Smoking is the most important risk factor for laryngeal cancer. Death from laryngeal cancer is 20 times more likely for heaviest smokers than for nonsmokers. Heavy chronic consumption of alcohol, particularly alcoholic spirits, is also significant. When combined, these two factors appear to have a synergistic effect.

Some other quoted risk factors are likely, in part, to be related to prolonged alcohol and tobacco consumption. These include low socioeconomic status, male sex, and age greater than 55 years.

People with a history of head and neck cancer are known to be at higher risk (about 25%) of developing a second cancer of the head, neck, or lung. This is mainly because in a significant proportion of these patients, the aerodigestive tract and lung epithelium have been exposed chronically to the carcinogenic effects of alcohol and tobacco. In this situation, a field change effect may occur, where the epithelial tissues start to become diffusely dysplastic with a reduced threshold for malignant change. This risk may be reduced by quitting alcohol and tobacco.

Factors that contribute to the development of hypopharyngeal cancer include:

- Smoking

- Chewing tobacco

- Heavy alcohol use

- Poor diet

Smoking, like lung cancer, can cause hypopharyngeal cancer because it contains carcinogens that alter the DNA or RNA in a dividing cell. These alterations may change a normal DNA sequence to an oncogene, a gene that causes cancer after exposure to a carcinogen.

Squamous cells, a type of cell that lines hollow organs like the throat, mouth, lungs, and outer layer of skin, are particularly vulnerable when exposed to cigarette smoke.

Chewing tobacco can have the same effects as smoking and is also linked to hypopharyngeal cancer. The chewing tobacco is placed into the mouth, leaving it exposed to enzymes, like amylase, which partly digests the carcinogenic material. Saliva is swallowed, along with the cancer-promoting material, which passes through the hypopharynx on its way to the esophagus.

Heavy alcohol use is linked to Hypopharyngeal Cancer as well. Alcohol damages the lining of the hypopharynx, increasing the amount of chemicals that are allowed to seep into the underlying membranes. Heavy alcohol use is also associated with nutritional deficiencies.

A disease called Plummer-Vinson syndrome, a genetic disorder that causes a long-term iron deficiency, may also lead to Hypopharyngeal Cancer. Other factors like a deficiency in certain vitamins also appear to contribute to this type of cancer.

Smoking and alcohol abuse as the major risk factors. Viral causes has recently been taken under consideration as one of the risk factors. Viruses such as Epstein-Barr virus (EBV) (majorly involved in causing nasopharyngeal carcinoma) and human papilloma virus are included in this category. Chewing of betel nut ("Areca catechu") quid has been directly associated to cause oral cancers. It has also been stated under the FDA poisonous plant data base by the U.S Food and Drug Administration

An unbalanced diet, deficit in fruits and vegetables has shown to increase the risk of cancer.

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.

The ultraviolet radiation from tanning beds increases the risk of melanoma. The International Agency for Research on Cancer finds that tanning beds are "carcinogenic to humans" and that people who begin using tanning devices before the age of thirty years are 75% more likely to develop melanoma.

Those who work in airplanes also appear to have an increased risk, believed to be due to greater exposure to UV.

Ultraviolet UVB light (wavelengths between 315 – 280 nm) from the sun is absorbed by skin cell DNA and results in a type of direct DNA damage called cyclobutane pyrimidine dimers (CPDs). Thymine-thymine, cytosine-cytosine or cytosine-thymine dimers are formed by the joining of two adjacent pyrimidine bases within a DNA strand. Somewhat similarly to UVB, UVA light (longer wavelengths between 400 – 315 nm) from the sun or from tanning beds can also be directly absorbed by skin DNA (at about 100 to 1000 fold lower efficiency than UVB is absorbed).

Studies suggest that exposure to ultraviolet radiation (UVA and UVB) is one of the major contributors to the development of melanoma. Occasional extreme sun exposure (resulting in "sunburn") is causally related to melanoma. Melanoma is most common on the back in men and on legs in women (areas of intermittent sun exposure). The risk appears to be strongly influenced by socio-economic conditions rather than indoor versus outdoor occupations; it is more common in professional and administrative workers than unskilled workers. Other factors are mutations in or total loss of tumor suppressor genes. Use of sunbeds (with deeply penetrating UVA rays) has been linked to the development of skin cancers, including melanoma.

