|Year : 2022 | Volume
| Issue : 3 | Page : 281-289
Influence of prognostic factors on survival in lymphoma of oral cavity and maxillofacial region in a Peruvian population: A historical cohort study
Janet-Ofelia Guevara-Canales1, Rafael Morales-Vadillo1, Jaime-Enrique Montes-Gil2, Carlos-Edmundo Barrionuevo-Cornejo2, Carlos-Enrique Cava-Vergiú1, Sonia-Julia Sacsaquispe-Contreras3
1 Faculty of Dentistry, Universidad de San Martín de Porres, FO-USMP, Lima, Peru
2 National Institute for Neoplastic Diseases, INEN, Lima, Peru
3 Faculty of Dentistry, Universidad Peruana Cayetano Heredia, Lima, Peru
|Date of Submission||03-Dec-2021|
|Date of Decision||01-Feb-2022|
|Date of Acceptance||24-Mar-2022|
|Date of Web Publication||28-Jun-2022|
Dr. Janet-Ofelia Guevara-Canales
Calle Manuel Scorza 102, Departamento 201, San Borja, Lima 41, Lima
Source of Support: None, Conflict of Interest: None
Aim: To determine the influence of prognostic factors on the survival of patients who had been diagnosed with lymphoma of the oral cavity and maxillofacial region (OC/MR) and received care at the National Institute for Neoplastic Diseases (INEN). Materials and Methods: This was a retrospective cohort study. This type of study is classified as observational, analytic, longitudinal, and retrospective. The sample consisted of cases diagnosed with primary lymphoma of the OC/MR (151 altogether), over the 13 years included in the study (1997–2010). The sample only included patients for whom histopathological diagnosis was confirmed by re-evaluation of the histological section. Clinical histories were reviewed to retrieve the following variables as potential prognostic factors: age, sex, location of the lesion, size, signs/symptoms, diagnosis, clinical stage, international prognostic index, serum lactate dehydrogenase levels, extranodal involvement, and treatment. The study was approved by the hospital Institutional Review Board. The following statistical analyses were applied: (1) analysis by actuarial technique and Kaplan–Meier product-limit method for survival and (2) univariate analysis with the log-rank test and multivariate analysis using Cox regression model for prognostic factors and hazard function. Results: Out of the 151 patients diagnosed, 50 were included in the study. Survival at 2 and 5 years was 69% and 47%, respectively. Multivariate analysis showed that survival is influenced by presence of pain, clinical stage, extranodal involvement, and treatment type. A single significant variable was established as the best hazard function: clinical stage III/IV, with patients at these stages being 6.86 times more likely to die than patients at clinical stage I/II. Conclusion: Based on the methodology and statistical analyses used, it was mainly found that survival at 5 years was lower than specified in international reports and that prognostic factors influencing survival jointly were pain, clinical stage, extranodal involvement, and treatment. For hazard function, it was found that the probability of dying was high when the patient was at clinical stage III/IV, which had the greatest influence or created the highest risk of dying among all prognostic factors analyzed.
Keywords: Lymphoma, Mouth Neoplasm, Non-Hodgkin, Oral Cavity, Prognosis, Survival
|How to cite this article:|
Guevara-Canales JO, Morales-Vadillo R, Montes-Gil JE, Barrionuevo-Cornejo CE, Cava-Vergiú CE, Sacsaquispe-Contreras SJ. Influence of prognostic factors on survival in lymphoma of oral cavity and maxillofacial region in a Peruvian population: A historical cohort study. J Int Oral Health 2022;14:281-9
|How to cite this URL:|
Guevara-Canales JO, Morales-Vadillo R, Montes-Gil JE, Barrionuevo-Cornejo CE, Cava-Vergiú CE, Sacsaquispe-Contreras SJ. Influence of prognostic factors on survival in lymphoma of oral cavity and maxillofacial region in a Peruvian population: A historical cohort study. J Int Oral Health [serial online] 2022 [cited 2022 Aug 17];14:281-9. Available from: https://www.jioh.org/text.asp?2022/14/3/281/348418
| Introduction|| |
Malignant neoplasms of the oral cavity (OC) and maxillofacial region (MR) are infrequent and account for only 2% of all lymphomas occurring in the human body. Lymphomas are a heterogeneous group of tumors classically divided into two subgroups: Hodgkin’s lymphoma (HL) and non-Hodgkin’s lymphoma (NHL).
