A Comparison of therapeutic strategies consisting of different combinations of surgery and/or radiotherapy in Pulmonary MALT-MZL: A population-based Analysis of SEER Data, 1992-2013

Abstract Background Pulmonary marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue type (MALT) is recognized as the most common type of primary pulmonary lymphomas. However, due to its relatively-low proportion, the studies focused on this patient population were limited. We aimed to reveal the status of surgery and radiotherapy in survival of pulmonary MALT lymphoma patients. Methods A retrospective analysis was conducted on patients who were pathologically diagnosed as pulmonary MALT lymphoma between 1992 and 2013. Their treatment information was collected in Surveillance, Epidemiology, and End Results (SEER) database. According to the different treatments, they were divided into four groups: Both Surgery and Radiation(SR), Surgery(S), Radiation(R) and No Surgery Or Radiation(NSR). The further subgroup analyses were performed according to age of onset and clinical stages. Overall survival (OS) was calculated from diagnosis up to the date of death or the last follow-up of each patient. Survival curves constructed by the Kaplan-Meier method and log-rank test were utilized for comparison. Results There were 860 pulmonary MALT lymphoma patients were enrolled. The median OS was 55.0 months (0-256.0 months). The OS between patients who underwent surgery and/or radiotherapy(S/R/SR) or not(NSR)(473 VS 387) had shown a significant difference of each other(P < 0.0001), so did the comparison among the four subgroups(SR VS S VS R VS NSR, P < 0.0001). Although there wasn’t any statistical difference in the OS between SR and S groups (P = 0.1174), further analysis on the causes of death revealed that, additional radiation therapy may lead to good short-term efficacy, while elevated mortality associated with long-term pulmonary complications was noteworthy. In the subgroup analyses, patients in stage I-II and over 60 years old shared similar trends with total population involved in the study(P = 0.0001;P < 0.0001). Conclusions The present study confirmed the value of surgery and the possible effects of radiotherapy among patients with pulmonary MALT lymphoma by clinical data from a large number of samples. If the improved radiotherapy regimens are chosen or the pulmonary complications caused by radiotherapy are well-managed, chances will be high that extra benefits could be achieved by combining radiotherapy with the surgical-based therapy.