An external review released March 30 concluded there is no evidence of a workplace tumor cluster at Newton-Wellesley Hospital after 11 nurses on the fifth floor reported being diagnosed with brain tumors. The review found the hospital environment is safe and i
For nurses at Newton-Wellesley Hospital, the fear started with a diagnosis—and then multiplied. Over time. 11 nurses who had worked on the hospital’s fifth floor reported being diagnosed with brain tumors. raising alarm inside the workplace and prompting a widening investigation into possible environmental causes.
An external review published March 30 concluded there is no evidence that the hospital’s facility caused the tumors. The report. written by Stefanos Kales. a professor of medicine at Harvard Medical School. found that “the overall hospital environment is safe” and that the reported cases do not appear to represent a true workplace tumor cluster.
Kales said the most important finding was that no known. reported or documented carcinogenic or tumorigenic exposures were identified on the 5th floor. or in any other randomly selected patient-care units. In the review, Kales, working with the Environment Health & Engineering unit, examined the 11 reported brain tumor cases. According to the report, two of the tumors were malignant, while the remaining cases involved benign tumors.
Newton-Wellesley Hospital President and Chief Operating Officer Ellen Moloney said the cases involved nurses who worked on the hospital’s fifth floor over the past 23 years. In a letter to the Mass General Brigham staff announcing the external review results. Moloney wrote that the findings align with previous assessments and that no environmental risks have been identified in the hospital workplace.
The review comes after concerns first surfaced in April 2025. when Newton-Wellesley Hospital disclosed that five nurses working on the same floor had been diagnosed with non-cancerous brain tumors. Hospital officials later confirmed a sixth case a week afterward. By May, at least seven current or former staff members had reported brain tumors.
At the time those worries were emerging. hospital officials said an investigation by Mass General Brigham Occupational Health Services found no evidence that workplace conditions caused the tumors. The investigation looked at potential exposures that included radiation from x-rays, drinking water, and ionizing radiation from chemotherapy.
The Massachusetts Nurse Association criticized the hospital’s earlier approach. calling its environmental testing “not comprehensive.” The union said the hospital’s investigation focused on the maternity unit. while reports of cases extended beyond that area. In contrast, the external review backed the earlier conclusions. Kales wrote that investigators had “gone well beyond the expected” and conducted “exhaustive environmental evaluations,” finding no relevant exposures.
Moloney said the external review included testing air and water quality, radiation exposure, and chemical and pharmaceutical safety. The review also included interviews with current and past staff and the review of potential risk factors.
In her letter. Moloney wrote. “No exposures or environmental conditions were identified that could cause the types of benign brain tumors reported.” The report states the diagnoses do not meet the public health definition of a tumor cluster because they do not involve an unusual number of the same type of tumor. Instead, the 11 diagnoses included several different tumor types with different causes and risk factors.
The external review found no workplace exposure that could explain the tumors. and it also found no evidence of harmful chemical exposure and excess radiation exposure. Kales wrote that “the likelihood that additional investigations will yield evidence-based information leading to a different conclusion is highly unlikely.”.
Newton-Wellesley Hospital tumor cluster brain tumors fifth floor nurses Stefanos Kales Harvard Medical School Mass General Brigham Massachusetts Nurse Association
So basically it’s all in their heads? Kinda feel like that’s what they’re saying.
I don’t buy it. 11 nurses is still a lot. Even if they found no “carcinogenic exposures,” how do they know for sure nothing was missed on that floor over 23 years? Feels like they’re just closing the book.
Wait I thought this was about a “tumor cluster” like one contagious thing?? Like radiation from something? Also the article says benign tumors too so I’m confused what they’re calling a cluster in the first place. Glad they say environment is safe but… I dunno.
Harvard professor review means nothing to me tbh. They “randomly selected patient-care units”?? Randomly how, like pick and choose vibes? If the fear started because of the diagnosis, of course people are gonna assume it’s the workplace. I think the hospital should’ve done better sooner and kept testing, not just one external report on March 30.