Induction of IL19 expression through JNK and cGAS-STING modulates DNA damage-induced cytokine production.

Cytokine production is a critical component of cell-extrinsic responses to DNA damage and cellular senescence. Here, we demonstrated that expression of the gene encoding interleukin-19 (IL-19) was enhanced by DNA damage through pathways mediated by c-Jun amino-terminal kinase (JNK) and cGAS-STING and that IL19 expression was required for the subsequent production of the cytokines IL-1, IL-6, and IL-8. IL19 expression was stimulated by diverse cellular stresses, including inhibition of the DNA replication checkpoint kinase ATR (ataxia telangiectasia and Rad3-related protein), oncogene expression, replicative exhaustion, oxidative stress, and DNA double-strand breaks. Unlike the production of IL-6 and IL-8, IL19 expression was not affected by abrogation of signaling by the IL-1 receptor (IL-1R) or the mitogen-activated protein kinase p38. Instead, the DNA damage­induced production of IL-1, IL-6, and IL-8 was substantially reduced by suppression of IL19 expression. The signaling pathways required to stimulate IL19 expression selectively depended on the type of DNA-damaging agent. Reactive oxygen species and the ASK1-JNK pathway were critical for responses to ionizing radiation (IR), whereas the cGAS-STING pathway stimulated IL19 expression in response to either IR or ATR inhibition. Whereas induction of IL1, IL6, and IL8 by IR depended on IL19 expression, the cGAS-STING­dependent induction of the immune checkpoint gene PDL1 after IR and ATR inhibition was independent of IL19. Together, these results suggest that IL-19 production by diverse pathways forms a distinct cytokine regulatory arm of the response to DNA damage.

Utilization of Silicone Sheet as a Protective Guide During Transoral Robotic Tongue Base Surgery.

This article presents a simple technique where a silicone sheet is used during transoral robotic surgery (TORS) to protect the upper airway structures from thermal damage during a base of tongue procedure. We review 10 cases of TORS tongue base reduction with the use of this technique, with no complications and with reduction of thermal damage to the lingual epiglottis and surrounding pharyngeal wall. Furthermore, it served as a guide during tongue base dissection to provide visual and tactile feedback to the inferior limit of resection, as well as to protect the endotracheal tube. The silicone sheet is an ideal material for use as a thermal barrier due to its widespread availability, intrinsic thermal properties, and translucency. The technique of using the silicone sheet is easy to implement and may prove useful to many transoral robotic surgeons, especially for newly trained TORS users and trainees.

Operative Management of Vocal Fold Avulsion Following Pediatric Laryngotracheal Separation.

Laryngotracheal disruption in children is rare but life-threatening, and endolaryngeal injuries may go overlooked. We present the case of a 10-year-old boy who sustained near-complete laryngotracheal separation, multiple laryngeal fractures, and arytenoid and vocal fold avulsion following blunt cervical trauma. These injuries were not identified radiographically and only became apparent intraoperatively. Following surgical repair, the patient was successfully decannulated, eating a normal diet, and had a serviceable speaking voice within 2 months. In children, the diagnosis of severe endolaryngeal injuries may be elusive and therefore require high degree of clinical suspicion. Surgical success requires accurate diagnosis and prompt intervention.

The Role of Age and Merkel Cell Polyomavirus in Oral Cavity Cancers.

The incidence of oral tongue cancer, the majority subsite of oral cavity cancer, is rising among young people with less exposure to tobacco and alcohol. Viral causes have been proposed, including Merkel cell polyomavirus (MCPyV). We evaluated patient and tumor characteristics among 126 incident oral cavity cancers (OCCs). Consistent with generational norms, younger patients had less exposure to tobacco and a greater number of oral sexual partners than older OCCs. In addition, younger patients were more likely to present at an earlier stage and with cancer arising from the oral tongue (each P < .05). A subset of 44 cases was centrally tested for MCPyV large T antigen expression by immunohistochemistry. In the presence of controls, none of the tumors expressed MCPyV. These findings exclude consideration of MCPyV as an etiologic factor in OCC and may generate hypotheses for future examinations of the factors underlying the rise in oral tongue cancers.

Predictors of Mortality in HPV-Associated Oropharynx Carcinoma Treated With Surgery Alone.

