The Vatican said that after part of Pope Leo’s right lung was removed during surgery, he was diagnosed with lung cancer.

Reuters reported that tests showed the 71-year-old pope has “lung adenocarcinoma.” Pope Leo was taken to Gemelli Hospital in Rome for surgery on Tuesday after a mass was identified during a routine examination.

The doctors said the operation took about 90 minutes and was carried out without complications. They removed the lower part of his right lung to remove cancerous tissue.

Steven Liu, a lung cancer specialist, told Reuters that the stage of the cancer is not yet known and that the size of the tumor and the likelihood of the disease spreading to the lymph nodes need to be assessed to determine the treatment approach. According to him, if the cancer is small and the lymph nodes are not involved, surgery may be sufficient for treatment.

The Vatican said the pope regained consciousness naturally after the surgery and is resting in the hospital. He is expected to remain hospitalized for about a week, and his public engagements have been canceled until October 20. It is not yet clear whether his trip to South America in November will take place or not.