Minimally invasive distal pancreatectomy with splenectomy is a safe and effective alternative to traditional open surgery for patients with resectable pancreatic cancer, according to results from DIPLOMA, an international randomised trial.

This surgical approach, which removes tumours located on the body or the tail of the pancreas and the spleen, uses smaller incisions and offers a lower risk of serious complications compared to open surgery.

The research will be presented at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting. 

DIPLOMA is the first randomised, patient-blinded study to compare outcomes between open surgery and minimally invasive surgery for patients with early-stage pancreatic cancer when tumours are present on the body or tail of the pancreas.

Open distal pancreatectomy uses one large incision, while minimally invasive surgery uses several smaller incisions.

During this surgery, the spleen is also removed for further lymph node retrieval.

This is a non-inferiority trial, which compares an established treatment with another treatment to confirm that the new treatment is not worse than the established standard of care.

Both surgical techniques had comparable results.

The primary endpoint for the study was radical resection or complete removal of the tumour and some surrounding healthy tissue.

Radical resection occurred in 83 patients (73%) in the minimally invasive group and in 76 patients (69%) in the open surgery group.

After surgery, researchers also found:

The number of lymph nodes removed during surgery, or the median lymph node yield, was 22 in the minimally invasive group and 23 in the open surgery group.

The minimum lymph node yield for a successful distal pancreatectomy is 13 lymph nodes.

Intraperitoneal recurrence, or a cancer recurrence that occurs in the peritoneal cavity, was 41% in the minimally invasive group and 38% in the open surgery group.

“Surgery has made significant advances in the last two decades. One of the most important is the introduction of minimally invasive surgery. For pancreatic cancer, we have proven for the first time that minimally invasive distal pancreatectomy is as good as open surgery. Our research provides reassurance for surgeons and can help patients by giving them the information they need to have a conversation with their doctor about how they want to be treated,” said lead author Mohammad Abu Hilal, MD, PhD, Surgical Director at the Instituto Ospedaliero Fondazione Poliambulanza in Brescia, Italy.

In 2023, an estimated 64,050 adults will be diagnosed with pancreatic cancer in the United States, and only 12% of them will be diagnosed at an early stage when surgical removal of the tumour is possible.

The 5-year relative survival rate for early-stage pancreatic cancer that can be treated with surgery is 44%.¹

Previous research comparing these two surgical techniques has been in the form of systematic reviews, showing a similar outcome between open distal pancreatectomy and minimally invasive pancreatectomy.

However, concerns have been raised by one-third of pancreatic surgeons surveyed regarding the safety and efficacy of minimally invasive surgery compared to open surgery.

This randomised, blinded trial provides evidence that minimally invasive distal pancreatectomy is a viable option for people with early-stage resectable pancreatic cancer. 

Between May 2018 and May 2021, the international phase III DIPLOMA trial enrolled 258 patients with resectable pancreatic cancer.

Of those, 231 continued with the trial and were randomly assigned to either the intervention group, receiving minimally invasive distal pancreatectomy, or the control group, receiving standard open surgery. 

Both the patient and the pathologist who examined the samples were blind to the type of surgery received.

Researchers will continue to follow these patients to compare their outcomes at three years and five years and additional analysis of the samples retrieved during this study will look at the number of lymph nodes removed in the spleen to determine if removing the spleen is necessary.

Researchers will also do additional trials to compare outcomes between the laparoscopic and robotic minimally invasive surgical techniques.  

References:

1. Pancreatic Cancer: Statistics

Source: ASCO