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cancer(kan'ser) [L. cancer, crab, suppurating ulcer]
Cancer cells have several reproductive advantages over normal cells. They can make proteins that stimulate their own growth or new blood vessels to bring them nourishment. They can produce enzymes that prevent their chromosomes from aging. They can invade the lymphatic system and bloodstream and find places to grow in new tissues (metastasis).
Usually, as cancer cells proliferate, they become increasingly abnormal and require more of the body's metabolic output for their growth and development. Damage caused by their invasion of healthy tissues results in organ malfunction, pain, and, often, death. See: table (Estimated New Cancer Cases and Deaths by Sex, U.S. 2008)
Ionizing radiation, ultraviolet light, some viruses, and drugs that damage nucleic acids may initiate the genetic lesions that result in cancers. The best-known and most widespread type of carcinogen exposure, however, is consumption of tobacco. The ACS estimates that one third of the cancer deaths that occur annually in the U.S. are related to nutrition and other lifestyle factors. Some cancers are familial, i.e., genetic; others result from occupational exposures to carcinogens. Ironically, chemotherapeutic drugs used to treat some cancers may damage chromosomes and occasionally cause secondary malignancies.
Symptoms of widespread cancer include pain, malnutrition, weakness, fatigue, bone fractures, and strokelike syndromes. Early warning signs of cancer may be remembered by the mnemonic CAUTION: Change in bowel or bladder habit; A sore that does not heal; Unusual bleeding or discharge; Thickening or mass in the breast or other body parts; Indigestion or difficulty in swallowing; Obvious change in a wart or a mole; Nagging cough or hoarseness. People should seek prompt medical attention if they observe any of these signs.
The location of a suspected lesion often dictates the means to diagnose cancer: men with urinary symptoms may be screened for prostate cancer with a prostate specific antigen (PSA) test; an alpha-fetoprotein (AFP) test may be used to screen for liver cancer. Several other tumor markers (such as the CA 125 test for ovarian cancer) are used only after a diagnosis has already been made by other means. Endoscopy and radiography are typically used to locate and assess the extent of the disease, but definitive diagnosis still rests on the examination of cytological specimens (such as the Papanicolaou [Pap] test) or the pathological review of biopsy specimens. See: illustration; table (Controversies in Cancer Screening in the General Population)
Screening for cancers can identify some malignancies before they have invaded neighboring tissues or become widespread. The most widely used screening tests include the Pap test for cervical cancer, mammography for breast cancer, prostate specific antigen tests for prostate carcinoma, and occult blood tests and colonoscopy for intestinal cancers.
Surgery, chemotherapy, immunotherapy, hormone therapy, radiation therapy, and combined-modality therapies often are effective methods for treating patients with cancer. The specific treatment used depends on the type, stage, and location of the cancer and the patient's general health.
The pain associated with cancer is often severe. Cancer patients may suffer depression and anxiety and have nutritional deficits. Guidelines addressing these issues are readily available, e.g., from the U.S. Department of Health and Human Services' Agency for Health Care Policy and Research. Publications may be obtained by calling 1-800-4-CANCER or from websites such as from the ACS (www.cancer.org). See: chemotherapy.
There must be close collaboration among the entire health care team and the patient and family must be encouraged to participate in care . The patient's knowledge of the disease is determined, misinformation corrected, and information supplied about the disease, its progression, its treatment, and expected outcome. Such information should be updated regularly. The patient's and family's coping mechanisms are supported, and verbalization of feelings and fears, esp. with changes in body image, pain and suffering, and dying and death, is encouraged. Participation in local support groups is encouraged for both patients and families.
Assistance is provided with personal hygiene and physical care as needed. Physical care is directed at the maintenance of fluid and electrolyte balance and proper nutrition. Nutrition is a special concern because tumors compete with normal tissues for nutrients and grow at their expense and because the disease or treatments can cause anorexia, altered taste sensations, mouth ulcerations, vomiting, diarrhea, and draining fistulas. Nutritional support includes assessing the patient's status and problems, experimenting to find foods that the patient can tolerate, avoiding highly aromatic foods, and offering frequent small meals of high-calorie, high-nutrient soft foods along with fluids to limit fatigue and to encourage overall intake. Intake of noncaffeinated liquids should be encouraged: 2 quarts per day of juices or other caloric beverages in frequent, small amounts rather than water alone. Elimination is maintained by administering stool softeners as necessary if analgesic drugs result in constipation.
