There are really two distinct questions here, but they are common.
Is cancer heritable?
Is cancer (or cancer risk) contagious?
Most cancer cases are not heritable. Some are. Heritable cases have particular characteristics (early onset, more than one close relative, often with cancer at multiple sites).
Cancer is not contagious. Some cancer risk ...
To answer your question with the best quality evidence would require a double blinded prospective controlled study. Clearly that's not going to happen. But we do have a case control study looking at the bra wearing habits of those with breast cancer, and those without, to see if there is a dose response relationship. And there was none in this group.
A double-blind crossover study of placebo and the antiestrogen tamoxifen in ten men with gynecomastia of diverse etiology showed that:
The reduction of breast size was partial and may indicate the need for a longer course of therapy. A follow-up examination was performed in eight out of ten patients nine months to one year after discontinuing placebo and ...
The Allred score is based on an assessment of the percentage/proportion of tumor cells in a histopathologic specimen that stain positively and the intensity of the staining.
In 2010, the American Society of Clinical Oncology/College of American Pathologists Guideline Recommendations for Immunohistochemical Testing of Estrogen and Progesterone Receptors in ...
According to this review article:
Estradiol and, to lesser degree, other estrogens, increase proliferation of breast epithelium and stroma and, consequently, increase the chances of mutation in rapidly proliferating epithelium
Tamoxifen and other SERMs generally act as competitive antagonist on breast estrogen receptor, which decreases estrogen's ability ...
In most of the countries, obstetricians are the physicians specialised in breastfeeding. Sometimes, pediatricians are also involved but they often tend to focus more on the breastfeeded child, leaving obstetricians the lead concerning the mother.
Here a note from the American College of Obstetricians and Gynecologists:
Foods that may reduce Gynocamastia:
there's no association between any food and breast enlargement in men,
and no special food you need to eat or avoid when you have the
That said you can try food that are anti-inflammatory dor tenderness, low calorie to decrease total body fat, and avoiding foods that may encourage it.
Bras can negatively impact your breast.
Medical News Today
Jean-Denis Rouillon, a sports science expert from the University of
Besançon, France, reported after a 15-year study.
women who never wore bras had nipples on average seven millimeters
higher in relation to their shoulders each year
Do nothing for back pain and weaken muscles