Biomedical subjects

Carlos Suárez

Publications and source records attributed to Carlos Suárez.

At least 19 recordsLinked to original sources

PubMed2006

Preliminary multi-institutional prospective pathologic and molecular studies support preservation of sublevel IIB and level IV for laryngeal squamous carcinoma with clinically negative neck.

Level II-IV selective neck dissection, often performed bilaterally, has become the procedure of choice for elective dissection of the clinically negative (N0) neck in the treatment of laryngeal cancer. The most significant morbidity of this procedure is dysfunction of the accessory nerve, incurred by the necessity of mobilization and retraction of the nerve in order to remove the contents of sublevel IIB. Other morbidity includes possible injury to the phrenic nerve and chylous fistula. These complications are associated with the dissection of level IV. A number of prospective multi-institutional studies of the distribution of cervical lymph node metastases in the neck indicate that lymph nodes in sublevel IIB and level IV are rarely involved in cases of laryngeal cancer with N0 neck. Information was obtained by the study of neck dissection specimens by conventional light microscopy, and by molecular analysis of the specimens. Molecular analysis reveals a significant number of metastases that are not discovered by light microscopy, and is thus essential for this type of evaluation. The authors conclude that these preliminary studies indicate that it is safe and appropriate to eliminate dissection of sublevel IIB and level IV from the elective neck dissection performed for laryngeal cancer with N0 neck. This practice will reduce both operating time and morbidity, particularly accessory nerve dysfunction, without compromising the oncologic result. Further prospective studies are needed to confirm these conclusions.

Carcinoma, Squamous Cell↗

PubMed2006

Evolution of the management of laryngeal cancer.

The treatment of laryngeal cancer has evolved through several phases, starting with wide extirpative surgical resection, and evolving through an era of conservation surgery and, finally, planned treatment using modalities of irradiation, chemotherapy and surgery in various combinations. Attempts to extirpate laryngeal cancer date to the nineteenth century, but only by the mid-twentieth century did advances in anesthesia, blood transfusion and antibiotics, make this surgery safe and reliable. Techniques of partial laryngectomy by external approach developed in the second half of the twentieth century, and endoscopic use of the laser refined the concept and provided a new paradigm for surgical treatment, particularly for early lesions. During most of this era, radiation was employed as an alternative method of treatment, with surgery reserved for salvage of radiation failure. By the last decade of the twentieth century, and to the present time, the value of combined modality therapy, using planned combinations of irradiation, chemotherapy and surgery became the standard of care for advanced laryngeal cancer, permitting maximal laryngeal preservation with the highest attainable cure rates.

Antineoplastic Agents↗

PubMed2006

Is there an epidemiological link between human papillomavirus DNA and basaloid squamous cell carcinoma of the pharynx?

The epidemiological link between human papillomavirus (HPV) DNA and basaloid squamous cell carcinoma (BSCC) of the pharynx was studied. The expression of p53 protein was evaluated by immunohistochemical analysis. The presence of HPV DNA was evaluated by polymerase chain reaction amplification and "in situ" hybridization. The tobacco and alcohol consumption and the clinical outcomes of nine patients with BSCC of the pharynx are compared with site and stage matched 109 conventional squamous cell carcinoma (SCC) patients. The BSCC specimens were analyzed for the presence of HPV DNA and p53 expression. We did not find any significant differences in tobacco and alcohol consumption between patients with BSCC and patients with SCC. No HPV DNA was detected in BSCC, and p53 overexpression was found in five (55%) of the cases. Our results do not support an etiological link between HPV DNA and BSCC.

Aged↗

PubMed2006

Options for salvage after failed initial treatment of anterior vocal commissure squamous carcinoma.

