New research shows that the number of platelets and the levels of a protein called albumin can serve as robust prognostic factors for patients with diffuse large B-cell lymphoma (DLBCL), even among the elderly, whose prognosis is usually harder to make.
The study, “Utility Of A Simple Prognostic Stratification Based On Platelet Counts And Serum Albumin Levels In Elderly Patients With Diffuse Large B Cell Lymphoma,” published in the journal Annals of Hematology, suggests that combining these two measures may provide a better, easier way to stratify DLBCL patients based on their prognosis, compared to traditional analyses.
The evaluation of prognosis in DLBCL patients was initially made with the International Prognostic Index (IPI), which included five clinical factors: age; Ann Arbor stage, based on tumor location and symptoms; Eastern Cooperative Oncology Group (ECOG) performance status (PS), which assesses the functional status of the patients; blood levels of lactate dehydrogenase level (LDH); and the number of extranodal sites.
But in 2014, the National Comprehensive Cancer Network (NCCN) introduced a better version of the IPI, called the NCCN-IPI. This new version evaluates the same parameters, but gives more impact to age and LDH and uses a refined definition of extranodal disease.
Although the NCCN-IPI better distinguishes patients with low- and high-risk than the IPI, its prognostic value is reduced in patients age 60 or older, as the low-risk category is excluded due to the high impact of age. Also, it does not include certain blood markers that have been shown to contribute to the prediction of survival, such as serum C-reactive protein (CRP) levels, platelet counts, serum albumin levels, absolute lymphocyte counts (ALC), and absolute monocyte counts (AMC).
“The present study showed that platelet count and albumin levels were associated with OS [overall survival] independently of the NCCN-IPI, despite the finding that the latter was better than the IPI for predicting survival,” the authors wrote. “Combined use of platelet counts and albumin levels was predictive of survival, even in elderly patients. In particular, the platelet count was an important factor for identifying patients with a dismal outcome.”
In their study, the researchers analyzed samples from 391 DLBCL patients who had received treatment with Rituxan (rituximab) and chemotherapy, and examined the prognostic impact of simple blood markers in addition to the five factors of the NCCN-IPI, and correlated those measures with survival over a five-year follow-up period.
The authors found that both platelet count and albumin levels were independent risk factors for survival. Therefore, using the platelet-albumin score (PA score) that combined both parameters, patients were divided into three distinct groups: low-risk (platelet count equal or above 100,000/μl, albumin equal or above 3.5 g/dl); intermediate-risk (platelet count below 100,000/μl, albumin equal or above 3.5 g/dl, or platelet count equal or above 100,000/μl and albumin below 3.5 g/dl); and high-risk (platelet count below 100,000/μl and albumin below 3.5 g/dl).
The team noticed that both the five-year overall survival (OS) and five-year event-free survival (EFS) was lower in the intermediate-risk group (48.6% and 36.3%) than in the low-risk group (81.5% and 65.1%), but those in the high-risk group had the lowest five-year OS/EFS (20.2% and 11.3%).
The researchers also found that most patients with a platelet count below 100,000/μl were included in the high-risk group, suggesting that platelet count has a relevant contribution for patient prognosis.
Also, Yotaro Ochi and colleagues at the Kobe City Medical Center General in Japan found that the PA score was better at predicting DLBCL patient risk than NCCN-IPI when applied to patients age 60 or older.
“These results suggest that the PA score could identify high-risk patients with a dismal outcome, even in the elderly patient group,” the study authors wrote.
The authors recognize that the small number of patients and the short follow-up period are limitations for the study. Future studies with larger cohorts and a longer follow-up period are warranted to confirm the prognostic value of platelet counts and albumin levels.