An analysis of data on nearly 11,000 patients points to a surgical treatment approach that the study authors say could “provide a survival advantage” for certain patients with a form of stomach cancer that has spread to the liver – a strategy that probably would not have been attempted not long ago.
The study, “The Role of Metastasectomy in Patients with Liver-Only Metastases from Gastric Adenocarcinoma,” was published recently in the journal Annals of Surgical Oncology. It was co-authored by Ioannis Ziogas, MD, MPH, a University of Colorado Department of Surgery resident and surgical research fellow; and Benedetto Mungo, MD, a University of Colorado Cancer Center member and assistant professor in the CU Division of Surgical Oncology.
Several of their CU surgical oncology and medical oncology colleagues co-authored the paper, including Richard Schulick, MD, MBA, the CU Cancer Center’s director and chair of the CU Department of Surgery.
“It’s a team effort,” Ziogas says. “We’re very excited to be at a place where teamwork thrives, and we can work together to provide the best outcomes for patients.”
‘How do we make this even better?’
The study focused on gastric adenocarcinoma, the most common type of stomach cancer. Advanced-stage, metastatic stomach cancer that has spread to other organs has often been difficult to treat successfully.
Mungo says that when he began his medical training in the 2010s, “metastatic cancer, stage IV cancer, was something where you would not think about surgery, ever. But as chemotherapy got better, and immunotherapy came along, we were able to put some cancers on hold, so even people who had disease that had spread to other organs were alive for longer. So we started thinking, how do we make this even better? How do we finish off what the chemotherapy has started for us?”
Ziogas says that improvements in treatments “allow us to treat more patients and see who responds better to chemotherapy, and that way we can find ways to select patients that may respond better to surgery as well. These multidisciplinary treatments by both medical and surgical oncologists can offer better outcomes to well-selected patients nowadays than before.”
Comparing median overall survival
Ziogas, Mungo, and their colleagues set out to compare the benefits of various surgical strategies in patients with gastric adenocarcinoma when the cancer has spread to the liver but not to the brain, bones, lungs, or other organs. In particular, they hoped to learn more about the benefits of surgical removal (metastasectomy) of those secondary growths in the liver.
So, they studied a decade’s worth of clinical registry records in the National Cancer Database covering 10,977 adult patients with gastric adenocarcinoma and synchronous liver-only metastases. Of those patients, 93.6% had no surgical treatment, 4.6% had only the primary tumor in the stomach removed (resected), 0.8% had liver metastasectomy alone, and 1% had both primary tumor resection and liver metastasectomy. Most patients in all four groups had received chemotherapy treatment.
“What we found, surprisingly, is that the cohort that got both surgical treatment to the stomach and the liver metastases seemed to perform better than the rest of the population,” Ziogas says.
The study compared the four treatment strategies by median overall survival – the point of time after the start of treatment when half the patients in each group were still alive and half had died.
Median overall survival for the no-surgery patients was 6.5 months, for those with primary tumor resection alone was 10.9 months, and for those with liver metastasectomy alone was 9.9 months. But for those patients with both primary tumor resection and liver metastasectomy, median overall survival was 18.6 months, and some were still alive several years later.
Strict screening needed
“These data suggest that, in highly selected patients with gastric adenocarcinoma and synchronous liver-only metastases and favorable biology, surgical resection might grant a survival advantage,” Ziogas and Mungo wrote.
They stressed that “surgical treatment should be considered as an option only for a minority of patients with highly favorable biology and excellent functional status, who are carefully selected
through strict multidisciplinary screening.” They noted that the patients in the group with the longest median overall survival tended to be younger and have fewer threatening comorbidities.
“We’re not trying to say that everybody with stage IV gastric cancer with metastasis to the liver should get surgery,” Mungo says. “What we’re trying to bring attention to is that there’s a subpopulation of patients with good biology where there might be a role for very aggressive surgery as well.”
He also says the study “highlights the value of reviewing these challenging cases in a multidisciplinary fashion, which happens here at the CU Cancer Center, to select patients carefully.”
Hope for helping more patients
Ziogas notes that the database they analyzed has some limitations. “For example, we don’t know exactly how many cancer sites in the liver the patients may have had, their size, or whether they were in one or both lobes of the liver. So, moving forward, future studies that focus on these specific details can help us further delineate how to select patients best suited for this kind of treatment.”
Says Mungo: “We think there is a small number of patients with this disease for whom we can perhaps make a difference now. And as new discoveries come along – new drugs, new molecules – the hope is that we can extend this kind of surgical treatment to more and more people.”
Ziogas, from Greece, has completed his first two years of surgical residency and is now pursuing research before completing his residency. Mungo says Ziogas was recruited by the General Surgery Residency program of the Department of Surgery, which “targets talented medical students from all over the world to become residents with us with the goal of training the academic leaders of tomorrow. When we hired him, he already had a research CV comparable to that of someone 10 years ahead of him in career.”
Mungo also added a special mention of one of their co-authors, Martin McCarter, MD, a surgical oncology professor and surgical director of the CU Cancer Center’s Esophageal and Gastric Multidisciplinary Clinic. “He has been the cornerstone of gastric research here for a long time,” he says. “He is a phenomenal mentor who has trained generations of us.”
