While some dietary factors have been associated with prostate cancer the evidence is still tentative. Evidence supports little role for dietary fruits and vegetables in prostate cancer occurrence. Red meat and processed meat also appear to have little effect in human studies. Higher meat consumption has been associated with a higher risk in some studies.

Lower blood levels of vitamin D may increase the risk of developing prostate cancer.

Folic acid supplements have no effect on the risk of developing prostate cancer.

There are also some links between prostate cancer and medications, medical procedures, and medical conditions. Use of the cholesterol-lowering drugs known as the statins may also decrease prostate cancer risk.

Infection or inflammation of the prostate (prostatitis) may increase the chance for prostate cancer while another study shows infection may help prevent prostate cancer by increasing blood flow to the area. In particular, infection with the sexually transmitted infections chlamydia, gonorrhea, or syphilis seems to increase risk. Finally, obesity and elevated blood levels of testosterone may increase the risk for prostate cancer. There is an association between vasectomy and prostate cancer; however, more research is needed to determine if this is a causative relationship.

Research released in May 2007, found that US war veterans who had been exposed to Agent Orange had a 48% increased risk of prostate cancer recurrence following surgery.

In some population studies moderate alcohol consumption is associated with increase the breast cancer risk.

In contrast, research by the Danish National Institute for Public Health, comprising 13,074 women aged 20 to 91 years, found that moderate drinking had virtually no effect on breast cancer risk.

Studies that control for screening incidence show no association with moderate drinking and breast cancer, e.g.. Moderate drinkers tend to screen more which results in more diagnoses of breast cancer, including mis-diagnoses. A recent study of 23 years of breast cancer screening in the Netherlands concluded that 50% of diagnoses were over-diagnoses.

Studies suggest that drinking alcohol during pregnancy may affect the likelihood of breast cancer in daughters. "For women who are pregnant, ingestion of alcohol, even in moderation, may lead to elevated circulating oestradiol levels, either through a reduction of melatonin or some other mechanism. This may then affect the developing mammary tissue such that the lifetime risk of breast cancer is raised in their daughters."

Some conditions such as lichen sclerosus, squamous dysplasia or chronic vulvar itching may precede cancer. In younger women affected with vulvar cancer, risk factors include low socioeconomic status, multiple sexual partners, cigarette use and cervical cancer. Patients that are infected with HIV tend to be more susceptible to vulvar cancer as well. Human papillomavirus (HPV) infection is associated with vulvar cancer.

Although the exact cause of vulvar cancer isn't known, certain factors appear to increase your risk of the disease.

- Increasing age

- Exposure to human papillomavirus

- Smoking

- Being infected with the human immunodeficiency virus (HIV)

- Having a history of precancerous conditions of the vulva

- Having a skin condition involving the vulva

There are several reasons why PIN is the most likely prostate cancer precursor. PIN is more common in men with prostate cancer. High grade PIN can be found in 85 to 100% of radical prostatectomy specimens, nearby or even in connection with prostate cancer. It tends to occur in the peripheral zone of the prostate. With age, it becomes increasingly multifocal, like prostate cancer. Molecular analysis has shown that high grade PIN and prostate cancer share many genetic abnormalities. This has been confirmed in a transgenic mouse model.

The risk for men with high grade PIN of being diagnosed with prostate cancer after repeat biopsy has decreased since the introduction of biopsies at more than six locations (traditional sextant biopsies).

Though Bartholin gland carcinoma is rare, along with other unusual Bartholin gland growths, it many not be the typical practice for clinicians to consider lesions malignant. Early diagnosis can help to prevent the cancer from the glands to surrounding. Though malignancies of the Bartholin gland are rare clinicians biopsy Bartholin gland lesions in older women or when the growth reoccurs or does not respond to original treatment.

Bartholin gland can be differentiated by histology to determine whether the malignancy is due to squamous cell carcinoma, adenoid cystic carcinoma, or adenocarcinomas.

PIN was historically subdivided into different stages, based on the level of cell atypia. PIN was formerly classified as PIN 1, 2 or 3, in order of increasing cell irregularities. Nowadays, PIN 1 is referred to as low grade PIN, and PIN 2 and PIN 3 are grouped together as high grade PIN. Only high grade PIN has been shown to be a risk factor for prostate cancer. Because low grade PIN has no significance and does not require repeat biopsies or treatment, it is not mentioned in pathology reports. As such, PIN has become synonymous with high grade PIN.

