Abstract Background Lung adenocarcinoma in never-smokers is a major public health burden, especially among East Asian women. Polygenic risk scores (PRSs) are promising for risk stratification but are primarily developed in European-ancestry populations. We aimed to develop and validate single- and multi-ancestry PRSs for East Asian never-smokers to improve lung adenocarcinoma risk prediction. Methods PRSs were developed using genome-wide association study summary statistics from East Asian (8002 cases; 20 782 controls) and European (2058 cases; 5575 controls) populations. Single-ancestry models included a PRS with 25 single nucleotide variants (PRS-25), PRS clumping and thresholding (CT), and LDpred2; multi-ancestry models included LDpred2 plus European PRS-128, PRS-CSx, and clumping and thresholding, super learning, empirical Bayes (CT-SLEB). Performance was evaluated in independent East Asian data from the Female Lung Cancer Consortium and externally validated in the Nanjing Lung Cancer Cohort. We assessed predictive accuracy via area under the curve operating procedure (AUC), with 10-year and (ages 30-80 years) absolute risks estimates. Results The best multi-ancestry PRS, using East Asian and European data via CT-SLEB, outperformed the best East Asian-only (LDpred2; AUC = 0.629, 95% confidence interval [CI] = 0.618 to 0.641), achieving an AUC of 0.640 (95% CI = 0.629 to 0.653) and odds ratio of 1.71 (95% CI = 1.61 to 1.82) per standard deviation increase. Nanjing Lung Cancer Cohort validation confirmed robust performance (AUC = 0.649, 95% CI = 0.623 to 0.676). The top 20% PRS group had a 3.92-fold higher lung adenocarcinoma risk than the bottom 20%. Further, the top 5% PRS group reached a 6.69% lifetime absolute risk. Notably, this group reached the average population 10-year lung adenocarcinoma risk at age 50 years (0.42%) by age 41 years, 9 years earlier. Conclusions Multi-ancestry PRS approaches enhance lung adenocarcinoma risk stratification in East Asian never-smokers, with consistent external validation, suggesting future clinical utility.
Obesity is Associated with a 2-Fold Elevated Risk of Monoclonal Gammopathy of Undetermined Significance (MGUS) Among African-American and Caucasian Women.
Abstract Abstract 4876 Background Recent studies have found obesity to be associated with a 1.5- to 2-fold elevated risk of developing multiple myeloma. This is of particular interest given that elevated levels of the pro-inflammatory cytokine interleukin (IL)-6 have been found in obese persons, and, at the same time, IL-6 has well-known proliferative and anti-apoptotic effects on monoclonal plasma-cells. Also insulin-like growth factors (IGFs) have been proposed to play a role since obesity often causes insulin resistance, which in turn modulates the bioavailability of IGF-1 Similar to IL-6, prior studies have found IGF-1 to have both growth and survival effects on monoclonal plasma-cells. Based on these facts, we have speculated that obesity might increase the risk of the multiple myeloma precursor monoclonal gammopathy of undetermined significance (MGUS), or, alternatively, that obesity may increase the risk for transformation from MGUS to multiple myeloma. We conducted the first large screening study designed to assess the association between obesity and MGUS among almost 2,000 African-American and Caucasian women. Methods We included 1000 African-American and 996 Caucasian women (age 40-79, median 48 years) from the Southern Community Cohort Study to assess MGUS risk in relation to obesity. Per our sampling strategy, about 50% of the participants were obese. Medical record-abstracted weight and height (measured on the day of study enrollment) and self-reported values had very high concordance (Pearson correlation >0.95). Serum samples from all subjects were analyzed by electrophoresis performed on agarose gel; samples with a discrete or localized band were subjected to immunofixation. Using logistic regression models, we estimated odds ratios (ORs) as measures of risk. Results Among all study participants, 39 (3.9%) African-Americans and 21 (2.1%) Caucasians were found to have MGUS, yielding a 1.9-fold (95%CI 1.1-2.3; p=0.021) higher risk of MGUS among African-Americans (vs. Caucasians). On multivariate analysis, we found obesity (OR=1.8, 95%CI 1.03-3.1; p=0.039), African-American race (OR=1.8, 95%CI 1.04-3.1; p=0.037), and increasing age (quartiles: ≥55 vs. <43 years) (OR=2.5, 95%CI 1.1-5.7; p=0.028) to be independently associated with an excess risk of MGUS. Another interesting finding was that the distribution of the monoclonal immunoglobulin isotype usage among African-American and Caucasian women was significantly different (p=0.007). Their respective rates were: IgG in 79.5% and 71.3 %; IgA in 7.7% and 0%; IgM in 7.7% and 19%; biclonal in 5.1% and 4.7%; and triclonal in 0% and 4.7%. The distribution of serum light-chain types between the two races was also significantly different (P=0.003, chi-square test): kappa in 53.8% and 47.6%; lambda in 43.6% and 42.8%; biclonal 2.6% and 4.7%; and triclonal in 0% and 4.7%. Conclusions Our finding that MGUS is twice as common among obese (vs. non-obese) women, and independent of race, supports the hypothesis that obesity is etiologically linked to myelomagenesis and may have public health impact. The observed 2-fold excess of MGUS among African-Americans (vs. Caucasians) of similar socio-economic status, coupled with other recent studies supports a role for susceptibility genes as the cause for racial disparity in the prevalence of MGUS. Disclosures No relevant conflicts of interest to declare.
Pooling Prospective Studies to Investigate the Etiology of Second Cancers
Abstract Obesity and black race have been associated with excess risk of multiple myeloma. The association of obesity with monoclonal gammopathy of undetermined significance (MGUS) is unknown. Further, it is not known whether the increased risk of multiple myeloma and MGUS in blacks is related to socioeconomic status, genetic susceptibility, or both. We screened 1000 black and 996 white women (range, 40-79 years) of similar socioeconomic status for MGUS; the aim of the study was to assess MGUS risk in relation to obesity and race. A total of 39 (3.9%) blacks and 21 (2.1%) whites had MGUS. On multivariate analysis, obesity (odds ratio [OR] = 1.8; P = .04), black race (OR = 1.8; P = .04), and increasing age (> 55 vs < 43 years; OR = 2.5; P = .03) were independently associated with an excess risk of MGUS. Our findings support the hypothesis that obesity is etiologically linked to myelomagenesis. The 2-fold excess of MGUS among blacks compared with whites of similar socioeconomic status supports a role for susceptibility genes in MGUS.