People think of cancer as an older person’s diagnosis, or something that happens to smokers and alcoholics. When they see ads for St. Jude’s or hear the rare news story about a 20-something with breast cancer or a brain tumor, they think that’s a fluke occurrence – “that’s devastating…glad that won’t happen to me.”

The reality, though, is that it can. No one is one hundred percent guaranteed to avoid cancer in their lifetime, and while many forms of cancer are rare in children and younger adults, it’s not impossible that it can happen to anyone at any age.

This is why cancer screening is important, and it’s not just something that can be discussed with a doctor once someone turns 40 or 50. Parents and young adults can start talking to doctors about cancer risk factors and how to prevent cancer from a very early age, and early screening can give someone insight to their potential risk for cancer.

Certain types of cancer come with different age guidelines, and these are spelled out below.

Colon Cancer

As early as age 20, young men can talk to their doctor about their potential risk for colon cancer. First, they must discuss their family history and genetics with doctors. The outcome of this conversation can determine whether or not a man is a candidate for early screening.

For instance, John tells his doctor he has no family history of colon cancer and is a healthy individual, so his doctor tells him early screening isn’t necessary. William, however, has had a grandfather develop colon cancer, as well as an uncle, so early screening is a good idea for him.

If there are no suck risks involved, colon cancer screenings should begin at age 50 and should be received regularly from then on. Women should also consider colon cancer screenings starting at this age.

Breast Cancer

Breast cancer is yet another cancer that can be discussed with doctors even from an early age. Women who have a history of cancer, or specifically breast cancer, in their family should talk about early mammograms and their potential for cancer from as young as 20-29. All girls of puberty age and older should be instructed on how to feel their breasts for lumps and other abnormalities as a form of self-mammogram.

Otherwise, annual breast cancer screenings are recommended for women 45 and up, while women aged 40-44 can have the choice to receive a mammogram or not.

Cervical Cancer

Depending on the OBGYN in question, they may recommend a teenager begin cervical cancer screenings via Pap Smears starting from the point she becomes sexually active. If the woman isn’t sexually active until the age of 21, the Pap Smear test may not be necessary until then. In cases where women still aren’t sexually active, OBGYNs may forgo a Pap Smear until they are, though it’s up to the woman’s discretion.

Once a woman has reached a qualification for a Pap Smear, however, OBGYNs recommend receiving one regularly – once every 2 to 3 years. Once a woman turns 30, the numbers decrease to every 3 or 5 years.

Lung Cancer

Most obviously, those who are currently smoking are at an increased risk of lung cancer. However, even those who quit smoking are still at a higher risk than those who have never smoked in their life, even with a significant amount of time in between quitting smoking and their potential screening age.

Once a man or woman becomes 55, it may be necessary to go through a low dose CT scan in order to screen for early lung cancer. The potential risk for lung cancer in smoker is measured in pack-years – also known as one pack of day per year. A 30 pack-year smoker should be screened for cancer starting at 55, and pack-years stack. For instance, smoking two packs a day for 15 years is the same as a 30 pack-year, so keep this in mind when calculating your risk.

Those who smoke regularly, even at a younger age, are also at risk for lung cancer. If you’re a smoker below the age of 55, discuss your testing options with your doctor to see if you should also undergo a low dose CT scan.

Prostate Cancer

Prostate cancer is a cancer that isn’t discussed until a man turns 45, and science stands by the idea that there is no need to. Unless a younger man detects something wrong with his prostate, whether through a painful feeling or abnormal erectile or ejaculate patterns, then there is often not a need to screen him for prostate cancer.

Once a man becomes 45, his risk of prostate cancer increases to higher than average. If a man has a family history of prostate cancer, testing may begin as early as 40.