Abstract

Background: Treatment and prognosis of diffuse large B cell lymphoma (DLBCL) depends on the stage of lymphoma. We conducted this study to examine unstaged DLBCL in the United States.

Methods and methodology: We used Surveillance Epidemiology and End Result (SEER) 18 registries to select patients with DLBCL diagnosed during January 2000 to December 2012. We used LRD Summary stage 2000 was used to determine stage of the disease - localized, regional, distant or unstaged. We used Logistic regression to investigate factors associated with unstaged DLBCL. We used Cox Proportional Hazard model to compare survival outcomes.

Results: Among 67765 patients, 3194 (4.71%) were unstaged. Age (60+years), "Others" and Caucasian races, single or single/divorced/widow marital status, metropolitan residence, median household income> $50,000, lymph node as the primary site and cased with other primaries before diagnosis of DLBCL were the factors associated with unstaged cases (Table 1). The 5- year relative survival rate for unstaged patients was inferior to those with localized and regional disease, and superior to those with distant disease (HRs of 0.58, 0.66 and 1.24 for localized, regional and distant respectively when compared to unstaged cases).

Conclusion: In this large population-based study, 4.71% patients with DLBCL had unstaged disease. Patients with unstaged DLBC had significantly inferior survival rates compared to patients with localized and regional stage.

Table 1.

Factors associated with unstaged DLBCL cases

ParametersUnadjusted OR (95% CI)P valueAdjusted OR (95% CI)P value
Age (60+ Vs. <60 years) 1.478 (1.363 - 1.602) <0.001 1.458 (1.335 - 1.592) <0.001 
Sex (Female Vs. Male) 1.063 (0.990 - 1.141) 0.093 0.983 (0.911 - 1.059) 0.646 
Race     
Caucasians Reference  Reference  
African American 0.804 (0.691 - 0.935) 0.005 0.835 (0.715 - 0.974) 0.022 
Others 1.109 (0.976 - 1.261) 0.112 1.257 (1.104 - 1.431) 0.001 
Marital Status     
Married Reference  Reference  
Single 1.026 (0.927 - 1.135) 0.662 1.208 (1.086 - 1.345) 0.001 
Single/divorced/widow 1.249 (1.152 - 1.355) <0.001 1.185 (1.087 - 1.291) <0.001 
Rural/Urban     
Rural Reference  Reference  
Urban 0.878 (0.651 - 1.183) 0.393 0.896 (0.661 - 1.214) 0.479 
Metropolitan 0.882 (0.667 - 1.165) 0.882 1.028 (0.767 - 1.379) 0.852 
Median annual household income     
Upto 25,000 Reference  Reference  
>25,000-50,000 01.009 (0.753 - 1.354) 0.951 0.927 (0.675 - 1.271) 0.636 
>50,000 0.758 (0.563 - 1.021) 0.068 0.673 (0.486 - 0.933) 0.017 
Sequence (Not first or only primary vs. first or only primary) 1.261 (1.156 - 1.377) <0.001 1.219 (1.115 - 1.334) <0.001 
Site of primary     
Lymph nodes Reference  Reference  
Extra-lymphatic 0.760 (0.704 - 0.821) <0.001 0.748 (0.693 - 0.808) <0.001 
Unknown primary 6.295 (4.569 - 8.672) <0.001 6.727 (4.865 - 9.300) <0.001 
ParametersUnadjusted OR (95% CI)P valueAdjusted OR (95% CI)P value
Age (60+ Vs. <60 years) 1.478 (1.363 - 1.602) <0.001 1.458 (1.335 - 1.592) <0.001 
Sex (Female Vs. Male) 1.063 (0.990 - 1.141) 0.093 0.983 (0.911 - 1.059) 0.646 
Race     
Caucasians Reference  Reference  
African American 0.804 (0.691 - 0.935) 0.005 0.835 (0.715 - 0.974) 0.022 
Others 1.109 (0.976 - 1.261) 0.112 1.257 (1.104 - 1.431) 0.001 
Marital Status     
Married Reference  Reference  
Single 1.026 (0.927 - 1.135) 0.662 1.208 (1.086 - 1.345) 0.001 
Single/divorced/widow 1.249 (1.152 - 1.355) <0.001 1.185 (1.087 - 1.291) <0.001 
Rural/Urban     
Rural Reference  Reference  
Urban 0.878 (0.651 - 1.183) 0.393 0.896 (0.661 - 1.214) 0.479 
Metropolitan 0.882 (0.667 - 1.165) 0.882 1.028 (0.767 - 1.379) 0.852 
Median annual household income     
Upto 25,000 Reference  Reference  
>25,000-50,000 01.009 (0.753 - 1.354) 0.951 0.927 (0.675 - 1.271) 0.636 
>50,000 0.758 (0.563 - 1.021) 0.068 0.673 (0.486 - 0.933) 0.017 
Sequence (Not first or only primary vs. first or only primary) 1.261 (1.156 - 1.377) <0.001 1.219 (1.115 - 1.334) <0.001 
Site of primary     
Lymph nodes Reference  Reference  
Extra-lymphatic 0.760 (0.704 - 0.821) <0.001 0.748 (0.693 - 0.808) <0.001 
Unknown primary 6.295 (4.569 - 8.672) <0.001 6.727 (4.865 - 9.300) <0.001 

Disclosures

No relevant conflicts of interest to declare.

Author notes

*

Asterisk with author names denotes non-ASH members.