Possible significant elements in determining risk include the intensity and duration of sun exposure, the age at which sun exposure occurs, and the degree of skin pigmentation. Melanoma rates tend to be highest in countries settled by migrants from northern Europe that have a large amount of direct, intense sunlight that the skin of the settlers is not adapted to, most notably Australia. Exposure during childhood is a more important risk factor than exposure in adulthood. This is seen in migration studies in Australia.

Having multiple severe sunburns increases the likelihood that future sunburns develop into melanoma due to cumulative damage. The sun and tanning beds are the main sources of UV radiation that increase the risk for melanoma and living close to the equator increases exposure to UV radiation.

Most people with cancer of unknown primary origin have widely disseminated and incurable disease, although a few can be cured through treatment. With treatment, typical survival with CUP ranges from 6 to 16 months. Survival rates are lower in cases with visceral metastatic disease, ranging from 6 to 9 months. Survival rates are higher when the cancer is more limited to lymph nodes, pleura, or peritoneal metastasis, which ranges from 14 to 16 months. Long-term prognosis is somewhat better if a particular source of cancer is strongly suggested by clinical evidence.

Smoking tobacco appears to increase the risk of breast cancer, with the greater the amount smoked and the earlier in life that smoking began, the higher the risk. In those who are long-term smokers, the risk is increased 35% to 50%. A lack of physical activity has been linked to about 10% of cases. Sitting regularly for prolonged periods is associated with higher mortality from breast cancer. The risk is not negated by regular exercise, though it is lowered.

There is an association between use of hormonal birth control and the development of premenopausal breast cancer, but whether oral contraceptives use may actually cause premenopausal breast cancer is a matter of debate. If there is indeed a link, the absolute effect is small. Additionally, it is not clear if the association exists with newer hormonal birth controls. In those with mutations in the breast cancer susceptibility genes "BRCA1" or "BRCA2", or who have a family history of breast cancer, use of modern oral contraceptives does not appear to affect the risk of breast cancer.

The association between breast feeding and breast cancer has not been clearly determined; some studies have found support for an association while others have not. In the 1980s, the abortion–breast cancer hypothesis posited that induced abortion increased the risk of developing breast cancer. This hypothesis was the subject of extensive scientific inquiry, which concluded that neither miscarriages nor abortions are associated with a heightened risk for breast cancer.

A number of dietary factors have been linked to the risk for breast cancer. Dietary factors which may increase risk include a high fat diet, high alcohol intake, and obesity-related high cholesterol levels. Dietary iodine deficiency may also play a role. Evidence for fiber is unclear. A 2015 review found that studies trying to link fiber intake with breast cancer produced mixed results. In 2016 a tentative association between low fiber intake during adolescence and breast cancer was observed.

Other risk factors include radiation and shift-work. A number of chemicals have also been linked, including polychlorinated biphenyls, polycyclic aromatic hydrocarbons, and organic solvents Although the radiation from mammography is a low dose, it is estimated that yearly screening from 40 to 80 years of age will cause approximately 225 cases of fatal breast cancer per million women screened.

Removal of both breasts before any cancer has been diagnosed or any suspicious lump or other lesion has appeared (a procedure known as prophylactic bilateral mastectomy) may be considered in people with BRCA1 and BRCA2 mutations, which are associated with a substantially heightened risk for an eventual diagnosis of breast cancer. Evidence is not strong enough to support this procedure in anyone but those at the highest risk. BRCA testing is recommended in those with a high family risk after genetic counseling. It is not recommended routinely. This is because there are many forms of changes in "BRCA" genes, ranging from harmless polymorphisms to obviously dangerous frameshift mutations. The effect of most of the identifiable changes in the genes is uncertain. Testing in an average-risk person is particularly likely to return one of these indeterminate, useless results. It is unclear if removing the second breast in those who have breast cancer in one is beneficial.

