Good news! There is no causative correlation between wearing bras and developing breast cancer. Thus, there is no reason for you to worry
about wearing a bra and what implications it could have for your health. Often, there will be someone (usually not a doctor
) that notices a statistic such as one country having more breast cancer than an other country. They also may notice that less women from that country wear bras. They then make the incorrect conclusion that one (the bra) must be causing the other (the cancer). Most of the time there is another reason for the correlation. For example, there may be less breast cancer in another country because the women are only living to be 60 years old and thus, don't live long enough to get breast cancer.
The most important thing you can do at your age to prevent breast cancer is to have yearly exams by your primary care physician
or OBGYN, whoever you see for your feminine health. They can look for any lumps or other abnormalities during these exams. If you have a family history of breast cancer developing at a young age in close relatives, then you may need more aggressive screening at an earlier age.