The relationship of nasopharyngeal carcinomas and second independent malignancies based on the Radiation Therapy Oncology Group experience

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.

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 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.

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.

Second malignant tumors after treatment of nasopharyngeal carcinoma: four case reports and literature review

The purpose of this study was to identify the histopathology, location, and latency interval for the development of second malignant tumors (SMT) after successful treatment for nasopharyngeal carcinoma (NPC). Of 55 patients, four developed SMT after successful treatment of NPC in a single institutional series for an incidence of 7%. An additional 31 patients with SMT after treatment for NPC were identified from the literature. At minimum, all patients were treated with radiotherapy to the primary site. The histopathology of SMT included sarcoma (69%), squamous cell carcinoma (17%), adenocarcinoma (6%), meningioma (6%), and lymphoma (3%). SMT occurred at various sites in the head and neck, but most (51%) arose in the sinonasal cavity. For the entire group, the mean latency interval between treatment for NPC and the development of SMT was 11.8 years. These findings indicate that the development of SMT in patients achieving long-term survival after treatment for NPC may be radiation induced. Long-term follow-up for these patients is important to assess for this potentially late complication.

The cost-utility analysis of 18-fluoro-2-deoxyglucose positron emission tomography in the diagnosis of recurrent nasopharyngeal carcinoma

RATIONALE AND OBJECTIVES

18-Fluoro-2-deoxyglucose (18F-FDG) positron emission tomography (PET) is effective but costly in the early detection of recurrence for nasopharyngeal carcinoma (NPC) in patients after treatment. In this study, we developed a decision tree model to analyze the cost utility of 18F-FDG PET in detecting loco-regional recurrences for NPC patients after therapy.

MATERIALS AND METHODS

The analysis for cost utility is based on the decision-tree model for three different strategies: 1) magnetic resonance imaging (MRI)-only, 2) PET-only, and 3) MRI-PET (performing PET if MRI result is uncertain). Sensitivity analyses have been performed to examine changes in the cost ratio of PET/MRI and the probability of uncertain MRI.

RESULTS

After inputting the data for utilities and life expectancies into the decision tree model, the quality-adjusted life expectancies turn out to be 16.16 quality-adjusted life-years (QALYs) for strategy 1, 16.70 QALYs for strategy 2, and 17.35 QALYs for strategy 3. The additional cost per additional QALYs for strategy 3 relative to strategy 1 is calculated to be US $462. Strategy 3 dominates over strategy 2 because strategy 3 costs less and yields more QALYs than strategy 2. If the cost ratio of PET/MRI is less than 1.85 or the probability of uncertain MRI is greater than 73%, then the PET-only strategy becomes more cost-effective than the MRI-PET strategy.

CONCLUSION

Our analysis shows that the MRI-PET strategy is the most cost-effective for now. It is likely the PET-only strategy will become the most cost-effective for recurrent NPC in patients in the near future as the cost of PET has decreased in a faster rate than the cost of MRI.

Survival study and treatment strategy for second primary malignancies in patients with head and neck squamous cell carcinoma and nasopharyngeal carcinoma

CONCLUSION

Patients at risk of developing second primary malignancies (SPMs) comprise those with primary hypopharyngeal, laryngeal, and oral cavity index cancers, patients with well-differentiated squamous cell carcinomas, those aged >70 years, patients who are heavy smokers, alcohol drinkers, or betel quid chewers, and those with a family history of SPM.

OBJECTIVE

SPMs are commonly found after successful treatment of index cancers in the head and neck region; however, treatment guidelines for SPMs have not been established. We compared the differences in the clinical characteristics, treatment outcomes, and 10-year survival rate between patients with SPMs who had been treated for head and neck squamous cell carcinoma (HNSCC) and those who had been treated for nasopharyngeal carcinoma (NPC) in order to establish an effective treatment strategy.

PATIENTS AND METHODS

This was a 10-year retrospective study of 125 patients who had developed SPMs after being treated for either HNSCC or NPC during the period from January 1995 to July 2005. The average follow-up time was 34.9 months, and the setting for the study was a tertiary referral center.

RESULTS

The survival rate of patients with SPMs is not significantly poor. The survival is worse if the SPM is associated with a primary advanced stage index cancer or it is synchronous; if the SPM occurs in an area other than the head and neck region; or if SPM patients undergo palliative treatment.

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.

