Cancer Mythbusters: Early Cancer Detection and Risk

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MEGAN: Hi. I'm Megan Riesz, and this is Cancer Mythbusters, a podcast from Dana-Farber Cancer Institute about the many myths and misconceptions in the world of cancer. Every episode, we'll take a look at a myth and debunk it with the help of our world-leading clinicians and researchers.

Cancer research is often geared toward finding new and effective treatments, but researchers are also constantly trying to pinpoint ways to find cancer in its early stages, when it is often more treatable and even curable. Incredible advancements have been made in early detection in recent years, but it can still be hard to sift through all of the facts and false information to figure out what you need to know.

Today, we’ll address some common myths, misconceptions and questions about early detection of cancer with two Dana-Farber experts, Dr. Brittany Bychkovsky and, cancer genetic counselor, Jill Stopfer. Welcome both.

DR. BYCHKOVSKY: Thank you.

J. STOPFER: Thank you. Good to be here.

MEGAN: So, Brittany, we’ll start with you. So, as I mentioned, we know that there are no guaranteed ways to prevent cancer, but finding it early on is usually better when it comes to treatment options and outcomes. So, can you give us some examples of some cancers that can be detected early and how?

DR. BYCHKOVSKY: So, today, in 2018, we actually do cancer screening for breast cancer, colorectal cancer, cervical cancer, and the latest is lung cancer, and these screening protocols have been shown to save lives.

So, there are a handful of groups and medical societies that provide guideline recommendations on screening that includes the U.S. Preventive Services Task Force, the American Cancer Society, the American College of Obstetrics and Gynecology, and the National Comprehensive Cancer Network. So, for breast cancer there’s consensus that all women between the ages 50 and 69 should have mammogram screening either once a year or every two years.

So, after combining data from nine trials that were conducted in the 1970s and the 1990s, which included 600 women, researchers found that mammography screening reduces the risk of breast cancer mortality by 20 percent. So, between 40 and 49 it’s a little bit controversial whether women should have screening, but the standard is for women to have annual mammogram screening between 40 and 49 in the US and it reduces the risk of breast cancer death by 15 percent. This means that for every approximately 1,900 women that are screened, we prevent one breast cancer death.

So, for cervical cancer, we do screening with a combination of Pap smear screening and HPV testing, and this is to determine if the woman is at risk for developing cervical cancer. Cervical cancer screening was introduced in the 1950s and by the mid-1980s cervical cancer incidence had already decreased in the United States by 70 percent, so cervical cancer incidence and mortality is continuing to decline with the addition of HPV testing and with the HPV vaccine.

So, all cervical cancers are caused by a virus called HPV and today we have a vaccine, and there’s actually two versions of this — one is called Gardasil and the other is Cervarix — so, I highly recommend all people who are young and eligible to get the HPV vaccine to prevent cervical cancer.

So, regarding colorectal cancer screening, it also works and saves lives, and since it was introduced, there has been a decline in colorectal cancer in the United States.

Since 2011, we are now doing lung cancer screening. So, in patients at high-risk for lung cancer - that includes recent former smokers and current smokers between the ages of 55 and 80 - lung cancer screening with low-dose CT scans decreases lung cancer mortality by 20 percent.

For many cancers like ovarian, pancreatic, gastric and gallbladder cancer, we don’t have screening, and this is because either the incidence of these cancers is quite low and/or because we don’t have a good screening test that is sensitive and specific. So, for the cancers where we do have screening, I highly encourage everyone to participate.

MEGAN: So, kind of going off that, Brittany, once again, there are many different types of cancer and they obviously all have their different signs and symptoms, but are there any very general signs and symptoms that people should look out for?

DR. BYCHKOVSKY: So, this is a hard question to answer because cancer can cause all types of signs and symptoms. What I tell my patients to keep an eye out for is anything that’s new and it’s persistent in getting worse over a period of two weeks, and if that happens, to give us a call to let us know what’s going on and we’ll have you come in for an appointment.

So, if you’ve strained your knee running and it’s now better, I don’t need to know about it. If you have a stuffy nose and a sore throat, and it’s getting better, I also don’t need to know about it, but if you aren’t feeling well and something is going on that’s persistent and getting worse over a period of two weeks, come in and be seen.

MEGAN: So, another kind of very general question, but an important one that we get a lot — can you go over the overall current screening recommendations for women?

DR. BYCHKOVSKY: Okay, so, for women, I think the topic that most people are curious about is what they should have done for breast cancer screening. So, the lifetime risk of breast cancer in the United States for a woman is 12 percent, so that’s what we call as average risk.

So, for breast cancer, all women should have a mammogram once a year or every two years between the ages of 40 and 74. After the age of 75, the patient should have a discussion with their doctor about whether mammogram screening should be continued. For anyone who’s at a higher risk of breast cancer, and that includes a lifetime risk greater than 20 percent, they consider starting screening at a younger age, less than 40, and they can also consider a mammogram in addition to breast MRI.

