The cancer death rate in the U.S. fell by the most on record as advances in treatments for lung tumors （肿瘤） like video-assisted surgery helped prolong the lives of patients.

The death rate from cancer has been gradually declining for 26 years, thanks in large part to fewer people smoking cigarettes. But from 2016 to 2017, the most recent period available, it dropped by 2.2%, the most ever in a single year, according to a report released Wednesday by the American Cancer Society. That compares with an average 1.5% yearly decline over the decade. The drop translates to roughly 2.9 million fewer cancer deaths than would have occurred had death rates remained at their peak. For lung cancer specifically, the death rate declined 4.3% annually from 2013 to 2017.

"It is really lung cancer that is driving this," said Rebecca Siegel, scientific director of surveillance research at the American Cancer Society, and lead author on the new study. "We found increases in survival for lung cancer at every stage in diagnosis.”, She attributed the lower deaths to improvements in treatments, including video-assisted surgery that enables more patients with early lung tumors to become eligible for operations; more precise radiation treatment; and better scanning technology that allows doctors to better assess the stage of tumor, so the patient gets the best treatment right away. At later stages of illness, new, targeted drugs that aim at specific disease-causing genes are helping patients whose tumors have those genetic flaws （缺陷）.Overall, lung cancer death rates have dropped by 51% for men since their peak in 1990, and by 26% for women since their peak in 2002.

There's the potential for more progress in future reports. That's because the latest death-rate statistics go only through 2017, and likely don't include the potential impact in lung cancer death from immune-therapy drugs. They became widely used in lung cancer only in the past few years.

The report, based on U.S. government data, isn't all good news. Prostate （前列腺）cancer death rates have leveled off recently after a period of decline. That may be because many doctors pulled back on using the controversial prostate-specific antigen test, or PSA, which can spot the disease but can lead to over-treatment of men who may never have                        died from their tumors.

"Though it was definitely causing harm, it was also contributing to declines in death," Siegel said. What's needed now is better screening tests to detect only the prostate cancers that will go on to cause harm.

Population death rates are considered one of the most reliable ways of measuring progress in cancer treatment and prevention. By contrast, cancer survival rates can sometimes be influenced by improvements in diagnosing tiny, early stage tumors that wouldn't necessarily be deadly.

12. According to paragraph 2, ______.

A. cancer death rate reached its peak in 2017

B. death rate decreases over the past 2 decades

C. 2.9 million people die of cancer in America every year

D. most of the cancer patients in America suffer from lung cancer

13. We can learn from the passage that ______.

A. female death rate of lung cancer drops more than that of male

B. targeted drugs have led to rapid increase in cancer death rates

C. better scanning technology will lead to improvement in treating genetic flaws

D. improper use of prostate-specific antigen test can lead to over-treatment of men

14. The underlined expression "level off” in paragraph 5 means ______.

A. remain unchanged              B. show up

C. take off              D. become sharp

15. What might be the best title of the passage?

A. Medical Progress Prolonging Patients’ Lives

B. Cancer Death Rates Dropping at the Fastest Pace

C. Significant Improvement in Treating Lung Cancer

D. Advanced Technologies Applied in Cancer Treatment