Targeted Drugs Among Successes Against Cancer But aging population and increasing obesity threaten progress

TUESDAY, Sept. 16, 2014 (HealthDay News) -- About 14.5 million U.S.cancer survivors are alive today, compared to just 3 million in 1971, the American Association for Cancer Research reported Tuesday.

These individuals amount to 4 percent of the population and include nearly 380,000 survivors of childhood cancer, according to the association's annual progress report. The paper outlines advances in prevention, identification, research and treatment of cancer and details some of the challenges ahead.

But these numbers can be somewhat misleading unless they take into account advances in identifying cancers earlier, said Dr. Otis Brawley, chief medical officer of the American Cancer Society.

Survival rates refer to how long a person lives with cancer (including inremission) while mortality rates refer to the death rate, but survival will be longer if the cancer is found earlier, even if the person dies at the same time they would have.

"People don't want to live longer with cancer," Brawley said. "They want to not die with cancer." But he said mortality rates have also seen big drops, including an overall decline of 22 percent in cancer deaths from 1991 to 2011.

"Prevention has been the biggest contributor, with smoking cessation as a bigger overall driver of the decline in mortality" than scientific treatment advances, Brawley said. "People who stopped smoking in the 1960s and 1970s did not die in the 1990s and beyond, and that's why it took until 1991 for mortality to start going down big-time."

Yet two looming issues may have a significant impact on increasing cancer rates in the future, the report noted.

One is the currently aging population. Most cancers occur in people aged 65 and older, and the number of Americans in this age group is expected to double by the year 2060, the report said.

That portends an increase in cancer diagnoses from 1.6 million in the United States in 2014 to an estimated 2.4 million in 2035, the report stated.

The other issue relates to widespread obesity. The report notes that one-third of all newly diagnosed cancers in the United States are related to being overweight or obese. These include esophageal, colorectal, endometrial, gallbladder, kidney, pancreatic and postmenopausal breast cancers.

"One of the great threats in terms of cancer in the U.S. is the increasing obesity rates," Brawley said. "We think it's the high levels of insulin that obese people have in their blood because insulin spurs on tumor development."

As smoking rates continue declining, "the leading cause of cancer in the U.S. may very well be obesity rather than tobacco use soon," Brawley said.

Another challenge related to cancer prevention, detection and treatment in the United States are health care access disparities for racial and ethnic minorities and poorer people.

Lower incomes are the primary driver of these disparities, Brawley said.

"There is a whole slew of issues with education and access," he said, noting that the black-white disparity in cancer deaths seen in the general population is particularly striking when compared to a population with equal access to care.

"When you start looking at black women treated for breast cancer in military hospitals," for example, Brawley said, "you end up with a population of black women whose outcomes look a lot more like those of white women than those of black women in the U.S. overall. Access to care and equalization of care is really important."

Also noteworthy, the Food and Drug Administration approved six new anticancer drugs in the past year and allowed new uses for five existing anticancer therapeutics, the report said. The FDA has also approved two imaging agents for uses related to cancer.

The new drugs were approved to treat certain types of stomach cancer, thyroid cancer, leukemia, lymphoma, non-Hodgkin lymphoma,pancreatic cancer, melanoma, lung cancer and breast cancer.

Dr. Tomasz Beer, deputy director of the Knight Cancer Center at Oregon Health and Science University, said it was particularly interesting that only one of the six newly approved therapies was achemotherapy drug.

"I think the public may not know that cancer therapy is not just chemotherapy anymore," Beer said. "What's new now is focusing on biologic agents that are targeted, and immunotherapy agents. What you're seeing in this report is a sign of what's to come."

Those five new drugs are targeted cancer therapies, which fight cancer differently from chemotherapy. Chemotherapy works by killing all cells in an area, including both normal and cancerous cells.

Targeted therapies, however, focus on specific molecules to prevent a tumor from growing or a cancer from progressing and spreading. These therapies might interfere with blood vessel development in a tumor, kill only cancer cells or, in the case of immunotherapy, help the immune system identify and kill cancer cells.