Persistence or recurrent cancer in the anterior commissure (AC) after primary radiotherapy may remain localized to its pretreatment anatomical site. If so, endoscopic CO(2) laser excision, in experienced hands, may achieve complete tumor excision and result in cure for many patients. Occasionally, second and third recurrences may be similarly salvaged by further endoscopic surgery. The use of the vertical hemilaryngectomy is an alternative treatment for similar localized lesions, with a higher first time surgical tumor eradication rate, but with a more protracted hospitalization and a less satisfactory voice and swallowing outcome. In both types of such surgical salvage, CT scanning must demonstrate no evidence of cartilage invasion or destruction. When there is evidence of minimal thyroid cartilage invasion, then the supracricoid partial laryngectomy is an alternative conservation option, and is likely to result in a cure, with the retention of a voicing larynx without a stoma. When the tumor has increased in size from the original pretreatment dimension and/or site, then imaging must be used to identify possible cartilage invasion, in which case the likelihood of tumor eradication by endoscopic or external vertical partial laryngectomy is highly unlikely. The indications for the routine use of total laryngectomy for the treatment of recurrent or persistent cancer involving the AC must be reviewed; there is current evidence that cure can be achieved by a less radical procedure. However, total laryngectomy may remain the only treatment option for advanced or aggressive first time recurrence, or in patients who develop subsequent recurrence following previous less aggressive surgery (endoscopic or external).

Carcinoma, Squamous Cell↗

PubMed2006

Primary treatment of the anterior vocal commissure squamous carcinoma.

Squamous cell carcinoma may involve the anterior commissure (AC) area of the laryngeal glottis, and can be grouped morphologically into four groups; (1) tumor confined to the AC, (2) tumor involving one cord and the AC, (3) tumor involving the AC and a portion of both vocal cords, and (4) tumor involving a greater part of one cord and crossing over to involve a variable length of the other cord. Some of these patients when evaluated by imaging, either CT and/or MRI, may demonstrate thyroid cartilage erosion or involvement, thereby upstaging a T1a, T1b into a T3 or a T4 glottic cancer. The majority of patients treated by radiotherapy have only been staged clinically, and hence a failure or recurrence rate of 15%. In patients treated surgically by endoscopic or external surgery, the local recurrence rates are similar at 15%. Therefore, future reporting of patients treated with AC involvement should be staged radiologically, to include CT or MRI, and documentation of the treatment results be reported in subgroups, according to whether there is no cartilage involvement, inner-table cartilage erosion, or through-and-through cartilage invasion. Should endoscopic cordectomy be used, then the type of surgery performed should be based on the classification as suggested by the European Laryngological Society. The use of the above recommendations would allow for more meaningful results to be reported and for cause specific analysis of failure of treatment techniques applied.

Carcinoma, Squamous Cell↗

PubMed2006

Neck dissection: then and now.

The significance of metastatic disease in the lymph nodes of the neck as a critical independent prognostic factor in head and neck cancer has long been appreciated. Although 19th century surgeons attempted to remove involved cervical lymph nodes at the time of resection of the primary cancer, a systematic approach to en bloc removal of cervical lymph node disease, described in detail by Jawdyński in 1888 and popularized and illustrated by Crile in the early 20th century, provided consistent and more effective treatment, and forms the basis of our current techniques. During the first half of the 20th century, developments included preservation of the accessory nerve in selected cases, elective neck dissection performed in association with resection of various primary tumors, bilateral neck dissection and limited neck dissection. The greatest impetus to the status of radical neck dissection came from Martin, whose technique consisted of resection of all lymph nodes from level I-V together with the accessory nerve, internal jugular vein, sternocleidomastoid muscle and various other structures in a single block of resected tissue. Martin's technical precepts were followed until the latter part of the 20th century when modifications in technique began to find general acceptance. The first description of an effective technique of modified radical neck dissection was published in Spanish by Suárez, in 1963. This technique, which preserves important structures, such as the internal jugular vein, sternocleidomastoid muscle and accessory nerve, was refined and popularized by various authors who published their results in the English language literature during the period from 1964 through 1990 and beyond. Modified or "functional" neck dissection avoids much of the morbidity of radical neck dissection while achieving equivalent degrees of control of regional disease in properly selected cases. By the late 20th century, the concept of selective neck dissection, consisting of resection of only the nodal groups at greatest risk for metastasis from a given primary site, was studied and developed. These limited dissections are now widely employed for elective, and in properly selected cases, therapeutic treatment and staging of the neck, and have been proposed for limited cervical recurrences after various chemoradiation protocols. Prospective studies have demonstrated similar rates of neck recurrence and survival after elective selective neck dissection compared to elective modified radical neck dissection. Other modifications and factors applied to treatment of cervical lymph node disease include the use of adjuvant and neo-adjuvant radiation and chemotherapy, a revised system for classification of neck dissections, the identification of various adverse prognostic factors such as extracapsular spread and extranodal soft tissue deposits, application of sentinel lymph node biopsy to staging of the neck, the use of immunohistochemical and molecular techniques for identification of lymph node metastases not detectable by light microscopy, and the possibility of endoscopic neck dissection. The authors conclude that neck dissection, as evolved over the past century, is a fundamental tool in management of patients with head and neck cancer, but is still a work in progress.