Nasopharyngeal carcinoma: molecular biomarker discovery and progress

Nasopharyngeal carcinoma (NPC) is a rare malignancy in most part of the world and it is one of the most confusing, commonly misdiagnosed and poorly understood diseases. The cancer is an Epstein-Barr virus-associated malignancy with a remarkable racial and geographical distribution. It is highly prevalent in southern Asia where the disease occurs at a prevalence about a 100-fold higher compared with other populations not at risk. The etiology of NPC is thought to be associated with a complex interaction of genetic, viral, environmental and dietary factors. Thanks to the advancements in genomics, proteomics and bioinformatics in recent decades, more understanding of the disease etiology, carcinogenesis and progression has been gained. Research into these components may unravel the pathways in NPC development and potentially decipher the molecular characteristics of the malignancy. In the era of molecular medicine, specific treatment to the potential target using technologies such as immunotherapy and RNAi becomes formulating from bench to bedside application and thus makes molecular biomarker discovery more meaningful for NPC management. In this article, the latest molecular biomarker discovery and progress in NPC is reviewed with respect to the diagnosis, monitoring, treatment and prognostication of the disease.

The risk of second primary tumors in patients with nasopharyngeal carcinoma after definitive radiotherapy

BACKGROUND

Second primary tumors (SPTs) have a substantial impact on survival in cancer patients. However, risk factors for SPTs have not been documented well, especially in nasopharyngeal carcinoma (NPC). The objective of this retrospective analysis was to evaluate such risks in patients with NPC after they received definitive radiation treatment.

METHODS

Three hundred twenty-six consecutive patients with pathologically confirmed, nonmetastatic, undifferentiated NPC who received treatment between January 1, 1994 and December 30, 1995 were analyzed. All patients were restaged in accordance with the 2002 American Joint Committee on Cancer staging classification. There were 18 patients (5.5%) with Stage I NPC, 152 patients (46.6%) with Stage II NPC, 101 patients (31.0%) with Stage III NPC, and 55 patients (16.9%) with Stage IVA or IVB NPC at initial diagnosis. All patients received definitive radiotherapy with either Cobalt-60 or megavoltage therapy. High-dose-rate brachytherapy was given to 23 patients either as part of their primary treatment or as adjuvant treatment for residual lesions.

RESULTS

The median follow-up for all patients was 5.6 years (range, 1.0-8.0 years). Seventeen patients (5.2%) developed SPTs, for an average annual rate of 1.0%, and the 5-year cumulative incidence was 5.8%. Six SPTs were located within the radiation field. The cumulative incidence of in-field SPTs was 0.35% at 3 years and 1.2% at 5 years, and the average annual rate was 0.35%. Eleven patients (64.7%) had tumors of the upper aerodigestive tract (UADT). Among the 14 SPTs that occurred within 5 years after radiotherapy, only 3 tumors (21.4%) occurred within the radiation field. In contrast, all 3 SPTs that occurred >5 years after radiotherapy occurred within the radiation field (P = .029). Multivariate analysis showed that age was the only independent risk factor for developing SPTs after RT for NPC. Advanced age (age >or=50 years) was associated with a 37% increased risk of developing SPTs (relative risk, 1.367; 95% confidence interval, 1.067-1.1753; P = .014). Other factors, including gender, tumor or lymph node classification, chemotherapy, total radiation dose to the nasopharynx, reirradiation, and adjuvant brachytherapy did not influence the risk of SPTs.

CONCLUSIONS

SPTs in patients with NPC occurred preferentially in the UADT and tended to develop within the irradiated field >5 years after patients received radiation. Older patients with NPC (age >or=50 years) may be at increased risk. Further studies with larger samples and longer follow-up will be needed to confirm these findings.

Polyadenylate polymerase (PAP) and 3' end pre-mRNA processing: function, assays, and association with disease

Polyadenylate polymerase (PAP) is one of the enzymes involved in the formation of the polyadenylate tail of the 3' end of mRNA. Poly (A) tail formation is a significant component of 3' processing, a link in the chain of events, including transcription, splicing, and cleavage/polyadenylation of pre-mRNA. Transcription, capping, splicing, polyadenylation, and transport take place as coupled processes that can regulate one another. The poly(A) tail is found in almost all eukaryotic mRNA and is important in enhancing translation initiation and determining mRNA stability. Control of poly(A) tail synthesis could possibly be a key regulatory step in gene expression. PAP-specific activity values are measured by a highly sensitive assays and immunocytochemical methods. High levels of PAP activity are associated with rapidly proliferating cells, it also prevents apoptosis. Changes of PAP activity may cause a decrease in the rate of polyadenylation in the brain during epileptic seizures. Testis-specific PAP may play an important role in spermiogenesis. PAP was found to be an unfavorable prognostic factor in leukemia and breast cancer. Furthermore, measurements of PAP activity may contribute to the definition of the biological profile of tumor cells. It is crucial to know the specific target causing the elevation of serum PAP, for it to be used as a marker for disease. This review summarizes the recently accumulated knowledge on PAP including its function, assays, and association with various human diseases, and proposes future avenues for research.

