Gender Aspects in Extranodal Marginal Zone B-Cell Lymphoma of the Mucosa-Associated Lymphoid Tissue: Does Sex Matter?

The National Landscapes of Gastric Mucosa-Associated Lymphoid Tissue Lymphoma: Stable Trends in Black Populations and Late-Stage Tumors

BACKGROUND

Helicobacter pylori (H. Pylori) eradication has been the mainstream for preventing and treating gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Prior data showed disparities in eradication rates of H. Pylori between different populations. This can potentially impact the occurrence of gastric MALT lymphoma. There are limited data on the incidence and mortality rates and trends of gastric MALT lymphoma in the US. Therefore, the aim of the current study was to conduct a time-trend analysis of gastric MALT lymphoma incidence and mortality rates in different populations.

METHODS

The incidence rates of gastric MALT lymphoma were calculated from the United States Cancer Statistics (USCS) database (which covers nearly 98% of the US population) between 2001-2020 and were age-adjusted to the standard 2000 US population using SEER*Stat software (version 8.4.3, national cancer institute "NCI"). Incidence-based mortality (IBM) rates, also age-adjusted to the standard 2000 US population, were calculated from the Surveillance Epidemiology and End Results (SEER) database. Tumor location was specified using ICD-O-3 codes C 160-C 169 with malignant behavior. Histopathology was specified using the ICD-O-3 code 9699. The rates were categorized by sex, age, race/ethnicity, and tumor stage at diagnosis. Age groups were older adults (aged 55 years or older) and younger adults (aged younger than 55 years). Race/ethnic groups included Non-Hispanic White (White), Non-Hispanic Black (Black), Hispanic, Non-Hispanic Asian/Pacific Islander (API), and Non-Hispanic American Indian/Alaska Native (AI/AN), as reported in the database. Stage at diagnosis included early stage (in situ and localized tumors) and late stage (regional and distant site tumors). Joinpoint Regression Software (version 5.0.2, NCI) using the weighted Bayesian Information Criteria method was used to generate time trends. Trends were reported as annual percentage change (APC) and average APC (AAPC). Parametric estimations were used with a two-sided t-test to evaluate the trends with a p-value cutoff at 0.05.

RESULTS

There were 21,625 patients diagnosed with gastric MALT lymphoma in the US between 2001 and 2020. Overall, incidence rates were significantly decreasing over the study period (AAPC = -1.93). This decrease was seen in males (AAPC = -1.67) and in females (AAPC = -1.66) (Figure). When categorized by age groups, older adults also experienced a significant decrease in gastric MALT lymphoma incidence rates (AAPC = -1.66). While this was also seen in younger adults, the rates were decreasing at a slower pace (AAPC = -1.38). When categorizing the trends by race/ethnicity, incidence rates were significantly decreasing in White (AAPC = -2.09), Hispanic (AAPC = -1.61), and API (AAPC = -3.92) populations. However, the rates were stable among Blacks. While early-stage tumors experienced a significant decrease (AAPC = -1.10), the rates were stable for late-stage tumors. When evaluating mortality, there were 11,036 patients whose death was attributed to gastric MALT lymphoma between 2000 and 2020. IBM rates were decreasing in males (AAPC = -1.47), older adults (AAPC = -1.55), Whites (AAPC = -1.23), Hispanics (AAPC = -1.73), APIs (AAPC = -2.30), and early-stage tumors (AAPC = -1.08). On the other hand, IBM rates were stable in females, younger adults, Blacks, and late-stage tumors.

DISCUSSION

An extensive nationwide data analysis encompassing nearly 98% of patients diagnosed with gastric MALT lymphoma in the US unveils a declining trend in the incidence of cancer overall over the past two decades. This decline is observed in both sexes and various age groups. When stratifying by race and ethnicity, this incidence has been decreasing in all populations except among Black individuals. While early-stage tumors have also demonstrated a significant decrease in incidence rates, late-stage tumors have shown no parallel decline. Mortality evaluation also revealed an improvement in most of the US population except among females, younger adults, Black individuals, and late-stage tumors. While the cause of our findings is unclear, it could be driven by disproportionate exposure to risk factors, including H. Pylori, and disparities in screening, management, and outcomes. Future studies are warranted to investigate factors contributing to worse outcomes of gastric MALT lymphoma, especially in the Black population.

