The Head and Neck Intergroup conducted a phase III randomized trial to test the benefit of adding chemotherapy to radiation in patients with unresectable squamous cell head and neck cancer.
Eligible ...patients were randomly assigned between arm A (the control), single daily fractionated radiation (70 Gy at 2 Gy/d); arm B, identical radiation therapy with concurrent bolus cisplatin, given on days 1, 22, and 43; and arm C, a split course of single daily fractionated radiation and three cycles of concurrent infusional fluorouracil and bolus cisplatin chemotherapy, 30 Gy given with the first cycle and 30 to 40 Gy given with the third cycle. Surgical resection was encouraged if possible after the second chemotherapy cycle on arm C and, if necessary, as salvage therapy on all three treatment arms. Survival data were compared between each experimental arm and the control arm using a one-sided log-rank test.
Between 1992 and 1999, 295 patients were entered on this trial. This did not meet the accrual goal of 362 patients and resulted in premature study closure. Grade 3 or worse toxicity occurred in 52% of patients enrolled in arm A, compared with 89% enrolled in arm B (P <.0001) and 77% enrolled in arm C (P <.001). With a median follow-up of 41 months, the 3-year projected overall survival for patients enrolled in arm A is 23%, compared with 37% for arm B (P =.014) and 27% for arm C (P = not significant).
The addition of concurrent high-dose, single-agent cisplatin to conventional single daily fractionated radiation significantly improves survival, although it also increases toxicity. The loss of efficacy resulting from split-course radiation was not offset by either multiagent chemotherapy or the possibility of midcourse surgery.
Epithelial to mesenchymal transition (EMT) has been hypothesized as a mechanism by which cells change phenotype during carcinogenesis, as well as tumor metastasis. Whether EMT is involved in cancer ...metastasis has a specific, practical impact on the field of circulating tumor cells (CTCs). Since the generally accepted definition of a CTC includes the expression of epithelial surface markers, such as EpCAM, if a cancer cell loses its epithelial surface markers (which is suggested in EMT), it will not be separated and/or identified as a CTC. We have developed, and previously reported on the use of, a purely negative enrichment technology enriching for CTCs in the blood of squamous cell carcinoma of the head and neck (SCCHN). This methodology does not depend on the expression of surface epithelial markers. Using this technology, our initial data on SCCHN patient blood indicates that the presence of CTCs correlates with worse disease-free survival. Since our enrichment is not dependent on epithelial markers, we have initiated investigation of the presence of mesenchymal markers in these CTC cells to include analysis of: vimentin, epidermal growth factor receptor, N-cadherin, and CD44. With the aid of confocal microscopy, we have demonstrated not only presumed CTCs that express and/or contain: a nucleus, cytokeratins, vimentin, and either EGFR, CD44, or N-cadherin, but also cells that contain all of the aforementioned proteins except cytokeratins, suggesting that the cells have undergone the EMT process. We suggest that our negative depletion enrichment methodology provides a more objective approach in identifying and evaluating CTCs, as opposed to positive selection approaches, as it is not subjective to a selection bias and can be tailored to accommodate a variety of cytoplasmic and surface markers which can be evaluated to identify a multitude of phenotypic patterns within CTCs from individual patients, including so-called EMT as presented here.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The validity of sentinel lymph node biopsy (SLNB) for T1 or T2, clinically N0, oral cancer was tested by correlation of sentinel node pathologic status with that of nodes within the completion neck ...dissection.
This prospective, cooperative group trial involved 25 institutions over a 3-year period. One hundred forty patients with invasive oral cancers, stage T1 and T2, N0 including 95 cancers of the tongue, 26 of the floor of mouth, and 19 other oral cancers were studied. The study excluded lesions with diameter smaller than 6 mm or minimal invasion. Imaging was used to exclude nonpalpable gross nodal disease. Patients underwent injection of the lesion with (99m)Tc-sulfur colloid, nuclear imaging, narrow-exposure SLNB, and completion selective neck dissection. The major end point was the negative-predictive value (NPV) of SLNB.
In the 106 SLNBs, which were found to be pathologically and clinically node-negative by routine hematoxylin and eosin stain, 100 patients were found to have no other pathologically positive nodes, corresponding to a NPV of 94%. With additional sectioning and immunohistochemistry, NPV was improved to 96%. In the forty patients with proven cervical metastases, the true-positive rate was 90.2% and was superior for tongue tumors relative to floor of mouth. For T1 lesions, metastases were correctly identified in 100%.