Melanomas are usually caused by DNA damage resulting from exposure to ultraviolet light from the sun. Genetics also plays a role.

Having more than fifty moles indicates an increased risk melanoma might arise. A weakened immune system makes it easier for cancer to arise due to the body’s weakened ability to fight cancer cells.

Tonsillar carcinoma can be either HPV related or HPV unrelated. It is shown that cases which are HPV positive have a better prognosis than those with HPV negative oropharyngeal cancer.

CUP sometimes runs in families. It has been associated with familial lung, kidney, and colorectal cancers, which suggests that these sites may often be the origin of unidentifiable CUP cancers.

Chemotherapy is the mainstay of treatment for lymphoma in cats. Most of the drugs used in dogs are used in cats, but the most common protocol uses cyclophosphamide, vincristine, and prednisone. Gastrointestinal lymphoma has also commonly been treated with a combination of prednisolone and high dose pulse chlorambucil with success. The white blood cell count must be monitored. Remission and survival times are comparable to dogs. Lower stage lymphoma has a better prognosis. Multicentric lymphoma has a better response to treatment than the gastrointestinal form, but infection with FeLV worsens the prognosis.

About 75% of cats treated with chemotherapy for lymphoma go into remission. Unfortunately, after an initial remission, most cats experience a relapse, after which they have a median survival of 6 months. However, about one-third of cats treated with chemotherapy will survive more than 2 years after diagnosis; a small number of these cats may be cured of their disease. Untreated, most cats with lymphoma die within 4–6 weeks. Most cats tolerate their chemotherapy well, and fewer than 5% have severe side effects. Cats do not lose their fur from chemotherapy, though loss of whiskers is possible. Other side effects include low white blood cell count, vomiting, loss of appetite, diarrhea, or fatigue. These can typically be controlled well, and most cats have a good quality of life during treatment. If a cat relapses after attaining remission, the cat can be treated with different chemotherapy drugs to try for a second remission. The chances of a second remission are much lower than the chances of obtaining a first, and the second remission is often shorter than the first.

This type of cancer occurs most often in Caucasians between 60 and 80 years of age, and its rate of incidence is about twice as high in males as in females. There are roughly 1,500 new cases of MCC diagnosed each year in the United States, as compared to around 60,000 new cases of melanoma and over 1 million new cases of nonmelanoma skin cancer. MCC is sometimes mistaken for other histological types of cancer, including basal cell carcinoma, squamous cell carcinoma, malignant melanoma, lymphoma, and small cell carcinoma, or as a benign cyst. Researchers believe that exposure to sunlight or ultraviolet light (such as in a tanning bed) may increase the risk of developing this disease. Similar to melanoma, the incidence of MCC in the US is increasing rapidly.

Immunosuppression can profoundly increase the odds of developing Merkel-cell carcinoma. Merkel-cell carcinoma occurs 30 times more often in people with chronic lymphocytic leukemia and 13.4 times more often in people with advanced HIV as compared to the general population; solid organ transplant recipients have a 10-fold increased risk compared to the general population.

Untreated dogs have an average survival time of 60 days. Lymphoma with a histologic high grade generally respond better to treatment but have shorter survival times than dogs with low grade lymphoma. Dogs with B-lymphocyte tumors have a longer survival time than T-lymphocyte tumors. Mediastinal lymphoma has a poorer prognosis than other types, especially those with hypercalcemia. Clinical stage and substage have some prognostic value, with poorer prognosis associated with Stage V disease, and with substage b (clinical illness at time of presentation).

Childhood rhabdomyosarcoma has been fatal. Recovery rates have increased by 50 percent since 1975. In children five years of age or younger survival rates are up to 65 percent. In adolescents younger than 15 years old, the survival rate has increased up to 30 percent.

