Fox Chase Cancer Center Study Shows That Examining More Lymph Nodes Was Associated With Improved Outcomes for Patients With Colon Cancer

PHILADELPHIA (March 31, 2025) — Removing and testing at least 18 lymph nodes during surgery was associated with more accurate staging and better survival rates for colon cancer patients, according to research presented today at the Society of Surgical Oncology 2025 Annual Meeting. The findings from researchers at Fox Chase Cancer Center challenge the current standard of care for staging colon cancer, which calls for removal and examination of 12 lymph nodes.

Patients with colon cancer have lymph nodes removed along with their colon to determine whether their cancer has started to spread to the nodes. Patients with cancer that has spread benefit from receiving chemotherapy after surgery, which has been proven to increase their survival and cure rates. Thus, taking out enough lymph nodes during surgery to accurately determine if the cancer has spread is a critical step in a patient’s care.

A team of Fox Chase researchers set out to determine whether removing and testing more than the current standard resulted in more accurate staging and better outcomes. The team was headed by Praveen Chatani, MD, a Complex General Surgical Oncology Fellow at Fox Chase and lead author on the study, and senior author Anthony Villano, MD, FACS, Assistant Professor in the Department of Surgery.  

Using data from the National Cancer Database (NCDB), the team analyzed the records of 195,000 patients who underwent colon resection surgery between 2010 and 2021. The researchers determined the likelihood of a patient being “upstaged” to stage III based on the number of lymph nodes they had removed and tested. Patients who had at least 18 nodes taken out were more likely to have disease found in their lymph nodes, compared to patients who had 12 to 17 nodes removed. With each additional node removed, the odds of upstaging increased.

Thus, removing at least 18 nodes improved the accuracy of identifying who needs chemotherapy. Importantly, patients who had at least 18 lymph nodes removed received indicated chemotherapy more frequently and lived 21 months longer on average than those who had fewer lymph nodes removed.

“For patients with colon cancer, having disease in your lymph nodes is the difference between stage II and stage III. For most patients, it determines whether they need chemotherapy after surgery,” said Chatani. “Our results show that by taking out and studying more lymph nodes — at least 18 — we are far less likely to incorrectly label a patient as stage II. This means patients are more likely to get the right treatment after surgery and, ultimately, live longer.”

Chatani and his colleagues also found that more than a quarter of patients will have their cancer upstaged to stage III after lymph node removal. They were also able to identify specific risk factors for being “upstaged,” so they could more appropriately counsel patients on this risk before operating.  

“Patients want to know their odds of needing postoperative chemotherapy” said Chatani. “Prior to our research, we have not had convenient tools to accurately predict who will have involved lymph nodes following surgery. We should be able to quantify someone’s risk of having nodal disease and use that to frame the conversation. Telling someone ‘You’re probably going to need chemo’ and mentally preparing them for that goes a long way in fostering a patient’s comfort with their treatment plan. Nobody likes surprises.”

Based on their research, Chatani and his team identified numerous predictive factors for upstaging and are using them to quantify the likelihood of having cancerous lymph nodes despite a negative CT scan. Jordan Fredette, MPH, a statistician and co-author on the study, translated the data into a user-friendly risk calculator. “Once finalized, it will be made available to physicians nationwide and could fundamentally change the way we counsel patients before colon cancer operations,” said Chatani.

The study, “Incidence of and Risk Factors for Radiographically Occult Nodal Metastases in Colon Cancer: Is it Time for a New Lymphadenectomy Standard?” was delivered as a podium presentation at the Society of Surgical Oncology 2025 Annual Meeting, which is being held in Tampa, Florida, March 27-29.