Intraoperative indocyanine green angiography in preventing hypoparathyroidism after thyroid cancer surgery.

BACKGROUND: The aim of this study was to determine whether the use of indocyanine green angiography to identify devascularized parathyroids during thyroidectomy for thyroid cancer would decrease the rates of postoperative hypoparathyroidism. METHODS: Retrospective study of patients who had undergone total thyroidectomy for treatment of thyroid cancer between March 2021 and March 2023. The indocyanine group included patients with all four parathyroids identified and evaluated by indocyanine green angiography at the end of the procedure. Those with parathyroid glands classified with no vascularization had the glands autotransplanted. A group without indocyanine angiography was used to compare results. RESULTS: The analysis included 100 patients in each group. Indocyanine angiography identified 14.75% of devascularized parathyroids at surgery. The number of parathyroids with a score of 2 (i.e., good vascularization) was not a safe predictor of normal parathyroid hormone levels after surgery. Indeed, 29.2% of the patients with three parathyroids with a score of 2 developed transient hypoparathyroidism. Permanent hypoparathyroidism occurred in 7% of the patients without indocyanine group and in none of the patients in the indocyanine group (p = 0.014). CONCLUSION: Intraoperative angiography with indocyanine green could contribute to reduce the occurrence of permanent hypoparathyroidism in patients undergoing surgical treatment for thyroid cancer.

Brazilian Society of Surgical Oncology recommendations on Merkel cell carcinoma surgical treatment.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare neuroendocrine skin cancer with poor 5-year survival rates. Surgery and radiation are the current first-line treatments for local and nodal disease. OBJECTIVES: The Brazilian Society of Surgical Oncology developed this document aiming to guide the surgical oncology role in multimodal MCC management. METHODS: The consensus was established in three rounds of online discussion, achieving consensus on specific topics including diagnosis, staging, treatment, and follow-up. RESULTS: Patients suspected of having MCC should undergo immunohistochemical examination and preferably undergo pathology review by a dermatopathologist. Initial staging should be performed with dermatologic and nodal physical examination, combined with complementary imaging. Whole-body imaging, preferably with positron emission tomography (PET) or computed tomography (CT) scans, are recommended. Due to the need for multidisciplinary approaches, we recommend that all cases should be discussed in tumor boards and referred to other specialties as soon as possible, reducing potential treatment delays. We recommend that all patients with clinical stage I or II may undergo local excision associated with sentinel lymph node biopsy. The decision on margin size should consider time to recovery, patient's comorbidities, and risk factors. Patients with positive sentinel lymph nodes or the presence of risk factors should undergo postoperative radiation therapy at the primary site. Exclusive radiation is a viable option for patients with low performance. Patients with positive sentinel lymph node biopsy should undergo nodal radiation therapy or lymphadenectomy. In patients with nodal clinical disease, in addition to primary tumor treatment, nodal radiation therapy and/or lymphadenectomy are recommended. Patients with advanced disease should preferably be enrolled in clinical trials and discussed in multidisciplinary meetings. The role of surgery and radiation therapy in the metastatic/advanced setting should be discussed individually and always in tumor boards. CONCLUSION: This document aims to standardize a protocol for initial assessment and treatment for Merkel cell carcinoma, optimizing oncologic outcomes in middle-income countries such as Brazil.

Current clinical practice in the management of Brazilian patients with potentially resectable pancreatic ductal adenocarcinoma (PDAC).

BACKGROUND AND OBJECTIVES: We aimed to describe the routine clinical practice of physicians involved in the treatment of patients with localized pancreatic ductal adenocarcinoma (PDAC) in Brazil. METHODS: Physicians were invited through email and text messages to participate in an electronic survey sponsored by the Brazilian Gastrointestinal Tumor Group (GTG) and the Brazilian Society of Surgical Oncology (SBCO). We evaluated the relationship between variable categories numerically with false discovery rate-adjusted Fisher's exact test p values and graphically with Multiple Correspondence Analysis. RESULTS: Overall, 255 physicians answered the survey. Most (52.5%) were medical oncologists, treated patients predominantly in the private setting (71.0%), and had access to multidisciplinary tumor boards (MTDTB; 76.1%). Medical oncologists were more likely to describe neoadjuvant therapy as beneficial in the resectable setting and surgeons in the borderline resectable setting. Most physicians would use information on risk factors for early recurrence, frailty, and type of surgery to decide treatment strategy. Doctors working predominantly in public institutions were less likely to have access to MTDTB and to consider FOLFIRINOX the most adequate regimen in the neoadjuvant setting. CONCLUSIONS: Considerable differences exist in the management of localized PDAC, some of them possibly explained by the medical specialty, but also by the funding source of health care.

