Novel PRKD gene rearrangements and variant fusions in cribriform adenocarcinoma of salivary gland origin

Polymorphous low-grade adenocarcinoma (PLGA) and cribriform adenocarcinoma of minor salivary gland (CAMSG) are low-grade carcinomas arising most often in oral cavity and oropharynx, respectively. Controversy exists as to whether these tumors represent separate entities or variants of one spectrum, as they appear to have significant overlap, but also clinicopathologic differences. As many salivary carcinomas harbor recurrent translocations, paired-end RNA sequencing and FusionSeq data analysis was applied for novel fusion discovery on two CAMSGs and two PLGAs. Validated rearrangements were then screened by fluorescence in situ hybridization (FISH) in 60 cases. Histologic classification was performed without knowledge of fusion status and included: 21 CAMSG, 18 classic PLGA, and 21 with "mixed/indeterminate" features. The RNAseq of 2 CAMSGs showed ARID1A-PRKD1 and DDX3X-PRKD1 fusions, respectively, while no fusion candidates were identified in two PLGAs. FISH for PRKD1 rearrangements identified 11 additional cases (22%), two more showing ARID1A-PRKD1 fusions. As PRKD2 and PRKD3 share similar functions with PRKD1 in the diacylglycerol and protein kinase C signal transduction pathway, we expanded the investigation for these genes by FISH. Six additional cases each showed PRKD2 and PRKD3 rearrangements. Of the 26 (43%) fusion-positive tumors, there were 16 (80%) CAMSGs and 9 (45%) indeterminate cases. A PRKD2 rearrangement was detected in one PLGA (6%). We describe novel and recurrent gene rearrangements in PRKD1-3 primarily in CAMSG, suggesting a possible pathogenetic dichotomy from "classic" PLGA. However, the presence of similar genetic findings in half of the indeterminate cases and a single PLGA suggests a possible shared pathogenesis for these tumor types.

Mammary analogue secretory carcinoma mimicking salivary adenoma

Mammary analogue secretory carcinoma (MASC) is a recently described salivary gland tumor characterized by ETV6 translocation. It appears that prior studies have identified MASC by reviewing salivary gland carcinomas, such as acinic cell carcinoma and adenocarcinoma, not otherwise specified. To address the possibility of MASC mimicking benign salivary neoplasms we reviewed 12 salivary gland (cyst)adenomas diagnosed prior to the discovery of MASC. One encapsulated (cyst)adenoma of the parotid gland demonstrated features of MASC. The diagnosis was confirmed by fluorescence in situ hybridization with an ETV6 break-apart probe. An unusual complex pattern of ETV6 rearrangement with duplication of the telomeric/distal ETV6 probe was identified. This case illustrates that MASC may mimic salivary (cyst)adenomas. To more accurately assess true clinical and morphologic spectrum of MASC, future studies may have to include review of salivary (cyst)adenomas. The differential diagnosis of MASC may have to be expanded to include cases resembling salivary (cyst)adenomas.

HRAS mutations in epithelial-myoepithelial carcinoma

The molecular profile of epithelial-myoepithelial carcinomas (EMCa) has not been well studied, though a recent association with Harvey rat sarcoma viral oncogene homolog (HRAS) mutations has been noted. To confirm and validate this, we surveyed fifteen EMCa for HRAS codon 61 mutations and correlated HRAS status with clinicopathologic parameters. There were 11 females and 4 males and mean patient age was 64 (range 49-90). Parotid gland was most commonly involved (n = 10) and the most common histologic appearance was that of a 'classic' EMCa (7/15). Four of fifteen (26.7 %) cases demonstrated local recurrence, while 2/15 (13.3 %) demonstrated distant metastases. Other variant morphologies included EMCa arising from pleomorphic adenoma (3/15), and high grade EMCa (2/15). HRAS exon 3, codon 61 mutations, p.Q61R (n = 3) and p.Q61 K (n = 1) were identified in 4 of 15 successfully tested EMCAs (14 patients). Two cases were classic type, while the other cases consisted of one oncocytic variant, and one tumor with myoepithelial overgrowth, the latter of which showed the same mutation in both the primary and recurrence. Of note, the high grade EMCa and EMCa ex pleomorphic adenoma were negative for mutations. Given the small number of cases, there were no significant differences between mutation positive and mutation negative cases in terms of age, gender and outcome.