Second malignant tumors in patients with nasopharyngeal carcinoma and their association with Epstein-Barr virus

Since previous published studies about second malignant tumors (SMTs) in nasopharyngeal carcinoma (NPC) patients usually included a limited sample size and did not attain consistent results, we conducted a large retrospective study in a cohort of 1,549 patients to assess the risk of SMT in NPC patients following radiotherapy (RT) in Taiwan. The follow-up period ranged from 2 to 16 years, with a median of 7 years. Thirty-nine patients developed SMTs during the 7,145 person-year follow-up [standardized incidence ratio (SIR): 2. 8; 95% confidence interval (CI): 2.0 to 3.9]. Increased risks of developing SMTs were observed for head and neck (H/N) cancer (SIR: 16.5; 95% CI: 10.0 to 26.8), gastric cancer (SIR: 5.5; 95% CI: 2.2 to 11.4) and leukemia (SIR: 9; 95% CI: 1.9 to 26.3). Paraffin-embedded specimens of secondary H/N cancer (11), secondary gastric cancer (6) and their corresponding NPC specimens were examined by EBER in situ hybridization to assess the association between Epstein-Barr virus (EBV) and these SMTs. Twenty-six primary H/N and 5 gastric cancer specimens were chosen as the control groups. In H/N cancer, EBV was detected in 3.8% of the primary cancers and 9.1% of the secondary cancers. All the positive specimens resulted from hypopharyngeal cancer. Of the secondary gastric cancers, only 1 case (16.6%) was associated with EBV. None of the primary gastric cancers was associated with EBV. Our results indicate an increased risk of developing SMTs, with a preference for head and neck cancer, gastric cancer and leukemia, in NPC patients after RT in Taiwan. Only a small proportion of the secondary H/N and gastric cancers was associated with EBV.

Locally recurrent nasopharyngeal carcinoma

PURPOSE

To assess the outcome of and determine prognostic factors for locally recurrent nasopharyngeal carcinoma (NPC) in patients treated with a second course of radiotherapy (RT).

MATERIALS AND METHODS

From 1982 to 1995, 186 NPC patients, who had initially been treated in the Department of Radiation Oncology, Chang Gung Memorial Hospital-Linkou, developed local recurrence in the nasopharynx and were re-treated with RT (>/=20 Gy). The time from the initial RT to re-treatment ranged from 8 to 136 months (median: 23 months). All patients were treated with external RT and conformal radiotherapy was used in 35 patients after 1993. Fifteen received radiosurgery as a boost treatment. The RT dose at the nasopharyngeal tumor area ranged from 20 to 67.2 Gy (median 50 Gy). Eighty-two patients received one to eight courses of cisplatin-based chemotherapy in addition to RT.

RESULTS

The 1-, 3- and 5-year survival was 54.9, 22. 1 and 12.4%, respectively. Patients whose tumor relapsed later than 2 years after the first treatment had a better survival than those with earlier relapse (3-year survival: 30.1 vs. 10.8%; P=0.015), but the difference became insignificant in patients who received >/=50 Gy. Patients without evidence of intracranial invasion or cranial nerve palsy had better survival than those with such lesions (3-year survival: 30.9 vs. 3.7%; P=0.006). A re-treatment dose >/=50 Gy yielded better survival (3-year survival: 22.8 vs. 18.5%; P=0.003). Addition use of radiosurgery may improve survival. The use of chemotherapy did not improve survival. Conformal radiotherapy resulted in significantly fewer severe complications than conventional RT.

CONCLUSIONS

A repeat course of RT for locally recurrent NPC successfully prolongs survival in a significant number of patients. Intracranial invasion and/or cranial nerve palsy and re-treatment dose affect the prognosis, with a dose of >/=50 Gy significantly improving survival. Radiosurgery boost may also improve survival. Our preliminary data indicates that conformal radiotherapy may decrease the severity of radiation-induced complications. However; longer follow-up and larger sample size is necessary to document the findings.