Sex differences in lymphoma incidence and mortality by subtype: A population-based study

It is well established that the male sex is associated with increased risk for, as well as poorer survival of, most cancers. A similar pattern has been described in lymphomas but has not yet been comprehensively assessed. In this nationwide population-based cohort study, we used the Swedish Lymphoma Register to investigate sex differences in lymphoma subtype incidence and excess mortality in adults (age 18-99) diagnosed in 2000-2019. Male-to-female incidence rate ratios (IRRs) and excess mortality ratios (EMRs) adjusted for age and calendar year were predicted using Poisson regression. We identified 36 795 lymphoma cases, 20 738 (56.4%) in men and 16 057 (43.6%) in women. Men were at significantly higher risk of 14 out of 16 lymphoma subtypes with IRRs ranging from 1.15 (95% confidence interval [CI] 1.09-1.22) in follicular lymphoma to 5.95 (95% CI 4.89-7.24) in hairy cell leukemia. EMRs >1 were seen in 13 out of 16 lymphoma subtypes indicating higher mortality in men, although only statistically significant for classical Hodgkin lymphoma 1.26 (95% CI 1.04-1.54), aggressive lymphoma not otherwise specified 1.29 (95% CI 1.08-1.55), and small lymphocytic lymphoma 1.52 (95% CI 1.11-2.07). A corresponding analysis using data from the Danish Lymphoma Register was performed with comparable results. In conclusion, we demonstrate a significantly higher incidence and trend toward higher mortality in men for most lymphoma subtypes. Future studies with large patient material that include detailed clinicopathological prognostic factors are warranted to further delineate and explain sex differences in lymphoma survival to enable optimal management of lymphoma patients regardless of sex.

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma: clinicopathological study and treatment outcome in 50 patients

The stomach is the most frequent site of extranodal lymphoma. Mucosa-associated lymphoid tissue (MALT) lymphoma is a low-grade, B-cell neoplasm strongly associated with Helicobacter pylori (HP) infection. The presenting complaints of gastric MALT lymphoma are usually nonspecific. HP eradication is regarded as the first-line therapy in early stage disease. Management of patients who failed to achieve remission following HP eradication include chemotherapy, radiotherapy and in selected cases, surgery. The aim of the present study was to examine the clinical characteristics and treatment outcome of patients with gastric MALT lymphoma.

Trends of Incidence and Survival Rates of Mucosa-associated Lymphoid Tissue Lymphoma in the Korean Population: Analysis of the Korea Central Cancer Registry Database

BACKGROUND

Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT-lymphoma) is an extranodal lymphoma that occurs at various sites in the body. There is a limited understanding of the incidence and survival rates of MALT-lymphoma. To investigate the nation-wide incidence and survival rates of MALT-lymphoma in Korea during 1999-2017, the data on MALT-lymphoma were retrieved from the Korea Central Cancer Registry.

METHODS

During the time period of 1999-2017, 11,128 patients were diagnosed with MALT-lymphoma. The age and sex of the patients and the Surveillance, Epidemiology, and End Results (SEER) summary stage of the tumor were analyzed, and the relative survival rates (RSRs) were calculated.

RESULTS

The age-standardized incidence rates of MALT-lymphoma in 2017 among males and females were 1.53 and 1.61 per 100,000 individuals, respectively, whereas those in 1999 among males and females were 0.21 and 0.20, respectively in Korea. The RSRs were more than 97% at 10 years post-diagnosis between 1993 and 2017. The 5-year RSRs were 87.4%, 94.8%, 97.8%, and 98.6% during 1996-2000, 2001-2005, 2006-2010, and 2013-2017, respectively. Based on SEER summary staging, the 5-year RSRs during 2013-2017 were 100.3%, 90.8%, 91.3%, and 97.9% for patients with localized, regional, distant, and unknown stages of MALT-lymphoma, respectively.

CONCLUSION

Although the incidence of MALT-lymphoma is low in Korea, it has been increasing in recent years. The prognosis of MALT-lymphoma is good even at advanced stages. These findings provide useful insights to clinicians about MALT-lymphoma and inform patients about the survival rate.