Human papillomavirus and Epstein-Barr virus in nasopharyngeal carcinoma in a low-incidence population

BACKGROUND

The significance of human papillomavirus (HPV) in nasopharyngeal carcinomas (NPCs) in a low-incidence population remains unknown.

METHODS

Samples from 90 patients with NPC (years, 1957-2012) were analyzed for Epstein-Barr virus (EBV). Clinical data, EBV, HPV, and p16 status were correlated with overall survival (OS; 63 cases; years, 1981-2012).

RESULTS

Of 9 HPV-positive cases, 3 extended from extra-nasopharyngeal sites. Nasopharyngeal origin was confirmed in 6 cases. HPV-positive NPC had OS similar to EBV-positive NPC (85 vs 141 months; p > .05). The OS of patients with EBV/HPV-negative NPC was worse (34 months; p = .004). Nonkeratinizing histology was associated with better outcome than keratinizing (115 vs 25 months; p = .001). Over the last several decades, the proportion of keratinizing NPC decreased from 34.5% to 14.3% (p = .026).

CONCLUSION

The etiologic role of HPV in NPC is confirmed. The favorable prognostic significance of HPV positivity is similar to that of EBV positivity.

Neoadjuvant erlotinib, erlotinib-sulindac, or placebo: A randomized, double-blind biomarker modulation study in operable head and neck squamous cell carcinoma (HNSCC)

6051

Background: The epidermal growth factor receptor (EGFR) and cyclooxygenase-2 (COX-2) pathways are upregulated in HNSCC. Crosstalk potentiates growth, proliferation and invasion. Preclinical models show synergistic anti-tumor effects from dual blockade. We evaluated biomarker modulation in paired tumor specimens from a 3-arm phase 0 trial of erlotinib, a small molecule EGFR inhibitor; erlotinib + sulindac, a non-selective COX inhibitor; vs. placebo. Methods: Patients (pts) with untreated stage II-IVb HNSCC were randomized 5:5:3 to neoadjuvant erlotinib 150 mg daily (Arm 1, n = 19), erlotinib + sulindac 150 mg twice daily (Arm 2, n = 16), or placebo (n = 12). Pts were treated for 7-14 days. Tumor specimens were collected pre- and post-treatment. The primary endpoint was change in Ki-67 proliferative index. We hypothesized an ordering in Ki-67 down-modulation, with Arm 2 > Arm 1 > placebo. A Jonckheere-Terpstra test evaluated trend; a Wilcoxon test was applied to pairwise contrasts. We prepared tissue microarrays for IHC, to explore pharmacodynamic modulation of 21 EGFR and COX-2 pathway constituents including EGFR, Src, STAT3, Akt, EP2 and EP4. Results: From Dec 2005 – Dec 2008, 48 pts enrolled; 28 tumor pairs were evaluable for biomarker modulation. Class toxicities of EGFR inhibition, including acneiform rash and diarrhea, were observed on Arms 1 and 2. Compared to placebo, Ki-67 was reduced by erlotinib (p = 0.0005) or by erlotinib-sulindac (p = 0.0001). There was a trend in ordering of Ki-67 down-modulation, with greater effect from the addition of sulindac (exact Jonckeheere-Terpstra, Arm 1 vs. 2, p = 0.003). Among 21 protein candidates tested for association with Ki-67, only low baseline p-Src correlated with greater Ki-67 reduction in both erlotinib groups (R2 = 0.312, p = 0.024). Conclusions: Relative to placebo, brief neoadjuvant treatment with erlotinib or erlotinib-sulindac significantly decreased the proliferative index in operable HNSCC. Sulindac enhanced Ki-67 down-modulation. Efficacy studies of dual EGFR-COX inhibition are justified. Baseline p-Src warrants further study as a resistance biomarker for anti-EGFR therapy. Clinical trial information: NCT01515137.