Extranodal involvement of NHL often affects the OC/MR and may involve the OC mucosa, maxillary bones, and even salivary glands.
For malignity prognosis, the literature reports factors such as age, patient’s general status, number of extranodal sites involved, clinical stage, level of serum lactate dehydrogenase (LDH), and treatment. Most studies that have analyzed these survival prognostic factors to classify risk groups only consider the systemic presentation of the disease, not its presentation in OC/MR. Moreover, most of these studies were conducted on Asian and European populations.
It is important to interpret and weigh the features of NHL located specifically in the field of competency of the dental surgeon, which is OC/MR, in order to predict patient survival, to understand the natural history of the disease, and to provide proper treatment according to the specific response to therapy and to the improvement in quality of life in these patients. Thus, the present study describes the factors influencing survival, starting from the null hypothesis that the coefficients of the prognostic factors do not alter the survival of patients with OC/MR lymphoma, with the specific aims of determining overall survival (OS) at 2 and 5 years, survival at 2 and 5 years for each variable analyzed, prognostic factors according to univariate and multivariate analyses, and the model of the risk function with highest statistical significance in 50 out of 151 patients diagnosed with primary NHL of the OC/MR, at the Dr. Eduardo Cáceres Graziani National Institute for Neoplastic Diseases (INEN), Lima, Peru.
| Materials and Methods|| |
This was a historical cohort study (non-concurrent cohort) because both the exposure to a risk factor and the expected outcome had already occurred before the study was designed, providing a time relationship. This type of study is classified as observational, analytic, longitudinal, and retrospective.
The population consisted of all INEN patients who were diagnosed with primary lymphoma of the OC/MR, over 13 years, from January 1997 to December 2010. The sample included all cases in which this diagnosis was confirmed by reexamination of the histological slide.
Exclusion criteria were cases with OC/MR lymphoma lesions which were not an initial or primary manifestation or localization of the disease, cases with a concomitant disease, and cases with incomplete data records.
Procedures and techniques
Data were collected only by the principal investigator, in a single session, so no inter-observer or intra-observer statistical analysis was required. Anatomopathological analysis of the histological sections was only required for reclassification of the diagnosis to determine whether to include the study samples and was performed by consensus among the investigators.
Review of clinical histories:
The clinical histories of patients who met the inclusion criteria were evaluated and recorded. This provided data for all the variables selected for analysis as potential prognosis factors, coinciding with the variables studied by other authors,,, such as: age, sex, location of the lesion, size of lesion, signs/symptoms (general symptoms are presence of “B” symptoms, whereas dental symptoms are presence of dental mobility or exfoliation), diagnosis, clinical stage, international prognostic index (IPI), LDH, extranodal involvement, and treatment. In addition, we recorded any data needed for statistical calculations established for survival studies, such as follow-up status and follow-up duration (time, in years, from the date of definitive diagnosis to the date of last visit or death).
Review of histopathological samples
The histopathological slides or paraffin blocks for the cases included in the study were used to re-evaluate histopathology and reclassify the primary lymphoma of OC/MR diagnoses, according to the current World Health Organization (WHO). The reclassification was directed by pathologists, experts in hematopathology, who are also a member of the INEN Department of Pathology and the team of researchers for this study, with the participation of the principal investigator. Each case was initially reevaluated by observation of hematoxylin–eosin-stained sections, followed by evaluation of phenotype using immunohistochemical stains. For cases with incomplete immunophenotype, complementary tests were requested from the immunohistochemistry laboratory at the Department of Pathology, in order to proceed with the re-evaluation. Only successfully reclassified cases were considered in the study.
The project was submitted for review and acceptance to the Protocol Reviewing Committee at the Executive Office for Support of Research and Specialized Teaching at the INEN. Approval was granted under protocol number INEN-63. The study was conducted in accordance with the World Medical Association Declaration of Helsinki on medical research protocols and ethics.
Prior to any procedure at the INEN, patients provided written informed consent for medical procedures (diagnostic surgery or treatment), stating that they had received and understood the information about the studies that might be needed to achieve definitive diagnosis and treatment required.
The researchers agreed that any data recorded or obtained from patients would only be accessed and managed by the principal investigator and would be gathered confidentially and identified by codes. If a patient needed to be informed of a result, it would be recorded in the relevant clinical history so that the treating physician could inform the patient at subsequent visits.