Perioperative Cancer Care in the Context of Limited Resources during the COVID-19 Pandemic: Brazilian Society of Surgical Oncology Recommendations.

BACKGROUND: As the COVID-19 pandemic moves from rich to poor nations, the healthcare systems of developing countries have to deal with this extra burden. As cancer care cannot stop and surgery is the main mechanism for cure and palliation, it is important to provide safe and rational access to cancer surgery during the COVID-19 pandemic. METHODS: From April 1st to May 1st, the committee of the Brazilian Society of Surgical Oncology (BSSO) was responsible for reviewing the literature and writing recommendations for perioperative cancer care in the context of limited resources during the pandemic. The recommendations were submitted to the BSSO board of directors. The orientations that were not consensual were removed and the suggestions were added to the text. From May 15 to 30th, the committee revised the recommendations, aligned them with the objectives of the work and standardize the text. DISCUSSION: The rational use of resources to reduce the risk of surgical cancer patients being operated on during the incubation period of a corona virus infection is important in this context. Prevalence of corona virus in the region, the need for surgery, surgical complexity, patient age and comorbidities, and availability of corona virus testing are central aspects in this matter and are discussed. CONCLUSIONS: We present a protocol, focused on the patients' outcomes, for safe and rational use of resources to reduce the risk of surgical cancer patients being operated on during the virus incubation period, in the context of areas with limited resources.

The "quadrant-sandwich" method in clockwise modular D2 lymph node dissection in laparoscopic total gastrectomy: a retrospective cohort study.

Background: For patients who need laparoscopic radical gastrectomy, lymph node dissection (LND) and optimization of surgical procedures are particularly important. This study introduces the "quadrant-sandwich" method in clockwise modular D2 LND and evaluates the advantages and safety of this method. Methods: The clinical data of 108 laparoscopic total gastrectomy patients admitted to the Affiliated Cancer Hospital of Zhengzhou University from January 2019 to January 2022 were retrospectively analyzed. Based on the different LND processes, 55 patients were allocated to the observation group, which underwent clockwise modular LND using the "quadrant-sandwich method", and 53 patients were allocated to the control group, which underwent traditional LND. The effectiveness and safety of the approach in terms of operation time, blood loss, lymph node yield, postoperative recovery and postoperative complications were observed in the two groups. Results: There was no statistical difference between the baseline data of the two groups. In relation to the surgery, the observation group had an operation time of 227.0±48.5 minutes, and intraoperative bleeding of 100.0 mL [inter-quartile range (IQR), 30.0-200.0 mL], while the control group had an operation time of 247±41.5 minutes, and intraoperative bleeding of 180.0 mL (IQR, 130.0-245.0 mL). There were statistically significant differences between the two groups in terms of the operation time and intraoperative bleeding (P=0.001, P=0.020). In relation to the LND, there were no statistically significant differences between the two groups in terms of the total number of lymph nodes in each division, and the number of positive lymph nodes. In relation to the post-operative results, there were no statistically significant differences between the two groups in terms of the post-operative pathological stage, first postoperative oral feeding, post-operative hospitalization time, and post-operative complications. Conclusions: Clockwise modular D2 LND using the "quadrant-sandwich method" is potentially safe and feasible in laparoscopic total gastrectomy. It not only ensures the thoroughness of the LND, but also ensures and efficient and fast surgical process, shortens the operation time, and reduces the amount of intraoperative bleeding.

Influence of the centralizing gastric cancer surgery on the health-related quality of life in Brazil.

