After a surgery on Tuesday in which the lower lobe of his right lung was removed, Pope Leo XIV was diagnosed with lung cancer. Dr. Luis Ráez, a prominent oncologist, explained in an interview with EWTN News what pulmonary adenocarcinoma is and what factors will determine the Holy Father’s next medical steps.

Ráez, who is not treating the pope, serves as the medical director and head of the Thoracic Oncology Program at the Memorial Cancer Institute in Florida.

The Vatican reported that the pope had “the lower lobe of the right lung removed using a video-assisted technique. The intraoperative histological examination has confirmed the diagnosis of pulmonary adenocarcinoma, as was suspected from the preoperative tests.”

The most common lung tumor

“The Holy Father remained in the operating room for approximately 3 hours; the duration of the surgery was approximately 90 minutes. The surgery was a success and there were no complications,” the Holy See added.

Ráez explained that adenocarcinoma “is the most common tumor in the lung” and noted that “in general, lung cancers are more aggressive than those of the prostate or breast.”

However, he clarified that seriousness is not defined solely by the type of cancer, but that “the prognosis depends on the stage, that is, the size of the tumor and how far it has spread.”

‘Stage one or stage two’

The pope said during the Angelus prayer on Sunday, Oct. 11, that a nodule on his lung was detected “at a very early stage” and was “well localized.” Ráez speculated that the decision to operate could confirm that the cancer is not at an advanced stage.

“We assume that is the case because they subjected him to surgery. If it were metastatic, for example, stage three or stage four, which are advanced, most likely they would not have operated on him. An operation usually implies stage one or stage two,” he said.

Asked what will determine whether removal of part of the lung is sufficient or whether additional treatment will be required, Ráez highlighted the importance of the tumor size and the absence of metastases.

“If the tumor is larger than four centimeters, the surgery will not be enough and chemotherapy will be necessary. If the tumor is smaller than four centimeters, the surgery is sufficient and nothing else is done. A patient then moves to an observation phase with check-ups every six months,” he explained.

The recovery process

Regarding the chances of a cure, Ráez noted that, under optimal conditions and with a tumor smaller than four centimeters, the figures are favorable: “The chance of cure for early-stage lung cancer is 80 to 90%; it is not total because the cancer can come back.”

Regarding the physical recovery of Pope Leo XIV, who is 71 years old, Ráez expressed a favorable short-term prognosis. “Since he is a healthy man, the most likely thing is that he will be fine” in a few weeks, he stated.

He added that this surgery usually requires a hospital stay of two or three days in the United States and considered that, in the pontiff’s case, more days of hospitalization may have been planned as a precaution.

Regarding medical follow-up after discharge, the specialist stressed that the protocol does not end when one leaves the hospital. “For the next five years, control CT scans must be done every six months, until one is sure that the cancer has not returned and that he has been cured,” said Ráez, who has more than two decades of experience in hematology and medical oncology.

This story was first published by EWTN News Español, the Spanish-language sister service of EWTN News. It has been translated and adapted by EWTN News English.