When needed, the smallest possible portion of material was cut from the paraffin blocks from the INEN archive, after which the blocks were returned for storage.
Frequency values and analysis of survival, prognostic factors, and hazard function model for the different variables were calculated using the statistics software Statistical Package for Social Sciences (SPSS) (version 22.0) for Windows (Windows, SPSS Inc., Chicago, IL, USA).
Survival analysis was calculated using two statistical tests: (1) analysis by actuarial technique, also called mortality tables or life tables to find the percentage of OS at 2 and 5 years and the percentage of individual survival for each potential prognostic factor, and (2) the Kaplan–Meier product-limit method, which is a non-parametric test that provided the survival curves for each potential prognostic factor.
Prognostic factors were analyzed in two ways: (1) univariate analysis with the log-rank test, which provides the statistical significance of the differences between survival curves of the Kaplan–Meier product limit, individually for each variable, and (2) multivariate analysis using Cox regression model or proportional risk model, considering jointly all the variables which are potential prognostic factors. The multivariate analysis only included variables which in the univariate analysis had P < 0.75.
The Cox or proportional risk regression test also generated the best model for determining the hazard function with the highest statistical significance for the study variables as possible prognostic factors. This provided the hazard ratio and its corresponding 95% confidence interval.
Statistical test results were considered significant when P < 0.05. Analyses were performed on a computer with Windows® Operating System (Microsoft, Inc., Seattle, Washington, D.C., USA).
| Results|| |
Following the method described earlier, we obtained the clinical histories of 151 patients with histopathological diagnosis of NHL of the OC/MR. Over that time, 120,365 new cancer cases were recorded at the INEN, of which 0.13% (151 cases) were lymphomas of the OC/MR. Of the 1119 new cases of head and neck lymphoma, 13.49% (151 cases) were OC/MR lymphomas. Of the 151 cases of lymphoma of the OC/MR, only 50 were included in this study, for which there were available histopathological preparations or paraffin blocks to enable re-evaluation of the histopathological diagnosis in order to confirm or reclassify according to the current WHO guidelines. These 50 cases accounted for 4.47% of the patients with diagnosis of head and neck lymphoma who visited the INEN [Figure 1].
|Figure 1: Flow chart of population, sample, and study case selection. INEN: National Institute for Neoplastic Diseases, OC/MR: oral cavity and maxillofacial region|
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Re-evaluation of the histopathological slides did not differ from the original diagnosis, with most diagnoses being confirmed. Immunohistochemical analysis provided lymphoma subtype for some cases, making our study consistent with the new nomenclature used by researchers in current high-impact publications and enabling comparison of results.
[Table 1] shows the epidemiological distribution of age, sex, and diagnosis, comparing clinical stage I/II with stage III/IV. Outstanding in this table is the large number of cases (83.3%) diagnosed with diffuse large B-cell lymphoma (DLBCL). Other characteristics are uniformly distributed as 25 cases in OC, 20 in maxillary bones, and 5 cases in salivary glands; 13 cases presented B symptoms and 37 cases did not. The most frequently employed treatment was a combination of chemotherapy and radiotherapy in 14 cases, but 15 cases presented no treatment.
|Table 1: Epidemiological distribution of age, sex, and diagnosis for patients diagnosed with non-Hodgkin’s lymphoma of oral cavity and maxillofacial region, according to the clinical stage|
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OS was 69% and 47% at 2 and 5 years, respectively [Figure 2]. [Table 2] shows OS for each of the first 10 years.
|Figure 2: Overall survival curve for patients diagnosed with non-Hodgkin’s lymphoma of the oral cavity and maxillofacial region|
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|Table 2: Cumulative proportions of survival in patients diagnosed with non-Hodgkin’s lymphoma of oral cavity and maxillofacial region|
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[Table 3] shows survival percentage at 2 and 5 years for the different variables analyzed as potential prognostic factors (age, sex, location, size, signs/symptoms, diagnosis, clinical stage, IPI, LDH, extranodal involvement, and the different types of treatment), through survival statistics using the actuarial technique analysis (mortality table or life table).
|Table 3: Survival at 2 and 5 years as a percentage and univariate and multivariate analyses of the variables analyzed as potential prognostic factors in patients diagnosed with non-Hodgkin’s lymphoma of oral cavity and maxillofacial region|
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Prognostic factors results
The variables analyzed to calculate the prognostic factor were age, sex, location of lesion, size of lesion, increased volume, pain, dental symptoms, general symptoms, diagnosis, clinical stage, IPI, LDH, extranodal involvement, and treatment.
