotherapy: A retrospective analysis

To investigate the clinical characteristics associated with the risk of developing secondary primary tumors (SPTs) in patients with nasopharyngeal carcinoma (NPC) who underwent intensity-modulated radiotherapy (IMRT).Data from 527 patients with biopsy-proven nonmetastatic NPC who were treated with IMRT between January 2007 and December 2011 were analyzed retrospectively. The cumulative incidence of SPTs after IMRT completion was estimated using the Kaplan-Meier method. Intergroup differences in the cumulative incidence were determined using the log-rank test. The Cox proportional hazards regression model was used to confirm the risk factors associated with IMRT-induced SPTs.The median follow-up duration was 45.5 months (range, 4-97 months). Of the 527 patients, 12 (2.3%) developed posttreatment SPTs (9 men, 3 women), 6 of which were located in the irradiation field. SPTs were mostly located in the upper aerodigestive tract (n = 7), head and neck (n = 6), lungs (n = 3), and tongue (n = 2). The 1-, 3-, and 5-year cumulative SPT risk rates were 0.4%, 1.4%, and 3.1%, respectively, and the mean annual growth in cumulative incidence was approximately 0.6%. The 1-, 3-, and 5-year cumulative in-field SPT risk rates were 0.4%, 0.8%, and 1.5%, respectively, and the mean annual growth in the in-field cumulative incidence was approximately 0.3%. Univariate and multivariate analysis revealed that sex, age, clinical stage, chemotherapy, and overall IMRT duration did not significantly affect SPT risk. However, the history of smoking was the independent risk factor associated with SPT.The 5-year SPT incidence among patients with NPC after IMRT is concordant with or lower than that in previous 2-dimensional radiotherapy studies study. Among patients with NPC who underwent IMRT, the upper aerodigestive tract was the most common SPT site, and lung cancer was the most common pathology. Smoking history, but not sex, age, clinical stage, chemotherapy, and overall IMRT duration is the independent risk factor associated with SPT. Additional large-scale studies with longer-term follow-ups are needed to determine risk factors associated with SPT development after IMRT.

Clinicopathologic Characteristics and Prognosis of Tongue Squamous Cell Carcinoma in Patients with and without a History of Radiation for Nasopharyngeal Carcinoma: A Matched Case-Control Study

Purpose

Previous studies reported an association between an increased risk of tongue cancer and radiation treatment for nasopharyngeal carcinoma (NPC). This study compared the clinicopathologic characteristics and outcomes of tongue squamous cell carcinoma (TSCC) in patients with and without a history of radiotherapy for NPC.

Materials and Methods

From 1965 to 2009, a total of 73 patients were diagnosed with TSCC with a history of radiotherapy for NPC. The patients were matched in a 1:3 ratio with patients with sporadic TSCC according to age, sex, and year of the TSCC diagnosis. The primary endpoint was the overall survival.

Results

The median interval from NPC to TSCC was 82 months. The NPC survivors were more likely to be diagnosed with a more advanced T classification, less likely to have lymph node involvement, and more likely to have the tumor located in the dorsum of the tongue than sporadic TSCC. Regarding the histologic characteristics, the NPC survivors were more likely to have a weak lymphocytic host response, low tumor budding, and low risk of a worse pattern of invasion. The sporadic TSCC patients had a better overall survival (hazard ratio, 0.690; p=0.033) than the NPC survivors. In competing risks analysis, the cumulative incidence functions for the competing event (documented non-tongue cancer death) were significantly higher in the NPC survivors (Gray’s test, p=0.001).

Conclusion

TSCC patients with a history of radiotherapy for NPC appear to have particular clinicopathologic features, a poorer survival, and are more likely to die from non-tongue cancer causes than those with sporadic TSCC.

Risk of second primary malignancy after nasopharyngeal carcinoma in the United States: A population-based study

BACKGROUND

The purpose of this study was to evaluate the incidence of second primary malignancies in patients diagnosed with an index nasopharyngeal carcinoma (NPC) in the United States.

METHODS

The cohort was assembled from the Surveillance, Epidemiology, and End Results (SEER) database with a primary NPC between 1973 and 2005.

RESULTS

There was a 47% increased risk of second primary malignancy. The sites with increased risk include the oral cavity and pharynx (standardized incidence ratio [SIR] = 7.11; 95% confidence interval [CI] = 5.21-9.49), esophagus (SIR = 3.50; 95% CI = 1.68-6.44), nose, nasal cavity, and middle ear (SIR = 15.54; 95% CI = 5.70-33.83), and lung and bronchus (SIR = 2.39; 95% CI = 1.91-2.96).

CONCLUSION

Patients with NPC are likely at a significant risk for second primary malignancies, most notably in the oral cavity and pharynx, which is most likely related to genetic susceptibility, increased surveillance, and treatment effects. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1130-E1136, 2016.

Prognostic factors and survival in patients with radiation-related second malignant neoplasms following radiotherapy for nasopharyngeal carcinoma

Purpose

To analyze the clinicopathological characteristics, treatment modalities, and potential prognostic factors of radiation-related second malignant neoplasms (SMNs) in a large group of nasopharyngeal carcinoma (NPC) cases.

