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How to Decide What Cancer Screening Tests Are Right for You

By Melissa Pandika | December 1, 2017 | Rally Health

If you’ve hit middle age, you’ve probably begun thinking more about screenings, especially for breast and prostate cancer, the most common types of cancer in the United States. Should you get screened — or not?

The answer often depends on whom you ask. The breast cancer screening recommendations for women between 50 and 75 are fairly consistent. For others, it’s not so simple.

There’s a lot of gray area around screening guidelines. For women ages 40 to 49, the U.S. Preventive Services Task Force (USPSTF), a governmental advisory group that carefully weighs the evidence for and against preventive services, says the decision to get a mammogram every two years “should be an individual one and take patient context into account, including the patient’s values regarding specific benefits and harms.” Meanwhile, the American Cancer Society (ACS), a nonprofit cancer research and advocacy group, says women ages 40 to 44 should at least have the option of getting mammograms every year, while those ages 45 to 49 should definitely get annual mammograms. The American College of Radiology, a professional organization that represents radiologists, including those who perform mammograms, recommends annual screenings starting at age 40.

Likewise, recommendations for the prostate specific antigen (PSA) test used to screen for prostate cancer leave plenty of room for interpretation. While the USPSTF currently recommends against PSA testing, the organization’s latest draft guidelines say that clinicians should inform men between 55 and 69 years old about its possible benefits and harms, and that the decision to get tested “should be an individual one.” The American Urological Association says that average-risk men in this age group “should talk with their doctors about being tested.”

Why do some organizations lean toward more screening, and others less? “All of the organizations that make these recommendations are looking at the same data,” says Therese Bevers, professor of clinical cancer prevention at MD Anderson Cancer Center. But they may have different interpretations of that data. “It depends on where they place their focus.” They may give more weight to different types of studies. The USPSTF, for instance, is also “very harms averse,” she says.

What’s more, the data itself can vary. When it comes to whether the PSA test can prevent aggressive prostate cancer, “there are studies that suggest that it does, and there are studies that suggest it does not, and there are many studies out there with flaws,” says Otis Brawley, chief medical officer of the ACS. That’s why talking to your doctor and taking time to self-reflect are so important. “You need to weigh all of the benefits and risks, and look at what your values are, and make a decision.”

But how do you talk to your doctor about early cancer screening? And how do you factor your values into your decision, much less figure out what those values are? How do you make “an individual decision,” rather than just adopting your doctor’s personal preference?

We spoke to several experts to learn the best ways to navigate screening-test guidelines for breast and prostate cancer and to make the decision that’s right for you.

Clarify Your Values

We often hear about the need to factor our values into health care decisions. Your values are what you find most important, and they vary from person to person. Some value having the best quality of life possible more than living as long as possible. Others believe the potential for screening to save lives makes it worth the worry, follow-up visits, time off work and other drawbacks.

On the other hand, some people care more about avoiding the potential harms, including the stress and anxiety that often follows an abnormal screening result. Many prostate cancers grow so slowly, they never have the chance to become deadly. But for some men, the idea of harboring even harmless cancer in their bodies can still be scary. “There are some men who don’t get screened because they realize if they do get screened, there’s a 50 percent chance they’re living with cancer in their body,” Brawley says. “It’s totally up to the individual.”

The stress of waiting to hear if a result is abnormal can be intense. “Some people say it’s the worst thing they’ve been through, worse than the death of a family member. They can’t concentrate for two to three weeks waiting for the next screening,” says Joann Elmore, a professor of medicine at the University of Washington. “Even when I warn women about this, it feels like they’ve been caught off guard.”

Bevers suggests breast cancer screenings every other year instead of every year — her typical recommendation — as a “happier compromise” for women overwhelmed by the stress of potentially getting called back after a mammogram detects something suspicious. “That’s not our outright recommendation, but the important thing is she is getting screened at a rate that is comfortable for her.”

Another way to help you decide whether screening is worth the worry is to weigh your risk of dying of cancer versus other causes. For instance, when deciding to get the PSA test, “one thing a man can try to do is get an honest appraisal of his own health. Am I a healthy, fit person? Am I burdened by heart disease, or diabetes?” says John Gore, a urologic oncologist at the University of Washington. Otherwise, you may end up feeling anxious about something unlikely to kill you before something else does.

While it’s normal to feel scared, it’s also important to consider other factors, like your personal risk. Being informed can help dispel that fear. For instance, David Grossman, chairman of the USPSTF, suspects that “most women probably would guess that their risk [of dying of breast cancer] is higher than it actually is. Although many patients cite the statistic that women in the US have a one in eight chance of developing breast cancer, that’s a diagnosis over the course of a lifetime — not this year — and diagnosis doesn’t mean a death sentence, Elmore says. “Our treatment has gotten so much better that most women can be successfully treated, regardless of whether the cancer is diagnosed at an early or middle stage.”