The study variables were analyzed individually, and four of them were found to have statistically significant influence on the prognosis factor: (1) clinical stage (P < 0.001), (2) IPI (P < 0.001), (3) extranodal involvement (P < 0.001), and (4) treatment (P < 0.001) [Table 3].
The study variables were also analyzed jointly, and four of them were found to have statistically significant influence on the prognosis factor: (1) pain (P = 0.031), (2) clinical stage (P < 0.001), (3) extranodal involvement (P < 0.001), and (4) treatment (P = 0.006) [Table 3] and [Figure 3].
|Figure 3: Kaplan–Meier survival curve for the prognostic factors such as pain, clinical stage, extranodal involvement, and treatment for patients diagnosed with non-Hodgkin’s lymphoma of the oral cavity and maxillofacial region. Sg: surgery, Cht: chemotherapy, Rt: radiotherapy (P-value by Cox regression multivariate analysis)|
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The relationship between the four diagnoses or most frequent histological types and the clinical stage and duration of the lesion was 2 years in clinical stage I/II for DLBCL and 3 years for peripheral T-cell lymphoma (PTCL), also in clinical stage I/II.
Hazard function results
Analysis of hazard function as a potential prognostic factor showed that of all the variables analyzed for the prognostic factor, only the clinical stage was statistically significant. Patients in clinical stage III/IV were 6.86 times more likely to die than patients in stage I/II [Table 4]. In other words, patients in clinical stage I/II are approximately 85.4% more likely to survive than those in clinical stage III/IV.
|Table 4: Analysis of hazard function associated to survival of patients diagnosed with non-Hodgkin’s lymphoma of the oral cavity and maxillofacial region|
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| Discussion|| |
The main contribution of this study was to identify prognostic factors that influence the survival of lymphoma patients, specifically in the field of competency of dental surgeons, namely, OC/MR, based on data from patients diagnosed and treated at a healthcare facility in Lima, Peru. Most studies only present this pathology systemically, not in this specific location. For instance, Breen et al. found only 8.4% of mantle cell lymphoma cases in OC, and Morello et al. found only 13% (17 cases) of the same type of lymphoma in OC and salivary glands.
Of all the cancers presented in the INEN during the 13 years studied, 0.93% were head and neck lymphomas, of which 13.49% (151 patients) were OC/MR lymphomas. Of these 151 clinical histories of patients with NHL of the OC or MR, only 50 cases were included, accounting for 4.47% of the patients with head and neck lymphomas who received care at the INEN.
Discussion of epidemiology
Epidemiological distribution was consistent with that reported in other studies. For example, age distribution in our study was similar to that reported by Breen et al., in which the average patient age was 73 years. Previous studies, such as Sirsath et al., reported OC lymphomas with 10 years of casuistic, in which 100% of the cases were recorded in clinical stage I.
Discussion of survival
The OS among the 50 cases was 69% at 2 years and 47% at 5 years. Our 5-year value was much lower than the 63% survival rate reported by Breen et al. and the 78.7% survival rate for gastric DLBCL reported by Cheng et al., possibly because those studies were conducted on head and neck with greater likelihood of having occurred in cervical nodes. In addition, the patients in our study had pain symptoms, which indicated possible infection.
Our study analyzed lymphoma patient age in two groups: patients aged 60 years or less, whose survival rates were 73% and 52% at 2 and 5 years, respectively, and patients over 60 years of age, whose survival rates were 65% and 39% at 2 and 5 years, respectively, which was not found to be statistically significant as a potential prognostic factor for survival either in univariate or in multivariate analysis. In contrast, a study by Blansky et al. does present statistically significant differences in survival according to the age of patients with lymphoma, the finding that patients over 60 years had a 52% lower risk of mortality. This difference may be explained by the homogeneous distribution in age of the patients evaluated in our study and by the emphasis on race in the study by Blansky et al.