Mast cell tumors mainly occur in older adult dogs, but have been known to occur on rare occasions in puppies. The following breeds are commonly affected by mast cell tumors:

- Boxer

- Staffordshire bull terrier

- Bulldog

- Basset hound

- Weimaraner

- Boston terrier

- Great Dane

- Golden retriever

- Labrador retriever

- Beagle

- German shorthaired pointer

- Scottish terrier

- Pug

- Shar pei

- Rhodesian ridgeback

Incidence is five in 100,000 (12,500 new cases per year) in the USA. The American Cancer Society estimated that 9,510 men and women (7,700 men and 1,810 women) would be diagnosed with and 3,740 men and women would die of laryngeal cancer in 2006.

Laryngeal cancer is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). This means that laryngeal cancer affects fewer than 200,000 people in the U.S.

Most patients diagnosed with Paget's disease of the nipple are over age 50, but rare cases have been diagnosed in patients in their 20s. The average age at diagnosis is 62 for women and 69 for men. The disease is rare among both women and men.

Two types of mast cell tumors have been identified in cats, a mast cell type similar to dogs and a histiocytic type that appears as subcutaneous nodules and may resolve spontaneously. Young Siamese cats are at an increased risk for the histiocytic type, although the mast cell type is the most common in all cats and is considered to be benign when confined to the skin.

Mast cell tumors of the skin are usually located on the head or trunk. Gastrointestinal and splenic involvement is more common in cats than in dogs; 50 percent of cases in dogs primarily involved the spleen or intestines. Gastrointestinal mast cell tumors are most commonly found in the muscularis layer of the small intestine, but can also be found in the large intestine. It is the third most common intestinal tumor in cats, after lymphoma and adenocarcinoma.

Diagnosis and treatment are similar to that of the dog. Cases involving difficult to remove or multiple tumors have responded well to strontium-90 radiotherapy as an alternative to surgery. The prognosis for solitary skin tumors is good, but guarded for tumors in other organs. Histological grading of tumors has little bearing on prognosis.

Symptoms of Hypopharyngeal Cancer include:

- Swollen lymph nodes in the neck (first sign of a problem in half of all patients)

- Sore throat in one location that persists after treatment

- Pain that radiates from the throat to the ears

- Difficult or painful swallowing (often leads to malnutrition and weight loss because of a refusal to eat)

- Voice changes (late stage cancer)

While sarcoids may spontaneously regress regardless of treatment in some instances, course and duration of disease is highly unpredictable and should be considered on a case-by-case basis taking into account cost of the treatment and severity of clinical signs. Surgical removal alone is not effective, with recurrence occurring in 50 to 64% of cases, but removal is often done in conjunction with other treatments. Topical treatment with products containing bloodroot extract (from the plant "Sanguinaria canadensis") for 7 to 10 days has been reported to be effective in removing small sarcoids, but the salve's caustic nature may cause pain and the sarcoid must be in an area where a bandage can be applied. Freezing sarcoids with liquid nitrogen (cryotherapy) is another affordable method, but may result in scarring or depigmentation. Topical application of the anti-metabolite 5-fluorouracil has also obtained favorable results, but it usually takes 30 to 90 days of repeated application before any effect can be realized. Injection of small sarcoids (usually around the eyes) with the chemotherapeutic agent cisplatin and the immunomodulator BCG have also achieved some success. In one trial, BCG was 69% effective in treating nodular and small fibroblastic sarcoids around the eye when repeatedly injected into the lesion and injection with cisplatin was 33% effective overall (mostly in horses with nodular sarcoids). However, BCG treatment carries a risk of allergic reaction in some horses and cisplatin has a tendency to leak out of sarcoids during repeated dosing. External beam radiation can also be used on small sarcoids, but is often impractical. Cisplatin electrochemotherapy (the application of an electrical field to the sarcoid after the injection of cisplatin, with the horse under general anesthesia), when used with or without prior surgery to remove the sarcoid, had a non-recurrence rate after four years of 97.9% in one retrospective study. There is a chance of sarcoid recurrence for all modalities even after apparently successful treatment. While sarcoids are not fatal, large aggressive tumors that destroy surrounding tissue can cause discomfort and loss of function and be resistant to treatment, making euthanasia justifiable in some instances. Sarcoids may be the most common skin-related reason for euthanasia.

