Researchers from Fox Chase Cancer Center have found that in pancreatic cancer, when tumours respond most to preoperative chemotherapy and radiation, the patient is four times more likely to survive than those whose tumors respond.
Pancreatic adenocarcinoma is rarely detected in early stages, making treatment difficult and survival statistics particularly grim.
In 1986, the Center conducted the first trial in pancreatic cancer of "multimodal" preoperative therapy (the use of more than one kind of treatment, such as chemotherapy and radiation, to kill tumour cells before surgery), and a phase I trial of gemcitabine in the 1990s established the safe dosage for the chemotherapy drug, now widely used in treating the disease.
"For many cancers-breast, esophagus, stomach, and colorectal liver metastases-it has been shown that survival is much better in people who have a good pathologic response to preoperative therapy-meaning that many tumour cells are killed-than in people who do not have a good pathologic response. But this has not been established in pancreatic cancer; previous studies have shown conflicting results," said Chun.
In hopes of clearing up the confusion, the researchers reviewed data on 135 patients who had preoperative therapy and surgery.
Fox Chase pathologist Dr. Harry Cooper, examined slides of the patients' tumors and classified their response to preoperative treatment as minor, partial, or major, based on the amount of fibrosis (scarring) in tumor tissue.
For patients whose tumours showed major response to preoperative therapy, the median survival was more than five years, compared to seventeen months for those who showed minor response.
Although major response is relatively rare-only 19 percent of patients in the study were so classified-the findings give researchers and clinicians important information to build upon.
"Going forward, if we can identify molecular factors in tumours associated with a major pathologic response, then we can make important progress in this disease," said Chun.
The study will be presented at the 46th Annual Meeting of the American Society of Clinical Oncology.