OBJECTIVE: Survival outcomes for human papillomavirus-associated oropharynx squamous cell carcinoma (HPV + OPSCC) treated with surgery alone are unclear. To increase understanding, we assessed overall survival (OS) outcomes using the national cancer database (NCDB). METHODS: We conducted a retrospective analysis of OS of 736 NCDB HPV + OPSCC patients who underwent surgery alone from 2010 to 2014 using univariate and multivariate analyses and the Kaplan-Meir method. RESULTS: Multivariable analysis found the following independent risk factors for death: American Joint Commission on Cancer (AJCC) 8th edition pathologic stage(p)N2 versus pN0 disease (hazard ratio [HR], 5.5; P = 0.000006), macroscopic extranodal extension (ENE) versus non-ENE (HR, 4.9; P < 0.02), a positive lymph nodes (LN) percentage of ≥10% (HR, 4.2; P = 0.0002), and five or more positive LNs (HR, 4.9; P = 0.00004). Three-year OS was significantly worse for AJCC 8th edition pN2 versus pN0 but not for 7th edition pN2 versus pN0 disease. Five-year OS was significantly worse for positive versus negative surgical margins, AJCC 8th edition stage II versus I, and either microscopic or macroscopic ENE versus non-ENE positive LNs. For 523 (71%) AJCC 8th edition stage I patients and for 283 (38%) patients who were pT1-T2, with negative margins, pN0-N1, with ≤4 pathologic LNs, without ENE, and with >20 LNs removed during neck dissection, the 3-year OS rates were 93% and 95%, respectively, and the 5-year OS rates were 91% and 95%, respectively. CONCLUSION: In the context of the lack of detail and possible inaccuracies found in the NCDB, surgery alone for AJCC 8th edition stage I HPV + OPSCC, particularly pT1-T2, pN0-N1 with ≤4 pathologic LNs, without ENE, and with negative surgical margins has a high OS. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:E423-E435, 2020.

Assessing the Impact of Targeting CEACAM1 in Head and Neck Squamous Cell Carcinoma.

Objective In conjunction with advances made in cytotoxic chemotherapy, radiation, and surgery, immunotherapy has emerged as a fourth modality of treatment for head and neck squamous cell carcinoma (HNSCC). Understanding the mechanisms by which HNSCC evades immune-mediated control will aid in the development of new therapies to augment an antitumor immune response. Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is a cell surface receptor that is expressed on malignant cells and lymphocytes such as natural killer (NK) cells. We sought to determine whether tumor-derived CEACAM1 inhibits NK cell cytotoxicity and whether blockade of CEACAM1 restores antitumor immunity. Study Design In vitro HNSCC cell line study. Setting Research laboratory. Subject and Methods We utilized a real-time cell analyzer to assess NK cell cytotoxicity against an oral squamous cell carcinoma cell line after modulating CEACAM1 expression by cytokines and shRNA knockdown of CEACAM1 expression. Results NK cells and HNSCC cells both demonstrated cytokine-inducible expression of CEACAM1. Coincubation of NK cells and HNSCC cells resulted in the upregulation of CEACAM1 on the tumor cells. When compared with CEACAM1- cells, CEACAM1+ tumor cells exhibited increased cell growth and increased size and number of organoids in 3-dimensional culture. Notably, CEACAM1+ HNSCC cells were more resistant to NK cell-mediated killing, but the inhibited expression of CEACAM1 by an shRNA construct restored NK cell cytotoxicity. Conclusion Together, these data indicate that CEACAM1 acts as an inducible checkpoint molecule, and they support the idea that targeting CEACAM1 could serve as a novel immunotherapy approach in HNSCC.

Measuring Institutional Quality in Head and Neck Surgery Using Hospital-Level Data: Negative Margin Rates and Neck Dissection Yield.

