SUMMARY
Multiple Myeloma (MM) is almost always preceded by monoclonal gammopathy of undetermined significance
(MGUS) and smoldering myeloma (SMM), with a transformation rate of ~1% and ~10% per year, respectively.
Large racial disparities exist in MM and its premalignant conditions; compared to Whites, African-Americans
have a two-fold increased prevalence of MGUS/MM and are diagnosed with MM at younger ages. What is
lacking is the identification of the true transition steps that occur from early precancerous stages to overt MM
and identifying the biological precancer stages of the disease. Here, we propose to construct the Myeloma
Multidimensional Pre-Cancer Atlas (MMPCA). We believe that the identification of the transition stages
along the spectrum of healthy, precursor MM to overt MM in a racially diverse population represents a missed
opportunity to fully inform disease characterization, monitoring, and potential needs for patients to receive
early intervention therapies. We will leverage our large collection of samples from two cohort studies that are
racially diverse with over 30% African or African Americans and with over 10,000 samples collected serially
over the last 10 years; and with well-annotated data of disease progression. Our overarching hypothesis is
that malignant transformation occurs through the cooperative acquisition of genomic and microenvironment
alterations that occur in a susceptible host environment. The MMPCA will create a comprehensive spatial
and temporal atlas of precursor MM to understand genomic and microenvironmental alterations across the
spectrum of disease evolution from healthy to MM. In specific Aim 1, we will map the spatial interactions
among early B cell clonal expansions with the microenvironment using Xenium spatial transcriptomic and
imaging mass cytometry (IMC). In specific Aim 2, we will chart the subclonal genomic structure at the single
cell level across the spectrum of disease from healthy to MM, and in specific Aim 3, we will characterize at
the single cell level the microenvironment (immune and non-immune stromal cells) and its association with
progression across the spectrum of disease from healthy to MM. This provides a unique opportunity to study
events in a clinically well-defined precancer hematological condition that can be a great model of disease
progression and inform other precancer cell atlases. We also have access to serial blood and marrow
samples along the spectrum of the disease with long-term follow up of clinical progression for over 10 years.
Unlike in solid cancers, we can obtain biopsies from the tissue of origin without altering the natural course of
the precancerous lesions (no need for surgical resection) and therefore, we have a unique resource that can
be made available for other precancer atlases.