The prognostic and predictive value of KRAS oncogene substitutions in lung adenocarcinoma

BACKGROUND

The prognostic and therapeutic implications of the spectrum of v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) oncogene substitutions in lung cancer remain poorly understood. The objective of this study was to determine whether KRAS oncogene substitutions differed with regard to prognosis or predictive value in lung adenocarcinoma.

METHODS

KRAS oncogene substitutions and mutant allele-specific imbalance (MASI) were determined in patients with lung adenocarcinoma, and the associations with overall survival (OS), recurrence-free survival (RFS), and chemotherapy interactions were assessed.

RESULTS

KRAS mutational analysis was performed on 988 lung adenocarcinomas, and 318 KRAS mutations were identified. In this predominantly early stage cohort (78.6% of patients had stage I-III disease), OS and RFS did not differ according to the type of KRAS substitution (OS, P = .612; RFS, P = .089). There was a trend toward better OS in the subset of patients with KRAS codon 13 mutations (P = .052), but that trend was not significant in multivariate analysis (P = .076). RFS did not differ according to codon type in univariate analysis (P = .322). There was a marked difference in RFS based on the presence of MASI in univariate analysis (P = .004) and multivariate analysis (P = .009). A test for interaction was performed to determine whether the effect of chemotherapy on OS and RFS differed based on KRAS substitution type, codon type, or the presence of MASI. That test indicated that there were no differences in the effects of chemotherapy for any of variables examined.

CONCLUSIONS

KRAS codon 13 mutations and MASI were identified as candidate biomarkers for prognosis, and it may be useful to incorporate them into prospective studies evaluating novel therapies in KRAS-mutant lung adenocarcinoma.

Antitumor effects of EGFR antisense guanidine-based peptide nucleic acids in cancer models

Peptide nucleic acids have emerged over the past two decades as a promising class of nucleic acid mimics because of their strong binding affinity and sequence selectivity toward DNA and RNA, and resistance to enzymatic degradation by proteases and nucleases. While they have been shown to be effective in regulation of gene expression in vitro, and to a small extent in vivo, their full potential for molecular therapy has not yet been fully realized due to poor cellular uptake. Herein, we report the development of cell-permeable, guanidine-based peptide nucleic acids targeting the epidermal growth factor receptor (EGFR) in preclinical models as therapeutic modality for head and neck squamous cell carcinoma (HNSCC) and nonsmall cell lung cancer (NSCLC). A GPNA oligomer, 16 nucleotides in length, designed to bind to EGFR gene transcript elicited potent antisense effects in HNSCC and NSCLC cells in preclinical models. When administered intraperitoneally in mice, EGFRAS-GPNA was taken-up by several tissues including the xenograft tumor. Systemic administration of EGFRAS-GPNA induced antitumor effects in HNSCC xenografts, with similar efficacies as the FDA-approved EGFR inhibitors: cetuximab and erlotinib. In addition to targeting wild-type EGFR, EGFRAS-GPNA is effective against the constitutively active EGFR vIII mutant implicated in cetuximab resistance. Our data reveals that GPNA is just as effective as a molecular platform for treating cetuximab resistant cells, demonstrating its utility in the treatment of cancer.

The cytological features of mammary analogue secretory carcinoma: a series of 6 molecularly confirmed cases

BACKGROUND

Mammary analogue secretory carcinoma (MASC) of the salivary glands is a newly described tumor entity associated with the t(12;15)(p13;q25) ETV6-NTRK3 translocation. Early studies have shown this tumor to be a distinct entity with histologic, biologic, and clinical differences from acinic cell carcinoma and adenocarcinoma, not otherwise specified. Because this tumor was described only recently, it remains relatively unknown outside of head and neck specialty pathology centers.

