Comparative p53 mutational analysis of multiple primary cancers of the upper aerodigestive tract

Diagnostic accuracy of probe-based confocal laser endomicroscopy in Lugol-unstained esophageal superficial lesions of patients with head and neck cancer

BACKGROUND AND AIMS

Surveillance programs of patients with head and neck cancer (HNC) detect synchronous or metachronous esophageal squamous cell carcinoma (ESCC) in up to 15% of patients. Noninvasive, probe-based confocal laser endomicroscopy (pCLE) technique may improve the diagnosis allowing acquisition of high-resolution in vivo images at the cellular and microvascular levels. The aim of this study was to evaluate the accuracy of pCLE for the differential diagnosis of nonneoplastic and neoplastic Lugol-unstained esophageal lesions in patients with HNC.

METHODS

Twenty-seven patients with HNC who exhibited Lugol-unstained esophageal lesions at surveillance endoscopy were prospectively included for pCLE. Diagnostic pCLE was followed by subsequent biopsies or endoscopic resection of suspected lesions. A senior pathologist was blinded to the pCLE results.

RESULTS

Patients mean age was 59 years (SD = 8.8) and 70.4% were men. All patients were smokers, and 22 patients (81.5%) had a history of alcohol consumption. The locations of HNC were oral cavity (n = 13), larynx (n = 10), and pharynx (n = 4). Thirty-seven lesions in 27 patients were studied. The final diagnoses were ESCC in 17 patients and benign lesions in 20 patients. Sensitivity, specificity, and accuracy of pCLE for the histologic diagnosis of ESCC in patients with HNC were 94.1%, 90.0%, and 91.9%, respectively.

CONCLUSIONS

First, pCLE is highly accurate for real-time histology of Lugol-unstained esophageal lesions in patients with HNC. Second, pCLE may alter the management of patients under surveillance for ESCC, guiding biopsies and endoscopic resection, avoiding further diagnostic workup or therapy of benign lesions.

The Molecular Biology of Mucosal Field Cancerization of the Head and Neck

Field cancerization was first described in 1953 as histologically altered epithelium surrounding tumor samples taken from the upper aerodigestive tract. Since then, the term has been used to describe multiple patches of pre-malignant disease, a higher-than-expected prevalence of multiple local second primary tumors, and the presence of synchronous distant tumors within the upper aerodigestive tract. Molecular techniques such as karyotype analysis, microsatellite analysis, p53 mutation screening, and X-chromosome inactivation studies have further refined the relationship among these lesions. While there are differences in the techniques used to identify the clonal origins of the lesions, these studies indicate that there is often lateral clonal spread of pre-malignant or malignant disease, and a significant portion of local second primary tumors are in fact genetically related. Distant second primary tumors found in the esophagus are often not related to concurrent head and neck cancer, whereas synchronous squamous lung tumors with a head and neck primary are often, in fact, metastases, rather than independently arising malignancies. These observations help to explain the high incidence of recurrent disease, despite excision or other therapy—pre-malignant or malignant clones often have the ability to migrate and persist outside of the field of treatment. Therefore, alternative means of prevention or therapy that can affect the entire head and neck region may be of benefit to such patients. Future studies will further refine the relationship among these lesions and perhaps identify key molecular alterations to be used as targets for gene therapy.

Differential diagnosis between primary lung squamous cell carcinoma and pulmonary metastasis of head and neck squamous cell carcinoma

Differentiation between lung squamous cell carcinoma and pulmonary metastasis of head and neck squamous cell carcinoma is clinically important because the prognoses and therapeutic options are considerably different. However, the clinical, pathological, and immunohistochemical diagnostic methods have not yet been fully established. Although various molecular methods have been developed, they have not yet been practically applied. A combined approach involving molecular and immunohistochemical analysis, such as one that uses antibodies selected on the basis of comprehensive genetic analysis results, may be effective. We suggest a new diagnostic criteria using the clinical characteristics and the result of immunohistochemical analysis. However, there are two underlying problems in the development of new diagnostic methods: tumor heterogeneity and determination of the diagnostic accuracy.