Background: The assessment of health-related quality of life (QoL) has improved the treatment of gastric cancer. Aiming to compare the influence of skilled surgeons in general hospitals versus specialized hospitals in cancer in Brazil, this study evaluated the relationship between quality of life and types of hospitals (general or cancer) in treating patients with gastric adenocarcinoma operated by surgeons with specific training in Surgical Oncology. Methods: This was a cross-sectional study involving 104 patients. Inferential analyses were used to compare two Brazilian general hospitals and a cancer center, evaluating scores of the SF-36 and FACT-Ga QoL questionnaires (Kruskal-Wallis test, Mann-Whitney test); gender, smoking, and Helicobacter pylori tests status (Pearson's Chi-Square test); ethnicity, alcoholism, location of the tumor in the stomach, Lauren's histological types, and type of surgery (Fisher's exact test), number of lymph nodes resected by Surgical Oncologists [Analysis of Variance (ANOVA) with a Fixed Factor], and comparative survival analysis (Log-Rank test). Results: Patients treated at a cancer hospital had higher scores of the FACT-Ga (FACT-G total score, P=0.023; physical well-being, PWB, P=0.006; and functional well-being, FWB, P=0.011). The mean scores of the SF-36 questionnaire showed similar behavior but without reaching a significant difference. Patients operated by Surgical Oncologists at the cancer hospital had better scores in emotional well-being FACT-Ga domain (EWB, P=0.034 and P=0.047) compared to those operated by Surgical Oncologists in general hospitals. There was no significant difference in survival among the three hospitals (P=0.214). Conclusions: In this study, it was possible to suggest the relationship between QoL assessment scores with the centralization of care at specialized cancer hospital in the treatment of patients with gastric adenocarcinoma undergoing surgery with curative intent in Brazil.

Guidelines from the Brazilian society of surgical oncology regarding indications and technical aspects of neck dissection in papillary, follicular, and medullary thyroid cancers.

Objective: The purpose of these guidelines is to provide specific recommendations for the surgical treatment of neck metastases in patients with papillary, follicular, and medullary thyroid carcinomas. Materials and methods: Recommendations were developed based on research of scientific articles (preferentially meta-analyses) and guidelines issued by international medical specialty societies. The American College of Physicians' Guideline Grading System was used to determine the levels of evidence and grades of recommendations. The following questions were answered: A) Is elective neck dissection indicated in the treatment of papillary, follicular, and medullary thyroid carcinoma? B) When should central, lateral, and modified radical neck dissection be performed? C) Could molecular tests guide the extent of the neck dissection? Results and conclusion: Recommendation 1: Elective central neck dissection is not indicated in patients with cN0 well-differentiated thyroid carcinoma or in those with noninvasive T1 and T2 tumors but may be considered in T3-T4 tumors or in the presence of metastases in the lateral neck compartments. Recommendation 2: Elective central neck dissection is recommended in medullary thyroid carcinoma. Recommendation 3: Selective neck dissection of levels II-V should be indicated to treat neck metastases in papillary thyroid cancer, an approach that decreases the risk of recurrence and mortality. Recommendation 4: Compartmental neck dissection is indicated in the treatment of lymph node recurrence after elective or therapeutic neck dissection; "berry node picking" is not recommended. Recommendation 5: There are currently no recommendations regarding the use of molecular tests in guiding the extent of neck dissection in thyroid cancer.

A methylation-related signature for predicting prognosis and sensitivity to first-line therapies in gastric cancer.