METHODS

In the current study, 6 cases of fine-needle aspiration cytology from histologically and/or molecularly confirmed cases of MASC are presented.

RESULTS

Using cytomorphology, MASC primarily raises the differential diagnosis of an oncocytic salivary gland tumor but there are some features that can suggest the specific diagnosis of MASC. The 6 cases presented in the current study all demonstrated at least focal cytoplasmic vacuolization and papillary formations on smears. MASC can be differentiated from acinic cell carcinoma by a lack of periodic acid-Schiff diastase-positive zymogen granules and S-100 protein positivity.

CONCLUSIONS

The results of the current study the ability of ETV6 break-apart fluorescence in situ hybridization to detect gene rearrangement on cell block material. This is the first report of a case of MASC prospectively diagnosed on a cytology specimen.

Prospective testing of mucoepidermoid carcinoma for the MAML2 translocation: clinical implications

OBJECTIVES/HYPOTHESIS

Mucoepidermoid carcinoma (MEC) with MAML2 translocation is believed to be associated with lower clinical stage, lower histologic grade, and better outcome. We summarized our prospective experience testing MEC for the MAML2 translocation.

STUDY DESIGN

Prospective cohort study.

METHODS

One hundred eighteen head and neck tumors (55 MECs and 63 mimics) were prospectively tested for MAML2 translocation by fluorescence in situ hybridization as part of clinical care during a 36-month period.

RESULTS

MAML2 translocation was identified in 41 of 55 (75%) cases diagnosed as MEC. Translocation status did not correlate significantly with histologic grade, age, gender, tumor site, or T stage.

CONCLUSIONS

Routine testing for MAML2 translocation by fluorescence in situ hybridization is feasible and useful in confirming the diagnosis of MEC. The lack of significant correlation with histologic grade or pathologic stage implies that the previously reported prognostic value of the MAML2 translocation may be an artifact of misclassification of MEC as other tumors.

Clinicopathological characterization of mammary analogue secretory carcinoma of salivary glands

AIMS

Mammary analogue secretory carcinoma (MASC) is a recently described tumour with ETV6 translocation. We aimed to characterize the clinical significance of recognizing MASC.

METHODS AND RESULTS

Thirty-six patients with MASC (27 identified retrospectively and nine prospectively) are presented. Historically, MASC mimicked other salivary tumours, as follows: 14 of 37 (37.8%) adenocarcinoma, not otherwise specified, 11 of 89 (12.4%) acinic cell carcinomas (AciCC), one of five (20%) mucin-producing signet ring adenocarcinomas, and one of 165 (0.6%) mucoepidermoid carcinomas. Demographically, MASC affected males more commonly (1.4:1). The average age at diagnosis was 45.7 years. Parotid gland was the most common site of involvement (26 of 36, 72.2%), although other head and neck sites, including the base of tongue, were affected. Of 18 patients with neck dissection, lymph node involvement was identified in four patients (four of 18, 22.2%). Survival analysis of MASC cases presented here, combined with those reported previously, revealed a mean disease-free survival for patients with MASC of 92 months [n = 29; 95% confidence interval (CI) 71-115 months], compared with a mean DFS of 121 months for patients with AciCC (n = 38; 95% CI 92-149, P = 0.43).

CONCLUSIONS

Although perhaps slightly more aggressive, MASC clinical outcome mimics that of AciCC.

Molecular changes in the multistage pathogenesis of head and neck cancer

Head and neck squamous cell carcinomas (SCCHN) arise in the mucosa of the upper aerodigestive tract at multiple anatomic sites. While tobacco and alcohol exposure remain the primary risk factors for this malignancy, infection with the human papilloma virus is emerging as a major contributing factor to cancers that arise primarily in the oropharynx. Despite therapeutic advances, survival has remained relatively unchanged over the past few decades. Increased understand of the cellular and molecular biology of these cancers will improve our understanding of this malignancy and facilitate the development of more effective therapeutic strategies. Alterations that have been studied to date include genetic and epigenetic changes. While the epidermal growth factor receptor (EGFR) is the only established molecular therapeutic target, other proteins and pathways are under active investigation to determine their contribution to SCCHN carcinogenesis and progression.