A novel differential diagnostic model for multiple primary lung cancer: Differentially-expressed gene analysis of multiple primary lung cancer and intrapulmonary metastasis

The incidence of synchronous multiple primary lung cancer (MPLC) is increasing. However, present diagnostic methods are unable to satisfy the individualized treatment requirements of patients with MPLC. The present study aimed to establish a quantitative mathematical model and analyze its diagnostic value for distinguishing between MPLC and cases of the histologically similar disease, intrapulmonary metastasis (IPM). The sum value of the differential expression ratios of four proteins, namely p53, p16, p27 and c-erbB2, was evaluated by immunohistochemically-staining specimens of primary cancers, second separate cancers, metastatic lymph nodes and metastatic cancers. The sum value of the differential expression ratio of the four proteins from the primary tumor and the lymph-node metastasis or metastatic cancer was <90 in the 11 patients with a single metastatic cancer and in the 30 patients with lymph-node metastasis, but was >90 in the 14 patients with different histological types of MPLC. Therefore, a quantitative differentially-expressed gene mathematical model was established as follows: Sum of the differential expression ratios = p16T1 - T + p27T1 - T2 + C-erbB2T1 - T2 + p53T1 - T2, where T1 is the primary cancer and T2 is the lymph node metastasis, metastatic cancer or the second separate cancer. The quantitative differentially-expressed gene mathematical model is considered to be a useful tool for distinguishing between MPLC and IPM.

Primary jejunal adenocarcinoma as part of multiple primary cancers of the digestive tract

Multiple primary cancers including small intestinal tumors are rare. We describe the first curative resection case of metachronous triple early cancers involving the jejunum as well as the stomach and esophagus. The patient had undergone total gastrectomy for a gastric adenocarcinoma and subsequent esophagectomy for an esophageal squamous cell carcinoma. A jejunal adenocarcinoma, the third primary, occurred at the blind stump of the jejunal limb of a Roux-en-Y esophagojejunostomy reconstructed previously. This tumor was removed by partial resection of the limb with the preservation of the esophagojejunostomy. The patient died from complications of acute pancreatitis 3 years after the last operation, without overt clinical signs of cancer recurrence. Immunohistochemistry of the specimen showed the increased expression of p53 and cyclin D1 proteins in all three cancers, suggesting their involvement in metachronous carcinogenesis in this case. Early diagnosis of each cancer was made possible by regular endoscopic follow-up and favorable anatomical location of each tumor, which were considered to allow less invasive surgery as well as to contribute to the favorable outcome. This case suggests the importance of regular surveillance for metachronous carcinogenesis, especially when the preceding cancers carry genetic abnormalities that may potentially increase the risk for subsequent carcinogenesis.

Associated primary tumors in patients with gastric cancer

GOAL

To determine the prevalence of associated primary tumors in patients with gastric cancer.

STUDY

Retrospective study of 2,668 patients with gastric cancer observed at our department between July 1974 and December 1999. Associated tumors were diagnosed using Warren and Gates criteria, and included tumors that were not considered to be a metastasis, invasion, or recurrence of gastric cancer.

RESULTS

Of all, 3.4% (n = 78) had primary tumors other than gastric cancer, 27% of which were synchronous (n = 21) and 73%, metachronous (n = 57). The mean follow-up time was 4 years (range, 1-13 years), and the male-to-female ratio was 1:1. The median age at diagnosis of gastric cancer was 67 years (range, 37-84 years), 69 years for patients with synchronous tumors versus 60 years for those with metachronous (p = 0.050). For at least half the patients the median time interval to metachronous cancer was 3 years (range, 1-22 years). Seventy-eight percent (n = 61) had two cancers; most were colonic (19%), uterine and ovarian (16%), and breast tumors (13%). Seventeen percent (n = 13) had three tumors: colon (46%), breast (23%), and skin (23%). Four percent (n = 3) had four tumors. One case with seven tumors was also observed [colon, breast (two tumors), uterus, skin, and stomach (two tumors)]. No statistically significant differences were found between synchronous and metachronous with regard to sex, gastric cancer location, and staging (TNM). Sixty-three percent (n = 49) died while under observation.

