Can Smoking Affect the Prostate? Prostate Cancer Risk

Cigarette smoking may affect the prostate by changing circulating levels of steroid hormones in the body. Male smokers have been shown to have higher amounts of circulating androsterone and testosterone, which could raise prostate cancer risk or contribute to cancer development.

There are two distinct processes by which smoking affects the prostate:

Hormones

Smoking leads to higher levels of bioavailable testosterone and lower levels of bioavailable estradiol in men.

Some studies found significant positive correlations between the number of cigarettes smoked per day and serum total androstenedione, as well as total and free testosterone in men. This is significant because testosterone and the more potent metabolite dihydrotestosterone (DHT) are necessary for normal prostate development and growth. It may enhance cell proliferation in the prostate, which potentially could be associated with malignant transformation.

Conversely, estrogens act on the hypothalamus and pituitary to suppress the secretion of gonadotropins, which may reduce testicular androgen production.

Effectively, cigarette smoking may establish a hormonal environment that is favorable for the development or progression of prostate cancer.

Cadmium

Cigarettes contain significant levels of cadmium, which has been linked to prostate carcinogenesis.

Cadmium was classified as a human carcinogen by the International Agency for Research on Cancer in 1993. Although cadmium is not directly mutagenic in the prostate, it has been proven to cause prostate cancer indirectly through interacting with the androgen receptor. In the absence of testosterone but in the presence of the androgen receptor, cadmium activates the androgen receptor response in human prostate cancer cell lines.

Cadmium enhances androgen-mediated transcriptional activity in the prostate when used in conjunction with androgen. Chronic cadmium exposure in rats has been shown to induce prostate tumors in the presence of normal testicular function. Therefore, chronic smoking in men with otherwise normal testicular function and androgen levels may effectively increase their androgen exposure through the interaction of cadmium with the androgen receptor. Over the long term, their risk of developing prostate cancer increases.

Either or both mechanisms could support an association between cigarette smoking and prostate cancer.

The prostate gland is part of the male reproductive system and produces fluid that mixes with semen during ejaculation. This fluid helps protect the sperm and keeps it healthy for conception and pregnancy. Other facts about the prostate are as follows:

• Size of a walnut and weighs about 1 ounce.
• Located below the bladder and in front of the rectum.
• Surrounds the urethra, which is a tube that carries urine from the bladder out through the penis (this is why men with an enlarged prostate have difficulty urinating)
• Generates seminal fluid that nourishes and transports sperm, which is made in the testicles and then moves to the urethra. It mixes with the fluid from the prostate and seminal vesicles and moves out through the urethra during ejaculation.