Former U.S. President Jimmy Carter is undergoing treatment to battle cancer. Just recently, Carter's spokeswoman revealed that he is responding to treatments smoothly and there are no new cancer cells found.

Despite battling cancer, there is still good news from the 39th U.S. President. Spokeswoman Deanna Congileo provided the latest update about the 91-year-old's condition. According to her statement, as quoted by the Associated Press, doctors from Emory University's Winship Cancer Institute said that Carter's "recent tests have shown there is no evidence of new malignancy, and his original problem is responding well to treatment."

The news is a positive one especially for the health of the former president. Dr. Sapna Patel, a melanoma specialist at the MD Anderson Cancer Center in Houston, even released a statement saying that Carter has a lot of reason to be optimistic.

"We couldn't infer necessarily that the cancer is gone, but nothing is spreading, nothing is growing, nothing is worsening," she said. "This is considered really good news, if after a few short months, nothing is growing ... and there doesn't appear to be any new cancer."

The Associated Press further revealed that in August, Carter removed melanoma from his liver and discovered four small tumors on the back of his brain. Since then, he had been receiving radiation treatment including four doses of Keytruda, a newly approved drug that will make his immune system fight cancer cells.

So far, Carter has been responding well to that kind of treatments given to him. Dr. Len Lichtenfeld, deputy chief medical officer for the American Cancer Society said per the Associated Press, "We certainly hope the president will continue on his current course. At this point, it appears his treatment has been as effective as possible."

Congileo also informed that the former president will undergo more tests. What is important, according to reports, is that so far, Carter hasn't experienced any discomfort or illness following drug treatments for his illness.

BBC News noted that Carter served as U.S. president from 1977 to 1981 and won a Nobel Peace Prize in 2002. Since leaving office and announcing his illness back in August, the former president had been involved in humanitarian work including the latest one in Nepal. However, his volunteer work was previously halted as the country suffered from "civil unrest."