For T1 or T2 N0 oral squamous cell carcinoma, SLNB with step sectioning and immunohistochemistry, performed by surgeons of mixed experience levels, correctly predicted a pathologically negative neck in 96% of patients (NPV, 96%).
Loss of genome-wide methylation is a common feature of cancer, and the degree of hypomethylation has been correlated with genomic instability. Global methylation of repetitive elements possibly arose ...as a defense mechanism against parasitic DNA elements, including retrotransposons and viral pathogens. Given the alterations of global methylation in both viral infection and cancer, we examined genome-wide methylation levels in head and neck squamous cell carcinoma (HNSCC), a cancer causally associated with human papilloma virus (HPV). We assayed global hypomethylation levels in 26 HNSCC samples, compared with their matched normal adjacent tissue, using Pyrosequencing-based methylation assays for LINE repeats. In addition, we examined cell lines derived from a variety of solid tumors for LINE and SINE (Alu) repeats. The degree of LINE and Alu hypomethylation varied among different cancer cell lines. There was only moderate correlation between LINE and Alu methylation levels, with the range of variation in methylation levels being greater for the LINE elements. LINE hypomethylation was more pronounced in HPV-negative than in HPV-positive tumors. Moreover, genomic instability, as measured by genome-wide loss-of-heterozygosity (LOH) single nucleotide polymorphism (SNP) analysis, was greater in HNSCC samples with more pronounced LINE hypomethylation. Global hypomethylation was variable in HNSCC. Its correlation with both HPV status and degree of LOH as a surrogate for genomic instability may reflect alternative oncogenic pathways in HPV-positive versus HPV-negative tumors.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Objectives/Hypothesis:
To determine factors impacting recurrence and long‐term survival of adenoid cystic carcinoma (ACC) of the head and neck after definitive resection.
Study Design:
Retrospective ...cohort study at an academic tertiary care hospital.
Methods:
Patients with ACC of the head and neck treated at our institution were reviewed. Those not receiving surgery, or with metastatic disease were excluded. Clinicopathological data on each patient was collected.
Results:
Of 113 patients identified with ACC, 99 were studied. The overall median survival for the cohort was 71 months (mean ± standard deviation, 94 ± 79 months). American Joint Committee on Cancer (AJCC) tumor stage and N stage were independent predictors of survival on multivariate analysis. Mean overall survival (P = .001) and time to recurrence (P = .006) were lower for patients with cervical lymph node positive disease (N+). Tumors in major salivary glands were associated with longer survival (P = .027). The overall recurrence rate was 53%, with a mean time to recurrence of 63 ± 64 months. The presence of lymphovascular invasion predicted recurrence on multivariate analysis (P = .002), with advanced tumor stage predicting early (≤36 months) recurrence (P = .013). Among the 57 patients who received adjuvant radiation therapy, there was no difference in survival, rate of recurrence, or time to recurrence, when compared to patients treated with surgery alone.
Conclusions:
Clinicopathological variables including AJCC tumor stage, tumor site, presence of N+ disease, and lymphovascular invasion may be used as prognostic factors in predicting survival and recurrence after a definitive resection of ACC of the head and neck. Laryngoscope, 2010
The identification of tumor suppressor genes has classically depended on their localization within recurrent regions of loss of heterozygosity. According to Knudson's two-hit hypothesis, the ...remaining allele is lost, either genetically or, more recently identified, through epigenetic events. To date, retrospective analyses have determined promoter methylation as a common alternative alteration in cancer cells to silence cancer-related genes. Here we report an application of restriction landmark genomic scanning that allows for DNA methylation profiling along a region of recurrent loss of heterozygosity at chromosome 6q23-q24. This approach resulted in the identification of a tumor suppressor gene, TCF21, which is frequently lost in human malignancies. We demonstrate that TCF21 is expressed in normal lung airway epithelial cells and aberrantly methylated and silenced in the majority of head and neck squamous cell carcinomas and non-smallcell lung cancers analyzed. TCF21 is known to regulate mesenchymal cell transition into epithelial cells, a property that has been shown to be deficient in carcinomas. We further demonstrate that exogenous expression of TCF21 in cells that have silenced the endogenous TCF21 locus resulted in a reduction of tumor properties in vitro and in vivo.
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