Head and Neck Neoplasms↗

PubMed2006

Tumours of familial origin in the head and neck.

Individuals with inherited cancer syndromes are at significant risk of developing both benign and malignant tumours as a result of a germline mutation in a specific tumour suppressor gene. Tumours of familial origin are a rare event in the head and neck but despite this, they deserve a growing interest. Familial paragangliomas are most of the time limited to the paraganglionar system, but also may be part of different syndromic associations. Since early detection of paragangliomas reduces the incidence of morbidity and mortality, genotypic analysis in the search of SDHB, SDHC and SDHD mutations in families of affected patients plays a front-line diagnostic role, leading to more efficient patient management. Multiple endocrine neoplasias type 1 are characterized by the simultaneous occurrence of at least two of the three main related endocrine tumours: parathyroid, enteropancreatic and anterior pituitary. These tumours arise from inactivating germline mutations in the MEN-1 gene. No clear correlation of MEN-1 genotype with genotype has emerged to date, and MEN-1 mutation testing in tumours is not used clinically because it have not implications for tumour staging. Multiple endocrine neoplasia type 2 is due to a germline mutation in the RET proto-oncogene. Hallmarks of MEN-2A (the commonest phenotypic variant) include medullary thyroid carcinoma, pheochromocytoma, and hyperparathyroidism. The most central clinical difference with MEN-1 is that the associated cancer can be prevented or cured by early thyroidectomy in mutation carriers. Individuals with neurofibomatosis type 1 present early in life with pigmentary abnormalities, skinfold freckling and iris hamartomas, as result of NF1 gene mutation. Neurofibromatosis 2 is caused by inactivating mutations of the NF2 gene, and is characterized by the development of nervous system tumours (mainly bilateral vestibular schwannomas), ocular abnormalities, and skin tumours. The molecular genetic basis of nasopharyngeal carcinomas remains unknown, but there is evidence for the linkage of these tumours to chromosome 3p. Finally, the high rate of p16 mutations in squamous cell carcinomas and the association of p16 with familial melanoma propose p16 as an ideal candidate gene predisposing to familial squamous cell carcinomas. The elucidation of the cellular processes affected by dysfunction in familial tumours of the head and neck may serve to identify potential targets for future therapeutic interventions.

Carcinoma, Squamous Cell↗

PubMed2006

Planned neck dissection following chemoradiotherapy for advanced head and neck cancer: is it necessary for all?

In the absence of large-scale randomized trials evaluating dissection versus observation of the involved neck after neoadjuvant chemoradiotherapy, there is a need to collect data that will either support or ultimately refute a role for planned posttreatment neck dissection. A significant percentage of patients with extensive (N2 or N3) neck disease who demonstrate a complete response to chemoradiation therapy may harbor residual occult metastases, and identification of this subset of patients remains a clinical challenge. Because surgical salvage rates are greatly diminished when occult nodal disease becomes clinically manifest, planned posttreatment neck dissection is advocated but may not be necessary in all patients. The role of positron emission tomography chemoradiotherapy (PET-CT) in this scenario remains unproven but holds promise in being able to identify which patients may be harboring residual disease in the neck after chemoradiotherapy. The implementation of as yet unidentified molecular tumor markers in combination with PET-CT may ultimately prove to be effective in identifying patients who will best benefit from posttherapy neck dissection. Correlation of imaging results and pathologic node status will be important in determining the accuracy and, therefore, the value of this imaging modality for predicting the presence or absence of residual disease.

Carcinoma, Squamous Cell↗

PubMed2006

Efficacy of routine bilateral neck dissection in the management of the N0 neck in T1-T2 unilateral supraglottic cancer.