Using careful and gentle handling, the health care professional assists with range-of-motion exercises, encourages ambulation and mobility, and turns and repositions the immobile patient frequently to decrease the deleterious multisystemic effects of immobilization. The patient is made comfortable by correct body alignment, noninvasive measures (such as guided imagery and cutaneous stimulation), and medication (preferably administered on a regular schedule to prevent pain, with additional dosing to relieve breakthrough pain). Emotional assistance includes allaying the patient's fears of helplessness and loss of control; providing hope for remission or long-term survival but avoiding giving false hope; and providing the patient with realistic reassurance about pain control, comfort, and rest. Psychological counseling and antidepressant therapies may be helpful.
Hospice care (at home or in a dedicated center), if needed, is discussed with the patient and family. The goal is to provide good quality of life with minimal discomfort, pain, and restrictions rather than to continue specific therapy. Family members are encouraged to assume an active role in caring for the patient. Communication is fostered between patient and family and other health care providers, and the patient is helped to maintain control and to carry out realistic decisions about issues of life and death.
To provide effective emotional support to the patient and family, health care professionals must understand and cope with their own feelings about terminal illness and death and seek assistance with grieving and in developing a personal philosophy about dying and death. They will then be better able to listen sensitively to patients' concerns, to offer genuine understanding and comfort, and to help patients and family work through their grief.
breast cancerSee: breast cancer
Some strains of the human papillomavirus (HPV) are carcinogenic to cervical epithelium. While there are other risk factors (such as tobacco smoking, early age at first intercourse, and having multiple sex partners), HPV is the major factor responsible for the development of this cancer.
Periodic Pap tests are recommended for all sexually active women. The tests identify cellular changes with 95% accuracy. Dilatation and curettage, punch biopsy, and colposcopy may be done if Pap test findings raise the suspicion of cancer. If abnormal cells are detected, HPV testing is often performed to screen for presence of one of the high risk types of the virus. See: Bethesda System, The; cervical intraepithelial neoplasia; colposcopy; cryosurgery; loop electrode excision procedure; Papanicolaou test
Management varies from cryotherapy or laser therapy for low-grade squamous intraepithelial lesions, conization for carcinoma in situ, to hysterectomy for preinvasive cervical cancer in women who are not planning to have children. Stage-related management of invasive cervical carcinoma includes radiation and/or hysterectomy.
Vaccination against human papillomavirus virus (HPV).See: HPV vaccine.
chimney sweeps' cancer
colorectal cancerAbbreviation: CRC
The cancer occurs more often in people with a family history of the disease, those with familial adenomatous polyposis, and in those with inflammatory bowel diseases such as ulcerative colitis. It also occurs more often in people who are obese than in those who are not and in those who consume a high fat, low-fiber diet.
Symptoms may be absent or may include change in the usual pattern of bowel habits, esp. in those over 40; recent onset of constipation, diarrhea, or tenesmus in an older patient; bright red or dark blood in the stool. Laboratory findings may include iron-deficiency anemia or positive fecal occult blood tests.
Diagnosis may be suggested by findings on digital rectal examination, anoscopy, flexible or rigid sigmoidoscopy, colonoscopy, virtual colonoscopy, or barium enema examination. It is confirmed by biopsy of suspicious lesions. Prevention includes screening of asymptomatic men and women of average risk starting at age 50, annual home fecal occult blood testing (over a three-day period), and colonoscopy every 10 years. During colonoscopy, removal of benign polyps prevents progression to malignant tumors. If polyps are found, colonoscopy should be repeated in 3 to 5 years (depending on the presence of other risk factors). Detection of colorectal cancer at an early stage via colonoscopy offers patients a very high likelihood of cure rate at 5 years. Neither digital rectal examination nor testing of a single stool specimen from the digital exam provides adequate screening. Patients at increased risk for colorectal cancer (those who have had previous colorectal adenomas or resected cancers or a history of ulcerative colitis or of colon cancer in a first-degree relative younger than 60) should undergo screening more frequently and at an earlier age. When colorectal carcinoma is diagnosed, additional tests are conducted to determine the stage of the disease (chest radiographs, CT, MRI, and blood studies, including carcinoembryonic antigen levels, and liver function studies).