CONCLUSIONS

We found associated tumors in 3.4% of patients with gastric cancer. The most frequent associated tumors were breast and colon cancer. Surveillance for these tumors would be appropriate, at least in first years, after diagnosis of gastric cancer.

Determination of the molecular relationship between multiple tumors within one patient is of clinical importance

PURPOSE

To determine the molecular relationship between multiple tumors within one patient and to evaluate the impact of this knowledge on clinical management.

PATIENTS AND METHODS

In 25 consecutive patients with multiple tumors, proven by histology and immunohistochemistry to be identical, molecular aberrations were determined. Each patient had at least one lesion in the lung or head and neck region. Loss of heterozygosity (LOH) and p53 aberration analyses were carried out, and similar aberration profiles suggest clonality and metastasis whereas different profiles suggest independent primary tumors.

RESULTS

The molecular determinations indicated that 12 patients had a probable second primary tumor and 10 patients had a metastasis of the first lesion. In three patients, both an independent primary tumor and a metastasis were present. The molecular findings determined the course of additional treatment in all 10 patients with metastases, in all three patients with both a second primary tumor and a metastasis, and in seven of 12 patients with a second primary tumor.

CONCLUSION

By comparing DNA alterations of multiple tumors within one patient, the relationship between the tumors can be assessed. This study shows that in 20 of 25 patients, knowledge of the nature of both lesions was essential in clinical decision making. Furthermore, after thorough analysis of the five cases where clinical decision making was not influenced, there was in retrospect no clear indication for LOH or p53 analysis. Because these molecular analyses can be performed on routine specimens, they can be applied in almost all patients.

Second primary tumors and field cancerization in oral and oropharyngeal cancer: molecular techniques provide new insights and definitions

Second primary tumors (SPTs) are a significant problem in treating oral and oropharyngeal squamous cell carcinoma and have a negative impact on survival. In most studies the definition of SPT is based on the criteria of Warren and Gates, published in 1932. These criteria, however, are ill-defined and lead to confusion. Recent molecular studies have shown that a tumor can be surrounded by a mucosal field consisting of genetically altered cells. Furthermore, evidence has been provided that SPTs (defined by classical criteria) can share some or even all genetic markers with the index tumor, indicating that both tumors have arisen from a common cell clone. We propose that these secondary neoplastic lesions should not be considered SPTs, implying that the present concept of SPT needs revision. This review describes a novel classification of the secondary tumors that develop after treatment of a carcinoma in the oral cavity or oropharynx. On the basis of the molecular analysis of the tumors and the genetically altered mucosal field in between, we propose definitions for a "true SPT," a local recurrence, a "SFT" (second field tumor derived from the same genetically altered mucosal field as the primary tumor), and a metastasis. Considering the etiologic differences of these lesions, we believe that an accurate molecular definition is essential to make headway with the clinical management of oral and oropharyngeal cancer.

Karyotypic heterogeneity and clonal evolution in squamous cell carcinomas of the head and neck

Head and neck squamous cell carcinomas (HNSCC) are often characterized by complex karyotypic changes, and a substantial proportion of the reported tumors have shown intratumor heterogeneity in the form of cytogenetically related (40%) or unrelated clones (20%). In order to study intratumor heterogeneity and to distinguish the temporal order of chromosome rearrangements in these tumors, two or more samples from different areas of the same tumor were separately examined in 19 HNSCC, yielding karyotypes from a total of 42 tumor samples. Intrasample heterogeneity was observed in 16 samples. Two samples displayed both related and unrelated multiple clones, four samples showed only multiple unrelated clones, and the remaining 10 samples had only related subclones. Intersample heterogeneity was detected in all but one tumor. Five tumors showed both cytogenetically related and unrelated multiple clones, 11 were found to have only related subclones, and the remaining two tumors showed only unrelated clones. Clonal evolution could be assessed in 13 tumors. A comparison of chromosome imbalances in different subclones from these tumors suggests that partial or entire loss of 3p, 8p, 9p, and 18q and gain of genetic material from 3q and 8q are likely to be early genetic events. In contrast, loss of 1q, 6p, 7q, and chromosome 10, as well as gain of chromosome arms 5p and 7p, are most probably later genetic events. One of the examined tumors contained two highly complex clones that were cytogenetically unrelated, indicating that this tumor had a multicellular origin.