Dr. Carlos Arteaga, president of the American Association for Cancer Research, highlights the progress being made. "We're witnessing quite a transformative change in the way we treat patients with cancer," he said.

"As a result of advances like these, Americans today are more likely to survive a cancer diagnosis and then enjoy a higher quality of life than at any other time in history," Arteaga, who is director of the Center for Cancer Targeted Therapies at Vanderbilt-Ingram Cancer Center in Nashville, said.

One recent discovery that could lead to new treatments for a type of lung cancer reveals where cancer research is heading.

A study released Sept. 16 in the journal Clinical Cancer Researchdescribes two mutations that cause lung cancer resistance to a drug called alectinib.

Alectinib was developed to inhibit the expression of the ALK gene that causes growth of some non-small cell lung cancers -- the most common form of lung cancer -- after the cancer has become resistant to an older drug called crizotinib.

Discovering these mutations helped researchers understand how the cancer becomes resistant to alectinib. The researchers then successfully used a new drug, ceritinib (brand name: Zykadia), to treat a patient whose lung cancer had become resistant to alectinib.

"These studies have been invaluable in learning how ALK-positive cancers become resistant to different ALK inhibitors and in identifying the best therapeutic strategies that will re-induce remissions," said study author Dr. Jeffrey Engelman, director of the Center for Thoracic Cancers at the Massachusetts General Hospital Cancer Center, in a news release.

Blood Test May Identify Status of Prostate Cancer

May help doctors pinpoint best treatment, researchers say

WEDNESDAY, Sept. 17, 2014 (HealthDay News) -- A blood test that measures DNA from a prostate cancer tumor could provide doctors with a better assessment of the state of a man's disease, a new study suggests.

If used routinely, this blood test could reveal when treatment for advanced prostate cancer stops working and actually begins promoting tumor growth, the researchers suggested.

"Our study showed that a steroid treatment given to patients with advanced prostate cancer and often initially very effective started to activate harmful mutations and coincided with the cancer starting to grow again," study leader Dr. Gerhardt Attard, from the Institute of Cancer Research (ICR) in London, explained in an ICR news release.

"In the future, we hope to routinely monitor genetic mutations in patients with advanced disease using just a blood test -- enabling us to stop treatments when they become disease drivers and select the next best treatment option. We need to confirm these findings in larger numbers of patients, but using these types of blood tests could allow true personalization of treatment for prostate cancer patients, based on the cancer mutations we detect," he explained.

Using a blood test to measure circulating tumor DNA levels is less expensive and less invasive than needle biopsies. This test could be an effective way to monitor the emergence of treatment-resistant prostate cancer, the study published on Sept. 17 in Science Translational Medicine suggested.

"Drug resistance is the single biggest challenge we face in cancerresearch and treatment, and we are just beginning to understand how its development is driven by evolutionary pressures on tumors," Paul Workman, interim chief executive at the ICR, said in the news release.

This discovery "reveals how some cancer treatments can actually favor the survival of the nastiest cancer cells, and sets out the rationale for repeated monitoring of patients using blood tests, in order to track and intervene in the evolution of their cancers," Workman said.

"There are currently too few treatment options for men living with advanced stage prostate cancer. Not only do we desperately need to find more treatments for this group of men, we also need to understand more about when those that are available stop working and why," Dr. Matthew Hobbs, deputy director of research at Prostate Cancer UK, said in the news release.

"This research is important as it shows that there might be a new way to monitor how a man's cancer is changing during treatment, and that could help us to pinpoint the stage at which some drugs stop being effective. In the future, this could arm doctors with the knowledge they need to ensure that no time is wasted between a drug that stops working for a man and him moving on to another effective treatment," Hobbs said.

But, Hobbs also noted that this is preliminary research and that the study size was small -- just 16 men. He agreed with Attard that the findings need to be confirmed in a larger study.

