Cancer is a disease of uncontrolled multiplication of abnormal cells (malignant cells). Cancer can affect any part of the body. The abnormal growth of cells often results in a mass (tumor) of malignant cells that causes further problems by occupying space used by normal tissues. Cancers cells can also move away from (metastasize) their initial site of development to invade other tissues of the body.
Cancer is NOT contagious
A healthy person cannot “catch” cancer from someone who has it. There is no evidence that close contact or things like sex, kissing, touching, sharing meals, or breathing the same air can spread cancer from one person to another.
Cancer cells from one person are generally unable to live in the body of another healthy person. A healthy person’s immune system recognizes foreign cells and destroys them, including cancer cells from another person.
Cancer develops because the DNA in a cell changes.
Most cancers do not appear to be caused or affected by infectious agents. Cancer develops because of mutations (changes) that take place in a person’s DNA, the genetic blueprint in each cell. These changes may be inherited or develop during life. Some changes happen for no known reason, while others are due to environmental exposures, such as sun (UV) damage or cigarette smoke. Some viruses are known to directly cause mutations in DNA that can develop into cancer. Other germs promote cancer indirectly by causing chronic (long-term) inflammation, or by weakening a person’s immune system.
Is cancer contagious?
Cancer is not contagious. Close personal contact with a cancer patient, sexual relationships, kissing, touching, and sharing meals and/or utensils cannot cause other people to have cancer. Rarely, individuals who have received organ transplants from individuals that have cancer may also develop cancer from the transplant. However, currently a stricter screening procedure of organ donors has reduced the risk of transplants that cause cancer in organ recipients. Another very rare instance where cancer is transferred is from a pregnant mother to the fetus. A number of different viruses (human papilloma, Epstein-Barr, hepatitis B), bacteria (Helicobacter pylori) and parasites are associated with various cancers. However, although the viruses and other pathogens may be contagious or simply infectious, the cancers these organisms are associated with are not considered to be contagious.
Cancer transfer during organ transplant
There have been some cases in which organ transplants from people with cancer have been able to cause cancer in the person who got the organ. But there’s a major factor that makes this possible – people who get organ transplants take medicines that weaken their immune systems. This must be done so their immune system won’t attack and destroy the transplanted organ. This seems to be the main reason that cancer in a transplanted organ can, in rare cases, give cancer to the person who gets the organ. Organ donors are carefully screened to reduce this risk.
Cancer risk after transplant already high
Still, recent studies have shown that cancer is more common in people who get solid-organ transplants than in people who don’t – even when the donor doesn’t have cancer. This also appears to be due to the drugs that are given to reduce the risk of transplant rejection. Research has shown that the longer and more intensely the immune system is suppressed after transplant, the higher the risk of cancer. The drugs that allow the body to accept the organ also make the immune system less able to recognize and attack pre-cancer cells and the viruses that can cause cancer.
Cancer transfer during pregnancy
Even if a woman has cancer during pregnancy, the cancer rarely affects the fetus directly. Some cancers can spread from the mother to the placenta (the organ that connects the mother to the fetus), but most cancers cannot affect the fetus itself. In a few very rare cases, melanoma (a form of skin cancer) has been found to spread to the placenta and the fetus.
How will I know if I have cancer?
There are more than 100 types of cancers (including breast cancers, lung cancers, bowel cancers, metastatic cancers, and many more). If you have some of the following symptoms and signs, it would be reasonable to contact your physician and let the physician know you are concerned:
- Lumps, bumps, and/or masses underneath your skin
- Sores that do not heal on the skin
- Testicular changes (abnormal growths or masses)
- Breast lumps, bumps, or masses
- Nipple discharge and/or skin changes
- Changes in your bowel pattern such as pencil-thin stools and/or blood in the stools
- Sores that will not heal on any mucous membranes
- Persistent cough and/or shortness of breath
- Difficulty swallowing or speaking
- Unexplained weight loss
- Constant fatigue
- Persistent pain (constant headache, abdominal pains, chest discomfort)
- Abnormal vaginal bleeding or abnormal vaginal discharge
- Abnormal bloating and/or swelling
- Persistent indigestion, nausea, and/or vomiting.
Common Myths and Misconceptions about Skin, Lung, Cervical, Breast Cancer
You Can’t “Catch” Can’t Cancer in the Conventional Sense
Let’s start with the bottom line: cancer is not contagious in the conventional sense of the word, as in “catching” the flu or a cold. It is not classified as an infectious disease and therefore cannot be spread through kissing, touching, or even unprotected sex.
So it’s perfectly okay to hug or kiss someone with cancer. In fact, intimacy through touch is advised. It can not only help a friend or loved one better cope with their disease, it can ease any feelings of isolation a person may have during cancer therapy.
In a less conventional sense, cancer can be indirectly “passed” from parent to child through genetics. A number of genetic mutations are inherited by offspring during conception, some of which can place that individual at higher risk for certain cancers.
This doesn’t mean that the person will get cancer; it simply means that the likelihood is greater than if the mutation wasn’t there.
