Dear Doctor: I just had a scare with prostate cancer. The tests turned out negative, but it shook me up. Now I just want to make sure things stay that way. What should I be doing -- and what can my two sons do -- to reduce their risk? I’m 67, and they’re in their mid-40s.

Dear Reader: Prostate cancer is the most common cancer in men. Only the various types of skin cancers, when bundled together into a single category, get diagnosed more often. The majority of prostate cancers are found in men 65 and older, so at 67, you fall into that demographic.

It is estimated that 1 in every 8 men will be diagnosed with prostate cancer. More than 250,000 new cases are expected to be diagnosed this year, and the cancer is predicted to cause 35,000 deaths. Although your sons are a generation younger, the risk factors and lifestyle changes that we’re going to discuss apply to them as well.

To understand how to reduce the risk of developing prostate cancer, let’s first take a look at the risk factors. These include age, race, tobacco use, being sedentary, eating a diet high in red meat and saturated fat, and family history. There’s nothing you can do to change your age, race or family history. However, the risks associated with all of these can play a role in decisions men make around when to begin screening for prostate cancer.

Men of average risk should talk to their doctor about screening at age 50. Men at higher risk, which includes those with a father or brother diagnosed with prostate cancer before age 65, should have the screening conversation at age 45. Because the mortality rate is highest in men of African and Afro-Caribbean descent, they should also discuss early screening with their health care provider.

Studies have shown that changes to the factors you have some control over can help reduce risk. This includes reaching and maintaining a healthy weight, getting regular exercise, and limiting red meat and saturated fats. Instead, shift to a diet with proteins such as fresh fish, chicken, turkey and healthful oils. Round things out with plenty of leafy greens, an assortment of fresh vegetables and fruit, whole grains, nuts and legumes. Steer clear of highly processed foods, which are loaded with salt, fat and added sugar, and have little to no nutritional value.

If you smoke, try to quit. Tobacco products of all kinds play a role in numerous diseases and conditions, including prostate cancer. They put the people around the smoker at risk as well. There’s no question that quitting is difficult, but smokers don’t have to go it alone -- don’t be afraid to ask for help from your doctor.

Prostate cancers grow slowly and are slow to spread, so survival rates are quite good. The five-year survival rate is close to 100%. The 15-year survival rate is 95%. Cancers that are caught early are more easily treated, which makes being vigilant about screening all the more important. Thanks to new understanding about the prognosis of older men with slow-growing tumors, many doctors now counsel watchful waiting rather than immediate surgery.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: Our daughter is 5 months old, and we always put her to sleep on her back. Lately, when we check on her, she’s on her stomach. Should we be keeping an eye out and positioning her on her back again when that happens?

Dear Reader: First, congratulations on your daughter hitting an important developmental milestone! Rolling over, which typically occurs anywhere from the ages of 4 to 6 months, is an important part of a baby’s development. It’s one of the first steps on the journey to your baby becoming mobile. Your daughter is gaining in both muscle strength and coordination; that gentle rocking from side to side that you have noticed has now become forceful enough that she is able to flip herself over.

It’s true that since 1994, the American Academy of Pediatrics (AAP) has recommended that parents put babies to sleep on their backs. This is to prevent sudden infant death syndrome (SIDS), the unexpected and unexplained death of an apparently healthy baby, often during sleep.

The exact cause of SIDS remains unknown. However, researchers believe that it may occur when an infant’s airway becomes blocked for some reason, and the part of their brain that would normally wake them up isn’t developed enough yet, or isn’t functioning properly. The “Back to Sleep” campaign, which began in 1994 to urge parents to place sleeping infants on their backs, has helped significantly reduce SIDS deaths in the United States.

Here’s the good news: Now that your daughter is able to turn herself over unaided, her brain has developed enough that she will shift position should she experience any problems with breathing. The National Institutes of Health recommend -- and we agree -- that you should continue to start her out on her back when she’s going down for a nap or for the night. Should she turn over during her sleep, it’s fine -- you don’t need to reposition her on her back.

There are a few other simple precautions you can take to ensure a safe and comfortable sleep environment for your infant. First, make sure she’s lying on a firm mattress with a fitted sheet. Don’t cover her with loose bedding, such as a sheet, blanket or quilt. Instead, dress her in just enough sleep clothing to keep her comfortable throughout the night. Although she may need to fall asleep with her favorite pillow or stuffed toy, once she’s nodded off, keep her bed clear of them and other soft objects.

Overheating has been suspected to play a role in SIDS, so it’s important that your baby’s bedroom remain at a comfortable temperature. If your sleeping baby’s chest feels hot to the touch, or if they’re sweating, they may be too warm. To stave off potential problems, it’s recommended that babies sleep in their parents' bedroom -- in their own crib or bassinet, not in the parental bed -- until they’re at least 6 months old.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Hello again, dear readers, and welcome to our monthly letters column. We’re happy to hear that our recent focus on your questions regarding the coronavirus vaccines has been helpful. Keep sending them in, and we’ll keep addressing them. Speaking of which:

-- A reader with a petite friend wondered whether coronavirus vaccines should be tailored to a person’s physical size. “My neighbor weighs 94 pounds and worries she might get too much vaccine with a standard vaccination,” she wrote. “Should she get a smaller dosage?” Adults of all sizes can safely receive the same vaccine dose. Although medications are calibrated to reach certain blood concentrations based on body weight, the coronavirus vaccines “speak” directly to the immune system. That means the dosage remains constant, no matter a person’s size. Your neighbor can safely receive the standard dose of any of the three coronavirus vaccines available in the United States at this time.

-- Many of you who are about to get a coronavirus vaccine wanted to know when maximum immunity kicks in. According to the Centers for Disease Control and Prevention (CDC), you’re considered to be fully vaccinated two weeks after the second shot of the two-dose Moderna or Pfizer vaccines, and two weeks after the single-shot Johnson & Johnson vaccine.

-- Another frequently asked question is whether it’s OK to get the coronavirus vaccine at the same time as other vaccines. Just as a precaution, the current recommendation is that the COVID-19 series be administered alone, with at least a two-week interval before and after any other vaccines.

-- Some of you weren’t sure whether the vaccines contained ingredients to which you have known allergies. “I am severely allergic to povidone, which is frequently seen listed as an inactive ingredient in both over-the-counter and prescription medications,” a reader wrote. “Is this a cause of concern with the COVID-19 vaccines?” Polyvinylpyrrolidone, also known as povidone, or PVP, is a water-soluble synthetic polymer that helps keep drugs in suspension. We have reviewed the COVID-19 vaccine ingredients and do not see povidone listed.

-- A reader whose son recovered from Guillain-Barre syndrome (GBS) as a child asked whether the coronavirus vaccine is safe for him an adult. Persons with a history of GBS may receive the COVID-19 vaccine unless they have been previously instructed to avoid vaccination. As this is the case with your son, who has been advised to avoid the flu vaccine, be sure to check with your health care provider for specific recommendations before moving forward with coronavirus vaccination.

We’ll close with a reassurance to those of you who ask that your names not be used in the letters column. We do not publish the names of our correspondents. However, we do love picturing where you’re writing from -- so if you’re willing, feel free to include your city or state in your emails. As always, thank you to our readers who have taken the time to send kind and encouraging words. It really does mean a lot to us.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)