And remember, everyone has different values. Even if your decision to get screened — or not — doesn’t align with your doctor’s recommendations, that’s OK. “We need to find the answer that is right for you,” Bevers says. “Some patients ask, ‘What would you do?’ But maybe my values are different from your values.”

It’s crucial to consider all the consequences of screening, including the additional tests and treatment an abnormal result might require. “It doesn’t make sense to get a PSA test if you’re unwilling to get a prostate biopsy,” Grossman says. “It’s important to look not just at the test right in front of you.”

If a biopsy indicates prostate cancer, you might need to undergo CT scans or other imaging tests to determine whether the cancer has spread. If the cancer is small and expected to grow slowly, your urologist might recommend active surveillance, or close observation of the cancer. You might also have the option of undergoing a prostatectomy — surgery to remove the prostate gland — or radiation therapy. Both can lead to problems with erections, especially if you’re older, as well as with bladder control. If the cancer has spread beyond the prostate gland, your urologist might recommend treatments such as hormone therapy or chemotherapy.

Talking to your doctor can also help you make the best decision for you. Given how busy clinical practice can be, primary care physicians often have competing responsibilities, so patients should view themselves as active participants in their health care and feel empowered to ask questions about mammograms and PSA screenings if their doctor doesn’t bring them up, says Alicia Morgans, a medical oncologist at Northwestern Memorial Hospital. You can even begin the conversation with a question as simple as, “Can you tell me about this PSA test?” Having a spouse or other loved one in the exam room might also help you feel more comfortable, she says.

Do your homework on screenings and screening guidelines beforehand to make the most use of the little time primary doctors have with patients, says Julio Pow-Sang, chair of the Department of Genitourinary Oncology at the Moffitt Cancer Center. And given these time constraints, “it doesn’t take one visit to discuss. It takes about two to three visits at least for the patient to understand the risks and benefits and incorporate their values in their decision.”

Mammograms: Know the potential risks and benefits

A mammogram is a low-dose X-ray exam that can reveal abnormal changes in breast tissue. If a mammogram does detect an abnormality, the patient is called back for additional testing. That often includes a diagnostic mammogram, which is similar to the initial screening mammogram, but involves taking more X-rays of the breast. A callback could also entail an ultrasound or MRI. In some cases, clinicians will recommend a biopsy, or removal of a small sample of breast tissue for closer examination.

Many people believe any cancer cell in their body will divide, spread and eventually kill them, and that screening can catch these cells before it’s too late. The reality is more complex. While breast cancer can be aggressive, some cancers stop growing before they become deadly. Others grow so slowly that they essentially remain benign. But mammograms can’t tell the difference.

As a result, abnormalities may be overdiagnosed, meaning the test found cancer that would never have been detected, or threaten health, in the absence of screening. According to conservative estimates, one in eight breast cancer cases are overdiagnosed. Overdiagnosis can, in turn, result in unnecessary treatment. For every life breast cancer screening saves, two to three women undergo unnecessary treatment. “This involves, No. 1, labeling the woman so that she’s worried for the rest of her life that [the cancer] might come back,” Elmore says. “There’s surgery, radiation therapy, and chemotherapy. She could lose her hair. These are serious issues.”

And mammograms aren’t perfect. They often yield false positive results, which can cause intense anxiety. About one in 10 women receive a callback after a mammogram, but only 5 percent of those women actually end up having cancer. The probability of a false positive increases the more frequently women get screened. In a 2011 study, around 61 percent of women who get yearly mammograms will receive at least one false positive over the course of a decade.

Mammograms can indeed catch aggressive cancer before it spreads, but there’s some debate over how effectively they do so. For perspective, screening 10,000 women in their 40s would save only three of them. Screening the same amount of women in their 50s would save eight lives, and screening the same number of women in their 60s would save 21 lives.

But the Society of Breast Imaging and the The American College of Radiology recommend that women start annual screening at the age of 40, unless they put higher value on
the potential harms of screening, which should be an individual choice. They argue that the USPSTF’s analysis may overstate the potential harms of breast cancer screening and underestimate the benefit of mammography in reducing breast cancers and deaths from the disease.

While forgoing routine mammograms means not experiencing false positives or other harms, there’s still a trade-off. “Not screening also has harms that pile up,” Bevers says. “You can still get cancer, and you’re more likely to die from it. Because it is often more advanced without screening, you may need to have more intensive treatment.” Despite the short-term dread a callback triggers, “in terms of benefits vs. harms of breast cancer screening, short term anxiety regarding test results does not equate to dying from breast cancer,” the ACR wrote in a 2014 statement.

Questions to ask your doctor about routine mammograms

While most guidelines, including those from the USPSTF, ACS, and ACR, recommend that women who expect to live at least 10 more years should be getting routine mammograms in their 50s through at least their mid-70s, there’s more debate about women in their 40s. If you have a family history of breast cancer, or other risk factors, perhaps consider starting routine screenings earlier — although it’s important to note that most women with breast cancer don’t have a family history of the disease.

Here are the questions experts suggest you ask your doctor as you weigh your options: What are the potential harms and benefits of routine mammograms?