Importance: Negative margins and lymph node yields (LNY) of 18 or more from neck dissections in patients with head and neck squamous cell carcinomas (HNSCC) have been associated with improved patient survival. It is unclear whether these metrics can be used to identify hospitals with improved outcomes. Objective: To determine whether 2 patient-level metrics would predict outcomes at the hospital level. Design, Setting, and Participants: A retrospective review of records from the National Cancer Database (NCDB) was used to identify patients who underwent primary surgery and concurrent neck dissection for HNSCC between 2004 and 2013. The percentage of patients at each hospital with negative margins on primary resection and an LNY 18 or more from a neck dissection was quantified. Cox proportional hazard models were used to define the association between hospital performance on these metrics and overall survival. Main Outcomes and Measures: Margin status and lymph node yield at hospital level. Overall survival (OS). Results: We identified 1008 hospitals in the NCDB where 64 738 patients met inclusion criteria. Of the 64 738 participants, 45 170 (69.8%) were men and 19 568 (30.2%) were women. The mean SD age of included patients was 60.5 (12.0) years. Patients treated at hospitals attaining the combined metric of a 90% or higher negative margin rate and 80% or more of cases with LNYs of 18 or more experienced a significant reduction in mortality (hazard ratio [HR] 0.93; 95% CI, 0.89-0.98). This benefit in survival was independent of the patient-level improvement associated with negative margins (HR, 0.73; 95% CI, 0.71-0.76) and LNY of 18 or more (HR, 0.85; 95% CI, 0.83-0.88). Including these metrics in the model neutralized the association of traditional measures of hospital quality (volume and teaching status). Conclusions and Relevance: Treatment at hospitals that attain a high rate of negative margins and LNY of 18 or more is associated with improved survival in patients undergoing surgery for HNSCC. These surgical outcome measures predicted outcomes independent of traditional, but generally nonmodifiable characteristics. Tracking of these metrics may help identify high-quality centers and provide guidance for institution-level quality improvement.

Clinical Outcomes in Elderly Patients Treated for Oral Cavity Squamous Cell Carcinoma.

PURPOSE: Oral cavity squamous cell carcinoma (OCSCC) commonly occurs in elderly patients. This study explores the clinical outcomes in elderly patients with OCSCC based on their functional status and clinical comorbidities. METHODS AND MATERIALS: We retrospectively reviewed 180 patients aged ≥70 who were treated with definitive intent with surgery followed by adjuvant therapy if indicated for newly diagnosed OCSCC from 1998 to 2013. Pathology review was conducted, and Eastern Cooperative Oncology Group (ECOG) performance status and the Head and Neck Charlson Comorbidity Index (HN-CCI) were assessed. We performed Kaplan-Meier analyses and cumulative incidence estimates to assess overall survival (OS), progression-free survival (PFS), and locoregional recurrence (LRR). Univariate and multivariate analyses were used to test age, adjuvant therapy, adverse pathologic features, ECOG status, and HN-CCI status as predictors. RESULTS: The median age was 80 years (range, 70-95 years), with a median follow-up time of 23 months. The median OS was 18 months and 46 months for patients aged 70 to 84 and ≥85, respectively (P=.0017). The LRR was 24% at 1 year and 30% at 2 years for all patients. On univariate analysis, ECOG score ≥2 (hazard ratio [HR] = 1.96; confidence interval [CI] 1.19-3.21; P=.008) and HN-CCI score ≥2 (HR=1.97; CI 1.17-3.34; P=.011) were predictors of worse OS. On multivariate analysis, HN-CCI score was a better predictor of OS, PFS, and LRR than was ECOG score. Predictors of worse OS were age ≥85 (HR=1.78; CI 1.07-2.96; P=.026), HN-CCI score of ≥2 (HR=2.21; CI 1.20-4.08; P=.011), and adverse features (HR=2.35; CI 1.34-4.13; P=.003). Adjuvant therapy did not have a significant impact on OS or LRR for patients with adverse features even though 48% of them did not receive it. CONCLUSION: Elderly patients with good health and performance status may live long enough to experience disease progression from OCSCC. ECOG and HN-CCI scores may be useful to evaluate the candidacy of elderly patients for adjuvant therapy. However, the benefit of adjuvant therapy in this population remains elusive and should be investigated prospectively.

Retrograde Parotidectomy and facial nerve outcomes: A case series of 44 patients.

PURPOSE: The most common surgical method to remove benign parotid tumors remains the prograde approach. We examined if a retrograde surgical technique offers better outcomes than historical prograde controls. MATERIALS AND METHODS: A retrospective chart review at Stanford Hospital was conducted to identify retrograde parotidectomies between February 2012 and October 2014 that were staffed by the senior author (DS) with resident involvement. Facial nerve (FN) outcomes and other post-surgical parameters were recorded. RESULTS: We identified 44 consecutive cases and found that 18.2% (n=8) of patients experienced temporary paresis and 2.3% (n=1) experienced minor (HB 2) permanent paresis limited to one branch. The average hospital length of stay was 0.64 days and complication rate was 6.8%. CONCLUSION: The retrograde technique has complication rates comparable to historical rates for the prograde technique and is amenable to minimally invasive outpatient superficial parotidectomy.

