Introduction
Breast cancer has now become the most
common cancer and a leading cause of death among
Thai women.1
Although the etiology of breast cancer
remains unknown, one of the risks for this is a family
history of the disease.2 The risk of women with family
history of breast cancer (FHBC) developing this
condition is two to four times higher than those
women without a family history.3 Furthermore,a study in Thailand found that approximately 3.5%
of all cases and 1.6 % of control patients reported
a history of breast cancer in mothers or sisters which
was consistent with studies conducted in the developed
world.4 Although breast cancer is currently incurable,
there is evidence that survival rate can be improved if
breast cancer is detected early.2
Besides, the healthy
lifestyles such as maintaining healthy weight, staying
physically active throughout life, stopping alcohol
consumption, and maintaining a healthy diet can
substantially reduce one’s lifetime risk of developing
cancer.5
Literature related to breast cancer preventive
behaviors (BCPB) reveals that women with a FHBC
who perceive themselves to be at high risk for the
disease are more likely to engage in appropriate
screening behaviors and physical activity than those
without such a family history.6, 7 In addition, women
who perceive self-efficacy in relation to BCPB are
more likely to perform these behaviors than those
who do not perceive self-efficacy,8 and as well cultural
factors also may have an influence. Furthermore,
previous studies have found breast cancer-specific
distress to be more likely to occur in women with
FHBC than those without this.9
Older women with
high education attainments are more likely to engage
in such behaviors than younger women with lower
education attainments.10 Moreover, factors involved
in the relative breast cancer index, such as age at onset,
time at cancer diagnosis, the number and type of
relatives with breast cancer have been found to affect
BCPB.11
Although evidence has shown the great benefits
of regular breast cancer screening and increasing
healthier lifestyles, regular screening is underused among
high-risk women including women with a FHBC.12
In Thailand, studies reporting women with family
history of breast cancer who practice regular breast
self-examination (BSE) are rather low at approximately
21%.13,14 Many women are unaware of the associations
between healthy lifestyle behaviors and breast cancer
risks.15 According to previous studies demonstrating
the relationships among those factors and BCPB,
how those factors work to affect such behaviors has
not been clearly delineated. Thus, this study was designed
to test a causal model of factors influencing BCPB to
guide nursing interventions focusing on breast cancer
screening and healthy lifestyle behaviors.
Conceptual Framework and Literature
Review
The conceptual framework of this study was
based on the Health Belief Model (HBM) and literature
related to BCPB among women with a FHBC. HBM
has been one theory frequently used to explain cancer
prevention behaviors. According to the HBM, individuals
are more likely to take action toward preventing or
detecting ill health if they: (1) feel susceptible to
a specific condition; (2) perceive the severity of
that condition and (3) believe their actions will be
beneficial with few barriers.16 The HBM and recent
modifications of this theorize that five factors are
related to the performance of a surveillance behavior,
namely; perceived seriousness of the disease, perceived
susceptibility to the disease, perceived benefits of
engaging in the surveillance behavior, perceived
barriers to engaging in the behavior and confidence in
correctly performing the surveillance behavior to
maximize its utility.17
The literature on the relationship and factors
influencing BCPB shows that women with a family
history are at least aware of their increased risk.18
Women assigned a high relative risk for breast cancer
often seek information to alleviate risk through screening
and breast cancer preventive behaviors.19 The findings
of one qualitative study provided evidence that breast
cancer risk was perceived to be greatly influenced by
family history.20 Women with high risks for developing
breast cancer are more likely to perceive their risk for
developing the disease and more motivated to participate in breast cancer screening programs.6,21
and to engage in regular physical activity.7
Moreover,
women who report confidence in their ability to
perform BSE are more likely to practice this regularly.
Consistently, a study by Quach22 revealed that perceived
self-efficacy predicted health behaviors. Another
factor influencing BCPB among female relatives of
breast cancer patients is fatalism, a complex phenomenon
with potentially far-reaching implications for health
behaviors. Cancer fatalism has been identified as a
barrier to partic