Marginal zone B-cell lymphoma: lessons from Western and Eastern diagnostic approaches

Marginal zone B-cell lymphomas (MZLs) are a group of clinically indolent B-cell lymphomas postulated to derive from memory B lymphocytes in the 'marginal zone' of secondary lymphoid tissue. Today, MZL is recognised as a nosological umbrella term encompassing distinct entities with some shared phenotypic and genotypic features, including extranodal marginal zone B-cell lymphoma (EMZL) or mucosa-associated lymphoid tissue (MALT) lymphoma, splenic MZL, and nodal MZL, accounting for approximately 70%, 20%, and 10% of MZLs, respectively. These lymphomas share some phenotypic and genotypic features and have some variants and related provisional diseases, but are different in regards to their clinical and molecular characteristics. In addition, they are frequently associated with chronic antigenic stimulation represented either by infectious agents, particularly bacteria and viruses, or autoimmune diseases as exemplified by Sjögren syndrome, Hashimoto thyroiditis, and newly recognised IgG4-related disease. Furthermore, several chromosomal translocations have been identified in EMZL. In this review, we will focus on the updated histopathological criteria and the main problems with differential diagnoses in order to aid the diagnostic approach in our routine practice.

Changing trends in lymphoid neoplasm distribution in South Korea: analysis of 8615 cases from a single institute, 1997-2016: An observational study

The purpose of this study was to evaluate changes in the proportion of lymphoid neoplasm subtypes in South Korea. A total of 8615 cases of lymphoid neoplasms diagnosed in 1997-2016 at Samsung Medical Center in South Korea were classified according to the 2008 World Health Organization system. The total number and proportion of lymphoid neoplasms were compared between these two decades, with data from nationwide studies, and with other countries. To evaluate changes in the proportion of subtypes, crude rate of each subtype per 100 lymphoma patients during each decade and age adjusted rate were calculated. There were 3024 patients with lymphoid neoplasm in 1997-2006, and 5591 in 2007-2016, which represents an average increase of 1.85 times over the 20-year study period. Crude rate and age adjusted rate were increased in Hodgkin's lymphoma and mature B cell lymphoma while precursor lymphoid neoplasms and mature T cell lymphoma were decreased. Among B cell neoplasms, age adjusted rate of plasma cell neoplasm, follicular lymphoma, mantle cell lymphoma increased while there was no significant change in extranodal marginal zone lymphoma and Burkitt lymphoma. The increase in follicular lymphoma was due to the increases in nodal follicular lymphoma of low grade and duodenal-type follicular lymphoma. These results are consistent with the dynamics of causative factors, including socioeconomic factors, in Korea.

Prolonged follow-up on lenalidomide-based treatment for mucosa-associated lymphoid tissue lymphoma (MALT lymphoma)-Real-world data from the Medical University of Vienna

Based on results of two pilot trials, lenalidomide (LEN) was found to be active and safe as monotherapy and showed an increased response rate of 80% in combination with rituximab (R) for patients with mucosa‐associated lymphoid tissue (MALT) lymphoma. While initial results were promising, there are currently no data on long‐term outcome, and larger international phase II/III trials on LEN for indolent lymphoma lack specific subgroup analyses. Thus, we have systematically analyzed 50 patients treated with LEN‐based therapy (LEN‐monotherapy n = 16, R‐LEN n = 34) at the Medical University of Vienna 2009 to 2019 and investigated long‐term outcome and relapse patterns. At a follow‐up of more than 5 years (median 68 months), 54% of patients are free of relapse, and estimated median progression‐free survival (PFS) was 72 months (95%CI 49‐96). There was no difference in PFS according to stage of disease, i.e. localized versus disseminated disease (P = .67) and previous systemic treatment (P = .16). Interestingly, but with the caveat of the limited number of patients included in this series, primary extragastric disease had a superior PFS compared with gastric lymphoma (P = .04) and also depth of response, i.e. complete or partial response versus stable disease was associated with significantly prolonged PFS (P = .01). We documented four patients (8%) with pronounced improvement of response during follow‐up including three patients initially rated as partial remission and finally achieving complete remission at 12 to 32 months. This highlights the potential of delayed responses to LEN treatment. Estimated overall survival at 5 years was excellent at 92%. These “real‐world” data confirm long‐term activity of LEN in MALT lymphoma.