Intraductal papillary mucinous neoplasms (IPMNs) are cystic lesions that can form by the ducts of the pancreas. They generally are asymptomatic and discovered in the course of testing for other conditions.
In a minority of cases, intraductal papillary mucinous neoplasms (IPMNs) can progress to pancreatic cancer. This has become a confounding factor in solid organ transplantation: If a person on the transplant waiting list is discovered to have IPMNs, and then the immunosuppressants they take to help prevent organ rejection are associated with increased risk for some cancers – immunosuppressants make the immune system less able to detect and destroy cancer cells – should that person have surgery to remove the IPMN? Or be taken off the transplant list?
A recently published study by University of Colorado Cancer Center and Department of Surgery researchers indicates that transplant patients diagnosed with IPMN do not have a drastically increased risk for IPMN progression.
“Overall, the principle here is it seems that if you have a pre-transplant patient with IPMN who doesn’t require surgical resection, they can have the transplant without increased risk of cancer,” says Marco Del Chiaro, MD, PhD, professor and chief of surgical oncology in the CU Department of Surgery and the study’s lead author. “The number of transplant patients is increasing every year, and for a long time there’s been this question of, ‘This patient has been discovered to have IPMN, can we still perform a transplant?’ Even though generally we’ve said yes, now we have some data to support it.”
No significant increase in risk
Del Chiaro and his research colleagues analyzed data from 11 studies containing IPMNs in solid organ transplantation, representing 274 patients with IPMNs of 8,213 total solid organ transplant recipients.
The various studies followed solid organ transplant recipients for between two to 18 years. In 10 of the studies, researchers found that the median rate of all progressions to cancer was 20%. That progression happened within one to three and a half years of median follow-up time.
These findings do not represent a significant difference in rates of progression to cancer in solid organ transplant and non-transplant populations with IPMNs.
“The problem of IPMNs is actually bigger than transplant surgery,” Del Chiaro explains. “Because some IPMNs can progress to cancer, it creates a problem of differential diagnosis – when to treat and how to treat. Here you have a precancerous lesion and it is challenging to know the correct timing for surgery.”
Providing necessary data
The issue of IPMNs has become significant in transplant surgery for several reasons. Each type of solid organ that is transplanted requires a specific amount of immunosuppression, with some organs requiring more or less than others. And because immunosuppression can increase a person’s risk for certain types of cancer, care teams are considering how best to reduce a patient’s risk of progression to cancer.
However, major surgery is required to remove IPMNs and patients on transplant waiting lists can often be in more physically vulnerable states, making major surgery that much more difficult, Del Chiaro says. So, transplant care teams have grappled with how to proceed when a patient on the transplant waiting list is discovered to have IPMN.
While further research is needed, Del Chiaro says, “this is a good start in providing data so that we don’t feel we have to put pre-transplant patients through a major surgery, that we can give them the best possible care, we don’t need to take them off the waiting list, and their cancer risk isn’t necessarily increased.”
He adds that the current study lends support to the concept that transplant patients should be surgically treated in the same way as patients not receiving a transplant.