A Retrospective Analysis of the Trends in Mantle Cell Lymphomas in the United States

Introduction:

Mantle Cell Lymphoma (MCL) refers to the malignant B lymphocytes arising from the outer (mantle) zone of the lymphoid follicle. This rare and aggressive subtype of Non-Hodgkin Lymphoma, which accounts for ~5 percent of all NHL cases. It is associated with t(11:14) that leads to over-expression of cyclin D1, resulting in tumor cell proliferation via cell cycle dys-regulation, chromosomal instability, and epigenetic regulation. The aim of this study is to understand the epidemiology and survival predictors of MCL.

Methods:

The data was collected from Surveillance, Epidemiology and End Result database Research Plus Data, 17 Registries, Nov 2022 Sub (2000-2020). We extracted Mantle Cell Lymphoma cases diagnosed after 20 years of age, with Lymphoid neoplasm recode 2(a)2.1.3. The analysis was stratified based on age, sex, racial incidence rates, & survival curves based were compared, using the Log-rank test (GraphPad Prism).

Results:

A total of 14166 cases of MCL were found between 2000 to 2020. Out of these, ~70.73% cases were males, and ~29.27% were females. The median age at the time of diagnosis was 69 years. Of the affected population, ~80.60% were Caucasians, ~3.92% were African-Americans, ~4.10% were Asians/Pacific Islanders, only ~0.50% were American Indians/Alaskan Natives, and ~10.32% were Hispanics. The incidence per 1,000,000, as of 2020, was 10.83 for the general population, 13.00 for Caucasians, 5.01 for African-Americans, 13.71 for American Indians/Alaskan Natives, 3.28 for Asians/Pacific Islanders, and 9.43 for Hispanics. Survival curves were not significant when compared based on the race of the patients. However, survival curves showed statistical significance when compared based on gender, with median of survival (mOS) for males was 50 months, and for females mOS was 56 months (p-value 0.0.008, Hazard Ratio 1.084 [Confidence Interval 1.035 to 1.136], using Log-rank test.

Conclusions:

Mantle Cell Lymphoma has a strong predilection for males. It is more commonly diagnosed in the late 60s, median age being 69. Unequal racial distribution was noted, with caucasians (~80%) comprising most of the patient population, and the least commonly encountered were American Indians/Alaskan Natives(~0.50%). However, when incidence rates were calculated per 1,000,000 population in 2020, it was found that the incidence in American Indians/Alaskan Natives (13.71), is drastically higher than the general population(10.83) vs. incidence in Asians/Pacific Islanders(3.28) is significantly lower than the other races. Although race played no role in prognosis, females had better survival rates than males. This retrospective study was done to aid in better understanding of this curable malignancy, despite its rarity, aggressivity and the complexity in treatment.