Preparing for pancreatic cancer ‘tsunami’ ahead
AT THE NCCN ANNUAL CONFERENCE
ORLANDO – Overall cancer death rates are dropping dramatically, but pancreatic cancer mortality remains high.
“By 2020 we expect [pancreatic cancer] to be the second most common cause of cancer-related death, exceeded only by lung cancer, and if lung cancer deaths continue to fall – which we expect that they will – it will be the most common cause of cancer-related death,” Margaret A. Tempero, MD, said at the annual conference of the National Comprehensive Cancer Network.
Further, as the population ages there will be an increasing number of patients presenting with pancreatic cancer, said Dr. Tempero of the University of California, San Francisco.
Currently, 80% of pancreatic cancer patients are diagnosed with disease that is not amenable to resection, and 80% of those who have resection and adjuvant therapy experience relapse. The overall survival rate is only about 9%.
“This is really, really an aggressive malignancy,” Dr. Tempero said, noting that the survival among those with metastases who do not receive treatment is only about 3 months.
There are no early symptoms that direct attention to the pancreas. Additionally, some patients experience very early invasion and metastases; in fact, up to two-thirds of patients with lesions only 1 cm in size will already have lymph node metastasis, she said.
The disease tends to be chemoresistant, although this may be changing with treatment advances, but it is characterized by “a lot of desmoplastic stroma, so there’s a lot of microenvironment that’s perturbed around the malignancy,” making it difficult for drugs to permeate the stroma.
“That’s something we’re actively working on – ways that we can actually change the stroma so that we can get more drug into the cancer,” she said.
Another challenge is the disease’s “habit of elaborating a lot of cytokines that disable the person with the disease,” which can lead to frailty that makes it difficult to deliver potentially effective therapies that are well tolerated in patients with other types of cancer, she noted.
An important question is whether pancreatic cancer is diagnosed too late or metastasizes too early, and there is evidence to support both possibilities.
“Either way ... we need to work on better treatment,” she said.
Resectable/borderline resectable disease
One noteworthy recent advance for patients with resectable/borderline resectable disease is the addition of capecitabine to gemcitabine for adjuvant therapy. In the ESPAC 4 study published in March in the Lancet, the combination of gemcitabine and capecitabine showed a clear benefit over gemcitabine alone.
“So that has now entered [the NCCN] guidelines as an important option for adjuvant therapy,” said Dr. Tempero, chair of the NCCN pancreatic cancer guidelines panel.
Ongoing trials are also looking at the FOLFIRINOX (irinotecan plus 5-fluorouracil plus leucovorin plus oxaliplatin) and gemcitabine/nanoparticle albumin-bound paclitaxel (nab-P) regimens in the adjuvant setting. These have previously shown some efficacy in the metastatic setting.
“So we really wanted to get these therapies into the adjuvant setting as soon as we could,” she said.
In the ACCORD trial, FOLFIRINOX is being compared with gemcitabine in the postoperative adjuvant setting, and the APACT trial comparing gemcitabine/nab-P to gemcitabine monotherapy completed accrual last year.
“I’m pretty sure that we’ll have enough events on the APACT study by the end of this year, and hopefully we can present that data in the spring. I’m hoping it will be a positive trial for us,” she said.
Neoadjuvant therapy – a successful strategy used in many other malignancies – is also being looked at for pancreatic cancer.
A pilot study (A021101) completed last year suggested that chemotherapy (FOLFIRINOX for 2 months) and chemoradiation (capecitabine and radiation at 50.4 Gy) followed by surgical resection and adjuvant chemotherapy (gemcitabine for 2 months) provided some benefit in patients with borderline resectable pancreatic cancer. This trial led to another ongoing study (S1505) in which patients with borderline resectable disease will be treated with 4 months of FOLFIRINOX prior to resection, followed by chemoradiation and surgery or FOLFIRINOX and surgery, and patients with resectable disease will undergo resection followed by FOLFIRINOX and surgery or gemcitabine/nab-P and surgery.
“The goal is not to compare the two regimens; the goal is to identify the benchmarks that we get with these regimens. In other words, if you’re going to give FOLFIRINOX, what pathologic complete response rate can you expect? What will your R1 resection rate be? With gemcitabine and nab-paclitaxel, the same thing, because if you want to continue to build on these regimens in the neoadjuvant setting you need to know what you’re likely to get so you can make clinical trial assumptions when you add new drugs.
“Once we have these benchmarking data we can really sail in the neoadjuvant setting. It’s a great window-of-opportunity setting for new drugs, because you’re getting serial tissue,” Dr. Tempero said, explaining that in addition to resection of tissue, there is opportunity to get biopsies ahead of time and look at the effects of the drug.
