It starts as a single cell and grows into a merciless disease that claims millions of lives year after year.
Cancer, as the disease is called, is one of the leading killers around the world. It accounts for 6 million or 12 percent, of deaths globally, according to the Geneva-based World Health Organization (WHO).
Fifty-eight percent of those who succumbed to cancer come from developing countries. In the Philippines, for instance, cancer is the fifth leading cause of death. This is due to the fact that more than half of all cancer cases in the country “are diagnosed at an advanced stage, when it is already too late to save the patient.”
For every 1,000 Filipinos, one gets cancer. And the incidence is higher among females than males, according to the Philippine Cancer Society Inc. (PCSI). Ninety-one percent occur between the ages of 35 and above. Three-fourths of all cancer cases in the country occur between the ages 50 and above.
Health experts say there are more than 100 types, but all have in common: an uncontrollable growth and spread of abnormal cells. Many people mistakenly believe a diagnosis is a death sentence.
Cancer, which comes from the Greek word karkinos which means “crab,” is a group of cells that has lost its normal control mechanisms and thus has unregulated growth. “Cancerous [malignant] cells can develop from any tissue within any organ,” explains The Merck Manual of Medical Information. “As cancerous cells grow and multiply, they form a mass of cancerous tissue—called a tumor—that invades and destroys normal adjacent tissues.”
The term “tumor” refers to an abnormal growth or mass; it can be either cancerous or noncancerous. Cancerous cells from the primary (initial) site can spread (metastasize) throughout the body.
How cancer develops
Science tells us that each time a human cell divides, it must replicate its DNA, a biochemical manuscript some 3 billion characters long. In the course of transcribing such a lengthy document, even a skilled typist could be expected to make mistakes, and cells, like typist, occasional err. The mistakes they make are minor and quickly repaired by proteins that serve as miniature mechanics.
More often than not, cells with defects in their DNA will continue to divide, eventually forming small growths.
“The more cell-division cycles an organism undergoes, the more likely it is to accumulate colonies of abnormal cells, each of the offspring of a single progenitor,” writes Time science writer J. Madeleine Nash. “By the time humans reach middle adulthood, then their bodies contain millions of cells that have taken at least one step toward cancer.”
The Merck manual, however, gives specific details on how cancer develops. “Cancerous cells develop from healthy cells in a complex process called transformation,” it explains. “The first step in the process is initiation, in which a change in the cell’s genetic material [in the DNA and sometimes in the chromosome structure] primes the cell to become cancerous. The change in the cell’s genetic material may occur spontaneously or be brought by an agent that causes cancer [carcinogen].”
Carcinogens include many chemicals (arsenic, asbestos, benzene, and nickel, to name a few), tobacco, viruses, radiation, and sunlight. A person exposed to a carcinogen (by breathing, eating or touching it for long periods) does not necessarily mean he will certainly be afflicted with cancer, the PCSI said. “It only increases the possibility,” it added.
“However, not all cells are equally susceptible to carcinogens,” the Merck manual notes. “A genetic flaw in a cell may make it more susceptible. Even chronic physical irritation may make a cell more susceptible to carcinogens.”
Promotion is the second and final step in the development of cancer. “Agents that cause promotion are called promoters,” the Merck manual says. “Promoters may be substances in the environment or even some drugs [such as barbiturates]. Unlike carcinogens, promoters do not cause cancer by themselves. Instead, promoters allow a cell that has undergone initiation to become cancerous. Promotion has no effect on noninitiated cells. Thus, several factors, often the combination of a susceptible cell and a carcinogen, are needed to cause cancer.”
“What makes cancer very dangerous is that if not detected early and treated promptly, cancer cells have the capability of spreading not only by direct infiltration of the immediate surrounding area, but also transfer and grow in distant areas by passing through the blood stream and the lymphatic system,” one of the country’s noted oncologists once pointed out.
The most important factor that affects the chances for the cure of cancer is the stage at which it is detected. Two out of six cancer cases in the Philippines are cured, medical experts claimed. “But three out of six could have been cured, if only diagnosed earlier,” they maintained.
Among men, prostate cancer tops, while breast cancer is the No. 1 among women. “This disease is a traitor,” said an oncologist of breast cancer, which killed film director Marilou Diaz-Abaya and Hollywood actress Ingrid Bergman. But he added that “when detected early, it can be cured.”