  • Is there anything about me that makes you think I should or should not start getting screened?
  • What is the overall benefit of starting routine mammograms at age 40 versus at age 50?
  • When do you recommend I start routine mammograms, and why?
  • How often do you recommend I get a mammogram, and why?
  • What could happen if a mammogram detected something suspicious?
  • What is my absolute risk of dying of breast cancer?
  • If I undergo screening, how much will it reduce my risk of dying of breast cancer?  
  • When should I stop getting mammograms?

The PSA test: Know the benefits and the potential harms

The PSA test is a blood test that measures the levels of PSA protein released by the prostate. Elevated levels can indicate an abnormality, including cancer. If the test detects an abnormality, patients may need to get an ultrasound or biopsy, which involves taking tiny samples of prostate tissue for further examination.

The PSA test can help catch prostate cancer early, and can prevent deaths. But like mammograms, the test isn’t perfect. Abnormalities other than cancer, such as inflammation or the enlargement of the prostate, which naturally happen with age, can also boost PSA levels. As a result, false positives are common, causing unnecessary worry. Only about 25 percent of men with an abnormal PSA test result actually end up having prostate cancer.

And, also like mammograms, the PSA test can result in follow-up testing and lead to overdiagnosis of cancers that would have never progressed or caused harm. In fact, most prostate tumors grow so slowly, that even if you do have prostate cancer, it’s more likely that something else will kill you first, which means that “a lot of prostate cancer doesn’t need to be treated,” Gore says.

Estimates of the degree of overdiagnosis vary, but one study of US men between 54 and 80 years old estimated that in 23 to 42 percent of men with prostate cancer detected by the PSA test, the test found a cancer that, without screening, would never have been detected or caused harm.

As a result, some men may needlessly experience further tests, and ultimately the potential harms of treatment, which can include radiation therapy and surgery to remove the prostate. Treatment can have a number of side effects, such as erectile dysfunction and loss of bladder control, Gore says. Now, doctors increasingly recommend active surveillance for men with small or slow-growing tumors that don’t cause symptoms. Active surveillance typically involves closely observing the cancer, for instance, by getting the PSA test every six months. Doctors may also recommend less-vigilant watchful waiting, which mainly involves keeping an eye out for any changes in symptoms.

Research on whether the PSA test saves lives “is mixed,” Brawley says. In 2009, a US trial suggested it did not, while a European trial suggested it lowered the rate of death from prostate cancer by 20 percent. A September study attempting to reconcile those differences found that it decreased prostate cancer deaths by 25 to 32 percent among men who fell within the recommended screening age range. The PSA test can also spot what may turn into deadly prostate cancer early on, while it’s still restricted to the prostate and therefore easier to treat, Morgans says. “That’s a big benefit.” Pow-Sang agrees. “Catching cancer early, if clinically significant, can improve the survival of patients with active cancer,” he says.

The debate also stems from the limitations of the PSA test itself. “Part of the challenge with the PSA test is its sensitivity,” says David Jarrard, a chair in urologic oncology at the University of Wisconsin. “It’s sensitive to detecting abnormalities in the prostate” — including those unrelated to cancer, such as inflammation or benign enlargement of the prostate  — “but not specific.”

Questions to ask about the PSA test

Guidelines from the, ACS, American Urological Association and many other medical groups say men in their 50s should discuss the PSA test with their doctors if they expect to live at least 10 more years. Men at higher risk should consider getting screened earlier. That includes African- American men and men with a first-degree relative — a father, brother, or son — who has had  prostate cancer.

To help you in your decision-making process, here are some questions experts recommend asking your doctor:

  • What are potential the harms and benefits of the PSA test?
  • Is there anything about me that makes you think I should or should not get the test?
  • What could happen if prostate cancer cells are discovered?
  • What is my overall risk of dying from prostate cancer?
  • If I undergo screening, how much will it reduce my risk of dying of prostate cancer?  

Selected references

Chemotherapy for Prostate Cancer. American Cancer Society. 11 March 2016. [Link]

Draft Recommendation Statement: Prostate Cancer: Screening. U.S. Preventive Services Task Force. April 2017. [Link]

Final Update Summary: Breast Cancer: Screening. U.S. Preventive Services Task Force. 4 December 2009. [Link]

Hormone Therapy for Prostate Cancer. American Cancer Society. 11 March 2016. [Link]

Mammograms. WomensHealth.gov. 6 February 2017. [Link]

Mammograms. American Cancer Society.  18 August 2016. [Link]

Mayo Clinic Staff. Prostate biopsy - What you can expect. Mayo Clinic. 11 August 2017. [Link]

Surgery for Prostate Cancer. American Cancer Society. 11 March 2016. [Link]

Radiation Therapy for Prostate Cancer. American Cancer Society. 11 March 2016. [Link]

Watchful Waiting or Active Surveillance for Prostate Cancer. American Cancer Society. 11 March 2016. [Link]

Melissa Pandika
Rally Health