Pope Leo XIV, elected less than 18 months ago and widely viewed as a pope with the potential for a lengthy tenure, was diagnosed with lung cancer earlier this week, introducing uncertainty about his health and the future of his papacy. The Vatican announced on Tuesday that the pope underwent surgery to remove a lower lobe of his right lung, describing the procedure as successful and without complications. Officials also indicated that the cancer was detected at an early stage.

At 69 years old, Pope Leo — born Robert Francis Prevost in Chicago and the first U.S.-born pontiff — was considered relatively young compared to recent predecessors, many of whom assumed the papacy at older ages or with known health issues. His apparent good health and active lifestyle, which reportedly included regular tennis, bolstered expectations that he had many years ahead to lead the Roman Catholic Church.

Observers had noted his calm and steady approach to leadership, contrasting with the more tumultuous papacy of his predecessor, Pope Francis, who began his tenure at age 76 with existing lung issues. While Francis initially predicted a brief papacy of a few years, he served for more than a decade despite declining health marked by knee problems, intestinal ailments, and pneumonia in his final months.

Pope Leo’s diagnosis has disrupted a prevailing assumption among clergy and laity alike that his papacy would be long and stable. His demanding schedule, which included frequent public appearances and the recent publication of a significant document on artificial intelligence, did not show signs of health impairment until the diagnosis was publicly announced.

“The common consensus was he’s young, we’re in for a long papacy,” said Christopher White, a senior fellow at the Initiative on Catholic Social Thought and Public Life. White highlighted the pope’s disciplined self-care as a factor that contributed to the surprise surrounding the diagnosis.

From the beginning of his pontificate, Pope Leo appeared measured and deliberate. His initial months were marked by a cautious approach to personnel changes and policy statements, focusing more on reconciliation and listening than swift reform or controversy. Even when he faced political disputes, such as criticizing the Trump administration’s posture toward Iran, he responded modestly and sought to avoid escalating confrontations.

The pope’s illness poses questions about the Church’s leadership trajectory and could impact his ability to pursue his agenda, which has aimed at bridging divides within the Church and addressing contemporary moral issues. Transparency about the progression of his treatment may influence public confidence, with some experts noting that such health challenges have the potential to inspire a narrative of resilience and renewal if recovery proceeds well.

David Gibson, director of the Center on Religion and Culture at Fordham University, said the news “creates disquiet,” reflecting widespread concern about the pope’s condition. Nevertheless, with timely medical intervention and close monitoring, there remains cautious optimism about Leo’s ability to continue his papacy.