Cheng et al. studied 129 DLBCL (gastric) patients, out of which 66 were women and 63 were men; survival to 5 years was 78% for women and 81.8% for men, with no statistically significant difference. The current study also found higher survival in males than in female patients; for 50 patients, the OS at 5 years was 45% for women and 56% for men, also with no statistically significant difference.
van der Waal et al. reported 34 new cases and 6 previously presented cases of patients with primary extranodal NHL in Amsterdam (the Netherlands) with an average follow-up time of 38 months, the finding that no statistically significant difference was found between lymphomas located in soft tissues and those located in bone. Our study found better survival rate for lymphomas located in the OC mucosa, with 51% at 5 years, than for lymphomas located in maxillary bones. However, comparison of survival of OC lymphomas to systemic lymphomas, as in Shi et al., shows that OC lymphomas are found to have OS at 5 years of 42.9%, which is lower than that for the rest of the body.
Regarding clinical symptoms, pain is a reference of the seriousness of the disease for the 53 cases reported in OC, and our study shows the same for the regional OC/MR forms. Pain is a statistically significant indicator as a prognostic factor of seriousness. This may be explained by the fact that in our study, patients were from a low socio-cultural and -economic status and had limited health coverage for the prevention and solution of this type of condition and were thus already in pain at the time of diagnosis, in contrast to patients from other more developed populations with higher socio-cultural and -economic status.
No statistically significant difference was found for histopathological diagnosis either as a univariate factor or as a multivariate factor influencing patient survival. This does not agree with the study by Rodrigues-Fernandes et al., which concluded that survival of OC lymphoma is influenced by histological subtype; specifically, it has been reported that DLBCL is considered to have a 5-year survival rate of about 44.4%.
In general, the higher the clinical stage, the worse the prognosis; this was true in our study, in which survival rate among patients diagnosed with OC/MR lymphoma decreased as the clinical stage increased, with 77% and 64% survival at 2 and 5 years, respectively, for patients at clinical stage I/II and 33% at 2 years for patients at clinical stage III/IV. This sequence of survival rates according to the clinical stage was also reported in a study by Otmani and Khattab, in which a 45-month follow-up (range 9–99 months) found survival rates of 100%, 91%, and 27%, respectively, for stages II, III and IV in 37 children with OC Burkitt lymphoma. Local disease at stage I/II differed significantly from disseminated disease at stage III/IV with P < 0.001 during the average follow-up time for 40 primary extranodal NHLs of the OC in a study by van der Waal et al. Our study found similar results among the 50 patients evaluated, and there were statistically significant differences, both individually and jointly, between clinical stage indicators, with P < 0.001, for both univariate and multivariate analyses.
In our study, survival rate at 2 years was 100% for patients with normal LDH levels and 66% for patients with high LDH levels. There was no statistically significant difference between them with either univariate or multivariate analysis. In contrast, Geva et al. found lower survival values with respect to LDH in a study of 186 cases of NHL at the systemic level, where OS at 1 year was 63.2% for the normal LDH level and 39.9% for the high LDH level (P = 0.003) and OS at 3 years was 56.9% for the normal LDH level and 29.6% for the high LDH level (P = 0.001); the difference could be due to the number of cases included between these studies and the specific locations at the level of OC/MR and at the systemic level.
With regard to extranodal sites (of the IPI), the study by Blansky et al. found that this factor had no influence on survival (P = 0.44). In contrast, in our study, the number of extranodal sites involved in the disease was statistically significant, with P < 0.001, as a factor influencing prognosis for a single extranodal location (OC/MR) when compared with more than one extranodal locations, in both univariate and multivariate analyses. Survival rate at 5 years was 80% when the patient had one or less extranodal involvement site and 0% when the patient had more than one extranodal involvement site, possibly because the OC/MR sites considered in this study implied extranodal location.
Choice of treatment is influenced by prognosis as it largely depends on whether full excision can be achieved with radical surgery. Jiang and Yan reported an increase in survival rate to 5 years after receiving surgery with radiotherapy or chemotherapy (P < 0.001). Likewise, our study on 50 patients found that treatment has an influence as a prognostic factor for survival, as both univariate and multivariate analyses provided statistically significant values.