It is also known that disruption of the endocrine system by certain chemicals adversely affects the development of the reproductive system and can cause vaginal cancer. Many other reproductive diseases have also been link to exposure to synthetic and environmental chemicals. Common chemicals with known links to reproductive disorders include: lead, dioxins and dioxin-like compounds, styrene, toluene, BPA (Bisphenol A) and pesticides.

Endometrial hyperplasia is a condition of excessive proliferation of the cells of the endometrium, or inner lining of the uterus.

Most cases of endometrial hyperplasia result from high levels of estrogens, combined with insufficient levels of the progesterone-like hormones which ordinarily counteract estrogen's proliferative effects on this tissue. This may occur in a number of settings, including obesity, polycystic ovary syndrome, estrogen producing tumours (e.g. granulosa cell tumour) and certain formulations of estrogen replacement therapy. Endometrial hyperplasia is a significant risk factor for the development or even co-existence of endometrial cancer, so careful monitoring and treatment of women with this disorder is essential.

Nipple discharge refers to any fluid that seeps out of the nipple of the breast. Discharge from the nipple does not occur in lactating women. And discharge in non-pregnant women or women who are not breasfeeding may not cause concern. Men that have discharge from their nipples are not typical. Discharge from the nipples of men or boys may indicate a problem. Discharge from the nipples can appear without squeezing or may only be noticeable if the nipples are squeezed. One nipple can have discharge while the other does not. The discharge can be clear, green, bloody, brown or straw-colored. The consistenct can be thick, thin, sticky or watery.

Some cases of nipple discharge will clear on their own without treatment. Nipple discharge is most often not cancer (benign), but rarely, it can be a sign of breast cancer. It is important to find out what is causing it and to get treatment. Here are some reasons for nipple discharge:

- Pregnancy

- Recent breastfeeding

- Rubbing on the area from a bra or t-shirt

- Trauma

- Infection

- Inflammation and clogging of the breast ducts

- Noncancerous pituitary tumors

- Small growth in the breast that is usually not cancer

- Severe underactive thyroid gland (hypothyroidism)

- Fibrocystic breast (normal lumpiness in the breast)

- Use of certain medicines

- Use of certain herbs, such as anise and fennel

- Widening of the milk ducts

- Intraductal pipilloma

- Subareolar abscess

- Mammary duct ectasia

- Pituitary tumor

Sometimes, babies can have nipple discharge. This is caused by hormones from the mother before birth. It usually goes away in 2 weeks. Cancers such as Paget disease (a rare type of cancer involving the skin of the nipple) can also cause nipple discharge.

Nipple discharge that is NOT normal is bloody, comes from only one nipple, or comes out on its own without squeezing or touching the nipple. Nipple discharge is more likely to be normal if it comes out of both nipples or happens when the nipple is squeezed. Squeezing the nipple to check for discharge can make it worse. Leaving the nipple alone may make the discharge stop.

Lymphoma is the most common type of blood-related cancer in horses and while it can affect horses of all ages, it typically occurs in horses aged 4–11 years.

Initially, an evaluation of malignancy is always indicated. If no abnormality is found, then a surgical duct excision may resolve the symptoms. Treatment also depends on whether single-duct or multiple-duct discharge is present, and whether the symptoms of nipple discharge are distressing to the patient. In some cases, there may be no need for any further intervention; in others, microdochectomy or a total duct excision may be appropriate. If the patient wishes to conserve the ability to breastfeed and only single-duct discharge is present, then ductoscopy or galactography should be considered in view of performing a localised duct excision. Once the cause of the nipple discharge is found, it will be treated by the health provider who will evaluate:

- Whether changing any medicine that has caused the discharge is appropriate

- Whether any lumps should be removed

- Whether some or all of the breast ducts should be removed

- If a prescription for cream to treat skin changes around the nipple will be helpful

- If medicines to treat a health condition are required

If all the tests are normal, treatment may not be necessary. A follow up mamogram mammogram and physical exam may be prescribed within 1 year.

Examples of cancers of the reproductive system include:

- Prostate cancer - Cancer of the prostate gland

- Breast cancer - Cancer of the mammary gland.

- Ovarian cancer - Cancer of the ovary.

- Penile cancer - Cancer of the penis.

- Uterine cancer - Cancer of the uterus.

- Testicular cancer - Cancer of the testicle/(plural:testes).

- Cervical Cancer - Cancer of the cervix.

Extramammary Paget's disease is usually seen in isolation and is associated with an underlying invasive malignancy about 12% of the time. It is associated with an underlying adnexal malignancy about 24% of the time. Paget's disease of the breast is almost always associated with an underlying invasive malignancy, i.e. breast cancer (e.g. mammary ductal carcinoma).