Surgical resection performed by laparotomy, minimally invasive surgery, microsurgery, or laparoscopy can cure localized colorectal cancer. Whatever procedure is used, the type of surgery depends on the location of the tumor, and the goal of the surgery is removal of the malignant tumor and adjacent tissue and any lymph nodes that may contain cancer cells. Adjuvant therapies may include chemoembolization of blood vessels that feed the primary tumor or metastases; radiation therapy; brachytherapy; chemotherapy; or monoclonal antibody therapy. Carcinoembryonic antigen is helpful in monitoring patients during and following treatment to determine effectiveness and detect recurrence or metasasis.
Health care providers should teach patients the importance of colorectal screening and indicate applicable lifestyle modifications (a low-fat diet, maintenance of a normal body mass index). Patients with familial colon cancer syndromes, such as familial adenomatous polyposis, should be counseled about the need for close surveillance by professional gastroenterologists.
Aspirin and other nonsteroidal anti-inflammatory drugs appear to reduce the number of colon polyps, thus decreasing the risk of developing colorectal cancer. Patients interested in such therapy should discuss its potential risks and benefits with their health care providers.
Patients diagnosed with colorectal cancer who undergo surgery need counseling about the operation, the duration of recovery, and, in many cases, the use of a postoperative colostomy . Before surgery, a stomal therapist consults with the surgeon regarding appropriate stoma location, and the abdomen is marked. The therapist answers questions from the patient and family and begins to develop a relationship that will support the patient through postoperative care and teaching. Patient and family are encouraged to access the ACS (800-ACS-2345 or www.cancer.org) for additional information.
epithelial cancerBasal cell carcinoma.
epithelial cancer of the ovarySee: ovarian cancer
esophageal cancerSee: esophageal cancer
fallopian tube cancer
familial medullary thyroid cancerAbbreviation: FMTC
From 1930 to the 1990s, the incidence of gastric cancer declined from about 38 cases per 100,000 to about 6 cases per 100,000. In 2010, the ACS estimated there would be 21,000 new cases of gastric cancer in the U.S. and 10,570 deaths from this disease. The prognosis for a particular patient depends on the stage of the disease at the time of diagnosis, but overall the 5-year survival rate is about 19%.
Although the cause of gastric cancer is unknown, predisposing factors include a diet rich in pickled or smoked foods, a history of gastric surgery, and a history of infection by Helicobacter pylori. The disease runs in some families; therefore, there may also be a genetic component.
Malnutrition occurs as a result of impaired eating, the metabolic demands of the growing tumor, or obstruction of the GI tract. Iron deficiency anemia results as the tumor causes ulceration and bleeding. The tumor can interfere with the production of the intrinsic factor needed for vitamin B12 absorption, resulting in pernicious anemia. As the cancer spreads to regional lymph nodes and nearby structures and metastasizes to other structures, related complications occur.
Signs and Symptoms
In the early stages, the patient may occasionally experience pain in the back or in the epigastric or retrosternal areas that is relieved with nonprescription analgesics. As the tumor grows, the patient may notice a vague feeling of fullness, heaviness, and abdominal distention after meals. Depending on the progression of the cancer, the patient may report weight loss due to disturbance of the appetite; nausea; and vomiting. There may be dysphagia and coffee-ground vomitus if the tumor is located in the cardia and slowly bleeds. Weakness and fatigue are common. Because early symptoms include chronic dyspepsia and epigastric discomfort, patients may self-treat with OTC antacids or histamine blockers, delaying prescribed therapies and allowing the cancer to progress.
Palpation of the abdomen may disclose a mass. A skilled examiner may be able to palpate enlarged lymph nodes, esp. in the supraclavicular and axillary regions.
Gastric cancer is diagnosed by fiber-optic endoscopy with biopsy. Studies to rule out specific organ metastases include endoscopic ultrasonography, computed tomography scans, chest radiographs, liver and bone scans, and liver biopsy.
Radical surgery to remove the tumor is possible in more than one third of patients. Even in the patient whose disease is not considered surgically curable, resection may temporarily ease symptoms and improve the patient’s response to chemotherapy and radiation therapy. The nature and extent of the lesion determine the type of surgery. Surgical procedures include gastroduodenostomy, gastrojejunostomy, partial gastric resection, and total gastrectomy. If metastasis has occurred, the omentum and spleen may have to be removed.
