Bendamustine + Rituximab in Older Patients With Previously Untreated Diffuse Large B-cell Lymphoma

The purpose of this research study is to learn about the safety of the treatment with a combination of bendamustine and rituximab and to find out what effects, both good and bad this treatment has on DLBCL. In addition to learning about the combination of bendamustine and rituximab, the researchers are interested in learning about how this cancer treatment affects daily activities. Subjects will be asked to complete a Geriatric Assessment (GA). GAs are designed to gather information on memory, nutritional status, mental health, and level of social support. GAs are also designed to help the health care team understand how well subjects can carry out their day to day activities and to briefly describe what other medical conditions subjects may have. This assessment will help the health care team understand a subject's "functional age" (the age a subject functions at) as compared to a subject's actual age. The researchers also want to learn how chemotherapy affects the aging process in our bodies. This is done by measuring the amount of p16 in blood. Researchers want to understand if chemotherapy changes the levels of p16 in blood.