Paget's disease of the vulva, a rare disease, may be a primary lesion or associated with adenocarcinoma originating from local organs such as the Bartholin gland, the urethra, or the rectum and thus be secondary. Patients tend to be postmenopausal.

Paget's disease of the penis may also be primary or secondary, and is even rarer than genital Paget’s disease in women. At least one case has been misdiagnosed as Bowen's disease. Isolated Paget's disease of the penis is extremely rare.

Treatment of endometrial hyperplasia is individualized, and may include hormonal therapy, such as cyclic or continuous progestin therapy, or hysterectomy.

Two percent of women will have a Bartholin's gland cyst at some point in their lives. They occur at a rate of 0.55 per 1000 person-years and in women aged 35–50 years at a rate of 1.21 per 1000 person-years. The incidence of Bartholin duct cysts increases with age until menopause, and decreases thereafter. Hispanic women may be more often affected than white women and black women. The risk of developing a Bartholin's gland cyst increases with the number of childbirths.

While Bartholin cysts can be quite painful, they are not life-threatening. New cysts cannot absolutely be prevented from forming, but surgical or laser removal of a cyst makes it less likely that a new one will form at the same site. Those with a cyst are more likely than those without a cyst to get one in the future. They can recur every few years or more frequently. Many women who have marsupialization done find that the recurrences may slow, but do not actually stop.

According to Surveillance, Epidemiology, and End Results (SEER), the incidence of papillary cancer has increase from 4.8 to 14.9 per 100,000 from 1975 to 2012. Females are more likely to get papillary cancer when compared to males with incidence ratio of 2.5 to 1 where most of the cancers are diagnosed between 40 to 50 years old in females. However, death rates from papillary cancer remains static from 2003 to 2012 at 0.5 per 100,000 men and women. There was an increased incidence of papillary cancer from 1910 to 1960 due to the use of ioninsing radiation in treating childhood head and neck cancers. The incidence decreased after radiation therapy was abondoned. Environmental exposures to radiation such as atomic bombings of Hiroshima and Nagasaki and Chernobyl disaster also causes an increase in childhood papillary thyroid cancer at 5 to 20 years after the exposure to radiation. Family history of thyroid cancer syndrome such as familial adenomatous polyposis, Carney complex, Multiple endocrine neoplasia type 2 (MEN-2), Werner syndrome, and Cowden syndrome increases the risk of getting papillary cancer.

Tumors related to squamous-cell carcinoma (SCC) can appear anywhere on the body, but they are most often located in non-pigmented skin near mucocutaneous junctions (where skin meets mucous membranes) such as on the eyelids, around the nostrils, lips, vulva, prepuce, penis or anus. The tumors are raised, fleshy, often ulcerated or infected and may have an irregular surface. Rarely, primary SCC develops in the esophagus, stomach (non-glandular portion), nasal passages and sinuses, the hard palate, gums, guttural pouches and lung. The eyelid is the most common site, accounting for 40-50% of cases, followed by male (25-10% of cases) and female (10% of cases) genitalia. Horses with lightly pigmented skin, such as those with a gray hair coat or white faces, are especially prone to developing SCC, and some breeds, such as Clydesdales, may have a genetic predisposition. Exposure of light-colored skin to UV light has often been cited as a predisposing factor, but lesions can occur in dark skin and in areas that are not usually exposed to sunlight, such as around the anus. Buildup of smegma ("the bean" in horseman's terms) on the penis is also linked to SCC and is thought to be a carcinogen through penile irritation. Pony geldings and work horses are more prone to developing SCC on the penis, due to less frequent penile washing when compared to stallions. Equine papillomavirus-2 has also been found within penile SCCs, but has not been determined to cause SCC.

Parathyroid cancer occurs in midlife at the same rate in men and women.

Conditions that appear to result in an increased risk of parathyroid cancer include multiple endocrine neoplasia type 1, autosomal dominant familial isolated hyperparathyroidism and hyperparathyroidism-jaw tumor syndrome (which also is hereditary). Parathyroid cancer has also been associated with external radiation exposure, but, most reports describe an association between radiation and the more common parathyroid adenoma.

Prostatic stromal tumour of uncertain malignant potential, abbreviated PSTUMP, is a rare tumour of the prostate gland stroma that may behave benign or like cancer, i.e. "malignant".

It can be abbreviated STUMP; an abbreviation used for a uterine lesion of uncertain malignant potential.

It is also known as prostatic stromal proliferation of uncertain malignant potential (abbreviated PSPUMP).