BACKGROUND: The treatment of the clinically negative (N0) neck in supraglottic laryngeal cancer continues to be an area of controversy. The aim of this study was to analyze the long-term efficacy of routine bilateral neck dissection compared with ipsilateral neck dissection in T1-T2 N0 lateral supraglottic carcinomas. METHODS: A retrospective review of 108 patients who underwent surgery for T1-T2 supraglottic squamous cell carcinoma was performed. Forty-eight had undergone ipsilateral functional neck dissection, and 60 had undergone bilateral functional neck dissections. None of these patients received adjuvant radiotherapy. RESULTS: No significant differences (p = .78) in regional recurrence were observed between the patients treated with bilateral neck dissection (13%) and those treated with ipsilateral neck dissection (17%). The 5-year survival rates were 73% and 80% for the patients who received a bilateral and ipsilateral neck dissection, respectively (p = .51). CONCLUSIONS: This study suggests that routine bilateral neck dissection may not be necessary in the surgical treatment of all supraglottic cancers.

Adult↗

PubMed2006

Amplification of CCND1, EMS1, PIK3CA, and ERBB oncogenes in ethmoid sinus adenocarcinomas.

OBJECTIVE: Assess the amplification of CCND1, EMS1, PIK3CA, ERBB1, and ERBB2 oncogenes in ethmoid sinus adenocarcinomas. STUDY DESIGN AND SETTING: Tissue samples from 13 primary ethmoid adenocarcinomas and 2 recurrences were studied at Hospital Central de Asturias, Oviedo, Spain, between July 1998 and February 2002. A semiquantitative evaluation of CCND1, EMS1, PIK3CA, ERBB1, and ERBB2 amplification was performed by multiplex polymerase chain reaction. RESULTS: Three (23%) cases presented CCND1 amplification, one of them with a concurrent PIK3CA amplification. EMS1 was amplified in the 2 studied recurrences. ERBB1 was amplified in 1 case (8%), whereas none presented ERBB2 amplification. Oncogenic amplifications were only detected in advanced (stage III) tumors; however, no prognostic value could be shown for them. CONCLUSIONS: CCND1, EMS1, PIK3CA, and ERBB1 amplifications are uncommon and appear to be late events in the development of ethmoid sinus adenocarcinoma. SIGNIFICANCE: New information on the carcinogenesis of this infrequent sinonasal tumor is presented.

Adenocarcinoma↗

PubMed2006

Subtemporal-preauricular approach in the management of infratemporal and nasopharyngeal tumours.

OBJECTIVES: To evaluate the indication, advantages, and results of the subtemporal-preauricular approach in the resection of tumours arising in the infratemporal fossa and related structures of the lateral cranial base. DESIGN: Retrospective analysis of patients treated by the subtemporal-preauricular approach to resect nasopharyngeal and infratemporal tumours. SETTING: Tertiary hospital. METHODS: Forty patients with lateral skull base lesions were managed with the subtemporal-preauricular approach. There were 19 benign lesions and 21 malignant tumours, the most common being nasopharyngeal carcinomas, juvenile angiofibromas, and adenoid-cystic carcinomas. Most of the tumours were at an advanced stage, with skull base involvement in 13 benign tumours and in 14 malignant ones. RESULTS: Major complications occurred in 6 (14%) patients, and there were 2 (5%) postoperative deaths. All 19 patients with benign tumours are alive, although 5 of them (26%) presented with residual or recurrent disease. The 5-year estimated survival rate of the 21 patients with malignant neoplasms was 39%. CONCLUSIONS: The subtemporal-preauricular approach is a safe and versatile approach to the infratemporal fossa and neighbouring areas of the lateral cranial base, offering satisfactory oncologic results in the absence of intracranial involvement.

Adolescent↗

PubMed2005

Referral guidelines for suspected cancer of the head and neck.

OBJECTIVE: To identify the impact of referral guidelines for head and neck cancer on the economics and effectiveness of the delivery of care. METHODS: A retrospective review of the literature was performed to examine the current referral guidelines and referral models that have impacted the delivery of care. RESULTS: Advances in technology and changes in the diagnostic work up of head and neck cancer require that common symptoms and presentations of head and neck cancer are made available to primary care physicians to improve the expeditious referral of head and neck cancer patients. CONCLUSION: Physician awareness and symptom guidelines may prove effective in expediting the care of patients with head and neck cancer.