Transoral endoscopic head and neck surgery (eHNS) for minor salivary gland tumors of the oropharynx.

BACKGROUND: Transoral endoscopic head and neck surgery (eHNS), including transoral laser microsurgery (TLM) and transoral robotic surgery (TORS), provides access to subsites in the head and neck that have traditionally been difficult to approach. Minor salivary gland tumors, while relatively uncommon, are frequently malignant and can occur at sites in the oropharynx accessible by transoral eHNS. Presented here is the largest review to date of patients with minor salivary gland tumors of the oropharynx managed with transoral eHNS as primary or salvage therapy. METHODS: A retrospective chart review was performed, including data from 20 patients with minor salivary gland tumors of the oropharynx managed with transoral eHNS at 2 tertiary, academic medical centers. Details of tumor pathology, margin analysis, adjuvant therapy, and an assessment of oncologic outcome were included. RESULTS: The base of tongue was the most common tumor site (75%). Adenoid cystic carcinoma (ACC) accounted for most cases (35%), and negative margins were obtained in most (95%) through an endoscopic-only approach. Overall, 50% of patients received post-operative radiation therapy. Postoperative complications were limited, with one patient (5%) returning to the OR for control of post-operative oropharyngeal bleeding. On average follow-up of 36 months, 90% of patients were alive with no evidence of recurrence. CONCLUSION: In this experience, transoral eHNS provided a safe and consistent surgical approach to management of minor salivary gland malignancies, with low complication rates and good locoregional control. Thus, transoral eHNS may play a valuable role in the multi-disciplinary management of these malignancies. TRIAL REGISTRATION NUMBER: None/not applicable.

Contemporary mandibular reconstruction.

PURPOSE OF REVIEW: Multiple disease processes, including neoplasia, trauma, and medication side-effects, necessitate segmental resection and subsequent reconstruction of the mandible. As surgical techniques have advanced, several technologies have been developed with the potential to significantly transform a surgeon's approach to the restoration of mandibular continuity. The purpose of this review is to highlight many of these relatively newer tools and discuss their evolving role in mandibular reconstruction. RECENT FINDINGS: Several contemporary studies have documented the application of different approaches and modifications to mandibular reconstruction - including computer-aided design or computer-aided modeling, contemporary plating systems, osseointegrated implants, and various modifications to existing osseocutaneous free tissue transfer options - and have reported relatively high success rates. SUMMARY: In discussing these reports, we present a survey of current and developing technologies in the field of mandibular reconstruction and aim to provide sufficient context for the gradual integration of these techniques into practice.

Immunotherapy for Head and Neck Squamous Cell Carcinoma.

Although head and neck squamous cell carcinoma has traditionally been considered to be a very immunosuppressive, or at least nonimmunogenic, tumor type, recent results from clinical studies of immune checkpoint blockade strategies have led to resurgence in the enthusiasm for immunotherapeutic approaches. Additional strategies for immunotherapy that are under active investigation include enhancement of cetuximab-mediated antibody-dependent cell-mediated cytotoxicity, tumor vaccines, and engineered T cells for adoptive therapy. All of these studies have early-phase clinical trials under way, and the next several years will be exciting as the results of these studies are reported.

Management of the neck in thyroid cancer.

The management of regional lymph nodes in thyroid carcinoma is guided by preoperative evaluation, histologic subtype, and often a consideration of data for potential benefit and morbidity of a neck dissection. The goal of lymphadenectomy is complete surgical resection of grossly evident metastatic disease and the removal of regional lymph node groups at highest risk for microscopic disease. Surgery should achieve disease eradication but preserve voice, airway, swallowing, and parathyroid function. This article discusses recommendations for addressing cervical lymph nodes in thyroid carcinoma, discusses current literature regarding the common histologic subtype (papillary carcinoma), and details our operative approach.

Chk'ing p53-deficient breast cancers.

