Dear Dr. Roach: I I had my first mammogram and was found to have a lesion. The mammographer said that I should follow up in six months with another mammogram and sonogram, but I have a grandmother who died of breast cancer. So, instead of waiting, I underwent a biopsy that showed a fibroadenoma.

What is it? Does it ever become cancerous? I also read that they are associated with being overweight. I did have bariatric surgery in the past. — V.P.

Answer: A fibroadenoma is a benign breast mass. Most fibroadenomas are “simple” and do not increase the risk of developing breast cancer. They do not need to be removed since they won’t become cancer, but some women choose to remove them so that they won’t have to worry about them, although this can cause a scar and some dimpling.

Complex fibroadenomas slightly increase the risk of breast cancer. Some experts believe they should be removed so that the whole tumor can be evaluated, while others do not feel that a complete removal is necessary.

Fibroadenomas do seem to be related to estrogen levels as they tend to occur during a woman’s reproductive years and may increase in size when taking estrogen or during pregnancy (since estrogen levels are high). They also tend to shrink after menopause.

Women who are overweight enough to be considered for bariatric surgery tend to have higher levels of estrogen as fat cells can make a type of estrogen called estrone, which is not very potent but lasts for a long time. If you lost weight as most do with bariatric surgery, your estrogen levels are likely to go down.

Dear Dr. Roach: I am 89 years old and doing reasonably well, but I have noticed some loss of energy and a bit of my balance. I try to walk, do some exercises, and then hit the hot tub every day to help relax my joints. I recall reading an article about a study concluding that 15 minutes in a hot tub equated, cardio-wise, to a 15-minute jog. I would really appreciate your opinion on this proposition. — J.D.

Answer: I read the study that I think you are referencing, from Coventry, England, and I think the headline writers overstated the more cautious conclusions of the actual study. Being in a hot tub or sauna does increase the heart rate and the ability of the heart to exert itself when done daily for four weeks in people with heart failure.

Other studies have found that healthy volunteers also get small but significant improvements in their cardiac reserve, similar to (but not quite as much as) what would be expected with exercise.

The benefits of exercise are well-known and large and go beyond the effects of the heart, while the benefits of regular hot-tub or sauna bathing appear to give some but not all the benefits of regular exercise. At age 89, there is a risk of heat-related injuries, including lightheadedness and falling, so I would urge caution for new users not to use too high of a heat or stay in for too long, especially when first starting.