Prevention

Prevention

Quitting smoking, eating a healthy diet, and avoiding excess sun exposure have all been shown to reduce cancer risk. Declining use of tobacco, in particular, is a major factor in the rate of new cancer cases in the United States decreasing by 10 percent since peaking in the early 1990s.

In addition to lifestyle changes, researchers are discovering a growing number of biomedical tools to prevent cancer, including preventive drugs and surgery for women at high risk of breast or ovarian cancer; removal of precancerous polyps for colorectal cancer; and vaccines to prevent the viruses that cause cervical, head and neck, and liver cancers.

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2015

Vitamin B3 may lower risk of non-melanoma skin cancers

Vitamin B3 may lower risk of non-melanoma skin cancers

A clinical trial finds that taking a form of vitamin B3 called nicotinamide can modestly lower the risk of developing new nonmelanoma skin cancers among individuals with a history of such lesions. This is the first evidence that skin cancers can be prevented with simple, widely-available vitamins in conjunction with sun protection. The results follow a decade of preclinical and early clinical research suggesting that nicotinamide can help skin cells repair DNA damaged by UV radiation and protect the skin’s immune system.

2014

New HPV vaccine protects against more cancer-causing virus types

New HPV vaccine protects against more cancer-causing virus types

The FDA approves a new human papillomavirus (HPV) vaccine, Gardasil 9 following a large clinical trial. The vaccine is approved for use in girls and young women for the prevention of cervical, vulvar, vaginal, and anal cancers caused by HPV, and in boys and young men for the prevention of HPV-related anal cancer and genital warts. Gardasil 9 vaccine protects against five more high-risk strains of HPV than previous vaccines, and researchers estimate it could prevent up to 90% of cervical cancers worldwide.

2012

Routine hepatitis C screening recommended

Routine hepatitis C screening recommended

The U.S. Centers for Disease Control and Prevention proposes that all baby boomers (individuals born 1945-1965) be screened for the hepatitis C virus (HCV), as this group is five times more likely than other American adults to be infected and overall deaths due to HCV are on the rise.

Early diagnosis of HCV is vital, since the longer the virus goes undetected, the greater a person's risk of developing serious liver disease, including liver cancer and cirrhosis.

2011

Aromatase inhibitors cut breast cancer risk in postmenopausal women

Aromatase inhibitors cut breast cancer risk in postmenopausal women

2011-2014

A large Phase III trial shows for the first time that exemestane (Aromasin) – part of a group of drugs called aromatase inhibitors – greatly lowers the chance of developing invasive breast cancer in postmenopausal women who are at a high risk for breast cancer. This includes women with BRCA gene mutations, as well as other risk factors. In 2014, another aromatase inhibitor, anastrozole (Arimidex), was shown to lower the risk of breast cancer by nearly 50% over five years.

Two other drugs, tamoxifen (Nolvadex) and raloxifene (Evista), are also FDA-approved for breast cancer prevention in women at high risk for the disease Aromatase inhibitors work differently, however, and tend to carry milder side effects.

2010

New prohibitions on indoor tanning after it’s declared carcinogenic

New prohibitions on indoor tanning after it’s declared carcinogenic

2009-2017

In 2009, the International Agency for Research on Cancer, a working group of the World Health Organization, declared that UV-emitting tanning devices are “carcinogenic to humans.”

Between 2011 and 2017, several new pieces of legislation are enacted to restrict the use of indoor tanning, starting with a new California law prohibiting indoor tanning to people under the age of 18. Fourteen other states and the District of Columbia subsequently follow suit.  In 2014, the U.S. Food & Drug Administration issues an order requiring all indoor tanning devices to carry a visible black-box warning against use before age 18, and it reclassifies indoor tanning devices from a low to a moderate risk, allowing the agency greater control over the devices. Policy changes continue in Australia, where nearly all states enact bans on indoor tanning in 2015.

HPV status and smoking affect prognosis for oropharyngeal cancer

2009

HPV vaccine benefits women over age 26

HPV vaccine benefits women over age 26

A large, randomized trial shows that the HPV vaccine Gardasil is more than 90 percent effective in preventing cervical cancer in women aged 24 to 45 who received all three vaccine doses, and who were not infected by the virus. While the vaccine is currently approved only for younger women, it is being considered by the FDA for use in women over age 26.

2008

New research highlights role of HPV infection in head and neck

New research highlights role of HPV infection in head and neck

While studies over the prior decade had suggested a connection between HPV infection and oropharyngeal cancers, several studies offer important new insight. The first finds that DNA from HPV-16, one of the strains of HPV most commonly associated with cervical cancer, is present in nearly three-quarters of oropharyngeal tumor samples. These findings help spur research to determine if HPV vaccination could help prevent these cancers.