Methods and Materials

Institutional electronic medical records of 39,118 patients with NPC treated by definitive radiotherapy between February 1964 and December 2003 were reviewed. A total of 247 patients with confirmed SMN attributable to radiotherapy were included.

Results

Median latency between radiotherapy for NPC and the diagnosis of SMN was 9.5 years (range, 3.1–36.8 years). Squamous cell carcinoma was the most common histologic type, followed by fibrosarcoma and adenocarcinoma. Median progression-free survival and overall survival (OS) of the 235 patients who underwent treatment were 17.3 months and 28.5 months, respectively. The 5-year OS rates were 42.9%, 23.7%, and 0% for the surgery, radiotherapy, and chemotherapy groups, respectively. The independent prognostic factors associated with survival were sex, histologic type, and treatment modality in both the early stage subgroup and the advanced stage subgroup of SMN.

Conclusions

Sex, histologic type, and treatment modality were the significant prognostic factors for SMN. Complete resection offers the best chance for long-term survival. In select patients with locally advanced and unresectable SMN, reirradiation should be strongly considered as a curative option.

MRI of radiation-induced tumors of the head and neck in post-radiation nasopharyngeal carcinoma

The aim of this study was to document the sites and MRI features of radiation-induced tumors (RITs) in the head and neck following treatment for nasopharyngeal carcinoma (NPC). The MRI examinations and clinical records of 20 patients with 21 RITs were reviewed retrospectively. RITs developed 3-30 years after radiotherapy and included eleven squamous cell carcinomas, six sarcomas, two neuroendocrine carcinomas, one mucoepidermoid carcinoma and one meningioma. RITs arose in the maxillary region (9), oro/hypopharynx and oral cavity (5), external auditory canal (4), nasopharynx and sphenoid sinus (2) and brain (1). Radiation-induced carcinoma and sarcoma had MRI features that were useful to distinguish them from recurrent NPC. To improve early detection of RITs, the check areas on an MRI of a patient with previous NPC treated by radiation should always include the maxillary region, tongue, and external auditory canal/temporal bone.

Second primary cancers in patients with nasopharyngeal carcinoma: a pooled analysis of 13 cancer registries

OBJECTIVE

To study the risk of second primary cancers in nasopharyngeal carcinoma (NPC) patients and the risk of NPC as second primary cancer.

METHODS

We used data from the cancer registries from Singapore and from 12 low-incidence areas, including a total of 8,947 first occurring NPC cases, and 167 second occurring cases. We calculated standardized incidence ratios (SIRs) by comparing the second cancer incidence in NPC patients to the first primary cancer incidence in non-cancer population. We also calculated SIRs of second NPC after other primaries.

RESULTS

In Singapore, the risk of cancers of the lung (SIR=0.42), stomach (SIR=0.41), and colon (SIR=0.23) was significantly decreased after NPC, whereas that of cancer of the tongue (SIR=11.1) was significantly increased. In Australia, Canada, and Europe, the risk of non-Hodgkin's lymphoma (NHL) (SIR=3.06), tongue cancer (SIR=5.29), brain cancer (SIR=3.89), myeloid leukemia (SIR=3.85), and non-melanoma skin cancer (NMSC) (SIR=3.47) was significantly increased after NPC. Incidences of second occurring NPCs following various primary cancers were not significantly altered compared to the incidence of first occurring NPCs.

CONCLUSIONS

Immune suppression (NHL, NMSC), shared genetic factors (lung cancer, NHL, myeloid leukemia), and shared environmental risk factors (tongue and brain cancers) might explain the associations. Except for NHL, there was no evidence of association with other Epstein-Barr virus-related cancers.

[Metachronous cancers after treatment for undifferentiated nasopharyngeal carcinoma]

OBJECTIVE

To collect second cancers occurring in the head and neck area after treatment by chemotherapy and/or radiotherapy for undifferentiated nasopharyngeal carcinoma in Tunisia.

PATIENTS AND METHODS

This is a retrospective study of patients developing second cancers after treatment for nasopharyngeal UCNT by radiotherapy and/or chemotherapy. To be retained in this study, second tumour had to be histologically different from the initial UCNT, localised in the irradiated area and occurring after a minimal delay of 3 years.

RESULTS

We collect 11 cases of second cancers occurring among 2346 patients treated from 1984 to 2001 in Tunisia (0.46%). Patients have been treated for nasopharyngeal UCNT mainly advanced T3-T4 (72%) or N2-N3 (63%). Median age was 20 years (11 to 48) with a sex-ratio of 0.3 (3 M/8 F). Treatment protocol included primary chemotherapy in 4 cases (adriamycin-cisplatin) or adjuvant (in 4) associated to the loco-regional irradiation at a mean dose of 72 Gy (70 to 75). Median delay of second cancer occurrence was 9 years (3 to 17). Tumors were epidermoid carcinomas in 4 cases, fibrosarcomas (2), osteosarcomas (2), glioblastoma (1) and basocellular carcinomas in 2. Second tumors have been treated by surgery alone in 4 cases and chemotherapy alone in 7 patients. No patient have been reirradiated. Median survival was 17 months, 4 patients died and 7 are still alive including 4 in complete remission (24+, 36, 36 and 48+ months) and 3 with progressing disease (8, 16 and 18 months).

CONCLUSION

Even very rare, second cancers after treatment for UCNT need to be detected and have a poor prognosis.