Chemotherapy for GI tumors may help control signs and symptoms and prolong survival. Gastric adenocarcinomas respond to several agents, including fluorouracil, carmustine, doxorubicin, and mitomycin. Tumors that express HER2 antigens respond to treatment with trastuzumab (a monoclonal antibody that targets the human epidermal growth factor). Antispasmodics, antacids, and proton pump inhibitors may help relieve GI acidity and reflux symptoms. Antiemetics can control nausea, which intensifies as the tumor grows. Analgesics, sedatives, and tranquilizers are used to control pain and anxiety.
Nutritional intake is monitored, and the patient is weighed periodically. The health care provider initiates comprehensive clinical and laboratory investigations, including serial studies as indicated, if these have not already been done. The patient is prepared physically and emotionally for surgery, chemotherapy, or radiotherapy. During hospitalization, all general patient care concerns apply.
Throughout the course of the illness, a high-protein, high-calorie diet with vitamin supplementation helps the patient avoid or recover from weight loss, malnutrition, and anemia, and promote wound healing. Frequent small meals are offered.
To stimulate a poor appetite, antidepressant or steroid drugs may be administered. The patient is instructed in use of all drugs and the expected adverse effects of treatment, as well as in management strategies for these effects.
Radiation therapy may cause nausea, vomiting, local skin damage, malaise, diarrhea, and fatigue. Chemotherapy may cause bone marrow suppression, infection, nausea, vomiting, mouth ulcers, and hair loss. During radiation or chemotherapy, oral intake is encouraged to remove toxic metabolites. Bland fruit juices, ginger ale, or other fluids, and prescribed antiemetics are provided to minimize nausea and vomiting; comfort and reassurance are offered as needed. The patient is advised to report persistent adverse reactions.
The patient is encouraged to follow a normal routine as much as possible after recovery from surgery and during radiation therapy and chemotherapy. He should stop activities that cause excessive fatigue (at least temporarily) and incorporate rest periods. The patient should avoid crowds and people with known infections. Home-health care is provided as necessary. If curative treatment fails, palliative care and psychological support continues, with questions answered honestly but tactfully. Home or in-patient hospice care referrals are suggested as available.
Synonym: stomach cancer
head and neck cancer
kidney cancerRenal cell carcinoma.
The disease may cause severe pain and tenderness; cachexia (loss of weight); and encephalopathy. Jaundice is common. The liver is enlarged, its surface is nodular, and a central depression or umbilications can often be detected.
Treatment includes lung surgery, radiation therapy, and chemotherapy usually in combination.
Staging determines the extent of the disease and aids in planning treatment and predicting the prognosis. Lung cancer is relatively difficult to cure but much easier to prevent. Children and adolescents should be discouraged from smoking tobacco products, and current smokers should be assisted in their efforts to quit, e.g., through referrals to local branches of the ACS, smoking-cessation programs, individual counseling, or group therapy.
Screening and Public Health
Chest x-rays do not show small, early cancers, but CT scanning can be used to screen people who have a long history of smoking and who are 50 to 60 years old. In this high-risk group, screening detects the disease in its early stages when it is most likely to be curable. However, since screening is very expensive, and since there are millions of smokers, the public health costs of mass screening are high compared with the cost of encouraging smokers to quit or of teaching teenagers not to start smoking.
oral cavity cancer
Currently, more women die of epithelial ovarian cancer than of all other gynecological cancers combined. A small percentage of patients with ovarian cancer may have a hereditary predisposition, e.g., they have BRCA-1 or BRCA-2 genes. High-risk women include those with multiple first-degree relatives (mother, sister, daughter) or second-degree relatives (aunt, grandmother, cousin) with histories of breast or ovarian cancer. Preventive surgery to remove the ovaries and fallopian tubes is the only way such women can significantly reduce their risk.
Ovarian cancer patients may feel threatened or vulnerable. They benefit from pretreatment support and education. Health care professionals address the patient's psychosocial needs while preparing her for treatment and manage the potential adverse reactions and the treatment and changes related to advancing disease.
The first step in care is typically surgical debulking of the tumor. In this phase of care, the surgical oncologist attempts to remove not only the primary tumor, but also as many small tumorlets found within the peritoneum. The patient and family should be taught about the extensive surgical procedure and what to expect after surgery. After surgery, the patient is monitored for infection, circulatory complications, fluid and electrolyte imbalances, and pain. The patient who is to receive chemotherapy should be taught about major adverse reactions to the usual medications employed, taxanes and platinum-based drugs, such as fatigue, nausea and vomiting, hair loss, diarrhea, constipation, mucositis, neuropathy, arthralgia and myalgia, difficulty concentrating (chemobrain), and myelosuppression, as well as about measures to be taken to prevent and manage these problems. Chemotherapy may be given directly into the peritoneum or intravenously. Depression, anger, frustration, and anxiety are common.