Re-evaluating historic cohort of salivary acinic cell carcinoma with new diagnostic tools

Mammary analogue secretory carcinoma (MASC) was recently identified as a distinct salivary gland neoplasm, morphologically resembling intercalated duct cell predominant acinic cell carcinoma (AciCC). To determine how frequently MASC has mimicked an intercalated duct cell predominant AciCC, we reviewed AciCC diagnosed from 1956 to 1975. Nine AciCC consecutively diagnosed in that period were identified. Based on morphologic examination, one case diagnosed as AciCC in a male patient in 1960 was re-classified as MASC [confirmed by fluorescence in situ hybridization (FISH) showing ETV6 translocation]. Another case diagnosed as AciCC of the palate in a female patient in 1975 was re-classified as mucoepidermoid carcinoma (based on the lack of acinar differentiation, presence of mucous cells, and confirmed by FISH showing MAML2 translocation). In this proof-of-principle study, we show that 1 in 9 cases historically designated as AciCC represents a MASC. "Intercalated duct cell predominant AciCC", especially among male patients, most likely represent examples of MASC. For anatomic sites outside of the parotid glands, broader differential diagnoses should be considered before accepting morphologic variants of AciCC as the final diagnosis.

Lyn kinase mediates cell motility and tumor growth in EGFRvIII-expressing head and neck cancer

PURPOSE

EGF receptor variant III (EGFRvIII) has been detected in several cancers in which tumors expressing this truncated growth factor receptor show more aggressive behavior. The molecular mechanisms that contribute to EGFRvIII-mediated tumor progression that are amenable to targeted therapy are incompletely understood. The present study aimed to better define the role of Src family kinases (SFKs) in EGFRvIII-mediated cell motility and tumor growth of head and neck squamous cell carcinomas (HNSCC).

EXPERIMENTAL DESIGN

HNSCC models expressing EGFRvIII were treated with dasatinib, a pharmacologic inhibitor of SFKs.

RESULTS

SFK inhibition significantly decreased cell proliferation, migration, and invasion of EGFRvIII-expressing HNSCC cells. Administration of dasatinib to mice bearing EGFRvIII-expressing HNSCC xenografts resulted in a significant reduction of tumor volume compared with controls. Immunoprecipitation with anti-c-Src, Lyn, Fyn, and Yes antibodies followed by immunoblotting for phosphorylation of the SFK activation site (Y416) showed specific activation of Lyn kinase in EGFRvIII-expressing HNSCC cell lines and human HNSCC tumor specimens. Selective inhibition of Lyn using siRNA decreased cell migration and invasion of EGFRvIII-expressing HNSCCs compared with vector control cells.

CONCLUSIONS

These findings show that Lyn mediates tumor progression of EGFRvIII-expressing HNSCCs in which strategies to inhibit SFK may represent an effective therapeutic strategy.

Mutant allele-specific imbalance modulates prognostic impact of KRAS mutations in colorectal adenocarcinoma and is associated with worse overall survival