A second study finds that patients with certain squamous cell carcinomas of the oropharynx or larynx whose tumors test positive for the HPV virus have a better prognosis than patients with HPV-negative tumors treated with the same therapy. This is the first major study suggesting that HPV-related head and neck cancers are biologically different, and in some cases more treatable, than non-HPV-related cancers.

Around the same time, researchers report that U.S. cases of HPV-related head and neck cancers have risen nearly 1 percent each year since 1973.

2007

Declining breast cancer incidence linked to lower use of hormone replacement therapy

Declining breast cancer incidence linked to lower use of hormone replacement therapy

Studies link declines in breast cancer incidence in women aged 50 and older to decreased use of hormone replacement therapy involving estrogen and progestin. One study reports that the rate of new breast cancer cases declined as much as 13 percent between 2001 and 2003, though researchers suggest other factors could have also played a role, such as increased use of mammography. Until 2002, when researchers first identified this significantly increased breast cancer risk, hormone replacement therapy was commonly prescribed to relieve the symptoms of menopause, such as hot flashes and vaginal dryness.

2006

Tamoxifen and raloxifene equally effective for preventing invasive breast cancer

Tamoxifen and raloxifene equally effective for preventing invasive breast cancer

Findings from one of the largest-ever breast cancer prevention studies show that tamoxifen (Novaldex) and a newer drug, raloxifene (Evista), are equally effective in reducing the risk of invasive breast cancer in women at high risk for the disease. (Both drugs lowered the risk by about 50 percent.) The study found that raloxifene was not as effective, however, at reducing non-invasive breast cancer, such as ductal carcinoma in situ. Tamoxifen had greater side effects, including a higher risk of blood clots and uterine cancers.

Preventive cancer vaccine approved for cervical cancer

Preventive cancer vaccine approved for cervical cancer

The FDA approves Gardasil, a vaccine that prevents infection with the two high-risk strains of human papillomavirus (HPV) known to cause about 70 percent of cervical cancers. The vaccine is approved for girls and young women aged 9 to 26. The approval is based on data showing the vaccine is 100 percent effective in preventing HPV16- and HPV18-related cervical pre-cancers, as well as genital warts, for at least 4.5 years following vaccination. Later the same year, the CDC's Advisory Committee on Immunization Practices (ACIP) recommends routine HPV vaccination for girls aged 11 and 12; however, state requirements for HPV vaccinations vary. A second vaccine, Cervarix, was approved in 2009 to prevent infection against HPV16 and HPV18 in women aged 10 to 25. The cost of the three-dose regimen remains a persistent challenge to widespread HPV vaccination, with either version of the vaccine. Also in 2009, the Gardasil vaccine is approved for use in boys for the prevention of genital warts.

Gardasil is later approved to prevent additional HPV-related diseases in children and young adults aged 9 to 26, including vaginal, vulvar and anal cancers in females, and anal cancer and genital warts in males.

2003

Aspirin and similar anti-inflammatory medications help reduce colon cancer risk

Aspirin and similar anti-inflammatory medications help reduce colon cancer risk

Two large studies show that taking daily aspirin prevents the development of precancerous colorectal polyps, and a later trial involving another anti-inflammatory drug, celecoxib (Celebrex), reports a similar finding. However, this use of aspirin or similar anti-inflammatory drugs is not yet recommended for cancer prevention among the general public, due to the risk of potentially serious side effects, such as stomach bleeding. Large, randomized studies are currently underway to evaluate the benefit of these drugs in prevention of polyps, second colon cancers and cancer recurrence.

Obesity pinpointed as cause of many cancer deaths

Obesity pinpointed as cause of many cancer deaths

An important prospective analysis involving nearly 1 million Americans reports that obesity could account for up to 20 percent of U.S. cancer deaths. Obesity is linked to a higher risk of death from liver cancer, along with several other cancer types. The researchers also estimate that 90,000 cancer-related deaths could be prevented annually if Americans maintained a healthy weight.

As obesity becomes more prevalent, researchers project that deaths from liver cancer and other forms of the disease will rise as well.

First drugs proven effective for reducing prostate cancer risk

First drugs proven effective for reducing prostate cancer risk

Two large trials report that finasteride (Proscar) and dutasteride (Avodart) reduce the risk of developing prostate cancer by up to 25 percent, compared to placebo. However, debate persists about the optimal use of these drugs for prostate cancer prevention. Key issues of controversy include whether these agents increase aggressiveness of tumors that do arise, and whether they only inhibit less aggressive tumors that would not have been dangerous without treatment in the first place.

2000

Study links household radon exposure to lung cancer

Study links household radon exposure to lung cancer

The Iowa Radon Lung Cancer Study demonstrates that ongoing exposure to residential radon – a naturally-occurring radioactive gas that can emerge through basements and crawl spaces – is associated with increased risk of lung cancer. The Environmental Protection Agency now estimates that more than 20,000 lung cancer cases in the U.S. are due to long-term radon exposure in the home. Since the study, radon inspections have become a routine part of homeownership, promising to reduce the future burden of the disease.