Head and Neck Neoplasms↗

PubMed2005

Management of the N0 neck--reference or preference.

For patients with squamous cell carcinoma of the upper aerodigestive tract, appropriate management of the regional lymph nodes is an important and often controversial issue that has significant influence on survival. Over the years radical treatment either by surgery or radiotherapy contributed to improvement in prognosis. Recently, a more conservative approach has achieved a similar level of cancer control with less morbidity. This review considers the issues of selection of patients for treatment of the neck, choice of modality and extent of therapy, treatment of the contralateral neck, management of recurrence and influence of the site and status of the primary lesion.

Carcinoma, Squamous Cell↗

PubMed2005

Elective and therapeutic selective neck dissection.

Selective neck dissection is a modification of the more comprehensive modified radical or radical neck dissection that is designed to remove only those nodal levels considered to be at risk for harboring nodal metastases. The role of selective neck dissection continues to evolve: while initially designed as a staging and diagnostic procedure for patients without clinical evidence of nodal disease, a growing body of literature suggests that selective neck dissection has a therapeutic role in patients with clinical and histologic evidence of nodal metastases. The rationale behind selective neck dissection, its application in the clinically negative but histologically node-positive neck and the extended application of selective neck dissection in patients with clinical evidence of nodal disease are discussed.

Carcinoma, Squamous Cell↗

PubMed2005

Grisel's syndrome in head and neck practice.

Grisel's syndrome is a rare condition of uncertain etiology characterized by a non-traumatic atlanto-axial subluxation, secondary to an infection in the head and neck region. The authors discuss the history, pathogenesis, terminology, classification, clinical characteristics, diagnosis, treatment, prognosis and prevention of this syndrome.

Anti-Bacterial Agents↗

PubMed2005

Management of mandibular invasion: when is a marginal mandibulectomy appropriate?

There has been a great deal of controversy regarding the appropriate method of management of oral cavity and oropharyngeal tumors that invade the mandible. The inability to acquire intraoperative bone margins can make the decision process complex. Preoperative imaging offers several advantages, however, there is no single modality that has proven accurate. Intraoperative assessment has been suggested as a method of evaluation, however, this approach does not allow for preoperative planning. The following is a review of the current literature regarding mandibular invasion and the indications for a marginal mandibulectomy.

Carcinoma, Squamous Cell↗

PubMed2005

New molecular diagnostic methods in head and neck cancer.

Initial cancer evaluation includes assessment of histologic appearance, tumor grading, assessment of lymph node status, and presence of metastasis. However, traditional diagnostic methods such as histopathology and radiology are not sensitive enough to detect small numbers of cancer cells and are limited in their ability to predict response to treatment. Recently, there has been considerable progress in molecular diagnostics in these areas. Using molecular-based technologies, it is now possible to detect cancer early in asymptomatic individuals, identify minimal residual disease at histopathologic normal surgical margins, more precisely assess tumor burden in cancer patients, and more accurately assess the prognosis of the patients. Examples of these applications in the evaluation of head and neck cancer are reviewed here. However, despite the great promise of these new molecular approaches for cancer detection, much of the current technology limits their implementation into routine clinical use.

Biomarkers, Tumor↗

PubMed2005

A comparative study of MHC Class-II HLA-DRbeta10401-Col II and HLA-DRbeta10101-HA complexes: a theoretical point of view.

A study was performed on the HLA-DRbeta1*0401-collagen II peptide complex using the computation of electronic multipolar variables proposed by us previously. Furthermore, these results were compared with those obtained for the HLA-DRbeta1*0101-haemaglutinin peptide complex studied by us with the same tools, confirming that Pocket 1 for this new complex is also the most important pocket for the interaction between the presenting molecule and the presented peptide. The pocket hierarchy established for HLA-DRbeta1*0401 allele was P1 >> P9 approximately P7 > P6 > P4, whilst a P1 >> P4 > P9 approximately P7>P6 pocket hierarchy was found for HLA-DRbeta1*0101, showing how the relative importance of the pockets distinguishes the two alleles. There are high correlation levels with experimental results (when possible), again confirming the validity of using calculated values for electronic multipolar variables as a useful tool for studying interactions between immune system molecules and peptides.

Antigen Presentation↗