After the acute phase of treatment, the patient may undergo premature menopause; loss of fertility; alterations in body image, sexual function, and family relationships; impaired functional capacity; financial difficulties; and loss of spiritual well-being. The patient should be assessed for mood changes, inability to concentrate, fatigue, insomnia, and other symptoms of depression. Her medical history, current medications and treatments, nutritional status, pain rating, elimination pattern, and sexual history should be reviewed for factors that contribute to depression. Participating in a support group, meeting with mental health professionals, and taking an antidepressant or anti-anxiety medication can help alleviate depression and anxiety.
Advancing or relapsing ovarian cancer may cause complications. These may include development of ascites, intestinal obstruction, deep vein thrombosis, malnutrition and cachexia, lymphedema, and pleural effusion. Current five-year survival rates for ovarian cancer are about 30% to 40%. If ovarian cancer recurs after treatment or fails to regress with treatment, palliative and end-of-life care may aid both patients and their families.
cancer of the pancreasPancreatic cancer.
prostate cancerSee: prostate cancer
scirrhous cancerHard cancer.
According to the U.S. Preventative Services Task Force (USPSTF), benefits from routine screening for skin cancers with a total body skin examination are unproven, even in high-risk patients.
stomach cancerGastric cancer.
testicular cancer, germ-cell
cancer of unknown primary site
Patients with such cancers are usually evaluated for tumors that might respond well to therapy, such as a lymphoma, a thyroid cancer, a germ cell tumor, or neoplasms of the breast or prostate.
cancer of uterus
Vulvar cancer accounts for 4% of all gynecological malignancies. More than 50% of cases occur in postmenopausal women between 65 and 70. Generally, vulvar cancers are localized, slow-growing, and marked by late metastasis to the regional lymph nodes. Treatment may include surgery and/or radiation therapy. See: vulvectomy
|Estimated New Cases||Estimated Deaths|
|Oral cavity & pharynx||25,310||10,000||5,210||2,380|
|Colon & rectum||77,250||71,560||24,260||25,700|
|Liver & intrahepatic bile duct||15,190||6,180||12,570||5,840|
|Lung & bronchus||114,690||100,330||90,810||71,030|
|Kidney & renal pelvis||33,130||21,260||8,100||4,910|
|Brain & other nervous system||11,780||10,030||7,420||5,650|
|Breast self-examination||Breast cancer||Monthly self-examination by women is a noninvasive way to screen for changes in the breast. This method detects many benign and cancerous lumps, but its ability to prolong life is still debated.|
|Mammography||Breast cancer||Mammography is clearly effective screening in women over 50. Most mammograms are obtained by women in their 40s. The incidence of cancer is higher in later life, when mammography use tends to decline.|
|Digital rectal examination (DRE)||Colorectal cancer, prostate cancer||DRE is easy to perform and inexpensive but its cancer screening value is unproven; and, when it detects cancers, there is no proof that the test results in better patient outcomes. In addition, DRE detects a very small number of cancers, only those within the reach of the examiner.|
|Fecal occult blood test||Colorectal cancer||In people over 50, testing stool specimens for hidden bleeding detects many cancers; this detection results in earlier treatment and prolongation of life. The accuracy and value of the test relative to sigmoidoscopy and colonoscopy are uncertain.|
|Chest x-ray, sputum cytology, CT of the chest||Lung cancer||Prospective studies have yielded conflicting results for any method of screening for lung cancer in smokers, and the costs of screening, e.g., with computed tomography of the chest, may be prohibitive. The tests are of no value to nonsmokers.|
|Prostate specific antigen (PSA)||Prostate cancer||PSA testing detects many previously undetected prostate cancers but may result in increased death and disease due to complications from subsequent surgery. Refinements in its application may improve its usefulness as a screening tool.|
|Genetic testing||For predisposition to a variety of cancers||The predictive value of genetic testing for cancer is very small. Experts are debating the emotional and ethical consequences of genetic cancer screening tests.|