By cured, the oncologist meant that there has been no activity for five years. “But even after 20 years, nagigising iyan,” the doctor said. “So I advise my patients to go for regular checkups, even with the family doctors. Early detection is still the key—breast or any other kind of cancer.”
The PCSI, a private social-welfare organization, said there is no such thing as cancer for the rich and cancer for the poor. “People in the urban areas, however, have higher risk of getting cancer,” it said in a statement. “Whether there are less cases in the rural areas is hard to tell. Generally, cancer cases in remote barrios are not reported.”
Signs and symptoms
Because cancer is more likely to be cured if treated early, it is critical that cancer be discovered early. “Some symptoms may give early warning of cancer and should, therefore, trigger a person to seek medical care,” the Merck manual says. “Fortunately, most of these symptoms are usually caused by far less serious conditions. Nonetheless, the development of any of the warning signs should not be ignored.”
Some of the warming signs are general; that is, they are vague changes that do not help pinpoint any particular cancer. Still, their presence can help direct doctors to perform the physical examinations and laboratory tests necessary to exclude or confirm a diagnosis. Other symptoms are much more specific and steer doctors to a particular kind of cancer or location.
Some warning signs of cancer are, according to the Merck manual, are weight loss, fatigue, night sweats, loss of appetite, new and persistent pain, recurrent nausea or vomiting, blood in urine, blood in stool (either visible or detectable by special tests) and sudden depression.
Other common signs and symptoms of cancer are recurrent fever, chronic cough, a recent change in bowel habits (constipation or diarrhea), changes in the size or color of a mole or changes in a skin ulcer that does not heal, and enlarge lymph nodes.
“Cancer may be present in very many ways: as a lump, some change in body function, bleeding, anemia or weight loss,” says The New American Desk Encyclopedia. “Less often tumors produce substances mimicking the action of hormones or producing remote effects, such as neuritis.”
(Neuritis is any disorder of the peripheral nervous system, which interferes with sensation, the nerve control of muscle, or both.)
“Cancer is a complex disease but other viral diseases have been nearly wiped out through vaccination,” commented the Professional Health Media Services. “Perhaps, such a vaccine [or vaccines] will be developed to prevent cancer. But until such vaccines are developed, there is much that a person can do about cancer.”
Medical scientists claim cancer is neither infectious nor contagious. In fact, it is not hereditary, assured most oncologists. “The fact that cancer has occurred in a family is no cause for anxiety,” they stressed. “But people whose close relatives have cancer should have more regular checkups because of familiar tendency.”
Prevention
While not all cancers are preventable, there are some that can be prevented. Observing some measures can only avert these cancers.
For instance, smoking cigarettes must be avoided. In the strongest evidence yet, two studies involving more than 150,000 people in the United States show that cigarette smoking can lead to colon cancer in both men and women.
The parallel studies also found that early smoking apparently fixes for life the risk of colonrectal cancer, even if the smoking habit is dropped.
Alcoholic beverages must be taken moderately. Drinking excessively is hazardous to one’s health as “high intake of alcoholic drinks is related to cancers of the liver and esophagus.” If possible, chewing lime and betel nut must be avoided.
Personal hygiene and cleanliness, when practiced by women, has been found to reduce the incidence of cancer of the cervix. For their part, men who wash and keep their penis clean have a lower chance of developing cancer of the penis. Incidentally, it has been shown that women whose husbands are circumcised have a lower incidence of cervical cancer.
Filipinos must also avoid exposing their skin to the noonday sunlight. From 10 am to 12 pm, the sun’s ultraviolet rays are most merciless and may cause skin cancer.
Warts and moles, which are in the areas that are constantly being irritated or under pressure, must be removed “especially if they start to enlarge, change in color and bleed.”
In addition, men and women after 40 years of age are advised to undergo yearly stool examination and rectal examination for early detection of cancer of the colon and rectum.
At present, there is no direct cause-and-effect relationship between nutrition and cancer. However, statistics show that certain foods may decrease or increase the risk of certain types of cancer.
Filipinos are also advised to avoid frequently eating very salty, very hot, very spicy and heavily smoked foods, as they contain large amounts of salitre, which are linked to stomach cancer, health experts claim.
Moldy foods should not be eaten, as swallowing them may lead to liver cancer, he said. A diet with high-fat content must also be avoided. Obese individuals, it has been found, have an increased risk of developing cancers of the breast, colon, prostate, uterus, ovary and gallbladder.