Patients suffering from pancreatic cancer who are obese may have a shorter survival rate after diagnosis, compared with patients of a healthy weight, according to a study published in the Journal of Clinical Oncology.
The American Cancer Society says that around 45,220 people will be diagnosed with pancreatic cancer in the US this year, and around 38,460 will die from the disease. The majority of patients with pancreatic cancer (pancreatic adenocarcinoma) survive less that a year following diagnosis.
A team of US researchers say previous studies have shown that high body mass index (BMI) may increase the risk of developing pancreatic cancer. But they note there has been limited research on whether obesity affects disease aggression or survival following diagnosis.
In 1986, the researchers began to look for a link between patients' pre-diagnostic BMI and their survival after diagnosis of pancreatic cancer. Patients were selected from the Nurses' Health Study and the Health Professionals Follow-up study.
Importance of maintaining a healthy weight
Researchers say that obese patients with pancreatic cancer may live 2 to 3 months less, compared with healthy-weight patients who have the disease.
For this most recent study, the researchers analyzed 902 of these patients who had developed pancreatic adenocarcinoma over a 24-year follow-up period.
Results of the analysis revealed an overall median length of survival of 5 months after diagnosis.
However, the findings showed that on average, patients with a healthy weight (BMI less than 25 kg/m2) lived 2 to 3 months longer than patients who were obese (BMI more than or equal to 35 kg/m2).
The researchers note that this finding was relevant even after adjusting for age, gender, race/ethnicity, smoking status and the stage of the disease.
Furthermore, patients who were obese were more likely to be diagnosed with an advanced form of pancreatic cancer, with 72% of obese patients having metastatic cancer at diagnosis, compared with 59% of healthy-weight patients.
The study also found that the 202 patients who were obese 18 to 20 years prior to diagnosis demonstrated an even shorter survival rate following diagnosis. From this, the researchers hypothesize that being overweight for prolonged periods may lead to worse outcomes.
Brian M. Wolpin, assistant professor of medicine at Dana-Farber Cancer Institute and Harvard Medical School in Boston, says:
"This study adds to mounting evidence for the role of weight control in improving outcomes for patients with cancer.
It also reinforces the importance of maintaining a healthy weight throughout your life, which may lead to better outcomes after diagnosis and help prevent pancreatic cancer from developing."
The researchers say their findings warrant further research on the link between obesity and cancer. For example, they say it is unclear whether changes that lead to tumor development in those who are obese also play a part in the aggressiveness of the cancer after diagnosis.
"While our findings will not affect the way we treat patients today, they provide new leads for investigating the molecular pathways that may be responsible for the survival difference between obese and healthy-weight patients," says Prof. Wolpin.
"Hopefully, in the future, that research will bring new approaches for treatment of pancreatic cancer."
Medical News Today recently reported on a study suggesting that a chemotherapy drug called Gemzar may improve survival rates for pancreatic cancer.