The lymphoma is more common in the young and in males.

A 2008 study found an increased risk of ALCL of the breast in women with silicone breast implants (protheses), although the overall risk remained exceedingly low due to the rare occurrence of the tumor.

Lymph nodes may become enlarged in malignant disease. This cervical lymphadenopathy may be reactive or metastatic. Alternatively, enlarged lymph nodes may represent a primary malignancy of the lymphatic system itself, such as lymphoma (both Hodgkin's and non-Hodgkin's), lymphocytic leukemia,

Metastatic lymph nodes are enlarged because tumor cells have detached from the primary tumor and started growing in the lymph node ("seeded"). Since cancer generally occurs more frequently in older people, this kind of lymphadenopathy is more common in older persons. Metastatic lymph nodes tend to feel hard and may be fixed to underlying tissues and may or may not be tender. Usually the lymph nodes that directly drain the area of the cancer are affected by the spread (e.g. Sometimes metastatic cervical lymph node is detected before the main cancer). In such cases, this discovery leads to a search for the primary malignancy, firstly in the nearby area with endoscopy, "blind" biopsies, and tonsillectomy on the side of the lymphadenopathy. If no tumor is found, then the rest of the body is examined, looking for lung cancer or other possible sites. If still no primary tumor is detected, the term "occult primary" is used.

In lymphoma, usually there are multiple enlarged nodes which feel rubbery to palpation.

- Rhabdomyosarcoma

- Neuroblastoma

There is no known cause for any type of Marginal Zone non-Hodgkins lymphoma, but it occurs when the body produces large amounts of abnormal lymphocytes.

Factors that may increase an individuals chance of developing nodal MZL are being over the age of 60 and having been infected with hepatitis C virus. Factors that may increase an individuals chance of developing MALT lymphoma include being over the age of 50, having an autoimmune condition (rheumatoid arthritis, Hashimoto's thyroiditis), and long lasting chronic inflammation due to infection (H.pylori, Sjogren syndrome, chlamidia infection, Borrelia infection, Campylobacter jejuni infection). Factors that increase an individuals risk of developing splenic MZL include the hepatitis C virus, Epstein-Barr virus, malaria, Sjogren syndrome, and lupus.

In order to reduce the chances of developing MZL, an individual can decrease their exposure to the possible risk factors.

A newly discovered virus called Merkel cell polyomavirus (MCV) likely contributes to the development of the majority of MCC. Approximately 80% of MCC have this virus integrated in a monoclonal pattern, indicating that the infection was present in a precursor cell before it became cancerous. At least 20% of MCC tumors are not infected with MCV, suggesting that MCC may have other causes as well.

Polyomaviruses have been known to be oncogenic (cancer-causing) viruses in animals since the 1950s, but MCV is the first polyomavirus strongly suspected to cause tumors in humans. Like other tumor viruses, most people who are infected with MCV probably do not develop MCC. It is currently unknown what other steps or co-factors are required for MCC-type cancers to develop. MCC can also occur together with other sun exposure-related skin cancers that are not infected with MCV (i.e. basal cell carcinoma, squamous cell carcinoma, melanoma). Intriguingly, most MCV viruses obtained so far from tumors have specific mutations that render the virus uninfectious. It is unknown whether these particular mutations result from sun exposure. MCC also occurs more frequently than would otherwise be expected among immunosuppressed patients, such as transplant patients, AIDS patients, and the elderly persons, suggesting that the initiation and progression of the disease is modulated by the immune system.

While infection with MCV is common in humans, MCC patients whose tumors contain MCV have higher antibody levels against the virus than similarly infected healthy adults. A recent study of a large patient registry from Finland suggests that individuals with MCV-positive MCC's have better prognoses than do MCC patients without MCV infection. While MCV-positive MCC may be a less aggressive form of the disease, the results of the aforementioned study may instead be due to significant differences in other confounding factors, including tumor stage at the time of diagnosis, the age of the patient, or the location of the tumor rather than any intrinsic difference in disease aggressiveness or response to therapy.