The prognostic impact of distinct KRAS mutations in colorectal carcinomas is not fully characterized. We hypothesized that the prognostic impact of KRAS mutations is modulated by KRAS mutant allele-specific imbalance (MASI). KRAS MASI was assessed by sequencing electropherograms in KRAS-mutated colorectal carcinomas (N = 394, prospectively tested). The mechanism of KRAS MASI was studied by fluorescence in situ hybridization (FISH; N = 50). FISH showed that KRAS MASI developed by chromosome 12 hyperploidy (9/18, 50%) or KRAS amplification (1/18, 5.5%). KRAS MASI was more common in tumors with KRAS codon 13 than with codon 12 mutations [24/81, 30% vs. 54/313, 17%; odds ratio (OR), 2.0, 95% confidence interval (CI), 1.2-3.5; p = 0.01]. KRAS MASI was correlated with overall survival (N = 358, median follow-up = 21 months). In a multivariate analysis, KRAS codon 13 MASI was an independent adverse prognostic factor (compared to codon 13 mutants without MASI combined with all codon 12 mutants; adjusted hazard ratio, 2.2, 95% CI: 1.2-3.9; p = 0.01). KRAS MASI arises through chromosome 12 hyperploidy or KRAS amplification and, when affects KRAS codon 13, is associated with worse overall survival.

The profile of acinic cell carcinoma after recognition of mammary analog secretory carcinoma

To determine the influence of the newly described mammary analog secretory carcinoma (MASC) with ETV6 translocation on our understanding of salivary acinic cell carcinoma (AciCC), we reviewed 81 cases of AciCC: 64 "classic" AciCCs, 11 AciCCs with high-grade transformation (HGT), and 17 zymogen granule poor AciCCs. ETV6 fluorescence in situ hybridization revealed that classic AciCC (7 of 7 tested) and AciCC-HGT (4 of 4 tested) have intact ETV6. However, 10 of 17 zymogen granule poor AciCCs showed ETV6 translocation and were reclassified as MASC; the diagnosis of AciCC was retained for cases with intact ETV6. MASCs were distinguished by the lack of zymogen granules, mucin production, and stronger S100 reactivity. MASC showed a striking male predilection (male-to-female ratio, 8:2) in contrast to AciCC (male-to-female ratio, 1:1.5; P<0.01). Compared with cases of confirmed AciCC, AciCC-HGT occurred in older patients (mean age of 66.2 y vs. 47.7 y, P=0.007) and showed a poorer mean overall survival [40.2 mo (95% confidence interval (CI), 7.5-73 mo) vs. 125 mo (95% CI: 98-151 mo); P<0.001]. Patients with confirmed AciCC without HGT showed a recurrence rate of 15% (9/60) and a 7.9% (3/38) incidence of regional lymph node involvement. It appears that more than half of zymogen granule poor AciCCs are likely to represent MASC. Even after excluding cases of MASC, the presence of HGT in AciCC predicts poorer overall survival.

Squamous cell carcinoma metastatic to neck from an unknown primary: the potential impact of modern pathologic evaluation on perceived incidence of human papillomavirus-positive oropharyngeal carcinoma prior to 1970

OBJECTIVES/HYPOTHESIS

From the 1950s through the 1960s, an unknown number of oropharyngeal squamous cell carcinomas (SCCs) presented with metastases to cervical lymph nodes from an unknown primary (SCCUP) and were not recognized as oropharyngeal in origin. At present, pathologic evaluation of SCCUP for human papillomavirus (HPV) improves discovery of occult oropharyngeal SCC and may partially explain increased incidence of HPV-positive oropharyngeal SCC.

STUDY DESIGN

Retrospective cohort study.

METHODS

A retrospective study of 13 cases of SCCUP diagnosed from 1956 to 1969 was performed. The probability of these cases of metastatic SCC to originate from the oropharynx was assessed by characterizing their morphology (keratinizing vs. nonkeratinizing) and HPV status by in situ hybridization and p16 immunostaining.

RESULTS

Two cases of nonkeratinizing SCC positive for HPV by in situ hybridization and p16 immunohistochemistry were identified. These cases were most likely of oropharyngeal origin.

CONCLUSIONS

These two cases can be added to the other 15 cases of HPV-positive primary oropharyngeal SCC identified in our department from 1956 to 1969. When determining the incidence of HPV-positive oropharyngeal SCC before the 1970s, a correction factor of about +13% (2/15) accounting for modern pathologic workup of SCCUP during the last couple of decades may be appropriate.