Nasopharyngeal carcinoma

Nasopharyngeal carcinoma represents a morphologic spectrum of neoplasms localized to the nasopharynx and arising from nasopharyngeal epithelium. Nasopharyngeal carcinomas have rather unique clinical, epidemiologic, pathologic, and biologic features. The morphologic spectrum of nasopharyngeal carcinoma includes keratinizing, nonkeratinizing, and undifferentiated subtypes. The separation of these morphologic types is not an academic exercise, but has practical importance relative to differential diagnosis, management, and prognosis. A similar morphologic classification applies to carcinomas arising in the palatine tonsils and the base of tongue. The nasopharynx, palatine tonsils, and base of tongue are collectively designated as Waldeyer's tonsillar tissues. Awareness of the morphologic spectrum of Waldeyer's ring carcinomas may assist in suggesting the primary tumor site in the face of an occult metastatic carcinoma to cervical neck lymph nodes.

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

The aim of this study was to define the risk of tongue and other aerodigestive tract cancers developing after primary radiation therapy for nasopharyngeal carcinoma (NPC). A cohort of 903 patients with non-disseminated NPC given radical radiotherapy between 1984 and 1989 was studied for the incidence of tongue cancer and other malignancies during follow-up. A contemporary cohort of 87 patients with tongue cancer, without a history of NPC, was studied for demographic data, cigarette smoking and alcohol consumption habits. These were then compared with all the NPC patients and with the NPC patients who later developed tongue cancers. There was a significantly increased number of tongue cancers following radiotherapy for NPC. The risk of developing tongue cancer after radiotherapy for NPC was 0.13% per patient per year. There was no increase in the number of other malignancies. The association between NPC and tongue cancer was that of a non-random temporal sequence with tongue cancers following NPC but not in the reverse order. The demographic data and smoking and alcohol consumption history of the 7 NPC patients who subsequently developed tongue cancer were significantly different from the de novo tongue cancer patient population. The absence of common aetiological factors between NPC and tongue cancer and the non-random sequence of tongue cancers occurring after NPC suggests that these seven tongue cancers could be radiation induced. The estimated radiation dose received by the part of the tongue developing cancer was substantial and significantly higher than the dose to the cancer-free tongue. An increase of tongue cancers after radiotherapy for NPC is reported and arguments are made in support of the hypothesis that these were radiation-induced malignancies. We suggest a decrease in the volume of tongue included within the planning target volume of NPC in the absence of oropharyngeal and/or parapharyngeal infiltration. Awareness of the association should make early diagnosis of this likely radiation-induced cancer possible.

Evolution of the Radiation Therapy Oncology Group clinical trials for head and neck cancer

During the past 25 years, the Radiation Therapy Oncology Group (RTOG) has played a major role in head and neck cancer clinical research. The major research themes for recent and currently active trials have been: (a) combined modality therapy, (b) altered fractionation radiotherapy, (c) hypoxic cell sensitizers, (d) organ preservation, (e) chemoprevention, and (f) clinical/laboratory correlations. For advanced operable disease, the RTOG showed improved local-regional control with postoperative radiotherapy as compared to preoperative radiotherapy for carcinoma of the supraglottic larynx and hypopharynx. This established the use of surgery followed by postoperative radiotherapy as the standard treatment in subsequent RTOG and Intergroup trials for operable disease. For advanced inoperable disease, the RTOG demonstrated the feasibility of testing altered fractionation radiotherapy in a multiinstitutional clinical trials setting. A Phase III trial comparing hyperfractionation and accelerated fractionation to conventional fractionation is now in progress. Phase I/II combined modality studies established the efficacy of concurrent high-dose cisplatin and radiotherapy in the treatment of advanced disease and provided the basis for further testing in Phase III trials for nasopharyngeal carcinoma, larynx preservation, and high-risk advanced operable disease. Analysis of the extensive RTOG Head and Neck Cancer database established the incidence of second malignancies and their adverse impact on patients whose initial tumors were cured by radiotherapy, and provided the basis for chemoprevention trials. Recursive partitioning analysis identified 6 distinct prognostically homogeneous patient groups based on pretreatment tumor or patient characteristics and/or treatment variables. Retrospective analysis identified tumor p105 antigen density as an independent prognostic indicator in patients irradiated for head and neck cancer. Future trials will continue to focus on the reduction of morbidity and mortality, and improvement of the quality of life of head and neck cancer patients through innovative radiotherapy delivery, multimodality approaches, use of chemical and biological modifiers, and other novel therapies, identification of clinical and biological prognostic indicators, and prevention or diminution of acute morbidity and late complications of the disease and its treatment.