Loss or functional impairment of p53 occurs in many human cancers, and its absence is often associated with a poor response to conventional chemotherapy. Hence, much effort is currently devoted to developing novel treatments for p53-deficient malignancies. One approach is to target pathways that are selectively required for the survival of p53-deficient cancer cells, thus exploiting a synthetic lethal interaction. Previous studies have demonstrated that inhibition of the ataxia telangiectasia and Rad3-related (ATR) and checkpoint kinase 1 (Chk1) pathway in p53-deficient cells can induce such a synthetic lethal outcome. In this issue of the JCI, Ma et al. take these findings a step closer to the clinic by demonstrating that highly specific inhibitors of Chk1 synergize with chemotherapy to stem progression of p53-deficient triple-negative breast cancers in a xenotransplant model of this disease. Together with other recent studies, this report highlights the promise of ATR and Chk1 inhibitors in targeted cancer treatment.

Oncogenic stress sensitizes murine cancers to hypomorphic suppression of ATR.

Oncogenic Ras and p53 loss-of-function mutations are common in many advanced sporadic malignancies and together predict a limited responsiveness to conventional chemotherapy. Notably, studies in cultured cells have indicated that each of these genetic alterations creates a selective sensitivity to ataxia telangiectasia and Rad3-related (ATR) pathway inhibition. Here, we describe a genetic system to conditionally reduce ATR expression to 10% of normal levels in adult mice to compare the impact of this suppression on normal tissues and cancers in vivo. Hypomorphic suppression of ATR minimally affected normal bone marrow and intestinal homeostasis, indicating that this level of ATR expression was sufficient for highly proliferative adult tissues. In contrast, hypomorphic ATR reduction potently inhibited the growth of both p53-deficient fibrosarcomas expressing H-rasG12V and acute myeloid leukemias (AMLs) driven by MLL-ENL and N-rasG12D. Notably, DNA damage increased in a greater-than-additive fashion upon combining ATR suppression with oncogenic stress (H-rasG12V, K-rasG12D, or c-Myc overexpression), indicating that this cooperative genome-destabilizing interaction may contribute to tumor selectivity in vivo. This toxic interaction between ATR suppression and oncogenic stress occurred without regard to p53 status. These studies define a level of ATR pathway inhibition in which the growth of malignancies harboring oncogenic mutations can be suppressed with minimal impact on normal tissue homeostasis, highlighting ATR inhibition as a promising therapeutic strategy.

Combining ATR suppression with oncogenic Ras synergistically increases genomic instability, causing synthetic lethality or tumorigenesis in a dosage-dependent manner.

Previous studies indicate that oncogenic stress activates the ATR-Chk1 pathway. Here, we show that ATR-Chk1 pathway engagement is essential for limiting genomic instability following oncogenic Ras transformation. ATR pathway inhibition in combination with oncogenic Ras expression synergistically increased genomic instability, as quantified by chromatid breaks, sister chromatid exchanges, and H2AX phosphorylation. This level of instability was significantly greater than that observed following ATR suppression in untransformed control cells. In addition, consistent with a deficiency in long-term genome maintenance, hypomorphic ATR pathway reduction to 16% of normal levels was synthetic lethal with oncogenic Ras expression in cultured cells. Notably, elevated genomic instability and synthetic lethality following suppression of ATR were not due to accelerated cycling rates in Ras-transformed cells, indicating that these synergistic effects were generated on a per-cell-cycle basis. In contrast to the synthetic lethal effects of hypomorphic ATR suppression, subtle reduction of ATR expression (haploinsufficiency) in combination with endogenous levels of K-ras(G12D) expression elevated the incidence of lung adenocarcinoma, spindle cell sarcoma, and thymic lymphoma in p53 heterozygous mice. K-ras(G12D)-induced tumorigenesis in ATR(+/-)p53(+/-) mice was associated with intrachromosomal deletions and loss of wild-type p53. These findings indicate that synergistic increases in genomic instability following ATR reduction in oncogenic Ras-transformed cells can produce 2 distinct biological outcomes: synthetic lethality upon significant suppression of ATR expression and tumor promotion in the context of ATR haploinsufficiency. These results highlight the importance of the ATR pathway both as a barrier to malignant progression and as a potential target for cancer treatment.

Removing all obstacles: a critical role for p53 in promoting tissue renewal.