Discussion of prognostic factors
Some studies, such as Jiang et al., report worse prognosis for OC lymphomas in relation to age, diagnosis, and clinical status. Olszewski and Desai studied systemic lymphomas including cases in the OC and found no statistically significant difference for the prognostic factors such as clinical stage and treatment type, the finding that the result of the prognosis depends on many factors such as histological type, stage of the disease, treatment type, presentation of type “B” symptomatology, primary location site, tumor size, patient’s age, etc., as described by Raut et al. and Gupta et al. They studied 445 cases of salivary gland lymphomas and found that the univariate analysis showed that only the disease in late stage was significantly associated with higher risk of mortality (P = 0.003), whereas the multivariate analysis showed that female sex was significantly associated with higher risk (P = 0.018). Our study found that the factor with the greatest influence on prognosis of the survival of patients diagnosed with NHL of the OC/MR was clinical stage; patients at clinical stage III/IV being 6.86 times more likely to die than those at clinical stage I/II.
Discussion of hazard function
The statistical analysis performed in our study using Cox’s regression test adjusted model showed that patients who present at clinical stage III/IV were more likely to die than those who present at clinical stage I/II, in agreement with other studies such as Anacak et al., in which the univariate analysis found that the variable clinical stage was a statistically significant prognosis factor for patients with lymphoma, in addition to treatment and presence of residual tumor. van der Waal et al. also found that stage I/II differed significantly from disseminated disease at stages III/IV in OS (P < 0.001). Also in agreement is the study by Yuan et al., which found that clinical stage, in addition to the international prognosis index and the presence of “B” symptoms, was a risk indicator for patients with lymphoma.
Specifically, with regard to hazard function, no previous study was found specifying any value that we could contrast to the findings of our study. Thus, the finding in Peru that patients diagnosed with lymphoma of the OC/MR at clinical stage III/IV was 6.86 times more likely to die than those at clinical stage I/II is an important contribution to prevention and therapy.
This research presented some limitations and generated some suggestions for future research. The limitations are related to the confirmation and reclassification of all cases of primary lymphomas of the OC/MR, because out of the 151 potential cases, it was only possible to analyze 50. One of the main suggestions is to include epidemiological presentation of the remaining cases, which would provide a useful contribution; in addition, further comparison of survival from a molecular standpoint, produced by viral agents, would provide evidence of the evolution of this pathology from a different approach. Based on all of the aforementioned factors, the null hypothesis, stating that prognostic factor coefficients do not alter the survival of patients with OC/MR lymphoma, is rejected.
| Conclusion|| |
The findings of the statistical analyses allow us to conclude that for patients who received care at the INEN and were diagnosed with primary NHL of the OC/MR, OS rate at 2 and 5 years was lower than that in most international reports, and prognostic factors jointly influencing survival are presence of pain, clinical stage, extranodal involvement, and treatment type. Statistical analysis of hazard function showed that out of all survival prognostic factors analyzed, the only predictive variable with negative influence or indicating greater probability of death was clinical stage III/IV when compared with clinical stage I/II.
Financial support and sponsorship
Conflicts of interest
The authors declare that they have no competing interests.
J-OG-C: Study concept and design, data collection and analysis, drafting the article and revising it critically for important intellectual content, final approval of the version to be submitted. RM-V: Study concept and design, data collection and analysis, interpretation of data, drafting the article, and revising it critically for important intellectual content, final approval of the version to be submitted. J-EM-G: Study concept and design, data collection and analysis, revising it critically for important intellectual content, final approval of the version to be submitted. C-EB-C: Study concept and design, analysis, revising it critically for important intellectual content, final approval of the version to be submitted. C-EC-V: Study concept and design, revising it critically for important intellectual content, final approval of the version to be submitted. S-JS-C: Study concept and design, revising it critically for important intellectual content, and final approval of the version to be submitted.
Ethical policy and Institutional Review Board statement
The project was submitted for review and acceptance to the Protocol Reviewing Committee at the Executive Office for Support of Research and Specialized Teaching at the INEN. Approval was granted under protocol number INEN-63.
Patient declaration of consent
Data availability statement
| References|| |
Kobler P, Borcic J, Filipovic ZI, Nola M, Sertic D Primary non-Hodgkin’s lymphoma of the oral cavity. Oral Oncol 2005;41:12-4.
van der Waal RI, Huijgens PC, van der Valk P, van der Waal I Characteristics of 40 primary extranodal non-Hodgkin lymphomas of the oral cavity in perspective of the new WHO classification and the international prognostic index. Int J Oral Maxillofac Surg 2005;34:391-5.
Abdelwahed Hussein MR Non-Hodgkin’s lymphoma of the oral cavity and maxillofacial region: A pathologist viewpoint. Expert Rev Hematol 2018;11:737-48.