Head and neck cancer

This synthesis of the literature on radiotherapy for head and neck cancer is based on 424 scientific articles, including 3 meta-analyses, 38 randomized studies, 45 prospective studies, and 246 retrospective studies. These studies involve 79174 patients. The literature review shows that radiotherapy, either alone or in combination with surgery, plays an essential role in treating head and neck cancers. When tumors are localized, many tumor patients can be cured by radiotherapy alone and thereby maintain full organ function (1, 2). Current technical advancements in radiotherapy offer the potential for better local tumor control with lower morbidity (3). This, however, will require more sophisticated dose planning resources. To further improve treatment results for advanced tumors, other fractionation schedules, mainly hyperfractionation, should be introduced (5). This mainly increases the demands on staff resources for radiotherapy. The combination of radiotherapy and chemotherapy should be subjected to further controlled studies involving a sufficiently large number of patients (4, 5). Interstitial treatment (in the hands of experienced radiotherapists) yields good results for selected cancers. The method should be more generally accessible in Sweden. Intraoperative radiotherapy should be targeted for further study and development.

Overexpression of p53 and prognosis in breast cancer

BACKGROUND

Assessment of prognostic markers in breast cancer independent of the axillary lymph node status is of major concern for the application of adjuvant treatment regimens. The current treatment decision is based mainly on the axillary lymph node status. Because of improved screening methods, the number and proportion of patients with node-negative disease are increasing, which warrants a search for reliable prognostic parameters. The application of tumor suppressor gene expression appears to be especially suited as a marker of the progress in malignant cellular dedifferentiation.

METHODS

Tumor tissues of 156 patients with primary invasive breast cancer were analyzed immunohistochemically for the presence of p53 protein in paraffin-embedded material. The reaction to monoclonal antibody PAb1801 yielded better results than did reactions to monoclonal antibody DO1 and polyclonal antibody CM-1. The significance of the immunohistochemical data was compared with a panel of established risk factors.

RESULTS

Nuclear accumulation of p53 protein proved to be an independent marker of dedifferentiation, regardless of the lymph node status. Tumors showing p53 immunoreactivity were significantly more often related with histological Grade 3 and the absence of steroid hormone receptors. Kaplan-Meier estimation and multivariate analysis of disease-free and overall survival rate corroborated the importance of p53 as a prognostic parameter.

CONCLUSION

Overexpression of p53 protein emerged as a reliable and independent predictor for disease recurrence and reduced survival rates in patients with breast cancer.

The biology and pathology of selected skull base tumors

This paper describes the pathobiology of some of the more common skull base tumors. In addition to clinicopathologic features, emphasis is placed upon methods of diagnosis utilizing immunoperoxidase stains and molecular markers that may or may not impact upon prognosis.

Overexpression of p53 and prognosis in breast cancer

BACKGROUND

Assessment of prognostic markers in breast cancer independent of the axillary lymph node status is of major concern for the application of adjuvant treatment regimens. The current treatment decision is based mainly on the axillary lymph node status. Because of improved screening methods, the number and proportion of patients with node-negative disease are increasing, which warrants a search for reliable prognostic parameters. The application of tumor suppressor gene expression appears to be especially suited as a marker of the progress in malignant cellular dedifferentiation.

METHODS

Tumor tissues of 156 patients with primary invasive breast cancer were analyzed immunohistochemically for the presence of p53 protein in paraffin-embedded material. The reaction to monoclonal antibody PAb1801 yielded better results than did reactions to monoclonal antibody DO1 and polyclonal antibody CM-1. The significance of the immunohistochemical data was compared with a panel of established risk factors.

RESULTS

Nuclear accumulation of p53 protein proved to be an independent marker of dedifferentiation, regardless of the lymph node status. Tumors showing p53 immunoreactivity were significantly more often related with histological Grade 3 and the absence of steroid hormone receptors. Kaplan-Meier estimation and multivariate analysis of disease-free and overall survival rate corroborated the importance of p53 as a prognostic parameter.

CONCLUSION

Overexpression of p53 protein emerged as a reliable and independent predictor for disease recurrence and reduced survival rates in patients with breast cancer.

Head and neck carcinomas in patients under the age of forty years

From 1973 to 1988, 1,104 patients with head and neck carcinomas (excluding thyroid carcinoma) were admitted to the Yokohama City University Hospital, and among them, 48 (4.3%) were under the age of 40 years. We made a retrospective survey of these young patients. There were 36 males and 12 females. An increasing ratio of male to female was seen with increasing age. The primary site was most frequently the nasopharynx (29 cases), followed by the maxillary sinus (9 cases), and the tongue (4 cases). Squamous cell carcinoma in these young patients characteristically showed a low grade of differentiation.