The Pretreatment Controlling Nutritional Status (CONUT) Score Is an Independent Prognostic Factor in Elderly Patients with Diffuse Large B-Cell Lymphoma
Authors: Kaneda Yuto , Kanemura Nobuhiro , Nakamura Nobuhiko , Ikoma Yoshikazu , Yamaguchi Kimihiro , Matsumoto Takuro , Shibata Yuhei , Nakamura Hiroshi , Ninomiya Soranobu , Kitagawa Junichi , Kasahara Senji , Hara Takeshi , Shimizu Masahito , Tsurumi Hisashi 
Published: October 2019

Abstract
[Backgrounds] The controlling nutritional status (CONUT), one of the useful parameter of nutritional assessment tools, is a significant prognostic factor for various solid tumors. The CONUT score is an index calculated from the following factors; the serum albumin concentration (Alb), the total peripheral lymphocyte counts (Lymph) and total cholesterol concentration (Chol) (Table 1). Some predictive models specified the relationship between nutritional status and the prognostic value of malignant disease have been proposed. However, the role of the CONUT score in predicting clinical outcomes of diffuse large B cell lymphoma (DLBCL) patients has not been investigated. The aim of this study is to elucidate the impact of the pretreatment CONUT score on survival in patients with DLBCL who received rituximab (R) plus chemotherapy.
[Patients and Methods] We retrospectively investigated 240 patients who were histologically diagnosed with DLBCL between June 2004 and November 2015. All patients received R-CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) or R-THP-COP (cyclophosphamide, tetrahydropyranyl-adriamycin, vincristine, prednisone) regimen. We defined the best cutoff value of the CONUT score as 3 using a receiver operating characteristic curve.
[Result] The mean and median of the CONUT score of all patients (median age 68, range 19 - 93, 140 male and 100 female) were 2.85 and 2 (range 0 - 12). The data of each parameter's median and range constituting CONUT (Alb, Lymph, Chol) was as follows: 4 (1.9 - 5.3), 1170 (105 - 13192), and 173 (49 - 287), respectively. Patients with High-CONUT score (≥3, n = 109) had significantly lower overall survival (OS) and progression-free survival (PFS) than those with Low-CONUT score (≤2, n = 131) (5-year OS, 63.0 vs. 83.6%, P = 0.006; 5-year PFS, 56.5 vs. 78.0%, P = 0.003). The conventional predictive factors such as International Prognostic Index (IPI; age, performance status, Ann Arbor stage, extra-nodal involvement sites and lactate dehydrogenase) were all significantly associated with a worse OS and PFS. A subsequent subgroup analysis based on age indicated that 70 years or elder patients (n = 108) with High-CONUT had a significantly worse 5-year OS and PFS as compared to Low-CONUT patients (OS, 50.0 vs. 77.2%, P = 0.008; PFS, 41.6 vs. 77.6%, P = 0.0004). In contrast, no significant differences were observed in the OS and PFS when High- and Low-CONUT patients less than 70-year-old were compared. The multivariate analysis of all of the significant parameters in patients older than 70 years indicated that High-CONUT was an independent prognostic factor for PFS (HR = 2.20, 95 % CI = 1.08-4.66, p = 0.03).
[Discussion] The serum Alb concentration is a reliable indicator of nutritional status and systemic inflammation. Total peripheral Lymph, which play an important role in the immune response to the tumor, are known to indicate the immunological and nutritional status. It is also reported that Chol, an indicator of a patient's caloric reserves, increased the antigen-presenting function of monocytes. Organ function decreases with aging, and many elderly patients have comorbidities that compromise their capacity to tolerate standard dose chemotherapy. In addition, intensive chemotherapy is often complicated by deterioration of nutritional status as the elderly. Hence, elderly patients are an extremely heterogeneous population and optimal treatment strategy should be adapted in consideration of comorbidities. On the other hand, DLBCL is a curable disease even in the elderly population. Therefor prognostic stratification in older population should be focused on the real biological age of patients and on primary variables that reflect tumor aggressiveness, immune interaction and nutritional status. In this respect, the pretreatment CONUT score is considered suitable for prognostic model of elderly patients. Previously, we have reported that sarcopenia is an independent poor prognostic factor for PFS in male patients with DLBCL (Ann Hematol, 2015). In this cohort, sarcopenia has no effect on PFS in elderly patients.
[Conclusion] The pretreatment CONUT score is easily able to predict the prognosis of elderly patients with DLBCL.

Disclosures
No relevant conflicts of interest to declare.