Multiple primary malignant neoplasms in patients with esophageal cancer

This study aims to elucidate the incidence and the therapeutic and prognostic implications of co-existent non-esophageal primary malignant neoplasms in patients with esophageal cancer. Between 1974 and 1997, 33 patients with esophageal cancer treated at the Nippon Medical School Hospital were documented as having multiple primary malignant neoplasms (MPN). The therapeutic strategies and post-therapeutic survival of these patients were retrospectively investigated. Among 291 patients with esophageal cancer, 33 patients (11.3%) were also found to have non-esophageal primary malignant neoplasms. Twenty patients (60.6%) had synchronous MPN and 13 (39.4%) had metachronous MPN. Among the MPN, apart from esophageal cancer, gastric (32.6%) and head and neck cancer (32.6%) were the most common. The incidence of esophageal cancer occuring in association with cancers of the head and neck or gastric cancer was high. Frequent examination in these cancer patients, using fiberoptic esophagogastric endoscopy for example, may be helpful in the early diagnosis of esophageal cancer.

The origins of multiple squamous cell carcinomas in the aerodigestive tract

BACKGROUND

Chemoprevention and cessation of smoking and alcohol may prevent development of multiple tumors (MTs) in the aerodigestive tract if new MTs arise independently, but they are of no benefit if MTs are due to migration of an already transformed clone of tumor cells. This issue was addressed in this study by investigation of the clonality among MTs.

METHODS

Mutation analysis of the entire coding region of p53 and loss of heterozygosity (LOH) pattern analysis of microsatellite markers on chromosome arms 3p, 9p, and 17p are promising for the investigation of clonality. In the first part of this study, the authors established the variability and stability of these clonal markers by comparing primary head and neck squamous cell carcinomas (HNSCCs) with their metastases. In the second part of this study, the authors evaluated nine patients with multiple HNSCCs using these markers. In the final part, the authors illustrate the use of these clonal markers in 11 patients for whom there was diagnostic uncertainty as to whether their second squamous cell carcinoma was either a new primary tumor, a metastasis, or a recurrence.

RESULTS

Both p53 gene mutations and LOH patterns were stable during tumor progression. Furthermore, the variability of p53 gene mutations was high. More than 90% of the tumors contained a p53 mutation. A particular mutation never occurred more than twice in a total of 69 primary HNSCCs. Five of 69 cases presented a common mutation. In contrast, LOH patterns showed less variability; they were identical in 5 of 16 cases. The metachronous HNSCCs from nine patients all showed different p53 mutations, and in the three cases that were subjected to LOH analysis different patterns were observed. All 11 patients for whom there was diagnostic uncertainty about the origin of their second squamous cell carcinoma could be categorized as having multiple primary tumors, disseminated disease, or recurrent disease.

CONCLUSIONS

Metachronous HNSCCs at different locations are not clonally related and thus have not developed from the migration of tumor cells.

p53 tumor suppressor gene as a clonal marker in head and neck squamous cell carcinoma: p53 mutations in primary tumor and matched lymph node metastases

In order to define the diagnostic value of p53 tumor suppressor gene as a clonal marker in head and neck squamous cell carcinoma (HNSCC), we investigated p53 mutations in primary tumors (PT) and matched lymph node metastases (LNM); the underlying question being whether differentiation between metastatic disease of a known PT or (a metastasis of) a synchronous or metachronous second tumor is possible by means of p53 sequencing-based mutation analysis. In 15 PT, the p53 status was analyzed, following RNA isolation, cDNA synthesis and polymerase chain reaction amplification, by direct sequencing full-length mRNA. Mutations thus found were confirmed by DNA sequencing analysis of the corresponding exon in the PT. When RNA isolation was defective, DNA sequencing analysis of exons 1 through 11 was performed. In the matched LNM, DNA analysis of the corresponding exon was performed to prove the presence of the same p53 mutation. In the event of small clones not detectable by direct sequencing, an oligo ligation assay was developed to detect a specific mutation. The presence of germline mutations was excluded by DNA sequencing analysis of the corresponding exon of peripheral blood leucocytes. In 14 PT (94%), a mutation was identified. In one PT, no p53 mutation could be identified either after full-length mRNA sequencing or after sequencing exons 1 through 11. In all cases of PT and matched LNM, the mutations proved to be identical. We conclude that p53 mutations develop in carcinogenesis before metastases occur and are maintained during metastasis. Consequently, p53 may serve as a clonal marker not susceptible to change during tumor metastasis. This merits further exploration of the application of p53 mutation analysis in differentiating between metastatic disease from a known PT versus a metastasis of another second PT.

