Cancer

Carcinomas, the most common types of cancer, arise from the cells that cover external and internal body surfaces. Lung, breast, and colon are the most frequent cancers of this type in the United States.

Sarcomas are cancers arising from cells found in the supporting tissues of the body such as bone, cartilage, fat, connective tissue, and muscle.

Lymphomas are cancers that arise in the lymph nodes and tissues of the body's immune system.

Leukemias are cancers of the immature blood cells that grow in the bone marrow and tend to accumulate in large numbers in the bloodstream.

Prefixes used in naming cancers
• adeno = gland (adenocarcinoma)
• chondro = cartilage (chrondroma)
• erythro = red blood cell (erythroblastoma)
• hemangio = blood vessels (hemangiosarcoma)
• hepato = liver (hepatocarcinoma)
• lipo = fat (lipoma)
• lymph/o or a/ o = lymphocyte (lymphoblastoma, lymphangioma)
• melano = pigment cell (melanocytoma)
• myelo = bone marrow (myelosarcoma)
• myo = muscle (myocytoma)
• osteo = bone (osteoma, osteosarcoma)


Loss of Normal Growth Control

Cancer arises from a loss of normal growth control. In normal tissues, the rates of new cell growth and old cell death are kept in balance. In cancer, this balance is disrupted. This disruption can result from uncontrolled cell growth or loss of a cell's ability to undergo "apoptosis." Apoptosis, or "cell suicide," is the mechanism by which old or damaged cells normally self-destruct.

Cancers are capable of spreading through the body by two mechanisms: invasion and metastasis. Invasion refers to the direct migration and penetration by cancer cells into neighboring tissues. Metastasis refers to the ability of cancer cells to penetrate into lymphatic and blood vessels, circulate through the bloodstream, and then invade normal tissues elsewhere in the body.

Depending on whether or not they can spread by invasion and metastasis, tumors are classified as being either benign or malignant. Benign tumors are tumors that cannot spread by invasion or metastasis; hence, they only grow locally. Malignant tumors are tumors that are capable of spreading by invasion and metastasis. By definition, the term "cancer" applies only to malignant tumors.

To diagnose the presence of cancer, a doctor must look at a sample of the affected tissue under the microscope. Hence, when preliminary symptoms, Pap test, mammogram, PSA test, or fecal occult blood test indicate the possible existence of cancer, a doctor must then perform a biopsy, which is the surgical removal of a small piece of tissue for microscopic examination. (For leukemia, a small blood sample serves the same purpose.) Microscopic examination will tell the doctor whether a tumor is actually present and, if so, whether it is malignant (i.e., cancer) or benign.

Hyperplasia: Instead of finding a benign or malignant tumor, microscopic examination of a biopsy specimen will sometimes detect a condition called "hyperplasia." Hyperplasia refers to tissue growth based on an excessive rate of cell division, leading to a larger than usual number of cells. Nonetheless, cell structure and the orderly arrangement of cells within the tissue remain normal, and the process of hyperplasia is potentially reversible. Hyperplasia can be a normal tissue response to an irritating stimulus. For example, a callus that may form on your hand when you first learn to swing a tennis racket or a golf club is produced by hyperplasia.

Dysplasia: In addition to hyperplasia, microscopic examination of a biopsy specimen can detect another type of noncancerous condition called "dysplasia." Dysplasia is an abnormal type of excessive cell proliferation characterized by loss of normal tissue arrangement and cell structure. Often such cells revert back to normal behavior, but occasionally, they gradually become malignant.

Carcinoma in Situ: The most severe cases of dysplasia are sometimes referred to as "carcinoma in situ." In Latin, the term "in situ" means "in place," so carcinoma in situ refers to an uncontrolled growth of cells that remains in the original location. However, carcinoma in situ may develop into an invasive, metastatic malignancy and, therefore, is usually removed surgically, if possible.

Tumor Grading: Microscopic examination also provides information regarding the likely behavior of a tumor and its responsiveness to treatment. Cancers with highly abnormal cell appearance and large numbers of dividing cells tend to grow more quickly, spread to other organs more frequently, and be less responsive to therapy than cancers whose cells have a more normal appearance. Based on these differences in microscopic appearance, doctors assign a numerical "grade" to most cancers. In this grading system, a low number grade (grade I or II) refers to cancers with fewer cell abnormalities than those with higher numbers (grade III, IV).

Tumor Staging: After cancer has been diagnosed, doctors ask the following three questions to determine how far the disease has progressed:
1. How large is the tumor, and how far has it invaded into surrounding tissues?
2. Have cancer cells spread to regional lymph nodes?
3. Has the cancer spread (metastasized) to other regions of the body?

Based on the answers to these questions, the cancer is assigned a "stage." A patient's chances for survival are better when cancer is detected at a lower stage number (roman numerals are used for the stages, 1, 2, 3), and Arabic for grades.

Cancer Classifications:
Stage and grade - do not capitalize either one if it does not begin a sentence.
Use Roman numerals for cancer stages.
Use Arabic numerals for cancer grades.
For clarity, use capital letters or Arabic suffices without spaces or hyphens.
Here are some examples:


• stage 0
• stage I stage IA
• stage II
• stage III stage IIIA stage IIIB
• stage IV



• grade 1
• grade 2
• grade 3
• grade 4

BREAST CANCER - NEW HOPE

Herceptin was initially approved by the Food and Drug Administration in 1998 for use in HER2-positive women with metastatic breast cancer (meaning the cancer has spread beyond the breast to other parts of the body). Later trials revealed a 24 percent increase in median overall survival for women with HER2-positive metastatic breast cancer who were treated initially with Herceptin and chemotherapy rather than with chemotherapy alone. Studies have also shown that the drug may cause cardiac problems, but only in a small percentage of patients.

Earlier this year, HER2-positive breast cancer patients got even more good news. In May, the interim results of an analysis of 3,300 patients in two major trials that compared the use of Herceptin with chemotherapy to chemotherapy alone were released at the annual meeting of the American Society of Clinical Oncology. "You could have heard a pin drop when they released the results," remembers Pellegrino, the Montefiore oncologist, who attended the conference.

The results of the analysis, which were also published last week in The New England Journal of Medicine, showed that women with early stage HER2-positive breast cancer who received Herceptin in combination with chemotherapy cut their risk for breast cancer recurrence by 52 percent, and their risk of death by 33 percent, when compared with women who just received the chemotherapy. After four years, only 15 percent of women who had been treated with Herceptin plus chemotherapy experienced a recurrence of the cancer, compared to one third of the women who?d just had chemotherapy. "We found something that is directly affecting people's lives, bringing them hope," says Dr. Edith A. Perez, an oncologist at the Mayo Clinic in Jacksonville, Fla., who chaired one of the two trials (known as the North Central Cancer Treatment Group. "We are curing women here."