The researchers cautioned that any patients currently taking medication for advanced prostate cancer should continue to take their medications as prescribed and discuss any concerns about their treatment with their doctor.

Advanced Prostate Cancer: Frequently Asked Questions

If you just learned that you or a loved one has advanced prostate cancer, you may have many questions and concerns. By taking the time to research your condition, you've taken a good first step. Here are answers to the most common questions. After looking over these answers, click on other articles in this guide to find in-depth information about treatments, side effects, and other issues that affect you and your family.

What is advanced prostate cancer?

Prostate cancer is defined as ''advanced'' when it spreads outside the prostate gland. It may spread to nearby tissues, lymph nodes, bones, or other parts of the body. When it is spread beyond the tissues directly adjacent to the prostate gland, it is called metastatic prostate cancer.

Can advanced prostate cancer be cured?

No cure exists for advanced prostate cancer, but treatments may greatly extend life and reduce symptoms. A look at treatments:

• Most prostate cancer grows in response to male hormones (androgens) in the body, such as testosterone. That’s why one of the first treatments for advanced prostate cancer is to decrease these hormone levels (called androgen deprivation therapy). There are several medications that can do this, including Leupron (leuprolide), Trelstar (triptorelin), or Zoladex (goserelin). These drugs work to reduce testosterone levels to those seen in castrated patients. Other hormonal treatments include antiandrogens, estrogen- and progesterone-type drugs and cortisone derivatives. If these stop working, the drugs Zytiga (abiraterone) or Xtandi (enzalutamide) may still be effective. The most frequent side effects from hormone therapy include reduced sex drive, impotence, erectile dysfunction, infertility, and bone loss. Your doctor may be able to help prevent some side effects, such as bone loss. In the past, it was common for doctors to recommend surgical removal of the testicles to decrease hormone levels. This is usually not necessary, because medications typically work, though such medications are more expensive than the surgical procedure to remove the testes (bilateral orchiectomy). The use of medical rather than surgical treatment offers the option of stopping -- sometimes temporarily, sometimes permanently -- the medicines if the side effects are intolerable, or if the patient or doctor prefers. The surgery is not reversible.
• If hormone therapy ultimately fails to slow the growth of the cancer, the next step may be a prostate cancer "vaccine" called Provenge (sipuleucel-T). Most men who take Provenge survive at least 2 years after starting the treatment. Provenge isn't your everyday vaccine. It's a therapy created by taking immune cells from a patient, genetically engineering them to fight prostate cancer, and then putting them back into the patient. It's used for men with few or no symptoms and when advanced prostate cancer no longer responds to hormone therapy. Though relatively new, Provenge appears to be remarkably safe. However, clinical trials suggested the treatment might cause a slightly increased risk of stroke. The most common side effect is chills, which occurs in most men. Other common side effects include fatigue, fever, back pain, and nausea.
• Chemotherapy is another option when hormone therapy stops working. Only a few chemotherapy medications have been shown to work for advanced prostate cancer. The chemotherapy drug Taxotere, when taken with the steroid prednisone, can help extend survival in some men. When Taxotere stops working, the chemotherapy drug called Jevtana (carbazitaxel) can help extend survival in some men. Possible side effects of Taxotere include nausea, hair loss, and decreased production of blood cells. Men may also develop fluid retention and pain, tingling, or numbness in the fingers or toes. Jevtana has side effects similar to Taxotere.
• One drug, Xofigo (Radium -223), is approved for use in men who have advanced prostate cancer that has spread only to the bones. Candidates should have also received androgen deprivation therapy. Xofigo, given by injection once a month, works by binding to minerals within bones to deliver radiation directly to bone tumors. A study of 809 men showed that those taking Xofigo lived an average of 3 months longer than those taking a placebo.   

External beam radiation therapy may be used to reduce pain from bone metastases in advanced prostate cancer.

source:http://www.webmd.com/