The survival rate for esophageal cancer is, according to Dr. K. Robert Shen, bleak. Last year, there were 17,000 Americans diagnosed with the disease and nearly 16,000 of them died, the Mayo Clinic cardiothoracic surgeon told Drug Delivery Business News.
“It’s almost reached an epidemic,” Shen said. “It doesn’t get a lot of airplay and it’s not as commonly discussed as breast cancer or colon cancer, probably because the total number of patients is not as dramatic. I think the other thing that influences whether or not you see walks for fundraising is, unfortunately, there are very few survivors of this cancer.”
Shen thinks that in the last three or four decades, doctors have seen as much as a six-fold increase in the number of people coming to their clinics with esophageal cancer.
For patients with locally advanced cancer, the standard of care is aggressive.
“Those are the patients that are treated really with everything that we have in the tool-bag,” Shen said.
First, patients are treated with chemotherapy and radiation therapy for six weeks. That means radiation every day of the week, for five weeks, along with four to five rounds of chemotherapy. Then, after recovering for a month and a half, patients without evidence of metastatic cancer undergo an operation where a surgeon removes most of their esophagus, reconstructs their upper gastrointestinal tract and reroutes their stomach to replace the esophagus that was removed.
And for the most part, patients with locally advanced esophageal cancer are treated equally. But Shen thinks that, in light of his research, its time for a new approach.
In the early 2000s, his team began to notice that women with esophageal cancer were responding better to treatment than the men in their clinic. Shen and his colleagues decided to launch a study to try and rule out potential confounding variables.
They combined data from all three Mayo Clinic sites over a 23-year period. Ultimately, they came up with 145 female patients with locally advanced esophageal cancer. Matching them two-to-one against 221 male patients, the team controlled for variables like age, the clinical stage of the cancer and the era in which the patients received treatment.
Female patients had a 58% rate of pathologic complete response or near-complete response, compared to 47% of the male patients. Men had a 80% higher risk of recurrence, Shen noted, and female patients had a five-year disease-free survival rate of 72%, compared to 55% for the male patient group.
“I think it has a lot of intriguing potential implications for how patients are treating going forward,” Shen said. “I think the one obvious question that comes out of this kind of observational analysis is, what’s the reason that underlies that or explains the fact that women seem to do better?”
Women are less likely to develop esophageal cancer in the first place. Shen pointed out that one challenge his team faced in putting together this study was finding women to include in the analysis in the first place.
“The obvious potential factor that’s influencing things, of course, are the sex hormones themselves,” Shen said.
Heart disease is one therapeutic space that estrogen has proven to be protective. Women don’t develop coronary artery disease at the rate of men, Shen noted, until they reach menopause.
It could also be possible that testosterone is harmful, spurring on the pathogenesis of some cancers, according to Shen.
As his team continues to investigate why women respond better to treatment for esophageal cancer, Shen hopes that his findings will influence the way patients are treated.
“There’s increasing appreciation and realization that cancers, even the ones that are the same stage, in different patients is very different based on the underlying genetics and gene mutations that are driving the cancer,” he said. “The trend in cancer treatment overall is to be more individualized and personalized. We’re beginning to ask for all cancers, what are the genetic mutations or genetic patterns in the patient’s tumor that lend themselves to targeted therapies?”