Background: Methylation modification patterns play a crucial role in human cancer progression, especially in gastrointestinal cancers. We aimed to use methylation regulators to classify patients with gastric adenocarcinoma and build a model to predict prognosis, promoting the application of precision medicine. Methods: We obtained RNA sequencing data and clinical data from The Cancer Genome Atlas (TCGA) database (n=335) and Gene Expression Omnibus (GEO) database (n=865). Unsupervised consensus clustering was used to identify subtypes of gastric adenocarcinoma. We performed functional enrichment analysis, immune infiltration analysis, drug sensitivity analysis, and molecular feature analysis to determine the clinical application for different subtypes. The univariate Cox regression analysis and the LASSO regression analysis were subsequently used to identify prognosis-related methylation regulators and construct a risk model. Results: Through unsupervised consensus clustering, patients were divided into two subtypes (cluster A and cluster B) with different clinical outcomes. Cluster B included patients with a better prognosis outcome and who were more likely to respond to immunotherapy. We then successfully built a predictive model and found five methylation-related genes (CHAF1A, CPNE8, PHLDA3, SPARC, and EHF) potentially significant to the prognosis of patients. The 1-, 3-, and 5-year areas under the curve of the risk model were 0.712, 0.696, and 0.759, respectively. The risk score was an independent prognostic factor and had the highest concordance index among common clinical indicators. Meanwhile, the tumor microenvironment, sensitivity of chemotherapeutic drugs, molecular features, and oncogenic dedifferentiation differed significantly across the risk groups and subtypes. Conclusions: We classified patients with gastric adenocarcinoma based on methylation regulators, which has positive implications for first-line clinical treatment. The prognostic model could predict the prognosis of patients and help to promote the development of precision medicine.

HPV16 AND EXPRESSION OF PROTEIN P16INK4A AND E7 ONCOPROTEIN IN COLORECTAL CARCINOMA. / PRESENÇA DO PAPILOMAVIRUS HUMANO TIPO 16 E EXPRESSÃO GÊNICA DA PROTEÍNA P16INK4A E ONCOPROTEÍNA E7 NO CARCINOMA COLORRETAL.

OBJECTIVE: Human papillomavirus (HPV) is the agent of the most prevalent sexually transmitted diseases in the world associated with cervix and anal canal cancer. The action of HPV on colorectal carcinogenesis is not yet established. This research aimed to study the possible correlation between the presence of HPV16 and the gene expression of p16INK4a protein and HPV E7 oncoprotein and their levels in colorectal carcinoma tissue. METHODS: A retrospective case-control study of 79 patients with colorectal carcinoma was divided into two groups: HPV-positive and HPV-negative. The polymerase chain reaction was performed, in addition to dot-blot hybridization for HPV16 and HPV18. Colorectal tissue samples were also subjected to immunohistochemical study to assess the tissue level of E7 and p16INK4a proteins. RESULTS: HPV was identified in 36 (45.6%) cases. There was no significant difference between groups regarding gender (p=0.056), age (p=0.1), colic and/or rectal location (0.098), and presence of HPV. Gene expression of HPV E7 oncoprotein was present in 3.12% of cases (p=0.9), and p16INK4a protein expression was observed in 46.3% (p=0.27) of those selected with HPV detection. CONCLUSION: Gene expression and tissue levels of E7 oncoprotein and p16INK4a protein found in HPV-positive patients suggest the absence of HPV16 oncogenic activity in colorectal carcinoma.

OBJETIVO: O papilomavírus humano (HPV) é agente das doenças sexualmente transmissíveis de maior prevalência no mundo que estão associadas ao câncer do colo do útero e canal anal. A ação do HPV na carcinogênese colorretal não está ainda estabelecida. Estudar a eventual correlação entre a presença do HPV tipo 16 e a expressão gênica da proteína p16INK4a e da oncoproteína E7 de HPV e de seus níveis no tecido do carcinoma colorretal. METODOS: Estudo retrospectivo caso-controle de 79 doentes com carcinoma colorretal divididos em dois grupos: HPV presente e HPV ausente. Foi realizada reação em cadeia da polimerase (PCR), além da hibridização do tipo dot blot para o HPV 16 e o HPV 18 Amostras do tecido colorretal também foram submetidas ao estudo imuno-histoquimico para avaliar o nível tecidual das proteínas E7 e p16INK4a. RESULTADOS: O HPV foi identificado em 36 (45,6%) casos. Não houve diferença significante entre os grupos quanto ao sexo (p=0,056), idade (p=0,1), localização cólica e/ou retal (0,098) e presença do HPV. A expressão gênica da oncoproteína E7 de HPV estava presente em 3,12% dos casos (p=0,9) e a expressão da proteína p16INK4a foi observada em 46,3% (p=0,27) dos indivíduos com detecção do HPV. CONCLUSÃO: A expressão gênica e os níveis teciduais da oncoproteína E7 e da proteína p16INK4a encontrados nos pacientes positivos para o HPV sugerem a ausência de atividade oncogênica do HPV tipo 16 no carcinoma colorretal.

