Risk Stratification Using Multivariable Fractional Polynomials in Diffuse Large B-Cell Lymphoma

Abstract

The risk stratification of diffuse large B-cell lymphoma (DLBCL) is crucial. The International Prognostic Index, the most commonly used and the traditional risk stratification system, is composed of fixed and artificially dichotomized attributes. We aimed to develop a novel prognostic model that allows the incorporation of up-to-date attributes comprehensively without information loss. We analyzed 204 patients with primary DLBCL who were uniformly treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) from 2007 to 2012 at Asan Medical Center. Using the multivariable fractional polynomial (MFP) method and bootstrap resampling, we selected the variables of significance and the best fitted functional form in fractional polynomials. Age, serum β2-microglobulin, serum lactate dehydrogenase, and BCL2 expression were selected as significant variables in predicting overall survival (OS), while age was excluded in predicting 2-years event-free survival. The prognostic score calculated by the MFP model effectively classifies patients into four risk groups with 5-years OS of 89.91% (low risk), 81.21% (low-intermediate risk), 66.40% (high-intermediate risk), and 37.89% (high risk). We suggest a new prognostic model that is simple and flexible. By using the MFP method, we can incorporate various clinicopathologic factors into a risk stratification system without arbitrary dichotomization.

Clinical Characteristics, Outcomes, and Risk Factors for Patients with Diffuse Large B-Cell Lymphoma and Development of Nomogram to Identify High-Risk Patients

“…Te median age of patients with DLBCL in our study was 58 years, which was consistent with the data reported by other research centers in Asia [14,15], but lower than those reported in other continents [16,17]. Compared with other studies [13,[18][19][20][21][22][23][24][25][26][27], especially in cancer hospitals in China [6,12], our cohort had a higher proportion of patients with advanced stage and combined B symptoms, which indicated that patients in our center have a heavier burden of disease. Primary extranodal DLBCL can originate from almost any part of the body, and the most common site of involvement in our cohort was the gastrointestinal tract.…”

Consecutive Hypoalbuminemia Predicts Inferior Outcome in Patients With Diffuse Large B-Cell Lymphoma

“…Along with this, the prognostic significance of international prognostic index (IPI) was impaired and could only distinguish the low-risk with the high-risk group instead of the four risk groups as previously described (3)(4)(5). Alternatively, more and more clinical and biological markers were explored to predict the prognosis of DLBCL, including age, extranodal lesions, cell of origin, c-MYC and Bcl-2 co-expression or translocation, and different biochemical indicators (6)(7)(8)(9)(10)(11)(12)(13)(14). As the treatment developed, the prognostic values of these biochemical indicators may also change.…”

Nomogram model and risk score to predict 5‐year risk of progression from prediabetes to diabetes in Chinese adults: Development and validation of a novel model

“…Third, to establish a stable model (i.e. the multivariable fractional polynomials [MFP] model) in the real world, we used the iterative fashion to determine significant variables and functional form by backward elimination according to the MFP algorithm 33 …”