Defects in DNA repair pathways or exposure to high levels of DNA damaging agents limit the renewal potential of adult tissues and accelerate the development of age-related degenerative pathologies. Many studies suggest these tissue homeostatic defects can result from the accumulation of DNA damage in tissue-specific stem cells. Although maintenance of genome integrity in progenitor cells is required for the renewal of adult tissues, recent studies have highlighted the importance of additional mechanisms that facilitate and direct the process of tissue regeneration. These reports indicate that the p53 tumor suppressor gene maintains adult tissue homeostasis and promotes tissue renewal by suppressing the accumulation of DNA-damaged cells. Without p53, tissue deterioration caused by the elimination of genome maintenance regulators (ATR, Hus1 or Terc) is exacerbated and, in some cases, leads to synthetic lethality at the organismal level. Importantly, the accumulation of highly damaged cells in multiple tissues appears to severely impede regeneration from undamaged progenitors, suggesting that p53-mediated removal of damaged cells is a prerequisite for efficient progenitor driven renewal. These findings argue that tissue homeostasis is governed not only by the intrinsic repopulating potential of competent progenitors, but also by mechanisms that limit the accumulation of defective cells and, thereby, promote compensatory regeneration. As discussed in this review, these findings advance our understanding of mechanisms that counter the effects of DNA damage at the tissue level and have important implications for the development of therapeutic approaches to combating age-related pathologies and p53-deficient malignancies.

Tissue regenerative delays and synthetic lethality in adult mice after combined deletion of Atr and Trp53.

Trp53 loss of function has previously been shown to rescue tissue maintenance and developmental defects resulting from DNA damage or DNA-repair gene mutations. Here, we report that p53 deficiency severely exacerbates tissue degeneration caused by mosaic deletion of the essential genome maintenance regulator Atr. Combined loss of Atr and p53 (Trp53(-/-)Atr(mKO)) led to severe defects in hair follicle regeneration, localized inflammation (Mac1(+)Gr1(+) infiltrates), accelerated deterioration of the intestinal epithelium and synthetic lethality in adult mice. Tissue degeneration in Trp53(-/-)Atr(mKO) mice was characterized by the accumulation of cells maintaining high levels of DNA damage. Moreover, the elevated frequency of these damaged cells in both progenitor and downstream compartments in Trp53(-/-)Atr(mKO) skin coincided with delayed compensatory tissue renewal from residual ATR-expressing cells. Together, our results indicate that the combined loss of Atr and Trp53 in adult mice leads to the accumulation of highly damaged cells, which, consequently, impose a barrier to regeneration from undamaged progenitors.

Loss of distal 11q is associated with DNA repair deficiency and reduced sensitivity to ionizing radiation in head and neck squamous cell carcinoma.

About 45% of head and neck squamous cell carcinomas (HNSCC) are characterized by amplification of chromosomal band 11q13. This amplification occurs by a breakage-fusion-bridge (BFB) cycle mechanism. The first step in the BFB cycle involves breakage and loss of distal 11q, from FRA11F (11q14.2) to 11qter. Consequently, numerous genes, including three critical genes involved in the DNA damage response pathway, MRE11A, ATM, and H2AFX are lost in the step preceding 11q13 amplification. We hypothesized that this partial loss of genes on distal 11q may lead to a diminished DNA damage response in HNSCC. Characterization of HNSCC using fluorescence in situ hybridization (FISH) revealed concurrent partial loss of MRE11A, ATM, and H2AFX in all four cell lines with 11q13 amplification and in four of seven cell lines without 11q13 amplification. Quantitative microsatellite analysis and loss of heterozygosity studies confirmed the distal 11q loss. FISH evaluation of a small series of HNSCC, ovarian, and breast cancers confirmed the presence of 11q loss in at least 60% of these tumors. All cell lines with distal 11q loss exhibited a diminished DNA damage response, as measured by a decrease in the size and number of gamma-H2AX foci and increased chromosomal instability following treatment with ionizing radiation. In conclusion, loss of distal 11q results in a defective DNA damage response in HNSCC. Distal 11q loss was also unexpectedly associated with reduced sensitivity to ionizing radiation. Although the literature attributes the poor prognosis in HNSCC to 11q13 gene amplification, our results suggest that distal 11q deletions may be an equally significant factor.