KRAS mutant allele-specific imbalance in lung adenocarcinoma

The significance of KRAS mutant allele-specific imbalance (MASI) in lung adenocarcinomas is unknown. KRAS MASI was defined as predominance of the mutant allele over the wild-type allele. We assessed the frequency of KRAS MASI by comparing peak heights of mutant and wild-type alleles on sequencing electropherograms and by KRAS fluorescence in situ hybridization (FISH). A review of sequencing electropherograms of 207 KRAS-mutated lung adenocarcinomas demonstrated 23 (11%) cases with the mutant allele peak higher than the wild-type allele peak and 15 (7%) cases with the mutant allele peak equal to the wild-type allele peak. Of 17 cases with the mutant allele peak higher or equal to the wild-type allele peak, 8 (47%) showed KRAS amplification by FISH. KRAS FISH analysis of 36 KRAS-mutated lung adenocarcinomas with the mutant allele peak lower than the wild-type allele peak, 21 KRAS and EGFR wild-type and 16 EGFR-mutated adenocarcinomas showed no KRAS amplification. KRAS MASI was associated with selective amplification of the KRAS mutant allele (P<0.001). Patients with KRAS MASI showed worse overall survival. The cumulative proportion surviving at 17 months for KRAS MASI group was 35% compared with 84.1% for patients with KRAS mutant allele peak lower than wild-type allele peak (P=0.012). The adverse prognostic significance of KRAS MASI was independent of clinical stage and was maintained among stage I patients. The detection of KRAS MASI in lung adenocarcinomas by sequencing electropherograms may identify patients with more aggressive disease.

Pathology archive: evaluation of integrity, regulatory compliance, and construction of searchable database from print reports

Tissue repositories maintained by pathology departments represent an abundant resource of clinically annotated human specimens. The storage expenses associated with pathology archives are known to administrators of most pathology departments. However, such basic repository characteristics as the quality of stored materials, ease of access, and search and retrieval rates are often unclear. The aims of our work were to design a framework to assess the quality of a historic pathology archive, to propose the definition of "archive integrity," and to provide benchmarks for tissue block retrieval rates and DNA integrity. We share our experience with scanning approximately 120,000 pathology reports from 1956 to 1979 into an electronically searchable archive, with a $9,000 budget, completed in 6 weeks. Several ethical and legal considerations that shaped the technical side of this project are discussed.

Treatment and survival outcomes based on histologic grading in patients with head and neck mucoepidermoid carcinoma

BACKGROUND

Histopathologic grade of mucoepidermoid carcinoma (MEC) is an established predictor of prognosis and affects treatment protocol. Tumor behavior is more aggressive in high-grade than in low-grade MEC, leading to a more intensive treatment protocol. Outcomes for patients with intermediate-grade MEC are less clear; therefore, the optimal treatment protocol for this group is not well defined. The treatment protocol and survival outcomes of patients treated for MEC of the head and neck was investigated.

METHODS

A retrospective clinical review and prospective review of histopathologic grading were undertaken using the most recently established grading system of 50 patients with MEC of the head and neck from 1983 through 2004.

RESULTS

As histologic grade increased from low to intermediate to high, overall survival (P < .0001) and disease-free survival (P < .001) were significantly decreased. Overall and disease-free survival were significantly better for patients with intermediate-grade MEC than those with high-grade disease. Overall and disease-free survival were similar for patients with low-grade and intermediate-grade MEC. There was a low rate of disease recurrence in patients with intermediate-grade MEC, but this did not lead to death from disease. Although no patients with low-grade or intermediate-grade MEC died of disease, 52% of patients with high-grade MEC died of disease. Multivariate analysis revealed that histologic grade, age, and surgical margin status significantly predicted prognosis.

CONCLUSIONS

These findings suggest that, under the current histopathologic classification system, the behavior of intermediate-grade MEC is comparable to that of low-grade MEC and different from high-grade MEC, allowing for the establishment of an evidence-based treatment protocol.