colorectal

New Test Detects Most Colorectal Cancers, Study Finds

Still, the results fell short of investor expectations and even those of the company that developed the test, the Exact Sciences Corporation, sending its shares down about 20 percent in afternoon trading on Thursday.

In its news release about the study Thursday morning, Exact Sciences said its test detected 92 percent of the cancers picked up by colonoscopy, and 42 percent of potentially precancerous polyps. It had a false positive rate of 13 percent.

The test looks for alterations in human DNA found in a stool sample. The company contends that people will not find it off-putting to deposit a sample of their stool in the company’s collection apparatus and mail it to a laboratory.

The new test, called Cologuard, would not replace colonoscopy. Colonoscopy remains the gold standard for colorectal screening, in part because any polyps detected can also be removed during a colonoscopy, possibly preventing cancer.

But about half of people over 50, the recommended age to start screening for colorectal cancer, are either not adequately screened or not screened at all, in part because colonoscopy is invasive, uncomfortable, expensive and time-consuming.

Exact Sciences says the noninvasive test could allow more people to be screened, and those with a positive result could then get a colonoscopy.

“For the first time noninvasively, we can detect reliably precancerous polyps,” Kevin T. Conroy, the company’s chief executive, told analysts on Thursday. Exact Sciences, which is based in Madison, Wis., said it would soon complete its application to the Food and Drug Administration seeking approval of the Cologuard test.

There were about 143,000 new cases of colorectal cancer and 52,000 deaths in the United States last year, making it the second-leading cause of cancer death behind lung cancer, according to the American Cancer Society.

Dr. Deborah A. Fisher, an associate professor of medicine at Duke University, who was not involved in the study, said the Cologuard test appeared to be a viable option, but only one of several.

“I don’t think this is the holy grail,” said Dr. Fisher, a gastroenterologist who is a consultant to Epigenomics, a company developing a test that could compete with Cologuard. She said it was too soon to tell if the Cologuard test would actually increase the number of people being screened and said there was no data showing that its use actually prevented cancer deaths.

Dr. Fisher said existing noninvasive tests that look for blood in the stool can detect around 80 percent of cancers and 20 to 40 percent of polyps. These tests cost about $25, she said, while the Cologuard test is expected to cost a few hundred dollars.

Exact Sciences said participants in its study also received a stool blood test, known as a fecal immunochemical test. The Cologuard test, the company said, proved to be better than that test in detecting polyps and roughly equivalent in detecting cancer.

The company did not release the data, however, saying it would eventually be published in a peer-reviewed medical journal. The study involved about 10,000 people with an average risk of colorectal cancer. They were screened at 90 sites in the United States and Canada.

Mr. Conroy of Exact Sciences said the 42 percent success rate in detecting polyps, while below the company’s goal of 50 percent, was still a powerful result. He said the test caught 66 percent of polyps larger than two centimeters, which were more likely to become cancerous than smaller ones.

He also said that since colon cancer developed over many years, if people took the Cologuard test every three years, most polyps would be detected before they could cause problems. Such repeated testing is the reason the Pap test has greatly reduced deaths from cervical cancer, even though Pap tests miss precancerous lesions as much as half of the time.

But Dr. Fisher of Duke said yearly use of the less expensive fecal immunochemical test would also eventually detect many polyps.

The false positive rate of 13 percent for the Cologuard test was also higher than Exact Science’s goal of 10 percent. A false positive usually would mean that a person would get a colonoscopy that might not be needed.

The Cologuard test looks for mutations and chemical changes in DNA indicative of cancer. It takes advantage of the fact that cells lining the colon are continually sloughed off and broken apart, releasing their DNA.

But detecting that DNA in the stool is extremely difficult. Virtually all the DNA in the stool comes from bacteria, said Dr. David A. Ahlquist, a professor at the Mayo Clinic who helped develop the Cologuard test. Only 0.01 percent is the person’s own DNA, and of that, only a tiny fraction would be from cancerous cells, he said.

There have been some earlier versions of Exact Science’s test that did not work well.

Epigenomics, based in Germany, recently applied for F.D.A. approval of a screening test that looks for a chemical change to one gene.

Epigenomics has said its test, called Epi proColon, detected 71 percent of cancers in its large clinical trial, with a false positive rate of 19 percent. The test is not aimed at detecting polyps.

That would make it less accurate than the Cologuard test. It is a blood test, however, not a stool test.

“People are very comfortable with blood-based tests,” said Karen A. Heichman, vice president for oncology technology development and licensing at ARUP Laboratories in Salt Lake City, which offers its own version of the test under license from Epigenomics.

