World and Nation

Shorts (left)

Two new DNA tests are aimed at reducing colon cancer

Two new DNA-based tests, one of them described at a meeting in Philadelphia on Thursday, hold the promise of detecting early — and sharply reducing — colon cancer, a disease that afflicts 150,000 people a year in the United States and costs an estimated $14 billion to treat.

The new tests could help most people avoid colonoscopies, which are routinely prescribed for people over 50. Instead of screening the entire population, doctors could instead refer people for a colonoscopy only if they had tested positive in one of the DNA tests.

Unlike a colonoscopy, in which a seeing tube is threaded up the colon, the DNA tests are noninvasive, so more people would take them. Both tests could be brought to market within two years.

One of the tests, developed by Exact Sciences, of Madison, Wis., looks in stool samples for the presence of four altered genes that are diagnostic of colon cancer. The test could catch cancerous and precancerous tumors at an early stage, when they are curable, and allow doctors to remove them promptly.

The other test looks in blood for changes in a single gene, called Septin 9, which is not in the Exact Sciences’ panel of four genes. The test has been developed by Epigenomics AG, in Germany.

A Sunday Halloween is tricky business

The date of Halloween has always been one of the easy ones to remember: Oct. 31, plain and simple. No first Tuesday-after-the-first-Monday-of-November nonsense (that’s Election Day), no fourth-Thursday-in-November (Thanksgiving), no second-Monday-in-October (if you don’t know, ask a Canadian). Just the last day of October.

But this Sunday, Oct. 31, matters are not quite so simple. Across the country, people are monkeying with the optimal day to dress up. In some cities, residents have decided to celebrate Halloween on Saturday to preserve the purity of the Christian Sabbath, while others would rather not choose between Halloween and college football. There is even a vote for Monday.

Officials in Chatham County, Ga., which includes Savannah, also invoked a third reason — the desire to move Halloween off a school night — when they asked residents to trick or treat on Saturday this year.

China said to resume rare earth shipments

BAOTOU, China — The Chinese government Thursday abruptly ended its unannounced export embargo on crucial rare earth minerals to the United States, Europe and Japan, four industry officials said.

The embargo, which has raised trade tensions, ended as it had begun — with no official acknowledgment from Beijing or any explanation from customs agents at China’s ports.

Rare earths are increasingly in demand for their use in a broad range of sophisticated electronics, from smart phones to smart bombs.

Having blocked shipments of raw rare earth minerals to Japan since mid-September, and to the United States and Europe since early last week, Chinese customs agents Thursday morning allowed shipments to resume to all three destinations, the industry officials said. They spoke only on condition of anonymity because of the business and diplomatic sensitivity of the issue.