Radioisotope-guided laparoscopy: a case report and description of an alternative surgical technique.

Prostate cancer is the second most frequent cancer type among men worldwide. With the development of Radiology and Nuclear Medicine technologies, early diagnosis is increasingly common, and the possibility of using new minimally invasive techniques increases. With a narrative review of the literature, this case report describes an alternative radioisotope-guided laparoscopy technique for tumors in the peritoneal cavity. There may be benefits in associating nuclear medicine techniques in the management of patients with non-palpable tumors that are difficult to locate in the peritoneal cavity, enabling the use of less invasive and safer surgical procedures for diagnosis, staging and treatment.

Health-related quality of life after gastric cancer treatment in Brazil: Narrative review and reflections.

In Brazil, gastric cancer is the third most common type of cancer among men and fifth among women, with an estimated 13360 new cases among men and 7870 among women each year during the 2020-2022 period. This study presents reflections and attempts to add knowledge to the theme of quality of life (QoL) in patients with gastric adenocarcinoma and describes some of its characteristics in three regions of Brazil, with an evaluation of the disease's impacts in various dimensions of life, as reported by the patients themselves. We performed a narrative review of the literature and a data analysis of studies on QoL in Brazilian patients treated for gastric adenocarcinoma from three different cities in three geographic regions: Brasília (the midwest), Jaú (the southeast), and Macapá (the north).

Tailgut cyst: from differential diagnosis to surgical resection-case report and literature review.

Tailgut cyst is a rare tumor originating from the embryonic remnant located in the retrorectal space. The diagnosis is usually incidental duse to the absence of symptoms. When present, they are nonspecific, such as abdominal pain, dysuria and tenesmus. Imaging tests are a great help in the diagnosis and surgical planning. The standard treatment is resection, which the surgeon must perform to avoid future complications, such as malignancy. We present a case of tailgut cyst in a young patient with prior pilonidal cyst excision, subsequently submitted to surgical resection, to share our experience with a rare case, with few reports in the literature.

Incidental finding of adenocarcinoma in a gallbladder lumen with no wall involvement.

Gallbladder cancer (GBC) is a rare disease characterized by its aggressiveness. Resection with free tumour margins is the sole curative treatment and, in incidental findings, surgical reapproach is recommended for segmentectomy IVb and V or wedge resection of the gallbladder fossa and lymphadenectomy. Here we report a case of gallbladder adenocarcinoma as an incidental finding in a fragment in its lumen with no wall involvement evidentiated. The patient was reoperated for resection of the gallbladder bed with hepatic hilum and cystic duct lymphadenectomy, later evidentiated as free of residual disease. The normality of the bile ducts evidenced by imaging studies, in addition to signs of chronic cholecystitis corroborate to GBC diagnosis. We suspect that the fragment was detached gallbladder polypoid neoplastic lesion. Despite the lack of clinical manifestations, the fast surgical interventions and the histopathological analysis of the material was probably a prognostic determinant for the patient.

Surgical cancer care in the COVID-19 era: front line views and consensus.

OBJECTIVE: to suggest a script for surgical oncology assistance in COVID-19 pandemic in Brazil. METHOD: a narrative review and a "brainstorming" consensus were carried out after discussion with more than 350 Brazilian specialists and renowned surgeons from Portugal, France, Italy and United States of America. RESULTS: consensus on testing for COVID-19: 1- All patients to be operated should be tested between 24 and 48 before the procedure; 2- The team that has contact with sick or symptomatic patients should be tested; 3 - Chest tomography was suggested to investigate pulmonary changes. Consensus on protection of care teams: 1 - Use of surgical masks inside the hospitals. Use of N95 masks for all professionals in the operating room; 2 - Selection of cases for minimally invasive surgery and maximum pneumoperitoneal aspiration before removal of the surgical specimen; 2 - Optimization of the number of people in teams, with a minimum number of professionals, reducing their occupational exposure, the consumption of protective equipment and the circulation of people in the hospital environment; 3 - Isolation of contaminated patients. Priority consensus: 1- Construction of service priorities; 2 - Interdisciplinary discussion on minimally invasive or conventional pathways. CONCLUSION: the Brazilian Society of Surgical Oncology (BSSO) suggests a script for coping with oncological treatment, remembering that the impoundment in the assistance of these cases, can configure a new wave of overload in health systems.

