Handbook of Psychology

270 Psychosocial Oncology

immune system to “ght the tumor cells in order to engender a
therapeutic response. It is used for particular tumors such as
hairy cell leukemia, melanoma, and renal cell carcinoma. The
use of this treatment is somewhat problematic in that the
immune system does not always treat cancer cells as foreign.
Cancer cells have the ability to alter the cell membrane such
that the immune system does not •readŽ it as abnormal. The
three most commonly known BRMs are interferon (INF),
interleukin-2 (IL-2), and colony stimulating factors (CSF).
These are highly puri“ed proteins that are administered to
activate, modify, enhance, or restore the immune system. The
CSFs are used to treat the reduced white cell count associated
with chemotherapy. The most common side effect of this
treatment is a ”u-like syndrome consisting of headaches,
fever, chills, and muscle and joint aches and pains.

Bone Marrow Transplantation

Advances in laboratory techniques have made bone marrow
transplantation (BMT) a viable treatment option for a select
group of patients. For some disease entities, a BMT can
extend life or even cure a hematologic malignancy. How-
ever, for many solid tumors, BMT remains experimental.
Diagnoses for which BMT may be a treatment option include
aplastic anemia, leukemias, lymphomas, Hodgkin•s disease,
breast cancer, and multiple myeloma. Bone marrow is located
in the iliac crest, sternum, long bones, and ribs. The marrow
contains the blood-forming components that manufacture red
cells, white cells, and platelets. In the marrow and circulating
blood (peripheral), an immature cell, called a stem cell, exists
that is the •parentŽ cell for the development of red cells, white
cells, and platelets. If the marrow becomes malignant (i.e.,
leukemia), the blood-forming process is altered and results in
a life-threatening situation. The individual then becomes at
risk for lethal infections or hemorrhage. If the marrow can be
destroyed and replaced with normal marrow free from the
malignant cells, the malignancy can be potentially cured.

BEHAVIORAL RISK FACTORS

Only about 5% to 10% of all cancers are clearly hereditary.
The remaining cancers are caused by mutations resulting
from various internal (e.g., hormones) or external factors
(e.g., sunlight). Behavioral risk factors refer to those lifestyle
activities that increase the likelihood that a person will de-
velop cancer. Such factors include tobacco, alcohol, diet, and
exposure to sun. Additional psychosocial variables that have
been investigated regarding their causal link to cancer in-
clude socioeconomic status and personality.

Smoking

According to the American Cancer Society (2000), smokers

have a 10-fold relative risk of developing lung cancer

compared with nonsmokers. With regard to mortality

rates, cigarette smoking accounts for approximately 30%

of total cancer deaths and 87% of all lung cancer deaths

(Cinciripini, Gritz, Tsoh, & Skaar, 1998). Overall, smokers

have an increased risk for developing a wide range of can-

cers, including lung, oral cavity, pharynx, larynx, esophageal,

pancreatic, head and neck, and renal cancer. Ceasing tobacco

use has been found to be bene“cial with regard to cancer risk.

For example, after 10 years of nonsmoking, the risk for lung

cancer mortality decreases between 30% to 50%. Moreover,

a 50% reduction in cancer risk of the esophagus and oral cav-

ity has been found after only “ve years of smoking cessation

(U.S. Department of Health and Human Services, 1990).

Alcohol

Although the speci“c biological underpinnings linking alco-

hol and increased risk for cancer are unclear at present, stud-

ies have clearly shown a de“nite association. For example,

the American Cancer Society (2000) recommends that de-

creased alcohol consumption can decrease a person•s risk for

head, neck, and liver cancer. Recently, a study in Canada

(Rohan, Jain, Howe, & Miller, 2000) found that women who

drank more than 50 grams per day of alcohol (the equivalent

of about 4 to 5 beers) were almost twice more likely to de-

velop breast cancer than those who did not use alcohol.

Diet

A link between diet and cancer has been demonstrated in a

wide variety of investigations. For example, population

studies have shown that excessive fat intake (i.e., greater than

20% of total calories) is strongly associated with an increased

incidence of colon, breast, prostate, and possibly pancreatic

cancer (Winters, 1998). Increased cancer risk has also been

found to be linked to various dietary de“ciencies, such as low

intake of fruits and vegetables, “ber, and micronutrients (e.g.,

ribo”avin, iron). In addition, excessive pickling, smoking,

and salting of foods has been found to be associated with in-

creased cancer risk. Modi“cation of diets has also been found

to have a profound effect on cancer incidence (see chapter on

obesity this volume).

Sun Exposure

Ultraviolet radiation from the sun, in particular UVB (radia-

tion lying between 280 and 320 nanometers of the solar