Wagner VP, Rodrigues-Fernandes CI, Carvalho MVR, Dos Santos JN, Barra MB, Hunter KD, et al
. Mantle cell lymphoma, malt lymphoma, small lymphocytic lymphoma, and follicular lymphoma of the oral cavity: An update. J Oral Pathol Med 2021;50:622-30.
Anacak Y, Miller RC, Constantinou N, Mamusa AM, Epelbaum R, Li Y, et al
. Primary mucosa-associated lymphoid tissue lymphoma of the salivary glands: A multicenter rare cancer network study. Int J Radiat Oncol Biol Phys 2012;82:315-20.
Jiang F, Yan AH Survival analysis of 8785 malignant lymphoma cases in the oral and nasal cavities in the USA: A cohort study. BMJ Open 2021;11:e048876.
Breen CT, Chao J, Mehra S, Kohli N Extranodal head and neck mantle cell lymphoma: Characteristics, treatment, and survival. Ann Otol Rhinol Laryngol2022;131:412-9.
Morello L, Rattotti S, Giordano L, Jerkeman M, van Meerten T, Krawczyk K, et al
. Mantle cell lymphoma of mucosa-associated lymphoid tissue: A European Mantle Cell Lymphoma Network Study. HemaSphere 2020;4:e302.
Swerdlow SH, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, et al
. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Revised 4th ed. Lyon, France: IARC Press; 2017.
Sirsath NT, Lakshmaiah KC, Das U, Lokanatha D, Chennagiri SP, Ramarao C Primary extranodal non-Hodgkin’s lymphoma of oral cavity—A single centre retrospective study. J Cancer Res Ther 2014;10:945-50.
Cheng Y, Xiao Y, Zhou R, Liao Y, Zhou J, Ma X Prognostic significance of Helicobacter pylori
-infection in gastric diffuse large B-cell lymphoma. BMC Cancer 2019;19:842.
Blansky D, Fazzari M, Mantzaris I, Rohan T, Hosgood HD Racial and ethnic differences in diffuse large B-cell lymphoma survival among an underserved, urban population. Leuk Lymphoma 2021;62:581-9.
Shi Y, Han Y, Yang J, Liu P, He X, Zhang C, et al
. Clinical features and outcomes of diffuse large B-cell lymphoma based on nodal or extranodal primary sites of origin: Analysis of 1,085 WHO classified cases in a single institution in China. Chin J Cancer Res 2019;31:152-61.
Rodrigues-Fernandes CI, Junior AG, Soares CD, Morais TML, do Amaral-Silva GK, de Carvalho MGF, et al
. Oral and oropharyngeal diffuse large B-cell lymphoma and high-grade B-cell lymphoma: A clinicopathologic and prognostic study of 69 cases. Oral Surg Oral Med Oral Pathol Oral Radiol 2021;131:452-62.e4.
Angiero F, Stefani M, Crippa R Primary non-Hodgkin’s lymphoma of the mandibular gingiva with maxillary gingival recurrence. Oral Oncol Extra 2006;42:123-8.
Otmani N, Khattab M Oral Burkitt’s lymphoma in children: The Moroccan experience. Int J Oral Maxillofac Surg 2008;37:36-40.
Geva M, Pryce A, Shouval R, Fein JA, Danylesko I, Shem-Tov N, et al
. High lactate dehydrogenase at time of admission for allogeneic hematopoietic transplantation associates to poor survival in acute myeloid leukemia and non-Hodgkin lymphoma. Bone Marrow Transplant 2021;56:2690-6.
Olszewski AJ, Desai A Radiation therapy administration and survival in stage I/II extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue. Int J Radiat Oncol Biol Phys 2014;88:642-9.
Raut A, Huryn J, Pollack A, Zlotolow I Unusual gingival presentation of post-transplantation lymphoproliferative disorder: A case report and review of the literature. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000;90:436-41.
Gupta A, Lee JA, Nguyen SA, Lentsch EJ Primary diffuse large B-cell lymphoma of the major salivary glands: Increasing incidence and survival. Am J Otolaryngol 2021;42:102938.
Yuan ZY, Li YX, Zhao LJ, Gao YH, Liu XF, Gu DZ, et al
. [Clinical features, treatment and prognosis of 136 patients with primary non-Hodgkin’s lymphoma of the nasopharynx]. Zhonghua Zhong Liu Za Zhi 2004;26:425-9.
[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4]