Quality of life as a fundamental outcome after curative intent gastrectomy for adenocarcinoma: lessons learned from patients.

BACKGROUND: Gastric cancer has an important epidemiologic impact, and the main curative therapeutic modality for gastric cancer is surgical resection. However, even curative intent therapy can have negative effects on the quality of life (QoL) of these patients, which is undesirable; thus, it is difficult to balance the standardized treatment reported in the literature and treatment response to achieve full patient satisfaction. The purpose of our study was to evaluate the QoL and identify the association of scores on the Functional Assessment of Cancer Therapy-Gastric (FACT-Ga) and Short Form 36 Health Survey version 2 (SF36v2) questionnaires with sociodemographic, clinical and anatomopathological aspects of gastric adenocarcinoma patients undergoing curative surgery. METHODS: This was a cross-sectional study involving 104 patients from three regions of Brazil. Inferential analyses were used to compare (multiple regression and Mann-Whitney or Kruskal-Wallis tests) the relationships between these scores and variables (Spearman's coefficient). RESULTS: In the multiple regression analysis, we found correlations between Helicobacter pylori status and physical well-being (PWB) (P=0.026), between gender and emotional well-being (EWB) (P=0.008), between Lauren's histology and physical functioning (P=0.009), as well as the Short Form 36 Health Survey version 2 (SF-36v2) role-physical (P=0.027), between the tumor site and EWB (P=0.038), between the SF-36v2 mental health and N (the lower the staging, the better the score, P=0.006) and between the SF-36v2 mental health and lymph nodes removed (P=0.029). According to the Mann-Whitney or Kruskal-Wallis test, women had worse FACT-Ga total (P=0.049), PWB (P=0.005), EWB (P=0.007), gastric cancer subscale (GaCS, P=0.011), trial outcome index (TOI, P=0.030) and mental health scores than men (P=0.011). Patients with distal tumors had better scores (FACT-Ga, P=0.018; GaCS, P=0.014; TOI, P=0.020) than patients with proximal tumors. Patients with tumors located in the cardia had better physical functioning than those with proximal tumors (P=0.042). Patients who underwent partial gastrectomy had better FACT-Ga total scores (P=0.011), PWB (P=0.033), GaCS scores (P=0.006) and TOI scores (P=0.008) than those who underwent total gastrectomy. Patients who did not receive adjuvant therapy had worse bodily pain as reported on the SF-36v2 than those who received therapy (P=0.048). According to Spearman's coefficient, a higher lymph node stage corresponded to worse FACT-Ga total (s=-0.200, P=0.034), GaCS (s=-0.206, P=0.037), TOI (s=-0.216; P=0.028) and vitality (s=-0.215, P=0.029) scores. A longer time after treatment corresponded to a better SF-36v2 role-physical domain score (s=0.223; P=0.023). CONCLUSIONS: The type of treatment instituted, postoperative time and sociodemographic and anatomopathological factors influence the QoL.

Guidelines from the Brazilian society of surgical oncology regarding indications and technical aspects of neck dissection in papillary, follicular, and medullary thyroid cancers