Article source: http://www.nytimes.com/2013/04/19/business/new-test-detects-most-colorectal-cancers-study-finds.html?partner=rss&emc=rss

Hot Chemotherapy Bath: Patients See Hope, Critics Hold Doubts

The therapy, which couples extensive abdominal surgery with blasts of heated chemotherapy to the abdominal cavity and its organs, was once a niche procedure used mainly against rare cancers of the appendix. Most academic medical centers shunned it.

More recently, as competition for patients and treatments intensifies, an increasing number of the nation’s leading medical centers has been offering the costly — and controversial — therapy to patients with the more common colorectal or ovarian cancers. And some hospitals are even publicizing the treatment as a hot “chemo bath.”

To critics, the therapy is merely the latest example of one that catches on with little evidence that it really works. “We’re practicing this technique that has almost no basis in science,” said Dr. David P. Ryan, clinical director of the Massachusetts General Hospital Cancer Center.

But to some patients, the procedure, however grueling and invasive, represents their best hope for survival: “It’s throwing everything but the kitchen sink at cancer,” said Gloria Borges, a 29-year-old Los Angeles lawyer who had her colon cancer treated with what she called the “pick it out, pour it in” procedure.

For hours on a recent morning at the University of California, San Diego, Dr. Andrew Lowy painstakingly performed the therapy on a patient.

After slicing the man’s belly wide open, he thrust his gloved hands deep inside, and examined various organs, looking for tumors. He then lifted the small intestine out of the body to sift it through his fingers.

As he found tumors, he snipped them out. “You can see how this is coming off like wallpaper,” Dr. Lowy said as he stripped out part of the lining of the man’s abdominal cavity.

After about two hours of poking and cutting, Dr. Lowy began the so-called shake and bake. The machine pumped heated chemotherapy directly into the abdominal cavity for 90 minutes while nurses gently jiggled the man’s bloated belly to disperse the drug to every nook and cranny.

The treatment is formally called cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy, or Hipec.

Recent converts include University Hospitals Case Medical Center in Cleveland, Montefiore Medical Center in the Bronx, and even Massachusetts General. The Memorial Sloan-Kettering Cancer Center is looking at it, according to people in the field. Advocates predict that the number of procedures could grow to 10,000 a year from about 1,500 now.

The therapy has even been featured on an episode of the TV series “Grey’s Anatomy.”

But Dr. Ryan, a gastrointestinal oncologist, suggested in an interview that the procedure was being extended to colorectal cancer because “you can’t make a living doing this procedure in appendix cancer patients.”

He debated the procedure publicly at the recent annual meeting of the American Society of Clinical Oncology. While some patients did seem to live much longer than expected, he said that they had been carefully selected and might have fared well even without the therapy.

Proponents say that if cancer has spread into the abdominal cavity but not elsewhere, then lives can be prolonged by removing all the visible tumor and killing what’s missed with Hipec.

By contrast, said Dr. Paul Sugarbaker, a surgeon at Washington Hospital Center and the leading proponent of Hipec, “there are no long-term survivors with systemic chemotherapy — zero.”

Dr. Sugarbaker, who opposed Dr. Ryan in the debate, said that it has long been known that cancerous cells are unable to withstand as much heat as healthy cells. And putting the chemotherapy on top of tumors should be more effective than systematically delivering it through the bloodstream.

One randomized trial done more than a decade ago involving 105 patients in the Netherlands did show a striking benefit. The median survival of those getting surgery and Hipec, plus intravenous chemotherapy, was 22.3 months, almost double the 12.6 months for those getting only the intravenous chemotherapy. But 8 percent who got the surgery and Hipec died from the treatment itself. And critics say that since that trial was conducted, new drugs have come to market that allow patients with metastatic colorectal cancer to live two years with intravenous chemotherapy alone.

A new trial in the United States has been temporarily suspended so that researchers can find a way to recruit patients. After nearly a year only one patient had enrolled, because people were reluctant to chance winding up in the control group, according to one of the investigators.

While proponents contend that the risk of dying from the surgery has been reduced since the Dutch trial, the procedure still lasts eight hours or more and full recovery can take three to six months. “It’s maximally invasive,” said Dr. Sugarbaker, who often removes the “spare parts” — organs a patient can live without, like the spleen, the gall bladder, the ovaries and the uterus.

Article source: http://feeds.nytimes.com/click.phdo?i=9ee79c9f1c6e681ac5c97c1e06641680

New Test Detects Most Colorectal Cancers, Study Finds

Hot Chemotherapy Bath: Patients See Hope, Critics Hold Doubts

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