Pope Leo's doctors say final tissue and molecular tests have confirmed his lung cancer was localised, and no further treatment is needed, the Vatican said in a statement.
The Pope had the lower lobe of his right lung removed in surgery on 13 October and was diagnosed with lung adenocarcinoma, the most common form of lung cancer.
He returned to the Vatican on Saturday, four days after the procedure, and is gradually resuming his normal duties.
The Pope's personal physician, Dr Luigi Carbone, and his surgeon, Dr Stefano Margaritora, said in a statement that the results of the tests on tissue removed during his surgery confirmed the initial diagnosis, and the cancer had not spread.
"A subsequent oncology assessment confirmed that no further treatment is necessary," the doctors said.
Pope Leo returned to St Peter's Square on Wednesday, waving to pilgrims and blessing babies from his open-air popemobile.
His weekly audience, the first held by the 71-year-old pontiff since 7 October, followed the normal format.
Crowds started gathering hours beforehand, holding umbrellas under drizzling grey skies.
"The first thing I want to say to you is thank you for the support and prayers," Pope Leo said in his opening remarks, without specifically mentioning his health.
"Thanks be to God for his generosity," he added, as cheers broke out.
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The Pope was originally sent for treatment at Rome's Gemelli hospital for the removal of the small nodule, which he said was spotted early during a recent check-up.
Pre-operative tests had suggested adenocarcinoma, and this was confirmed during the operation, the Vatican said.
The surgery on 13 October lasted around 90 minutes and was described as successful.
The Pope was expected to recover in hospital for about a week, but left earlier than expected.
The pontiff left on Saturday afternoon after doctors said he was "fit for discharge" following blood tests and a chest X-ray.
He then led a traditional noontime Angelus prayer from a window of the papal apartment in the Apostolic Palace overlooking St Peter's Square in Vatican City.
After greeting the crowds gathered on Sunday, he thanked those around the world who have prayed for his health and recovery in recent days.
He said: "I have truly felt your support. Thank you."
It was still unclear whether the US-born pontiff would go ahead with a planned trip to Uruguay, Argentina and Peru, scheduled for 6 to 17 November.
The Pope's lead surgeon said last week there were "no clinical reasons" preventing him from travelling to South America, but the Vatican's secretary of state has indicated the pontiff may need to adjust the pace of his schedule.
The Vatican has provided no indication of Pope Leo's schedule beyond Wednesday.
(c) Sky News 2026: Pope Leo's doctors say tests show he needs no further treatment for lung cancer
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