Glutathione-linked enzymes in benign and malignant oesophageal tissue

Oxyradicals are involved in multiple mutational events and can contribute to the conversion of healthy cells to cancer cells. Glutathione (GSH) and the GSH-replenishing enzymes keep the antioxidant status of normal cells at a level where they can avert oxyradical derived mutations. The aim of this study was to determine whether in cancer cells the GSH-replenishing, GSH antioxidant and GSH-depleting enzymes were not at appropriate levels and therefore not able to protect cancer cells adequately against oxyradical-induced mutations. Cancer of the oesophagus was chosen since it is the most common gastrointestinal malignancy in South African Blacks. Biopsies and blood from 31 patients with cancer of the oesophagus and 29 non-cancer patients were assessed for these enzymes. The mean activity of the antioxidant and depleting enzyme GSH-peroxidase was elevated significantly by twofold in the cancer tissue compared to normal tissue. However, the activity of the replenishing enzyme GSSG-reductase and the level of the depleting enzyme GSH-s-transferase P1-isoenzyme were significantly reduced by 23% and 33% respectively. As in a previous paper we found that GSH was depleted and gamma-glutamine transpeptidase was diminished in oesophageal cancer. There can be two reasons for GSH depletion. Firstly, elevated GSH-peroxidase will use more GSH in an attempt to cope with the excessive production of oxyradicals as revealed by elevated lipid peroxidation; this was, as shown by us before, elevated sixfold in oesophageal cancer. Secondly, if little replenishment of GSH occurred the level of GSH would become lower. This was confirmed by our findings that the activities of the replenishing enzymes were significantly diminished in oesophageal cancer tissue. Contrary to what was expected, the other depleting enzyme GSH-s-transferase P1 was not elevated in cancer tissue but was significantly lower. However, in the blood of the same patients it was significantly elevated. An explanation for this phenomenon is that, although the production of GST-P1 was enhanced in cancer, it did not show because it was rapidly extruded into the blood by an unknown mechanism operational only in cancer cells.

Apoptosis in esophageal cancer following induction chemoradiotherapy

BACKGROUND

The poor survival of patients with esophageal cancer following esophagectomy has led to intense investigation into combined modality therapy. Based on results from clinical trials examining chemoradiotherapy alone without surgery, resection has come under increased scrutiny and its necessity as a component of a multimodal approach has been questioned. In this study, we examined whether residual tumor cells in esophagectomy specimens following induction chemoradiotherapy are viable and, therefore, provide putative evidence for the appropriateness of esophagectomy.

MATERIALS AND METHODS

Between August 1991 and January 1995, 46 patients were entered into an induction chemoradiotherapy trial consisting of 5-fluorouracil, cisplatin, alpha-interferon, and concurrent external beam radiotherapy followed by esophagectomy. Response was determined histologically and apoptosis assessed with a terminal deoxytransferase assay system. p53 status was determined by immunohistochemistry and mutational analysis.

RESULTS

Thirty-eight patients underwent esophagectomy, 33 of whom had either a complete (n = 10) or partial (n = 23) response. None of the 28 patients with residual tumor in the resected specimen had 100% apoptotic cells and the vast majority of specimens had less than a 10% apoptotic rate. The percentage of apoptotic cells did correlate with tumor differentiation but not with histologic type nor presence of p53 mutations.

CONCLUSIONS

These data suggest that resection following upfront chemoradiotherapy is a necessary component of a multimodality approach to esophageal cancer and will ultimately provide superior local-regional control to a nonsurgical approach.