So, for cervical cancer screening, women should have cervical cancer screening every three years between the ages of 21 and 39 with cytology alone. Between the ages 30 and 65, cervical cancer screening should be every three years if they're receiving cytology alone, every five years with HPV DNA testing and/or HPV DNA plus cytologies, and these are the recommendations per the U.S. Preventive Services Task Force.

Colon cancer screening can also be considered and it really should start at age 45 per the American Cancer Society and no later than 50, so that’s something that’s actually kind of new. So, there’s many appropriate methods for colon cancer screening and that includes sigmoidoscopy, fecal occult blood testing, colonoscopy or CT colonography, and I typically recommend for patients to have colonoscopy screening. It will be both diagnostic and therapeutic. So, for example, if on colonoscopy a polyp is identified, that could be an indicator that it’s precancerous. It can be removed. Colonoscopy screening in comparison to sigmoidoscopies, it actually covers the whole colon versus a sigmoidoscopy would miss the right side of the colon.

So, for lung cancer screening, women qualify for that, and lung cancer screening includes a low-dose CT scan for adults between the ages of 55 and 80 who have a 30 pack-year history of smoking and they're either currently a smoker or they quit in the last 15 years.

MEGAN: And so, moving on, what about men?

DR. BYCHKOVSKY: They can have lung cancer screening just like women, and so that definitely should be considered if they're current smokers or former smokers between the age of 55 and 80. Prostate cancer screening is important in men, but the recommendations have evolved in the last two decades. There was previously an emphasis that all men should have prostate cancer screening and now it’s more of something that should be discussed between a patient and their provider.

So, the current recommendations that men between the ages of 55 and 69 should consider prostate cancer screening with their clinician. This includes a digital rectal exam and a PSA check. Most men do not need prostate cancer screening after the age of 70. So, there are some populations that are at a high risk of prostate cancer and that includes men that harbor BRCA1 and 2 mutations, and they should have prostate cancer screening starting at age 40 with a digital rectal exam and a PSA check.

The last, I guess, cancer type I should discuss is men should also have colorectal cancer screening just like women beginning at age 45.

MEGAN: So, what are some kind of general, bogus, or misleading claims about early detection that you hear a lot that people should keep an eye out for and know about?

DR. BYCHKOVSKY: So, I think there’s a lot of alternative screening protocols out there, so this may include a new blood test or imaging modalities like thermal breast studies or whole breast ultrasound that can occasionally be offered to patients. However, they’ve not been clinically studied on a population level, so I think these methods may have a role in the future and I think that they may have a role in addition to mammogram screening, but I emphasize that we should really be following the tried and true methods.

MEGAN: So, Jill, we know that some people are born with gene mutations that they inherit from their parents as Brittany alluded to, which can increase the risk of the development of cancer. So, what kinds of people should consider genetic testing?

J. STOPFER: It’s true that some people are born with a significantly higher chance to develop a cancer versus someone else, and I think this also ties back into what we’ve been discussing in regard to screening, because there are these wonderful population screening guidelines, but they're not appropriate for everyone.

And so, what we do here at Dana-Farber at our Cancer Genetics and Prevention Clinic is we try to assess for genetic risk that may require a person to do something that’s different from what the average person is recommended to do.

So, the types of people that might benefit from genetic testing are those most likely to actually carry a gene that leads them to live their lives at higher than average risk. So, that might be someone themselves who has had a cancer diagnosed at an earlier than typical age, so it matters what is the typical age at which that cancer presents and then what is the age of the patient.

We look for people have significant family history. So, are there parents with cancer, siblings, children? Even more extended relatives sometimes provide the clues that we need to see a pattern, so just in hereditary cancer risk, and sometimes it’s the presence of a rare cancer all by itself such as a sarcoma or another form of rare cancer that indicates genetic testing.

We're learning that there are some cancers that have a high enough rate of having underlying genetic susceptibility that it’s worthwhile to test, for example, all women with ovarian cancer, all individuals with pancreatic cancer, and we're also now testing men who have a more aggressive form of prostate cancer and this genetic testing can inform us about risks that the person has, again, that differ from the general population that might suggest differences to their screening, and it also allows you to track cancer risk in a family with a blood test. You can figure out who has it also and could benefit from this specialized care and, just as importantly, who doesn’t have it and who can be reassured and just resort to the population screening guidelines.

MEGAN: Final question which, again, is a big one, but anything else that people should know about cancer detection or prevention that we haven’t discussed?

J. STOPFER: I think that the issue is to really have a discussion with your doctor about your personal situation, because, again, you can hear that there are these extensive guidelines and they may be appropriate for most people, but the key is that conversation that you have with your doctor to make sure that they're right for you across the board or are there special things that you personally might benefit from.

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