There are even some cancers that associated with viral infection. A prime example is the aforementioned HPV, wherein women and gay men infected the virus are at far greater risk of developing, respectively, cervical cancer and anal cancer than persons in the general population.
Is cancer a death sentence?
In the United States, the likelihood of dying from cancer has dropped steadily since the 1990s. Five-year survival rates for some cancers, such as breast, prostate, and thyroid cancers, now exceed 90 percent. The 5-year survival rate for all cancers combined is currently about 66 percent.
It is important to note, however, that these rates are based on data from large numbers of people. How long an individual cancer patient will live and whether he or she will die from the disease depend on many factors, including whether the cancer is slow or fast growing, how much the cancer has spread in the body, whether effective treatments are available, the person’s overall health, and more.
Will eating sugar make my cancer worse?
No. Although research has shown that cancer cells consume more sugar (glucose) than normal cells, no studies have shown that eating sugar will make your cancer worse or that, if you stop eating sugar, your cancer will shrink or disappear. However, a high-sugar diet may contribute to excess weight gain, and obesity is associated with an increased risk of developing several types of cancer.
Do artificial sweeteners cause cancer?
No. Researchers have conducted studies on the safety of the artificial sweeteners (sugar substitutes) saccharin (Sweet ‘N Low®, Sweet Twin®, NectaSweet®); cyclamate; aspartame (Equal®, NutraSweet®); acesulfame potassium (Sunett®, Sweet One®); sucralose (Splenda®); and neotame and found no evidence that they cause cancer in humans. All of these artificial sweeteners except for cyclamate have been approved by the Food and Drug Administration for sale in the United States.
Does my attitude—positive or negative—determine my risk of, or likely recovery from, cancer?
To date, there is no convincing scientific evidence that links a person’s “attitude” to his or her risk of developing or dying from cancer. If you have cancer, it’s normal to feel sad, angry, or discouraged sometimes and positive or upbeat at other times. People with a positive attitude may be more likely to maintain social connections and stay active, and physical activity and emotional support may help you cope with your cancer.
Can cancer surgery or a tumor biopsy cause cancer to spread in the body?
The chance that surgery will cause cancer to spread to other parts of the body is extremely low. Following standard procedures, surgeons use special methods and take many steps to prevent cancer cells from spreading during biopsies or surgery to remove tumors. For example, if they must remove tissue from more than one area of the body, they use different surgical tools for each area.
Will cancer get worse if exposed to air?
No. Exposure to air will not make tumors grow faster or cause cancer to spread to other parts of the body.
Do cell phones cause cancer?
No, not according to the best studies completed so far. Cancer is caused by genetic mutations, and cell phones emit a type of low-frequency energy that does not damage genes.
Do power lines cause cancer?
No, not according to the best studies completed so far. Power lines emit both electric and magnetic energy. The electric energy emitted by power lines is easily shielded or weakened by walls and other objects. The magnetic energy emitted by power lines is a low-frequency form of radiation that does not damage genes.
Are there herbal products that can cure cancer?
No. Although some studies suggest that alternative or complementary therapies, including some herbs, may help patients cope with the side effects of cancer treatment, no herbal products have been shown to be effective for treating cancer. In fact, some herbal products may be harmful when taken during chemotherapy or radiation therapy because they may interfere with how these treatments work. Cancer patients should talk with their doctor about any complementary and alternative medicine products—including vitamins and herbal supplements—they may be using.
If someone in my family has cancer, am I likely to get cancer, too?
Not necessarily. Cancer is caused by harmful changes (mutations) in genes. Only about 5 to 10 percent of cancers are caused by harmful mutations that are inherited from a person’s parents. In families with an inherited cancer-causing mutation, multiple family members will often develop the same type of cancer. These cancers are called “familial” or “hereditary” cancers.
The remaining 90 to 95 percent of cancers are caused by mutations that happen during a person’s lifetime as a natural result of aging and exposure to environmental factors, such as tobacco smoke and radiation. These cancers are called “non-hereditary” or “spontaneous” cancers.
If no one in my family has had cancer, does that mean I’m risk-free?
No. Based on the most recent data, about 40 percent of men and women will be diagnosed with cancer at some point during their lives. Most cancers are caused by genetic changes that occur throughout a person’s lifetime as a natural result of aging and exposure to environmental factors, such as tobacco smoke and radiation. Other factors, such as what kind of food you eat, how much you eat, and whether you exercise, may also influence your risk of developing cancer.
Do antiperspirants or deodorants cause breast cancer?
No. The best studies so far have found no evidence linking the chemicals typically found in antiperspirants and deodorants with changes in breast tissue.
Does hair dye use increase the risk of cancer?
There is no convincing scientific evidence that personal hair dye use increases the risk of cancer. Some studies suggest, however, that hairdressers and barbers who are regularly exposed to large quantities of hair dye and other chemical products may have an increased risk of bladder cancer.
It is impossible to protect against cancer, but there are ways to prevent cancer, significantly reducing the likelihood of the disease: read more.