ABSTRACT Objective: The purpose of these guidelines is to provide specific recommendations for the surgical treatment of neck metastases in patients with papillary, follicular, and medullary thyroid carcinomas. Materials and methods: Recommendations were developed based on research of scientific articles (preferentially meta-analyses) and guidelines issued by international medical specialty societies. The American College of Physicians' Guideline Grading System was used to determine the levels of evidence and grades of recommendations. The following questions were answered: A) Is elective neck dissection indicated in the treatment of papillary, follicular, and medullary thyroid carcinoma? B) When should central, lateral, and modified radical neck dissection be performed? C) Could molecular tests guide the extent of the neck dissection? Results/conclusion: Recommendation 1: Elective central neck dissection is not indicated in patients with cN0 well-differentiated thyroid carcinoma or in those with noninvasive T1 and T2 tumors but may be considered in T3-T4 tumors or in the presence of metastases in the lateral neck compartments. Recommendation 2: Elective central neck dissection is recommended in medullary thyroid carcinoma. Recommendation 3: Selective neck dissection of levels II-V should be indicated to treat neck metastases in papillary thyroid cancer, an approach that decreases the risk of recurrence and mortality. Recommendation 4: Compartmental neck dissection is indicated in the treatment of lymph node recurrence after elective or therapeutic neck dissection; "berry node picking" is not recommended. Recommendation 5: There are currently no recommendations regarding the use of molecular tests in guiding the extent of neck dissection in thyroid cancer.

Presença do papilomavirus humano tipo 16 e expressão gênica da proteína p16ink4a e oncoproteína e7 no carcinoma colorretal / Hpv16 and expression of protein p16ink4a and e7 oncoprotein in colorectal carcinoma

RESUMO - INTRODUÇÃO: O papilomavírus humano (HPV) é agente das doenças sexualmente transmissíveis de maior prevalência no mundo que estão associadas ao câncer do colo do útero e canal anal. A ação do HPV na carcinogênese colorretal não está ainda estabelecida. OBJETIVO: Estudar a eventual correlação entre a presença do HPV tipo 16 e a expressão gênica da proteína p16INK4a e da oncoproteína E7 de HPV e de seus níveis no tecido do carcinoma colorretal. METODOS: Estudo retrospectivo caso-controle de 79 doentes com carcinoma colorretal divididos em dois grupos: HPV presente e HPV ausente. Foi realizada reação em cadeia da polimerase (PCR), além da hibridização do tipo dot blot para o HPV 16 e o HPV 18 Amostras do tecido colorretal também foram submetidas ao estudo imuno-histoquimico para avaliar o nível tecidual das proteínas E7 e p16INK4a. RESULTADOS: O HPV foi identificado em 36 (45,6%) casos. Não houve diferença significante entre os grupos quanto ao sexo (p=0,056), idade (p=0,1), localização cólica e/ou retal (0,098) e presença do HPV. A expressão gênica da oncoproteína E7 de HPV estava presente em 3,12% dos casos (p=0,9) e a expressão da proteína p16INK4a foi observada em 46,3% (p=0,27) dos indivíduos com detecção do HPV. CONCLUSÃO: A expressão gênica e os níveis teciduais da oncoproteína E7 e da proteína p16INK4a encontrados nos pacientes positivos para o HPV sugerem a ausência de atividade oncogênica do HPV tipo 16 no carcinoma colorretal.

ABSTRACT - BACKGROUND: Human papillomavirus (HPV) is the agent of the most prevalent sexually transmitted diseases in the world associated with cervix and anal canal cancer. The action of HPV on colorectal carcinogenesis is not yet established. OBJECTIVE: This research aimed to study the possible correlation between the presence of HPV16 and the gene expression of p16INK4a protein and HPV E7 oncoprotein and their levels in colorectal carcinoma tissue. METHODS: A retrospective case-control study of 79 patients with colorectal carcinoma was divided into two groups: HPV-positive and HPV-negative. The polymerase chain reaction was performed, in addition to dot-blot hybridization for HPV16 and HPV18. Colorectal tissue samples were also subjected to immunohistochemical study to assess the tissue level of E7 and p16INK4a proteins. RESULTS: HPV was identified in 36 (45.6%) cases. There was no significant difference between groups regarding gender (p=0.056), age (p=0.1), colic and/or rectal location (0.098), and presence of HPV. Gene expression of HPV E7 oncoprotein was present in 3.12% of cases (p=0.9), and p16INK4a protein expression was observed in 46.3% (p=0.27) of those selected with HPV detection. CONCLUSION: Gene expression and tissue levels of E7 oncoprotein and p16INK4a protein found in HPV-positive patients suggest the absence of HPV16 oncogenic activity in colorectal carcinoma.