Sen. Frank Lautenberg (D-N.J.) has been diagnosed with B-Cell Lymphoma in his stomach, and will undergo between six and eight rounds of chemotherapy to treat the tumor, according to a statement from his office.

Lautenberg collapsed earlier this week, and was said to have a bleeding ulcer. But after several days of testing, his condition, also known as Non-Hodgkins Lymphoma, is clearly much more serious.

One of the doctors treating Lautenberg, Dr. James F. Holland, said in the statement he anticipated the senator would be returning to work between chemo treatments, which he said would be administered about every three weeks.

Numerous members of Congress have been treated for cancer while in office, most notably Lautenberg's fellow Democrat, Sen. Arlen Specter (Pa.), who battled Hodgkins Lymphoma in both 2005 and 2008. The lawmaker wrote a book about his experiences titled "Never Give In: Battling Cancer in the Senate"

Survival rates for non-Hodgkins Lymphoma vary widely, based on a number of risk factors. Lautenberg turned 86 years old last month.